The use of monoclonal antibodies for the identification and classification of acute myeloid leukemias

Leukemia Research Vol. 10, No. 3, pp. 279-290, 1986. Printed in Great Britain.

0145-2126/8653.00 + .00 © 1986 Pergamon Press Ltd.

THE USE OF M O N O C L O N A L ANTIBODIES FOR THE IDENTIFICATION A N D CLASSIFICATION OF A C U T E MYELOID LEUKEMIAS HANS GUENTER DREXLER and JUN MINOWADA Departments of Pathology and Surgery, Loyola University of Chicago Stritch School of Medicine, 2160 South First Avenue, Maywood, IL 60153, and Hines Veterans Administration Medical Center, Hines, IL 60141, U.S.A. (Received 6 June 1985. Accepted 29 September 1985) Abstract--We reviewed a library of monoclonal antibodies (MoAbs) detecting antigens on myelomonocytic cells and analysed their reactivity patterns as reported in the literature. On the basis of the frequency of positivity with the myelocytic variants (FAB M 1-3) or monocytic variants (FAB M4/5) of acute myeloid leukemias, the MoAbs were assigned to one of four groups. MoAbs of Group I identified most cases of both the myelocytic and the monocytic cell lineages ('panmyelomonocytic' reactivity) and can be used to identify acute myeloid leukemias regardless of the subtype. Group II comprised MoAbs which reacted with the majority of FAB M1-3 cases, but showed a preference in reactivity with AMMoL/AMoL cases (reactivity: myelocytic partly, monocytic predominantly). MoAbs of Group III stained most cases with monocytic phenotypes, but labelled only a small percentage of non-monocytic cases. These MoAbs are valuable tools for the detection of cases with monocytic features. Group IV MoAbs reacted with a small to intermediate percentage of myelocytic and/or monocytic cases. Besides their diagnostic application MoAbs might be used in new therapeutic approaches such as in-vivo serotherapy with MoAbs and purging of autologous bone marrow for transplantation. None of the described MoAbs appear to be leukemia-specific. Many MoAbs have been produced against non-myelomonocytic cells and were reactive with cells outside the myelomonocytic cell lineages and the hematopoietic system. Other MoAbs with apparent cell lineage-restricted reactivity regarding normal cells stained leukemic cells of other cell lineages. This phenomenon of translineage reactivity of leukemic cells with mutually exclusive markers indicating a biphenotypic marker profile might be the result of abnormal, disregulated gene expression. New classification systems of acute myeloid leukemias based on immunological marker profiles have been proposed. The analysis of reactivity of normal and malignant myelomonocytic cells with MoAbs has led to refined differentiation schemes of the normal hematopoiesis.

Key words: Monoclonal antibodies, myeloid leukemias. INTRODUCTION DIFFERENTIATION of normal and malignant myeloid cells has been characterized primarily by morphological [41, 90] and cytochemical [11, 29] criteria. Analyses of cells of the myelocytic and monocytic lineages have also relied to some extent on the cell surface expression of antigens detected by polyclonal antisera [53, 59]. The most c o m m o n l y used classification of acute myeloid leukemias is the so-called FAB-system M I - 6 [10] which is based on morpho-cytochemical features o f the malig-

Abbreviations: ALL, acute lymphoblastic leukemia; AML, acute myelocytic leukemia; AMMoL, acute myelomonocytic leukemia; AMoL, acute monocytic leukemia; AUL, acute undifferentiated leukemia; FAB, French-American-British classification; MoAb, monoclonal antibody. Correspondence to: H. G. Drexler at above address. 279

nant cells. But the reproducibility of the FABclassification appears to be limited: the same FABsubtype was recognized by two or three observers in only 60-70°7o of cases, a relatively low level [23, 58, 88]; the main points of disagreement were between the MI and M2 subtypes (acute myeloblastic leukemia without and with signs of maturation; for further details see [10]) on one hand and the M2 and M4 subtypes ( A M M o L , acute myelomonocytic leukemia) on the other hand. Until recently, the immunological approaches have not enabled isolation and further characterization of the diverse subtypes of cells within the myelocytic and monocytic cell lineages. In contrast, the identification of subsets of lymphoid leukemias, especially subtypes of acute lymphoblastic leukemias (ALL) has been greatly aided by application of polyclonal antisera and of the hybridoma monoclonal antibodies techniques [39, 61]. More recently, a large number of monoclonal antibodies (Mo.Abs) reactive with human myeloid cells have been generated, described and tested on cases of acute myeloid ieukemias.

280

HANS GUENTER DREXLER and JUN MINOWADA

We here intend to review (1) the frequency of positivity of a panel of MoAbs (which are purported to detect differentiation antigens on myelomonocytic cells) with cases of acute myeloid leukemias, (2) the use of various MoAbs for the identification of acute myeloid leukemias and for the discrimination between myelocytic and monocytic variants, (3) the use of MoAbs as a new therapeutic approach, (4) leukemia specificity, cell lineage specificity and translineage reactivity of MoAbs, and (5) classification and differentiation schemes of normal and malignant myelomonocytic cells based on reactivity with 'myeloid MoAbs'. FREQUENCY OF POSITIVITY AND REACTIVITY PATTERN OF 'MYELOID' MONOCLONAL ANTIBODIES Before the availability of MoAbs a number of polyclonal heteroantisera with specificity for myelomonocytic cells had been produced in the 1970s. These xenoantisera had been raised (mostly in rabbits) against immunogens on normal peripheral blood monocytes [3, 18], granulocytes [21, 30], AML cells [16, 53], AMMoL cells [73] and AMoL cells [80]. But polyclonal antisera did not contribute significantly to the identification and classification of acute myeloid leukemias in clinical and basic leukemia research, in part due to the following difficulties in the production of the reagents: (1) The extensive absorption necessary to prepare specific heteroantisera and the low titer obtained limited the quantity of serum available; (2) despite multi-step absorption procedures the specificity of the antisera was relatively poor; and (3) due to the complexity of the absorption procedures, it has been difficult to reproduce antisera with identical specificity and therefore to compare studies. As compared to polyclonal antisera, the major advantages of MoAbs are their higher specificity and their general availability due to standardized production and virtually unlimited supply [45]. During the last 4-6 yr a large number of MoAbs reactive with antigenic determinants expressed in a lineageand stage-restricted fashion on myelomonocytic cells have been produced and studied to map normal myeloid differentiation using normal cells. We reviewed the reactivity patterns and descriptions of some 150 MoAbs. About 50°70 of this panel of reported MoAbs has been analysed on leukemia cells from cases with acute myeloid leukemias (10 cases or more). The remaining MoAbs have not (yet) been tested on acute myeloid leukemias or only on a low number of cases ( < 10); their reactivity pattern will not be described in detail. Nevertheless, the reactivity of these MoAbs with the various cells of the myeloid system gives valuable insight into the normal immunological differentiation, proliferation and maturation processes. After testing of leukemias, a correlation of the data obtained on normal and malignant cells will provide useful information. The percentage of leukemia cells per case and the percentage of cases reacting with a single MoAb varied widely among the described MoAbs. Most studies used

the following arbitrary criterion for the distinction between positive and negative cases: a leukemia is classified as antigen-positive if 20°70 or more cells of the blast cell population are reactive with a particular MoAb. The incidences of positivity of the reviewed MoAbs with cases of acute myeloid leukemias and its subtypes are given Tables 1-4. A subclassification was usually made on the basis of morphological characteristics, mostly according to the FAB-critera [10]. But not all studies categorized the cases completely in the subtypes M1, M2, M3, M4 and M5. Therefore, the subtypes of acute myeloid leukemias are summarized into a group of acute myelocytic leukemias (FAB M1-3) and a group of acute (myelo-) monocytic leukemias (FAB M4/5). On the basis of their reactivity with monocytic and non-monocytic cases of acute myeloid leukemias, the MoAbs were assigned to one of the following groups: Group I with MoAbs which react with the vast majority (>70070) of cases of both cell lineages (reactivity: 'panmyelomonocytic'); Group II includes MoAbs being positive on most myelocytic leukemias (40-70070), but with a preference (>70°70) for monocytic cases (reactivity: myelocytic partly, monocytic predominantly); Group III contains MoAbs which recognize most cases of AMMoL/AMoL(>70070), but react only with a low percentage (<40°70) of the myelocytic variants (reactivity: 'monocyte-specific'); the MoAbs of Group IV stain between 40 and 70°70 of the cases of AML and/or AMMoL/AMoL (reactivity: myelocytic partly, monocytic partly). Table 5 lists the MoAbs which have been tested on less than 10 patients with acute myeloid leukemias and those MoAbs with a frequency of positivity of <40°70 for both cell lineages. The molecular weights of the antigens which are detected by the various MoAbs are not reported for most reagents. Several MoAbs produced in different laboratories certainly identify the same molecule, if not the same epitope; but as the antigens remained undefined, it is difficult to compare the antigenic specificity of the MoAbs. The listings in Tables 1-4 are not intended to be exhaustive and are certainly incomplete, in part because the number of cases studied with the different antibodies is low. IDENTIFICATION AND SUBCLASSIFICATION OF ACUTE MYELOID LEUKEMIAS The MoAbs assigned to Group I identified the vast majority of the cases of acute myeloid leukemias of both myelocytic and monocytic cell lineages. Several MoAbs (MCS-2, MMA, MY7, MY9 and VIM-2) have already been tested on larger series of patients and have been proven to be 'pan-myelomonocytic' in their reactivity patterns. These MoAbs appear to be useful for the differential diagnosis of acute leukemias (myeloid vs lymphoid), since it is sometimes difficult to distinguish ALL from acute myeloid forms by morphological and cytochemical criteria; many of the latter cases have been simply termed 'acute undifferentiated leukemias' (AUL). These data further emphasize that cells of the

Monoclonal antibodies reactive with acute mye|oid leukemias

281

p.

m

.~¢~ o

,-.]

•~

>-,

v

,.J p-

~o

:2 m .<

<~u., ;~

o~

.~

,.J 0

-'~ 0

Z

II

0

c~u

~.~.~

"~ ~

.ai:~

NN

<

.<

oc=

0

.<

.<

~

~

~

~

~ : ~

~

'-

.-~,~NN

Z

Z

..J

II

.< II

~'~

~

11 O 0 , ,

q~

282

HANS GUENTER DREXLER a n d JUN MINOWADA

TABLE 2,INCIDENCE OF POS1TIVITY OF M o A b s TESTED ON CASES OF ACUTE MYELOID LEUKEMIAS (GROUP II: REACTIVITY MYELOCYTIC PARTLY, MONOCYTIC PREDOMINANTLY)

MoAb

Immunogen

20.2

PB mononuclear Cells*

20.3

PB mononuclear cells

3C4 5F1

PB granulocytes AML

80H3 B2.12

CML PB T-lymphocytes

HL-I LB3-45 MCS-1

HL-60 AML ML-3

M-G1120 M-M522 M-M67 Mol

T-ALL T-ALL T-ALL AMoL

MeP-15 MOS-1

PB monocytes plemal phagocytes PB mononuclear cells

OKMI

$4-7 $5-7 SmO TG8 TM18 VIM-D5

KG-1 ML-3 brain cells n.r. n.r. K-562

AML (FAB M1-3) AMMoL/AMoL (FAB M4/5)

All c a s e s

3/4 (75%)I" 1/3 (33%) 4/7 (57%) 2/4 (50%) 5/7 (71%) 7/11 (64%) 10/18 (55%) 4/10 (40%) 4/7 (57%) n.r.~ 8/17 (47%) 2/4 (50%) 8/15 (53%) 12/28 (43%) 20/43 (46%) 9/16 (56%) 12/27 (44%) 93/144 (64%) 1/1 (100%) 94/145 (65%) 10/16 (62%) 8/13 (61%) 2/3 (67%) 20/39 (51%) 44/71 (62%) 10/29 (34%) 5/15 (33%) 79/154 (51%) 2/3 (67%) 2/3 (67%)

3/6 (50%) 10/11 (91%) 13/17 (76%) 6/6 (100%) 15/17 (88%) 21/23 (91%) 11/12 (92%) 11/12 (92%) 8/9 (89%) n.r.~t 19/21 (90%) 5/6 (83%) 13/15 (87%) 17/24 (71%) 30/39 (77%) 13/16 (81%) 27/36 (75%) 13/13 (100%) 7/10 (70%) 20/23 (87%) 14/15 (93%) 16/17 (94%) 12/13 (92%) 24/31 (77%) 9/11 (82%) 18/19 (95%) 15/17 (88°7o) 66/78 (85%) 10/12 (83%) 10/ll (91%)

6/10 11/14 17/24 8/10 20/24 28/24 21/30 15/22 12/16 33/54 60/92 7/10 21/30 29/52 50/82 22/32 39/63 106/157 8/11 114/168 24/31 24/30 14/16 44/70 53/82 28/48 20/32 145/232 12/15 12/14

(60%) (78%) (71%) (80%) (83%) (82%) (70%) (68%) (75%) (61%) (65%) (70%) (70%) (56%) (61%) (69%) (62%) (67%) (73%) (68%) (77%) (80%) (87%) (63%) (65%) (58%) (62%) (62%) (80%) (86%)

2/8 (25%) 98/140 (70%) 7/17 (41%)11 15/28 (53%) 122/193 (63%) 12/29 (41%) 17/27 (63%) 11/16 (69%)11 9/13 (69%) 2/5 (40%) 43/51 (84%)§ 7/15 (47%) 42/86 (49%) 92/152 (60%) n.r.

5/5 (100%) 12/14 (86%) 37/40 (92%)11 17/24 (71%) 71/83 (85%) 27/36 (75%) 24/32 (75%) 31/36 (86%)11 12/16 (75%) 11/15 (73%) 40/45 (89%)§ 11/15 (73°70) 9/10 (90%) 60/70 (86%) n.r.

7/13 110/154 44/57 32/52 193/276 39/65 41/59 42/52 21/29 13/20 83/96 18/30 51/96 152/222 122/169

(54%) (71%) (77%)U (61%) (70%) (60%) (69%) (81%)U (72%) (65%) (86%)§ (60%) (53%) (68%) (72%)§

References [40] [12] [40] [12] [12, 75] [1, 13] [12] [2] [12, 54, 55] [12, 81] [70] [62, 861 [68] [26,28] [121 [12, 71] [12, 50, 71] [12, 711 [34, 35] [28] [82-841 [12] [12, 24] [12, 24] [18] [28] [48] [70] [68] [68] [48] [12] [12] [14, 44, 51] [12] [281 [79]

Footnotes, see Table 1. myelocytic and monocytic series have a close common progenitor cell and share common membrane antigens. The common expression of myeloid-associated antigens by myelocytic and monocytic leukemias has also been demonstrated with the anti-myeloid antibodies of Group II. These MoAbs showed a certain preponderance of reactivity with the monocytic variants and probably stained only a certain subset(s) of myelocytic leukemias.

The MoAbs B2.12, LB3-45, MCS-1, Mol, OKMI, $4-7, SmO and VIM-D5 were analysed on a subtstantial number of patients. MoAbs of Group III labelled mainly cells of the monocytic cell lineage, whereas a low incidence of positivity was seen for the AML cases. These MoAbs having the most prominent restriction in their reactivity with the monocytic cases were tested on larger numbers

283

Monoclonal antibodies reactive with acute myeloid leukemias TABLE 3. INCIDENCEOF POSITIVITY OF MoAbs TESTED ON CASES OF ACUTE MYELOIDLEUKEMIAS(GRouP III: REACTIVITY 'MONOCYTE-SPECIFIC')

MoAb

Immunogen

63D3

PB monocytes*

75B10 AML-2-23 DU-HL60-3

AML AML HL-60

FMC10 FMCI1 Mo2

PB granulocytes PB granulocytes AMoL

M~P-9 (= Leu-M3)

PB monocytes

M¢S-39 MY3 MY4

phagocytes AMMoL AMMoL

MY8

AMMoL

TA-I TG-1

CCRF-HSB-2 thymic membrane glycoprotein

T05 UCHALF

AMMoL lactoferrin

UCHMI

thymocytes

VIM-D2

n.r.

AML (FAB M1-3) 12/57 0/8 12/65 2/7 0/12 4/10 5/13 9/23 3/10 2/8 1/30 23/67 2/13 26/110 1/4 21/78 22/82 1/6 6/53 7/53 1/3 21/70 29/126 20/53 4/8 .27/79 51/140 0/12 3/12 8/17 11/29 1/4 1/17 2/8 3/25 1/17 3/8 4/25 2/5 17/73 19/78

AMMoL/AMoL (FAB M4/5)

(21070)t (0%) (18%) (28%) (0%) (40°7o) (38°7o) (39%) (30%) (25%) (3%) (34%) (15%) (24%) (25%) (27%) (27%) (17%) (11%) (13%) (33°70) (30%) (23°/0) (38%) (50%) (34%) (36°70) (0070) (25%) (47%)11 (38%) (25%) (6%)11 (25%) (12%) (6°7o)11 (37%) (16%) (40°70) (23%) (24°7o)

8/11 3/4 11/15 14/15 12/14 0/2 14/16 14/18 10/11 10/13 13/19 8/11 9/11 30/41 11/13 10/11 21/24 12/15 18/19 20/31 13/14 7/11 40/56 24/31 11/13 8/11 43/55 5/5 14/16 39/40 53/56 11/14 38/40 24/32 62/72 38/40 24/32 62/72 12/13 10/10 22/23

(73%) (75%) (73%) (93%) (86%) (00/o) (87°7o) (78%) (91%) (77%) (68%) (72%) (82°7o) (73%) (85o7o) (91o7o) (87%) (80°70) (95%) (64°70) (93°7o) (64°70) (71%) (77%) (85%) (73%) (78%) (100%) (87070) (97%)11 (95%) (78%) (95%)11 (75%) (86%) (95%)11 (75%) (86%) (92o70) (100%) (96°7o)

All cases 20/68 3/12 23/80 16/22 12/26 4/12 19/29 23/41 13/21 12/21 14/49 31/78 11/24 56/151 12/17 31/89 43/106 13/21 24/72 27/84 14/17 28/81 69/182 44/84 15/21 35/90 94/195 5/17 17/28 47/57 64/85 12/18 39/57 26/40 65/97 39/57 27/40 66/97 14/18 27/83 41/101

References

(29%) [281 (25%) [76, 87] (29%) (73%) [12, 17] (46%) [4, 6] (33%) [57] (65%) [12] (56%) (620/o) [12, 89] (57%) [12, 89] (28%) [82-84] (40%) [28] (46%) [12, 76] (37%) (70°70) [12, 14] (35°7o) [28] (40%) (62%) [12, 24] (33%) [33] (32°70) [33-351 (82°7o) [121 (34°7o) [281 (38%) (52%) [33-35] (71%) [121 (39%) [281 (48%) (29%) [47] (61%) [12, 15] (82°7o)11 [48] (75%) (67%) [12, 85] (68%)11 [48] (65%) [76] (67°/0) (68%)11 [48] (67°7o) [76] (68%) (78%) [12, 43, 44] (32°7o) [28] (41°7o)

Footnotes, see Table 1.

of patients: 63D3, Mo2, MCP-9, MY3, MY4, MY8, TG1, U C H A L F , UCHM1 and VIM-D2. These MoAbs will be of considerable value in the more precise subtyping of acute myeloid leukemias. The MoAbs of Group IV staining a relatively low percentage of myelocytic and monocytic leukemias might detect particular subsets with a favorable or poor prognosis. Further studies are required to clarify this point in correlation with the clinical data of the patients and the outcome of specific therapeutic modalities.

MONOCLONAL ANTIBODIES AS A NEW THERAPEUTIC APPROACH There are promising reports indicating the potential application of MoAbs in the therapy of leukemia. MoAbs might be applied for in-vitro deletion of malignant cells from bone marrow in autologous bone marrow transplantation or for in vivo use as serotherapy. M o A b serotherapy trials in h u m a n T-cell leukemia and lymphoma have been attempted using MoAbs with T-cell

284

HANS GUENTER DREXLER a n d JUN MINOWADA

TABLE 4. INCIDENCE OF POSlTIVlTY OF M o A b s TESTED ON CASES OF ACUTE MYELOID LEUKEMIAS ( G R o u P IV: REACTIVITY MYELOCYTIC PARTLY, MONOCYTIC PARTLY)

MoAb

lmmunogen

1G10

AML*

28 B4.3

PB monocytes PB T-lymphocytes

CA-2-38 D5 DU-HL60-1 Ell

ML-3 K-562 HL-60 AMoL

FMC12 FMC17

PB granulocytes PB mononuclear cells

G2

PB granulocytes

HL-21 LB3-37 MI/NI Mo4 My-t (=1/12/13)

HL-60 AML neural cells PB monocytes HL-60

PMN 6 PMN 29 R1B19 $8-6 S16-444 S17-12 S17-14 Tu2 Tu9 U J308

PB neutrophils PB neutrophils HL-60 AML K-562 BV-173 BV-173 AMMoL AMMoL neural cells

AML (FAB M1-3)

AMMoL/AMoL (FAB M4/5)

2/6 4/7

(330/o)1(5707o) n.r. 6/13 (4607o) 2/17 (12%)11 5/12 (4207o) 3/28 (1107o) 8/40 (2007o) 18/65 (28070) 2/4 (50070) 9/16 (56°7o) 0/16 (0%)11 0/8 (007o) 0/24 (007o) 2/9 (2207o) 3/6 (5007o) 3/6 (50°7o) 6/12 (500/o) 2/5 (400/o) 7/16 (44%) 9/21 (43070) 1/16 (6°70) 8/27 (30°70) 5/28 (18%) 3/17 (1807o) 2/10 (20070) 43/99 (43O7o) n.r. 45/109 (41070) 0/12 (0%0) 0/12 (0070) 9/27 (33070) 16/27 (59070) 11/27 (4107o) 14/26 (4807o) 17/26 (65%) 4/6 (67°7o) 5/11 (45070) 10/28 (36°70)

5/11 8/9

(45070) (89%) n.r. 13/20 (65070) 21/31 (6807o)11 12/15 (8007o) 5/24 (2107o) 17/39 (43°7o) 6/11 (54%) 4/6 (67°7o) 9/13 (69°7o) 28/36 (78°7o)11 12/28 (43%) 40/64 (6207o) 6/9 (670/o) 1/3 (33070) 10/13 (77%) 11/16 (69070) 3/9 (3307o) 14/16 (8707o) 17/25 (6807o) 9/16 (56%) 15/35 (4307o) 10/24 (42070) 8/16 (5007o) 0/4 (0070) 4/13 (310/o) n.r. 4/17 (23070) 7/14 (50070) 9/14 (64070) 17/35 (4807o) 16/32 (50070) 16/32 (50%) 14/32 (44°7o) 21/30 (700/o) 4/8 (50%) 11/16 (6907o) 10/24 (42070)

All cases 7/17 12/16 32/54 51/87 23/48 17/27 8/52 25/79 24/76 6/10 18/29 28/52 12/36 40/88 8/18 4/9 13/19 17/28 5/14 21/32 26/46 10/32 23/62 15/52 11/33 2/14 47/112 14/30 63/156 7/26 9/26 26/62 32/59 27/59 28/58 38/56 8/14 16/27 20/52

References

(41%) [1, 13] (75070) [12] (59%) [2] (59%) (48%)11 [48] (6307o) [12, 81] (1507o) [70] (32%) (31%) 1281 (6007o) [12, 46] (62°7o) [12, 57] (540/o)11 [48] (33%) [76] (45°7o) (440/o) [12, 89] (44o/o) [20] (68%) [12] (61%) (360/o) [56] (6607o) [12] (56070) (31070) [62, 861 (37°7o) [68] (2907o) [42, 70] (33o7o) [83] (14070) [22] (4207o) [28] (470/o) [77] (4007o) (2707o) [4, 6] (35070) [4, 6] (4207o) [68] (5407o) [681 (46%) [68] (48%) [681 (68°7o) [681 (5707o) [12, 85] (59070) [12, 85] (38070) [70]

Footnotes, see Table 1.

specificity [65] and have been reported to be partially successful [66]. The MoAb J-5 which detects the c o m m o n ALL-antigen (cALLA) has been successfully used for conditioning of autologous bone marrow for transplantation ('purging') [72]. Although MoAbs that recognize tumor-specific antigens would be extremely useful in the diagnosis and treatment of leukemias, it is as yet unclear whether truly tumor-specific antigens exist on h u m a n tumor cells [64]. But it seems likely that quantitative differences in antigen expression might be found on leukemia ceils compared to normal cells, and such differences may be exploited in mediating lysis of tumor versus normal cells.

Several MoAbs reacting with myeloid antigens demonstrated in vitro and in vivo complement-dependent cytotoxicity to myeloid leukemia cells exclusively, while sparing normal cell populations [5]. Patients with AML in relapse were treated with intravenous infusions of MoAbs reacting with differentiation antigens on normal and malignant myeloid cells. Peripheral blood leukemia cell counts decreased significantly, but transiently, during treatment [7]. Approaches to antibody-mediated therapy might involve the coadministration of biological response modifiers, such as gamma interferon and IL-2, in conjunction with MoAbs. Alternatively, it might be possible

285

Monoclonal antibodies reactive with acute myeloid leukemias TABLE5. MoAbs WITHLOWINCIDENCEOFPOSITIVITYWITHCASESOFACUTEMYELOIDLEUKEMIAS ANDMoAbs NOTTESTEDONMORETHAN 10 PATIENTS MoAb

Immunogen

R e f e r e n c e s MoAb

lmmunogen

References

5.5 B13.9 C10H5 D5D6 FMC 13 HL-5 HL-47 L1B2 L4F3

PB monocytes* PB T-lymphocytes AML AML PB granulocytes HL-60 HL-60 AML AML

[48] [70, 81] [49] [49] [891 [62] [62] [1, 2] [1, 21

PB monocytes AMoL AMoL HL-60 HL-60 AML K-562 K-562 AML AMoL

[83, 84] [84] [84] [67] [67] [68] [68] [68] [1, 2] [38, 48]

Mo3 Mo5 Mo6 Pro-lml Pro-lm2 S1-37 S16.89 S16-109 T5A7 UC45

Footnote, see Table 1.

to couple MoAbs to cytotoxic drugs, radiopharmaceuticals or toxins, or to use combinations of MoAb therapy and chemotherapy as new approaches to the treatment of the myeloid leukemias. LEUKEMIA SPECIFICITY, CELL LINEAGE SPECIFICITY AND TRANSLINEAGE REACTIVITY To our knowledge there are no human surface antigens reported to be truly leukemia specific. The here reviewed MoAbs have been produced against either leukemia cells or normal cells as immunogens. All MoAbs have been tested on normal cells of the same cell lineage as the immunizing leukemia cells and have been found to bind to both normal and malignant cells. Therefore, it can be concluded that these MoAbs are not specific for leukemia and not specific for myeloid leukemias. It appears that 'myeloid' MoAbs are also not specific for myeloid cell lineages, but react with non-myeloid leukemia and normal cells as well. As shown earlier, the reactivity pattern of several MoAbs termed as 'panmyelomonocytic' indicated that myelocytic and monocytic cells share common antigens. A high percentage of the MoAhs detecting antigens on myeloid cells have been produced against normal and malignant non-myeloid cells: T lymphocytes (B2.12, B4.3, M-GI120, M-M522, M-M67), a T-cell leukemia cell line (TA-I), thymic membrane glycoprotein and thymocytes (TG-1, UCHM1), brain cells (SmO) and neuroblastoma cells (MI/N1, U J308). Immunocytochemical studies showed that MoAbs associated with the myeloid cell lineages stained cells of bile caniculi, renal tubular cells, hepatocytes, alveolar epithelium, tonsil epithelium, endothelium, connective tissue, Kupffer cells, Hassall's corpuscles and other tissue-specific cell types [69]. But also within the hematopoietic system results indicated that myeloid and monocytic normal cells share common antigens with cells of the erythroid and megakaryocytic lineages [40].

Translineage reactivity was observed for many MoAbs which at first were judged to be 'specific' for leukemias of a given cell lineage; for example the MoAbs Leu-I and T-101 detect an antigen of 65,000 dalton expressed on normal and leukemia T-lymphocytes, but not on normal B lymphocytes. However, these MoAbs also stain the majority of the cases of B-CLL [74]. This phenomenon of translineage reactivity in cases of leukemia has been described for the 'myeloid' MoAbs PM-81, VIM-D5, OKM1, MCS-1, MCS-2, MY9, VIM2, DU-HL60-1, DU-HL60-3, DU-HL60-4, HL-1, HL21, Pro-Iml, Pro-Im2 reacting with cALL [8, 14, 28, 36, 52, 57, 62, 67], with Null-ALL [14, 57], with leukemias of the T- [26, 28, 52, 57] or B-cell lineage [26, 28, 67]. The following theories have been proposed to explain these observations. The expression of antigens detected by these MoAbs may reflect the level of differentiation of the reactive cells within a particular cell lineage, probably in most cases a very immature, early stage of differentiation. This assumes the parallel expression of certain antigens across several cell lineages. Alternatively, it is also possible that the coexpression of two or more mutually exclusive lineage-related antigens (such as definite markers for the T-cell lineage and definite markers for the myeloid cell lineage) may represent an aberrant expression by malignant cells, possibly as a consequence of abnormal gene regulation in the malignant cells. The terms 'abnormal gene expression' [39], 'derepression of the genome' [14] and 'lineage infidelity' [78] have been created to describe these phenomena. On the other hand, leukemia cells with interlineage expression of certain antigens might represent a so far undetected, but possibly relevant new subclass of acute leukemias [43]. The question arises as to whether certain cases featuring the common expression of usually lineage-related characteristics (such as peroxidase, TdT, reactivity with well-defined MoAbs) are acute leukemias with two populations (lymphoblasts and myeloblasts) or with one population expressing both markers at the same time.

286

HANS GUENTER DREXLERand JUN MINOWADA

Both possible types of leukemias have been summarized under the new term 'hybrid acute leukemia' [9]. When the leukemia was characterized by a relatively homogeneous population of leukemia cells each of which demonstrated features of lymphoid and myeloid cells, it was referred to as a 'biphenotypic hybrid leukemia' [9]. If the leukemia population was heterogenous with some cells showing lymphoid parameters whereas others displayed myeloid characteristics, it was termed 'biclonal' (biclonal in terms of biclonal phenotypic expression) [9]. Malignant transformation might occur in such hybrid leukemias at the level of a pluripotential stem cell. The incidence of hybrid leukemias appears to be low, but many cases may remain undetected. Although most of the 'myeloid MoAbs' might not be cell lineage-restricted in their reactivity, the incidence of reactivity with non-lymphoid leukemias appears to be low. The MoAbs MCS-2, MY7, MY9, VIM-D5 and VIM-2 have been studied on larger numbers of nonmyeloid leukemias and have been found to react with 0-7°7o of cALL cases and 0-15O7o of T-ALL cases [28, 35, 52, 79]. No reactivity with cases of mature B-(B-CLL, B-lymphoma, hairy cell leukemia) or T-malignancies (T-CLL, T-lymphoma, S6zary-syndrome) have been reported for the mentioned MoAbs. CLASSIFICATION AND DIFFERENTIATION SCHEMES WITH MONOCLONAL ANTIBODIES The most widely used classification system of acute myeloid leukemias is based on the morphological and cytochemical features of the malignant cells as described by the FAB group [10]. But, as mentioned earlier, the reproducibility and reliability of the FAB-classification is limited and the subtyping of myeloid leukemias according to the FAB-criteria has not proven to be of definite prognostic significance. A subclassification of myeloid leukemias defined by surface marker parameters which is commonly accepted has not yet been elaborated. The identification of different stages of acute myeloid leukemia cell differentiation through the use of MoAbs might allow the development of a classification system that can provide information not obtainable by morphology and cytochemistry. An advantage of immunodiagnosis is the high degree of reproducibility and objectivity of the technique not always encountered in morphological classification systems. MoAbs may prove useful in the identification of distinct prognostic subgroups of acute myeloid leukemias. The use of MoAbs is indispensable for the distinction of the prognostically and therapeutically distinct subgroups of ALL: common ALL, T-ALL, B-ALL, pre B-ALL and Null-ALL [32]. To definitely assess the utility of such an immunological classification of myeloid leukemias, a multiparameter study considering a panel of markers should be performed on a large number of patients with the following objectives: (1) determination of the incidence of various immunological markers in acute myeloid leukemias; (2) correlation of presence of

markers with clinical characteristics of the patients; (3) identification of patient groups with particularly favorable or poor response to treatment; (4) detection of any significant differences in duration of remission among any of the phenotypic groups; (5) determination of whether the marker status changes at relapse; (6) analysis of chromosome abnormalities associated with immunologically defined subgroups; (7) correlation of the markers and defined phenotypes with the FAB classification. Indeed, regarding the latter point, the relationship between the level of morphological differentiation and the state of maturation determined by the immunological analysis has not been entirely examined. Griffin et al. showed that although there was some tendency for the morphology to correlate with the immunological phenotype, each phenotypic group (I-IV, see [34]) contained cases having different morphological types. These authors suggested that the surface antigen phenotypes reflected a related, but somewhat different view of the state of myeloid leukemic cell differentiation [34]. Other authors reported that the composite phenotype as determined by immunofluorescence did not correlate with the FAB morphological classification [68] and that only with the help of computerized analysis was it possible to show a correlation between the surface marker profile and the morphological FAB classification [70]. The relationship of cytochemical and antigenic phenotypes also deserves further study. An absence of a correlation between the cytochemical and immunological characterization of leukemic cells has been documented [13]. One explanation for this observation is that at certain stages of myeloid differentiation either the antigenic or the cytochemical markers characteristic of the cell line of origin may be expressed. Studies using MoAbs gave new insight into the normal differentiation and maturation of myeloid cells. Several authors proposed schemes of normal differentiation based on reactivity with immunological markers [6, 31, 34, 35, 61]. Ball et al. described differentiation pathways for myeloid cells according to reactivity with MoAbs [6]. Foon et al. proposed a scheme of myeloid differentiation showing a correlation of the normal ceil phenotypes with the respective malignant counterparts and their relation to the FAB subgroups and immunological characteristics [31]. Griffin and co-workers described a schematic representation of the distribution of various MoAbs on normal myeloid cells [34]. SUMMARY The use of polyclonal heteroantisera against antigens associated with the myeloid cell lineages is hampered by the necessary extensive absorption procedures, the low quantity and titer of the yielded reagents, the poor specificity and the extremely limited availability. MoAbs have the advantage of a higher specificity and a high general availability due to virtually unlimited production. We reviewed the reactivity pattern of 76 MoAbs which have been tested on cases of myeloid leukemias

Monoclonal antibodies reactive with acute myeloid leukemias (more than 10 cases per MoAb). On the basis of their frequency of positivity with the morpho-cytochemically determined subtypes AML (FAB M1-3) and A M M o L / A M o L (FAB M4/5) the M o A b s were assigned to one o f four groups. The M o A b s of G r o u p I, showing a 'pan-myelomonocytic' reactivity, stained more than 70% of cases of both the myelocytic and monocytic cell lineages. These M o A b s are useful for the identification of acute myeloid leukemias regardless of the subtype and for the differentiation of myeloid from lymphoid leukemias. M o A b s of Group II have a preponderance of reactivity with monocytic variants, but also labeled the majority of the myelocytic phenotypes (reactivity: myelocytic partly, monocytic predominantly). M o A b s of Group III were positive on most cases of A M M o L / A M o L , but showed a low percentage of staining with A M L cases (reactivity 'monocyte-specific'). These M o A b s are of particular value for the subclassification of acute myeloid leukemias into at least two types: those with monocytic and those with nonmonocytic features. Further studies will clarify whether some of the M o A b s listed in Group IV with low myelocytic and monocytic reactivity and other M o A b s not reviewed in detail detect certain particular subtypes or subsets with a biological, clinical, therapeutic or prognostic significance. Although the c o m m o n application of M o A b s still lies in the field of identification and classification of leukemias, MoAbs appear to be valuable for new therapeutic approaches. M o A b s can be used for i n - v i v o serotherapy and for in-vitro purging of bone marrow for autologous transplantation. More phase I and II trials are necessary to determine the ultimate value of M o A b therapy. No leukemia-specific antigen is described to this date. It also appears that the majority of M o A b s are not absolutely cell lineage-restricted in their reactivity pattern. Many of the reviewed 'myeloid M o A b s ' have been produced against non-myeloid cells as immunogens. Most of the M o A b s tested for that purpose also stained nonhematopoietic cells. The phenomenon of translineage reactivity in cases of leukemias has been described for many MoAbs. Possibly, the antigens detected by the M o A b s are expressed across several cell lineages. Alternatively, the coexpression of two or more mutually exclusive lineage-related or -restricted antigens may represent an abnormal gene expression by malignant cells. Nevertheless, the incidence of such cases appears to be low and does not substantially hamper the use of the 'myeloid M o A b s ' for diagnostic purposes. The most widely used classification of the myeloid leukemias based on morphological and cytochemical criteria is the FAB-system. However, the reproducibility of the FAB-classification has been reported to be somewhat limited. If myeloid leukemia cell surface antigens reflect those of the normal myeloid cell stage from which they are derived, then utilization of the appropriate MoAbs that recognize myeloid differentiation antigens could facilitate subclassification of the myeloid leukemias and more precisely characterize normal myeloid differentiation. This does not mean that the assessment of morphology and cytochemistry is obsolete

287

in the accurate diagnosis of acute myeloid leukemias. Rather, the disciplines morphology [90] and cytochemistry [29] should be combined with the immunological surface marker analysis [61] in the multiple marker analysis [27, 60], possibly supplemented by cytogenetic, functional and enzyme marker analysis [251. Studies using M o A b s gave new insight into the normal differentiation and maturation processes of myeloid cells. Refined schemes of normal differentiation based on reactivity with immunological markers and correlated with morpho-cytochemical parameters have been proposed. A c k n o w l e d g e m e n t s - - T h e authors would like to thank Ms Suzanne M. Gignac and Mrs Corrine Arthur for their help in the preparation of the manuscript.

REFERENCES 1. Andrews R. G., Torok-Storb B. & Bernstein I. D. (1983) Myeloid-associated differentiation antigens on stem cells and their progeny identified by monoclonal antibodies. Blood 62, 124, 2. Andrews R. G., Brentnall T. A., Torok-Storb B. & Bernstein I. D. (1984) Stages of myeloid differentiation identified by monoclonal antibodies. In Leucocyle Typing (Bernard A., Boumsell L., Dausset J., Milstein C. & Schlossman S. F., Eds), p. 398. Springer, Berlin. 3. Baker M. A., Falk R. E., Falk J. & Greaves M. F. (1976) Detection of monocyte specific antigen on human acute leukaemia cells. Br. J. Haemat. 32, 13. 4. Ball E. D., Graziano R. F., Shen L. & Fanger M. W. (1982) Monoclonal antibodies to novel myeloid antigens reveal human neutrophil heterogeneity. Proc. ham. Acad. Sci. U.S.A. 79, 5374. 5. Ball E. D., Kadushin J. M., Schacter B. & Fanger M. W. (1982) Studies on the ability of monoclonal antibodies to selectively mediate complement-dependent cytotoxicity of human myelogenous leukemia blasts cells. J. Immun. 128, 1476. 6. Ball E. D. & Fanger M. W. (1983) The expression of myeloid-specific antigens on myeloid leukemia cells: Correlations with leukemia sub-classes and implications for normal myeloid differentiation. Blood 61,456. 7. Ball E. D., Bernier G. M., Cornwell 11I G G., Mclntyre O. R., O'Donnell J. F. & Fanger M. W. (1983) Monoclonal antibodies to myeloid differentiation antigens: ln-vivo studies of three patients with acute myelogenous leukemia. Blood 62, 1203. 8. Ball E. D., Graziano R. F. & Fanger M. W. (1983) A unique antigen expressed on myeloid cells and acute leukemia blast cell defined by a monoclonal antibody. J. lmmun. 130, 2937. 9. Ben-Bassat I. & Gale R. P. (1984) Hybrid acute leukemia. Leukemia Res. 8, 929. 10. Bennet J. M., Catovsky D., Daniel M. -Th, Flandrin G., Galton A. G., Gralnick H. & Sultan C. (1976) Proposals for the classification of the acute leakaemias. Br. J. Haemat.33, 451. 11. Bennet J. M. & Reed C. E. (1979) Cytochemistry of the leukemic cell. In The Leukemic Cell (Rubin A. D. & Wax-

288

HANS GUENTERDREXLERand JUN MINOWADA

man S., Eds), p. 7. CRC Press, Palm Beach. 12. Bernard A., Boumsell L., Dausset J., Milstein J. & Schlossman S. F., Eds (1984) Leucocyte Typing, pp. 9 and 751. Springer, Berlin. 13. Bernstein I. D., Andrews R. G., Cohen S. F. & McMaster B. E. (1982) Normal and malignant human myelocytic and monocytic cells identified by monoclonal antibodies. J. Immun. 128, 876. 14. Bettelheim P., Paietta E., Majdic O., Gadner H., Schwarzmeier J. & Knapp W. (1982) Expression of a myeloid marker on TdT-positive acute lymphocytic leukemia cells: Evidence by double-flourescence staining. Blood 60, 1392. 15. Beverley P. C. L., Linch D. & Delia D. (1980) Isolation of human haematopoietic progenitor cells using monoclonal antibodies. Nature, Lond. 287, 332. 16. Billing R., Clark B., Koeffler P., Foon K. A. & Terasaki P. I..(1980) Acute myelogenous leukemia heteroantisera. Clin. Immun. Immunopath. 16, 202. 17. Billing R. J., Foon K. A. & Linker-Israeli M. (1982) The immunological classification of leukaemia based on a rapid microcytotoxicity test. Clin. exp. I m m u n . 49, 142. 18. Breard J., Lazarus H. & Schlossman S. F. (1980) Generation and specificity of a heteroantiserum to human peripheral blood monocytes. Clin. Immun. Immunopath. 16, 438. 19. Breard J., Reinherz E. L., Kung P. C., Goldstein G. & Schlossman S. F. (1980) A monoclonal antibody reactive with human peripheral blood monocytes. J. l m m u n . 12,4, 1943. 20. Brooks D., Zola H., McNamara P. J., Bradley J., Bradstock K. F., Hancock W. W. & Atkins R. C. 0983) Membrane antigens of human cells of the monocyte/macrophage lineage studied with monoclonal antibodies. Pathology 15, 45. 21. Brutel de la Riviere A., Verhoef-Karssen P. R., Bosha A., Borne A. E. G. Kr. von dem & Engelfriet P. (1976) Specific antisera against human blood cells applicable in the indirect immunofluorescence technique. Scand. J. lmmun. 5, 1065. 22. Civin C. I., Mirro J. & Banquerigo M. L. (1981) My-l, a new myeloid specific antigen identified by a mouse monoclonal antibody. Blood 57,842. 23. Dick F. R., Armitage J. O. & Burns C. P. (1982) Diagnostic concurrence in the subclassification of adult acute leukemia using French-American-British criteria. Cancer 49, 916. 24. Dimitriu-Bona A., Burmester G. R., Waters S. J. & Winchester R. J. (1983) Human mononuclear phagocyte differentiation antigens. I. Patterns of antigenic expression on the surface of human monocytes and macrophages defined by monoclonal antibodies. J. Immun. 130, 146. 25. Drexler H. G., Gaedicke G. & Minowada J. (1984) Enzyme markers in acute leukemias: Advances during the last decade. J. hath. Cancer Inst. 72, 1283. 26. Drexler H. G., Sagawa K., Menon M. & Minowada J. (1985) 'Pan-myeloid' reagent: The monoclonal antibody MCS-2 in the routine immunodiagnostic service of leukemia phenotyping. Gann 76, 235. 27. Drexler H. G., Menon M., Sagawa K., Tatsumi E., Koshiba H., Koishi T., Minato K., Sugimoto T., Saito M., Morita M., Pauly J. L., Han T., Freeman A. I., Messmore

28.

29.

30.

31.

32.

33.

34.

35.

36.

37.

38.

39.

40.

41. 42.

43.

H. & Minowada J. (submitted) Phenotyping of malignant hematopoietic cells. I. Analysis of 1200 cases of leukemia-lymphoma. Leukemia Res. Drexler H. G., Sagawa K., Menon M. & Minowada J. (submitted) Phenotyping of malignant hematopoietic cells. II. Reactivity pattern of 'myeloid monoclonal antibodies' with emphasis on MCS-2. Leukemia Res. Flandrin G. & Daniel M. -Th. (1981) Cytochemistry in the classification of leukemias. In The Leukemic Cell (Catovsky D., Ed.), p. 29. Churchill-Livingstone, Edinburgh. Foon K. A., Billing R. J., Fitchen J. H., Belzer M., Drew S. !., & Terasaki P. I. (1981) An antigen expressed by cells of the myelomonocytic lineage. A m . J. Hemat. 10, 259. Foon K. A., Schroff R. W. & Gale R. P. (1982) Surface markers in leukemia and lymphoma cells: Recent advances. Blood 60, I. Greaves M. F. (1981) Analysis of the clinical and biological significance of lymphoid phenotypes in acute leukemia. Cancer Res. 41, 4752. Griffin J. D., Ritz J., Nadler L. & Schlossman S. F. (1981) Expression of myeloid differentiation antigens on normal and malignant myeloid cells. J. clin. Invest. 68, 932. Griffin J. D., Mayer R. J., Weinstein H. J., Rosenthal D. S., Coral F. S., Beveridge R. P. & Schlossman S. F. (1983) Surface marker analysis of acute myeloblastic leukemia: identification of differentiation-associated phenotypes. Blood 62, 557. Griffin J. D. & Schlossman S. F. (1984) Expression of myeloid differentiation antigens in acute myeloblastic leukemia. In Leucocyte Typing (Bernard A., Boumsell L., Dausset J., Milstein C. & Schlossman S. F., Eds), p. 404. Springer, Berlin. Griffin J. D., Linch D., Sabbath K., Larcom P. & Schlossman S. F. (1984) A monoclonal antibody reactive with normal and leukemic human myeloid progenitor cells. Leukemia Res. 8, 521. Hanjan S. N. S., Kearney J. F. & Cooper M. D. (1982) A monoclonal antibody (MMA) that identifies a differentiation antigen on human myelomonocytic cells. Clin. Immun. lmmunopath. 23, 172. Hogg N., Slusarenko M., Cohen J. & Reiser J. (1981) Monoclonal antibody with specificity for monocytes and neurons. Cell 24, 875. Janossy G. (1981) Membrane markers in leukemia. In The Leukemic Cell (Catovsky D., Ed.), p. 128. ChurchillLivingstone, Edinburgh. Kamoun M., Martin P. J., Kadin M. E., Lum L. G. & Hansen J. A. (1983) Human monocyte-histiocyte differentiation antigens identified by monoclonal antibodies. Clin. l m m u n . Immunopath. 29, 181. Kass L., Ed. (1982) Leukemia Cytology and Cytochemistry. Lippincott, Philadelphia. Kemshead J. T., Bicknell D. & Greaves M. F. (1981) A monoclonal antibody detecting an antigen shared by neural and granulocytic cells. Pediatr. Res. 15, 1282. Knapp W., Bettelheim P., Majdic O., Liszka K., Schmidmeier W. & Lutz D. (1984) Diagnostic value of monoclonal antibodies to leucocyte-differentiation antigens in lymphoid and nonlymphoid leukemias. In Leucocyte Typing (Bernard A., Boumsell L., Dausset J., Milstein C. & Schlossman S. F., Eds), p. 564. Springer, Berlin.

Monoclonal antibodies reactive with acute myeloid leukemias 44. Knapp W., Majdic O., Bettelheim P., Liszka K., Aberer W. & Stingl G. (1984) Typing of leukemic cells with monoclonal antibodies. Ann. N. Y. Acad. Sci. 420, 251. 45. Koehler G. & Milstein C. (1975) Continuous cultures of fresh cells secreting antibodies of predefined specificity. Nature, Lond. 256, 495. 46. Lansdorp P. M., Kwast van der Th., Mourik P. & Zeijlemaker W. P. (1984) Analysis of monoclonal antibody binding using step-wise amplified immunoperoxidase staining. In Leucocyte Typing (Bernard A., Boumsell L., Dausset J., Milstein C. & Schlossman S. F., Eds), p. 488. Springer, Berlin. 47. LeBien T. & Kersey .I.H. (1980) A monoclonal antibody (TA-I) reactive with human T lymphocytes and monocytes. J. Immun. 125, 2208. 48. Linch D. C., Allen C., Beverley P. C. L., Bynoe A. G., Scott C. S. & Hogg N. (1984) Monoclonal antibodies differentiating between monocytic and nonmonocytic variants of AML. Blood 63, 566. 49. Linker-Israeli M., Billing R. J., Foon K. & Terasaki P. I. (1981) Monoclonal antibodies reactive with acute myelogenous leukemia cells. J. lmmun. 127, 2473. 50. Lohmeyer J., Rieber P., Feucht H., Johnson J., Hadam M. & Riethmueller G. (1981) A subset of human natural killer ceils isolated and characterized by monoclonal antibodies. Eur. J. Immun. 11,997. 51. Majdic O., Liszka K., Lutz D. & Knapp W. (1981) Myeloid differentiation antigen defined by a monoclonal antibody. Blood 58, 1127. 52. Majdic O., Bettelheim P., Stockinger H., Aberer W., Liszka K., Lutz D. & Knapp W. (1984) M2, a novel myelomonocytic cell surface antigen and its distribution on leukemic cells. Int. J. Cancer 33, 617. 53. Malcolm A. J., Logan P. M., Shipman R. C., Kurth R. & Levy J. G. (1983) Analysis of human myelogenous leukemia cells in the Fluorescence Activated Cell Sorter using a tumor-specific antigen. Blood 61,858. 54. Mannoni P., Janowska-Wieczorek A., Turner A. R., McGann L. & Turc J. M. (1982) Monoclonal antibodies against human granulocytes and myeloid differentiation antigens. Hum. lmmun. 5, 309. 55. Mannoni P., Janowska A., Fromont P., Weiblen B., Turner A. R. & Turc J. M. (1984) Human myeloid differentiation studied by monoclonal antibodies. In Leucocyte Typing (Bernard A., Boumsell L., Dausset J., Milstein C. & Schlossman S. F., Eds), p. 410. Springer, Berlin. 56. Martin L. S., McDougal J. S., Browning S. W. & Gordon D. S. (1984) Cellular specificity and functional studies of G2: A monoclonal antibody to human polymorphonuclear leucocytes. In Leucocyte Typing (Bernard A., Boumsell L., Dausset J., Milstein C. & Schlossman S. F., Eds), p. 438. Springer, Berlin. 57. McKolanis J. R., Borowitz M. J., Tuck F. L. & Metzgar R. S. (1984) Membrane antigens of human myeloid cells defined by monoclonal antibodies. In Leucocyte Typing (Bernard A., Boumsell L., Dausset J., Milstein C. & Schlossman S. F., Eds), p. 387. Springer, Berlin. 58. Mertelsmann R., Thaler H. T., To L., Gee T. S., McKenzie S., Schauer P., Friedman A., Arlin Z., Cirrincione C. & Clarkson B. (1980) Morphological classification, response to therapy, and survival in 263

289

adult patients with acute nonlymphocytic leukemia. Blood 56, 773. 59. Minowada J., Sagawa K., Trowbridge 1. S., Kung P. C. & Goldstein G. (1982) Marker profiles of 55 human leukemialymphoma cell lines. In Malignant Lymphomas. Etiology, Immunology, Pathology, Treatment (Rosenberg S. A. & Kaplan H. S., Eds), p. 53. Academic Press, New York. 60. Minowada J. (1983) Immunology of leukemic cells. In Leukemia (Gunz F. W., & Henderson E. S+, Eds), p. 119. Grune & Stratton, New York. 61. Minowada J. (1985) Immunology of leukemia and lymphoma. In Contemporary Issue in Clinical Oncology, Vol. 4: Leukemias and Lymphomas (Wiernik H. P., Ed.), p. 183+ Churchill-Livingstone, Edinburgh. 62. Namikawa R., Ogata S. -1., Ueda R., Tsuge 1., Nishida K. Minami S., Koike K., Suchi T., Ota K., lijima S. & Takamashi T. (1983) Serological analysis of cell surface antigens of HL-60 cells before and after treatment with a phorbol ester tumor promoter. Leukemia Res. 7, 375. 63. Neame P. B., Soamboonsrup P., Browman G., Barr R. D., Saeed N., Chan B., Pai M., Benger A., Wilson W. E. C., Walker 1. R. & McBridge J. A. (1985) Simultaneous or sequential expression of lymphoid and myeloid phenotypes in acute leukemia. Blood 65, 142. 64. Old L. J. (1981) Cancer Immunology. The search for specificity. Cancer Res. 41,361. 65. Oldham R. K. (1983) Monoclonal antibodies in cancer therapy. J. clin. Oncol. 1,582. 66. Oldham R. K., Thurman G. B., Talmadge J. E., Stevenson H. C. & Foon K. A. (1984) Lymphokines, monoclonal antibodies, and other biological response modifiers in the treatment of cancer. Cancer 54, 2795. 67. Peng R., AI-Katib A., Knowles 1I D, M., Lu L., Broxmeyer H., Tolidjian B., Chiao J. -W. Koziner B. & Wang C. Y. (1984) Preparation and characterization of monoclonal antibodies recognizing two distinct differentiation antigens
290

73.

74.

75.

76.

77.

78.

79.

80.

81.

HANS GUENTERDREXLERand JUN MINOWADA lymphoblastic leukaemia after in vivo treatment with J5 monoclonal antibody and complement. Lancet 8289, 60. Roberts M. M. & Greaves M. F. (1978) Maturation linked expression of a myeloid cell surface antigen. Br. J. Haemat. 38, 439. Royston 1., Majda J. A., Baird S. M., Meserve B. L. & Griffiths J. C. (1980) Human T-cell antigen defined by monoclonal antibodies: the 65,000 dalton antigen for T-cells (T65) is also found on chronic lymphocytic leukemia cells bearing surface immunoglobulins. J. Immun. 125, 725. Schienle H. W., Stein H. & Mueller-Ruchholtz W. (1982) Neutrophil granulocytic cell antigen defined by a monoclonal antibody - - Its distribution within normal haemic and non-haemic tissue. J. clin. Path. 35,959. Scott C. S., Linch D. C., Bynoe A. G., Allen C., Hogg N., Ainley M. J., Hough D. & Roberts B. E. (1984) Electrophoretic and cytochemical characterization of alphanaphthyl acetate esterases in acute myeloid leukemia: Relationships with membrane receptor and monocytespecific antigen expression. Blood 63,579. Skubitz K. M., Zhen Y. -S. & August J. T. (1983) A human granulocyte-specific antigen characterized by use of monoclonal antibodies. Blood 61, 19. Smith L. J., Curtis J. E., Messmer H. A., Senn J. S., Furthmayr H. & McCulloch E. A. (1983) Lineage infidelity in acute leukemia. Blood 61, 1138. Stockinger H., Majdic O., Liszka K., Aberer W., Bettelheim P., Lutz D. & Knapp W. (1984) Exposure by desialylation of myeloid antigens on acute lymphoblastic leukemia cells. J. hath. Cancer Inst. 73, 7. Stuart A. E., Young G. A. & Grant P. F. (1976) Identification of human mononuclear cells by anti-monocyte serum. Br, J. Haemat. 34, 457. Tetteroo P. A. T., Lansdorp P. M., Geurts Van Kessel A. H. M., Hagemeijier A. & Borne von dem A. E. G. Kr. (1984) Serological and biochemical characterization of human myeliod-associated antigens and their expression in

82.

83.

84.

85.

86.

87.

88.

89.

90.

human-mouse cell hybrids. In Leucocyte Typing (Bernard A., Boumsell L., Dausset J., Milstein C. & Schlossman S. F., Eds), p. 419. Springer, Berlin. Todd III R., Nadler L. M. & Schlossman S. F. (1981) Antigens on human monocytes identified by monoclonal antibodies. J. Immun. 126, 1435. Todd III R. & Schlossman S. F. (1982) Analysis of antigenic determinants on human monocytes and macrophages. Blood 59, 775. Todd II1 R., Bhan A. K., Kabawat S. E. & Schlossman S. F. (1984) Human myelomonocytic differentiation antigens defined by monoclonal antibodies. In Leucocyte Typing (Bernard A., Boumsell L., Dausset J., Milstein C. & Schlossman S. F., Eds), p. 424. Springer, Berlin. Uchanska-Ziegler B., Wernet P. & Ziegler A. (1981) Monoclonal antibodies against human lymphoid and myeloid antigens: AML cells as immunogens. In Leukemia Markers (Knapp W., Ed.), p. 243. Academic Press, London. Ueda R., Namikawa R., Ogata S., Matsuoka H., Tsuge I., Minami S., Nishida K., Koike K., Suchi T., Ota K. & Takahashi T. (1984) Immunological classification of leukemias with monoclonal antibodies. In Leucocyte Typing (Bernard A., Boumsell L., Dausset J., Milstein C. & Schlossman S. F., Eds), p. 603. Springer, Berlin. Ugolini V., Nunez G., Smith R. G., Stastny P. & Capra J. D. (1980) Initial characterization of monoclonal antibodies against human monocytes.'Proc, natn. Acad. Sci. U.S.A. 77, 6764. Zittoun R., Cadiou M., Bayle C., Suciu S., Solbu G. & Hayat M. (1984) Prognostic value of cytologic parameters in acute myelogenous leukemia. Cancer 53, 1526. Zola H., McNamara P., Thomas M., Smart 1. J. & Bradley J. (1981) The preparation and properties of monoclonal antibodies against human granulocytes membrane antigens. Br. J. Haemat. 48, 481. Zucker-Franklin D., Greaves M. F., Grossi C. E. & Marmont A. M., Eds (1981) Atlas o f Blood Cells - - Function and Pathology. Lea & Febiger, Philadelphia.