- Email: [email protected]
Trisomy 21 as a Sole Acquired Abnormality in an Adult Omani Patient with CD7- and CD9-Positive Acute Myeloid Leukemia
Archives of Medical Research 38 (2007) 797e802
CASE REPORT
Trisomy 21 as a Sole Acquired Abnormality in an Adult Omani Patient with CD7- and CD9-Positive Acute Myeloid Leukemia Achandira M. Udayakumar,a Anil V. Pathare,b S. Muralitharan,c Asem A. Alghzaly,b Salam Alkindi,b and J.A. Raeburna b
a Department of Genetics, College of Medicine and Health Sciences, Sultan Qaboos University, Sultanate of Oman Department of Haematology, cDepartment of Biochemistry, Sultan Qaboos University Hospital, Muscat, Sultanate of Oman
Received for publication January 10, 2007; accepted April 9, 2007 (ARCMED-D-07-00019).
We describe a case of acute myeloid leukemia (AML) in which trisomy 21 was the sole acquired cytogenetic abnormality. The immunophenotype showed positivity for CD7 and CD9 along with CD13, CD33, and CD34. The chromosomal analysis of bone marrow showed 47,XY þ21 in all the metaphases analyzed. The constitutional karyotype was normal. The patient was an adult and did not have any features of Down’s syndrome. The bone marrow morphology was AML-M2 as per the French-American-British (FAB) criteria. A final diagnosis of CD7- and CD9-positive AML-M2 was established with trisomy 21 as a sole cytogenetic abnormality. The patient responded remarkably well to chemotherapy and achieved complete clinical remission. This is the first case of CD7and CD9-positive AML with trisomy 21 as a sole abnormality. A putative role for the co-expression of abnormal lymphoid markers in achieving quick remission is discussed. Ó 2007 IMSS. Published by Elsevier Inc. Key Words: Acute myeloid leukemia, Cytogenetics, Prognosis, Trisomy 21.
Introduction Trisomy 21 is reported to be one of the most common acquired chromosomal abnormalities in hematological malignancies (1) but is very rarely reported as a sole anomaly at diagnosis among patients with acute myeloid leukemia (AML) (2,3). The clinical implications of this acquired anomaly in myeloid disorders are still unclear. In an institutional study from a series of þ21 in myeloid disorders (2), 3.3% patients showed an acquired þ21 [A-T21] in the newly diagnosed AML/myelodysplastic syndromes Conflict of Interest: None of the authors have declared any conflict of interest. Author’s contributions: AAG, AVP, and SAK participated in clinical assessment and management of the case. AVP and AMU were instrumental in preparation of the manuscript. AMU did the cytogenetic diagnosis, SM did the molecular work and AMU and JAR compiled the data as per ISCN (2005). All the authors contributed to the preparation of the final manuscript. Address reprint requests to: Achandira M. Udayakumar, Department of Genetics, College of Medicine and Health Sciences, P.O. Box 35, Sultan Qaboos University, Sultanate of Oman; E-mail: [email protected] or [email protected]
(MDS) and 0.3% occurred as the sole cytogenetic anomaly. Trisomy 21 was observed as a sole acquired abnormality in 13 patients who had hematological malignancies (4), 12 of which were myeloid and one a lymphoid leukemia. A first case of þ21 in an AML with immunophenotypically positive CD7 (as well as CD13, CD33, and CD34) was reported from Japan (5). Subsequently, another case of trisomy 21 in a CD7-positive AML as a sole abnormality was also reported (6), but cases having þ21 as sole anomaly along with immunophenotypic positivity for CD7 and CD9 have not been reported so far, to our knowledge. We report here an adult patient with constitutionally normal karyotype having CD7- and CD9-positive AML and showing trisomy 21 as the only acquired karyotypic abnormality. This is the first report of þ21 in an AML patient as sole anomaly from the Middle Eastern population. Case Report HHSN, a 24-year-old Omani male, was referred in August 2006 with fatigue and dizziness of 2-week duration. There was no significant past history. Physical examination was
0188-4409/07 $esee front matter. Copyright Ó 2007 IMSS. Published by Elsevier Inc. doi: 10.1016/j.arcmed.2007.04.007
798
Udayakumar et al./ Archives of Medical Research 38 (2007) 797e802
unremarkable except for a just palpable liver. The spleen was not enlarged, there was no lymphadenopathy, and the rest of his systemic examination was normal. Investigations revealed Hb 6.2 g/dL, WBC 199 109/L with 90% myeloblast, and platelet count 171 109/L. Bone marrow examination was reported as acute myeloid leukemia FAB M2 (WHO) (Figure 1). Flow cytometry with four-color analysis using monoclonal antibodies was performed on the marrow sample revealing CD7, 31%; CD9, 41%; CD13, 73%; CD15, 15%; CD33, 62%; CD34, 86%; CD64, 55%; CD117, 81%; and MPO, 90%, consistent with AML (Figure 2). The patient’s renal and liver functions were within normal range but he had a significantly elevated serum lactic dehydrogenase (2000 IU). Cytogenetic Analysis A bone marrow aspiration sample was received for cytogenetic analysis, and short-term cultures (24 and 48 h) were set up using Marrow MAX Bone Marrow medium (cat. #12260e014; Gibco, Grand Island, NY) and cultures were harvested using standard procedures. G-banded metaphases were analyzed and karyotyped as per the International System for Human Cytogenetic Nomenclature (ISCN) (7). Chromosome analysis showed 47,XY þ21 as sole abnormality in all 31 metaphases analyzed (Figure 3). Phytohemagglutinin (PHA)-induced 72-h cultures of peripheral blood were set up to study his constitutional karyotype and it showed 46,XY, a normal karyotype, in all 20 metaphases analyzed.
tient was in remission by standard methods using Qiagen Kits (Qiagen, Hilden, Germany). A cystathionine b-synthase (CBS) mutation was not detected by PCR amplification of the CBS gene by specific primers and restriction enzyme analysis of the PCR product by endonuclease Bsr1 (8). The patient showed a normal band (184 bp), whereas a known positive sample confirmed that PCR amplification was successfully achieved showing heterozygosity for the 68-bp insertion in exon 8 of the CBS gene and the presence of 833TC mutation (Figure 4). The patient was treated with the standard chemotherapy protocol (7þ3) for AML with cytosine arabinoside (100 mg/m2, continuous infusion, days 1e7) and daunorubicin (40 mg/m2, drip infusion with rapid push, days 1e3). He tolerated the chemotherapy quite well and a repeat bone marrow examination after 28 days showed that he was in clinical remission (CR), with the cytogenetic analysis revealing 46,XY in all the metaphases analyzed, indicating cytogenetic remission as well. Thereafter, he received two cycles of remission consolidation therapy with intermediate dose cytosine arabinoside at 2 g/m2 each. The patient tolerated the chemotherapy without any major complications but presented in relapse within a month of completion of consolidation. He is now receiving reinduction chemotherapy with IDA-FLAG protocol and is counselled to undergo bone marrow transplantation as soon as he has a suitable HLA identical donor, in view of the high WBC count, A-T21 at presentation and early relapse.
DNA Studies
Discussion
Genomic DNA was extracted from bone marrow sample obtained at diagnosis and peripheral blood obtained when pa-
The incidence of trisomy 21 as a sole abnormality was reported as between 0.3 and 1.7% in AML/MDS patients and they appear to show a poor prognosis (2,3,9). A majority showed morphologically M2 or M4 phenotype according to the FAB classification (Table 1) (3,5e7,10). Immunophenotypes in these cases at presentation were CD7 þve (5,6) but our patient was positive for both CD7 and CD9 with FAB-M2 type morphology. Although coexpression of CD7 in cases of AML with A-T21 is 12e17% in the overall group of AML patients (11), it is speculated that there are more cases of CD7 þve AML with A-T21. We do not fully understand the biological and clinical significance of CD7 expression in AML (12). In most reported cases, trisomy 21 was present along with normal clones (3,6,9), whereas in our case all cells had þ21 without any normal clone. Expression of lymphoid antigens is common in AML and is associated with variable CR rates: CD2 being expressed in 16e21% and CD19 in 7e14% (13,14). CD19 expression is associated with pediatric AML FAB-M2 and the t(8;21) translocation (15). However, CD7 is the most commonly expressed lymphoid antigen in AML (11e29%) (11,12). CD7þ AML patients have a significantly lower response rate and poorer prognosis than CD7 AML patients
Figure 1. May Grunwald Giemsa staining of the bone marrow slide showing pleomorphic large agranular myeloblasts with 2e3 nucleoli, no Auer rods and cytoplasmic vacuoles.
Trisomy 21 and Acute Myeloid Leukemia
799
Figure 2. Flow cytometry with four-color analysis using a panel of monoclonal antibodies showing myeloblasts with aberrant CD7 and CD9 positivity.
(12). CD7 þve AML patients have been younger males frequently with hepatosplenomegaly (12). Our patient was also a young male (24 years), supporting this statement. In contrast, his liver was only just palpable and he had no splenomegaly. AML patients whose cells express CD9 have a lower remission rate (16). Moreover, CD9 antigen on acute non-
lymphoid leukemia cells is preferentially expressed by promyelocytic (M3) subtype in up to 75% cases (17). CD9 is not expressed by normal hematopoietic precursors or normal peripheral B lymphocytes, but it is expressed by developing B-lineage cells, being lost following differentiation. It is present in a wide variety of tissues like platelets, eosinophils, basophils and stimulated T cells (18). It is also
800
Udayakumar et al./ Archives of Medical Research 38 (2007) 797e802
Figure 3. Karyotype of the patient showing 47,XY þ21 (arrow indicating the extra 21).
believed that CD9 is important in the regulation of leukemia cell motility (19). The prognostic role of CD7 expression in AML is contradictory, some stating it as adverse (poor) (11,20) and others claiming to have no effect (21). Similarly, AML patients with A-T21 as sole abnormality have been considered to have a poor prognosis (2e4,9). But there are instances where patients have shown CR and good prognostic indication (5,6). Co-expression of CD7 and CD9 is probably indicative of the very early stage at which the cell became malignant and is, until this report, unreported in AML. Thus, although these CD markers are suggestive of a poor prognosis, the rapidity with which this patient went into clinical and cytomorphologic remission, the relative paucity of complications, and the uneventful remission induction, intensification, and consolidation stages would hopefully suggest otherwise. On the other hand, CR in this patient was short-lived with the patient relapsing within a month after the last consolidation. Whether age of the patient at presentation and the status of CD7/CD9 expression play any role in response to treatment remains to be studied in more patients before arriving at any conclusion. Additionally, our patient had A-T21 in all the metaphases studied. It is believed that increased expression of chromosome 21-related genes like CBS plays a central role in the increased sensitivity of leukemic cells to chemotherapeutic agents like ara-C and daunorubicin (22). This has been particularly true of þ21 AML cases with Down’s syndrome. Furthermore, mutations in the CBS gene like CBS
68 bp del can influence prognosis in patients with AML (23,24). Hence, we specifically screened the initial as well as the postremission bone marrow sample (day 28) for this mutation but, as it was absent, it may be indicative of a good prognostic feature for this patient. Our patient had A-T21 with AML as the sole cytogenetic abnormality and it
Figure 4. Ethidium bromide-stained agarose gel containing PCR reaction products of BsrI digestion of CBS gene from a known positive control with 68 bp insertion mutation (252 and 184 bp) and patient l (184 bp).
Trisomy 21 and Acute Myeloid Leukemia Table 1. Reports of trisomy 21 as a sole abnormality in AML from the last 10 years 3. Reference
Age/ FAB Year Country Immunophenotype Sex subtype
Wei et al. (3)
1996 Taiwan
NA
Wan et al. (9)
1999 China
NA
Kondo et al. (5)
2001 Japan
CD7þ CD 13þ CD 33þ CD 34þ CD7þ CD 13þ CD33þ CD 34 þ CD7þ CD9þ CD13þ CD15þ CD33þ CD34 CD64þ CD117þ MPOþ
Yamamoto et al. (6) 2002 Japan
Present study
2006 Oman
35/M 30/M 28/M 78/F
M4 NA M2 M4
21/M
M2
4.
5.
6. 49/M
M2
7. 8.
24/M
M2
AML, acute myeloid leukemia; NA, not available; FAB, French-AmericanBritish classification.
disappeared completely with 7 days of induction therapy consisting of only ara-C for 7 days and daunorubicin for 3 days. Repeat bone marrow examinations at the end of induction and at the end of consolidation indicated CR, but he relapsed soon. Our findings thus support the relationship between A-T21 and CD7 expression as well as the role of CD9 expression (this being the first report) in the tolerance of and early response to treatment. We did not observe any complications in the patient. Although he tolerated the chemotherapy well and went into CR, it did not last long. Therefore, AML patients with both CD7 and CD9 expression need to be further studied in larger numbers to have a better understanding of the role of CD9 expression either alone or with CD7 in patients with A-T21. Nevertheless, this report further emphasizes the poor prognostic value of CD7 and CD9, especially when presented together.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
Acknowledgments
19.
We wish to thank Mr. Anand Madhava Rao Bhat for his technical assistance. 20.
References 1. Mitelman F, Heim S, Mandhal N. Trisomy 21 in neoplastic cells. Am J Med Genet 1990;7(Suppl):S262eS266. 2. Cortes JE, Kantarjian H, O’Brien S, Keating M, Pierce S, Freireich EJ, et al. Clinical and prognostic significance of trisomy 21 in adult
21.
22.
801
patients with acute myelogenous leukaemia and myelodysplastic syndrome. Leukemia 1995;9:115e117. Wei CH, Yu IT, Tzeng CH, Fan FS, Hsieh RK, Chiou TJ, et al. Trisomy 21 in acute myeloid leukaemia. Cancer Genet Cytogenet 1996;86:177e180. Dewald GW, Diez-Martin JL, Steffen SL, Jenkins RB, Stupca PJ. Burgert EO Jr, Hematologic disorders in 13 patients with acquired trisomy 21 and 13 individuals with Down syndrome. Am J Med Genet 1990; 7(Suppl):S247eS250. Kondo H, Kobayashi A, Iwasaki H. Trisomy 21 as the sole acquired karyotypic abnormality in an adult patient with CD 7 positive acute myeloid leukaemia. Cancer Genet Cytogenet 2001;127:77e79. Yamamoto K, Nagata K, Hamaguchi H. A new case of CD 7 positive acute myeloblastic leukaemia with trisomy 21 as a sole acquired abnormality. Cancer Genet Cytogenet 2002;133:183e184. ISCN. An International System for Human Cytogenetic Nomenclature. In: Mitelman F, ed. Basel: S. Karger;2005. Sebastio G, Sperandeo MP, Panico M, de Franchis R, Kraus JP, Andria G. The molecular basis of homocysteinuria due to cystathionine beta-synthase deficiency in Italian families, and report of four novel mutations. Am J Human Genet 1995;56:1324e1333. Wan TSK, Au WY, Chan JCW, Chan LC, Ma SK. Trisomy 21 as the sole acquired karyotypic abnormality in acute myeloid leukaemia and myelodysplatic syndrome. Leuk Res 1999;23:1079e1083. Gallego M, Sole F, Acin P, Florensa L, Sans-Sabrafen J, Woessner S. A new case of trisomy 21 in a patient with an acute nonlymphocytic leukaemia (M5b). Cancer Genet Cytogenet 1996;95:213e214. Drexler HG, Thiel E, Ludwig WD. Acute myeloid leukemias expressing lymphoid-associated antigens: diagnostic incidence and prognostic significance. Leukemia 1993;7:489e498. Kita K, Miwa H, Nakase K, Kawakani K, Kobayashi T, Shirakawa S, et al. Clinical importance of CD 7 expression in acute myeloid leukaemia. Blood 1993;81:2399e2405. Bradstock K, Matthews J, Benson E, Page F, Bishop J. Prognostic value of immunophenotyping in acute myeloid leukemia. Australian Leukaemia Study Group. Blood 1994;84:1220e1225. Ball ED, Davis RB, Griffin JD, Mayer RJ, Davey FR, Arthur DC, et al. Prognostic value of lymphocytic markers in acute myeloid leukemia. Blood 1991;77:2242e2250. Schwarzinger I, Valent P, Koller U, Marosi C, Schneider B, Haas O, et al. Prognostic significance of surface marker expression on blasts of patients with de novo acute myeloblastic leukemia. J Clin Oncol 1990;8:423e430. Hurwitz CA, Raimondi CA, Head D, Krance R, Mirro J Jr, Kalwinsky DK, et al. Distinctive immunophenotypic features of t(8; 21)(q22;q22) acute myeloblastic leukemia in children. Blood 1992; 80:3182e3188. Ferrero D, Carlesso N, Gallo E, Pregno P, De Fabritiis P, Petti MC, Mandelli F. CD9 antigen on acute non-lymphoid leukemia cells: preferential expression by promyelocytic (M3) subtype. Leuk Res 1991; 15:457e461. Boucheix C, Benoit P, Frachet P, Billard M, Worthington RE, Gagnon J, et al. Molecular cloning of the CD9 antigen. a new family of cell surface proteins. J Biol Chem 1991;266:117e122. Heagy W, Duca K, Finberg RW. Enkephalins stimulate leukemia cell migration and surface expression of CD9. J Clin Invest 1995;96: 1366e1374. Saxena A, Sheridan DP, Card RT, McPeek AM, Mewdell CC, Skinnider LF. Biologic and clinical significance of CD7 expression in acute meloid leukemia. Am J Hematol 1998;58:278e284. Lauria F, Raspadori D, Ventura MA, Ronelli D, Tura S. CD 7 expression does not affect the prognosis in acute myeloid leukemia. Blood 1994;83:3097e3098. Taub JW, Huang X, Matherly LH, Stout ML, Buck SA, Massey GV, et al. Expression of chromosome 21-localised genes in acute myeloid
802
Udayakumar et al./ Archives of Medical Research 38 (2007) 797e802
leukemia: differences between Down syndrome and non-Down syndrome blast cells and relationship to in vitro sensitivity to cytosine arbinoside and daunorubicin. Blood 1999;94:1393e1400. 23. Ge Y, Jensen T, James SJ, Becton DL, Massey GV, Weinstein HJ, et al. High frequency of the 844ins68 cystathionine-beta-synthase gene var-
iant in Down syndrome children with acute myeloid leukemia. Leukemia 2002;16:2339e2341. 24. Ge Y, Jensen T, Matherly LH, Taub JW. Transcriptional regulation of the cystathion-beta-synthase gene in Down syndrome and non-Down syndrome megakaryocytic leukaemia cell lines. Blood 2003;101:1551e1557.
CASE REPORT
Trisomy 21 as a Sole Acquired Abnormality in an Adult Omani Patient with CD7- and CD9-Positive Acute Myeloid Leukemia Achandira M. Udayakumar,a Anil V. Pathare,b S. Muralitharan,c Asem A. Alghzaly,b Salam Alkindi,b and J.A. Raeburna b
a Department of Genetics, College of Medicine and Health Sciences, Sultan Qaboos University, Sultanate of Oman Department of Haematology, cDepartment of Biochemistry, Sultan Qaboos University Hospital, Muscat, Sultanate of Oman
Received for publication January 10, 2007; accepted April 9, 2007 (ARCMED-D-07-00019).
We describe a case of acute myeloid leukemia (AML) in which trisomy 21 was the sole acquired cytogenetic abnormality. The immunophenotype showed positivity for CD7 and CD9 along with CD13, CD33, and CD34. The chromosomal analysis of bone marrow showed 47,XY þ21 in all the metaphases analyzed. The constitutional karyotype was normal. The patient was an adult and did not have any features of Down’s syndrome. The bone marrow morphology was AML-M2 as per the French-American-British (FAB) criteria. A final diagnosis of CD7- and CD9-positive AML-M2 was established with trisomy 21 as a sole cytogenetic abnormality. The patient responded remarkably well to chemotherapy and achieved complete clinical remission. This is the first case of CD7and CD9-positive AML with trisomy 21 as a sole abnormality. A putative role for the co-expression of abnormal lymphoid markers in achieving quick remission is discussed. Ó 2007 IMSS. Published by Elsevier Inc. Key Words: Acute myeloid leukemia, Cytogenetics, Prognosis, Trisomy 21.
Introduction Trisomy 21 is reported to be one of the most common acquired chromosomal abnormalities in hematological malignancies (1) but is very rarely reported as a sole anomaly at diagnosis among patients with acute myeloid leukemia (AML) (2,3). The clinical implications of this acquired anomaly in myeloid disorders are still unclear. In an institutional study from a series of þ21 in myeloid disorders (2), 3.3% patients showed an acquired þ21 [A-T21] in the newly diagnosed AML/myelodysplastic syndromes Conflict of Interest: None of the authors have declared any conflict of interest. Author’s contributions: AAG, AVP, and SAK participated in clinical assessment and management of the case. AVP and AMU were instrumental in preparation of the manuscript. AMU did the cytogenetic diagnosis, SM did the molecular work and AMU and JAR compiled the data as per ISCN (2005). All the authors contributed to the preparation of the final manuscript. Address reprint requests to: Achandira M. Udayakumar, Department of Genetics, College of Medicine and Health Sciences, P.O. Box 35, Sultan Qaboos University, Sultanate of Oman; E-mail: [email protected] or [email protected]
(MDS) and 0.3% occurred as the sole cytogenetic anomaly. Trisomy 21 was observed as a sole acquired abnormality in 13 patients who had hematological malignancies (4), 12 of which were myeloid and one a lymphoid leukemia. A first case of þ21 in an AML with immunophenotypically positive CD7 (as well as CD13, CD33, and CD34) was reported from Japan (5). Subsequently, another case of trisomy 21 in a CD7-positive AML as a sole abnormality was also reported (6), but cases having þ21 as sole anomaly along with immunophenotypic positivity for CD7 and CD9 have not been reported so far, to our knowledge. We report here an adult patient with constitutionally normal karyotype having CD7- and CD9-positive AML and showing trisomy 21 as the only acquired karyotypic abnormality. This is the first report of þ21 in an AML patient as sole anomaly from the Middle Eastern population. Case Report HHSN, a 24-year-old Omani male, was referred in August 2006 with fatigue and dizziness of 2-week duration. There was no significant past history. Physical examination was
0188-4409/07 $esee front matter. Copyright Ó 2007 IMSS. Published by Elsevier Inc. doi: 10.1016/j.arcmed.2007.04.007
798
Udayakumar et al./ Archives of Medical Research 38 (2007) 797e802
unremarkable except for a just palpable liver. The spleen was not enlarged, there was no lymphadenopathy, and the rest of his systemic examination was normal. Investigations revealed Hb 6.2 g/dL, WBC 199 109/L with 90% myeloblast, and platelet count 171 109/L. Bone marrow examination was reported as acute myeloid leukemia FAB M2 (WHO) (Figure 1). Flow cytometry with four-color analysis using monoclonal antibodies was performed on the marrow sample revealing CD7, 31%; CD9, 41%; CD13, 73%; CD15, 15%; CD33, 62%; CD34, 86%; CD64, 55%; CD117, 81%; and MPO, 90%, consistent with AML (Figure 2). The patient’s renal and liver functions were within normal range but he had a significantly elevated serum lactic dehydrogenase (2000 IU). Cytogenetic Analysis A bone marrow aspiration sample was received for cytogenetic analysis, and short-term cultures (24 and 48 h) were set up using Marrow MAX Bone Marrow medium (cat. #12260e014; Gibco, Grand Island, NY) and cultures were harvested using standard procedures. G-banded metaphases were analyzed and karyotyped as per the International System for Human Cytogenetic Nomenclature (ISCN) (7). Chromosome analysis showed 47,XY þ21 as sole abnormality in all 31 metaphases analyzed (Figure 3). Phytohemagglutinin (PHA)-induced 72-h cultures of peripheral blood were set up to study his constitutional karyotype and it showed 46,XY, a normal karyotype, in all 20 metaphases analyzed.
tient was in remission by standard methods using Qiagen Kits (Qiagen, Hilden, Germany). A cystathionine b-synthase (CBS) mutation was not detected by PCR amplification of the CBS gene by specific primers and restriction enzyme analysis of the PCR product by endonuclease Bsr1 (8). The patient showed a normal band (184 bp), whereas a known positive sample confirmed that PCR amplification was successfully achieved showing heterozygosity for the 68-bp insertion in exon 8 of the CBS gene and the presence of 833TC mutation (Figure 4). The patient was treated with the standard chemotherapy protocol (7þ3) for AML with cytosine arabinoside (100 mg/m2, continuous infusion, days 1e7) and daunorubicin (40 mg/m2, drip infusion with rapid push, days 1e3). He tolerated the chemotherapy quite well and a repeat bone marrow examination after 28 days showed that he was in clinical remission (CR), with the cytogenetic analysis revealing 46,XY in all the metaphases analyzed, indicating cytogenetic remission as well. Thereafter, he received two cycles of remission consolidation therapy with intermediate dose cytosine arabinoside at 2 g/m2 each. The patient tolerated the chemotherapy without any major complications but presented in relapse within a month of completion of consolidation. He is now receiving reinduction chemotherapy with IDA-FLAG protocol and is counselled to undergo bone marrow transplantation as soon as he has a suitable HLA identical donor, in view of the high WBC count, A-T21 at presentation and early relapse.
DNA Studies
Discussion
Genomic DNA was extracted from bone marrow sample obtained at diagnosis and peripheral blood obtained when pa-
The incidence of trisomy 21 as a sole abnormality was reported as between 0.3 and 1.7% in AML/MDS patients and they appear to show a poor prognosis (2,3,9). A majority showed morphologically M2 or M4 phenotype according to the FAB classification (Table 1) (3,5e7,10). Immunophenotypes in these cases at presentation were CD7 þve (5,6) but our patient was positive for both CD7 and CD9 with FAB-M2 type morphology. Although coexpression of CD7 in cases of AML with A-T21 is 12e17% in the overall group of AML patients (11), it is speculated that there are more cases of CD7 þve AML with A-T21. We do not fully understand the biological and clinical significance of CD7 expression in AML (12). In most reported cases, trisomy 21 was present along with normal clones (3,6,9), whereas in our case all cells had þ21 without any normal clone. Expression of lymphoid antigens is common in AML and is associated with variable CR rates: CD2 being expressed in 16e21% and CD19 in 7e14% (13,14). CD19 expression is associated with pediatric AML FAB-M2 and the t(8;21) translocation (15). However, CD7 is the most commonly expressed lymphoid antigen in AML (11e29%) (11,12). CD7þ AML patients have a significantly lower response rate and poorer prognosis than CD7 AML patients
Figure 1. May Grunwald Giemsa staining of the bone marrow slide showing pleomorphic large agranular myeloblasts with 2e3 nucleoli, no Auer rods and cytoplasmic vacuoles.
Trisomy 21 and Acute Myeloid Leukemia
799
Figure 2. Flow cytometry with four-color analysis using a panel of monoclonal antibodies showing myeloblasts with aberrant CD7 and CD9 positivity.
(12). CD7 þve AML patients have been younger males frequently with hepatosplenomegaly (12). Our patient was also a young male (24 years), supporting this statement. In contrast, his liver was only just palpable and he had no splenomegaly. AML patients whose cells express CD9 have a lower remission rate (16). Moreover, CD9 antigen on acute non-
lymphoid leukemia cells is preferentially expressed by promyelocytic (M3) subtype in up to 75% cases (17). CD9 is not expressed by normal hematopoietic precursors or normal peripheral B lymphocytes, but it is expressed by developing B-lineage cells, being lost following differentiation. It is present in a wide variety of tissues like platelets, eosinophils, basophils and stimulated T cells (18). It is also
800
Udayakumar et al./ Archives of Medical Research 38 (2007) 797e802
Figure 3. Karyotype of the patient showing 47,XY þ21 (arrow indicating the extra 21).
believed that CD9 is important in the regulation of leukemia cell motility (19). The prognostic role of CD7 expression in AML is contradictory, some stating it as adverse (poor) (11,20) and others claiming to have no effect (21). Similarly, AML patients with A-T21 as sole abnormality have been considered to have a poor prognosis (2e4,9). But there are instances where patients have shown CR and good prognostic indication (5,6). Co-expression of CD7 and CD9 is probably indicative of the very early stage at which the cell became malignant and is, until this report, unreported in AML. Thus, although these CD markers are suggestive of a poor prognosis, the rapidity with which this patient went into clinical and cytomorphologic remission, the relative paucity of complications, and the uneventful remission induction, intensification, and consolidation stages would hopefully suggest otherwise. On the other hand, CR in this patient was short-lived with the patient relapsing within a month after the last consolidation. Whether age of the patient at presentation and the status of CD7/CD9 expression play any role in response to treatment remains to be studied in more patients before arriving at any conclusion. Additionally, our patient had A-T21 in all the metaphases studied. It is believed that increased expression of chromosome 21-related genes like CBS plays a central role in the increased sensitivity of leukemic cells to chemotherapeutic agents like ara-C and daunorubicin (22). This has been particularly true of þ21 AML cases with Down’s syndrome. Furthermore, mutations in the CBS gene like CBS
68 bp del can influence prognosis in patients with AML (23,24). Hence, we specifically screened the initial as well as the postremission bone marrow sample (day 28) for this mutation but, as it was absent, it may be indicative of a good prognostic feature for this patient. Our patient had A-T21 with AML as the sole cytogenetic abnormality and it
Figure 4. Ethidium bromide-stained agarose gel containing PCR reaction products of BsrI digestion of CBS gene from a known positive control with 68 bp insertion mutation (252 and 184 bp) and patient l (184 bp).
Trisomy 21 and Acute Myeloid Leukemia Table 1. Reports of trisomy 21 as a sole abnormality in AML from the last 10 years 3. Reference
Age/ FAB Year Country Immunophenotype Sex subtype
Wei et al. (3)
1996 Taiwan
NA
Wan et al. (9)
1999 China
NA
Kondo et al. (5)
2001 Japan
CD7þ CD 13þ CD 33þ CD 34þ CD7þ CD 13þ CD33þ CD 34 þ CD7þ CD9þ CD13þ CD15þ CD33þ CD34 CD64þ CD117þ MPOþ
Yamamoto et al. (6) 2002 Japan
Present study
2006 Oman
35/M 30/M 28/M 78/F
M4 NA M2 M4
21/M
M2
4.
5.
6. 49/M
M2
7. 8.
24/M
M2
AML, acute myeloid leukemia; NA, not available; FAB, French-AmericanBritish classification.
disappeared completely with 7 days of induction therapy consisting of only ara-C for 7 days and daunorubicin for 3 days. Repeat bone marrow examinations at the end of induction and at the end of consolidation indicated CR, but he relapsed soon. Our findings thus support the relationship between A-T21 and CD7 expression as well as the role of CD9 expression (this being the first report) in the tolerance of and early response to treatment. We did not observe any complications in the patient. Although he tolerated the chemotherapy well and went into CR, it did not last long. Therefore, AML patients with both CD7 and CD9 expression need to be further studied in larger numbers to have a better understanding of the role of CD9 expression either alone or with CD7 in patients with A-T21. Nevertheless, this report further emphasizes the poor prognostic value of CD7 and CD9, especially when presented together.
9.
10.
11.
12.
13.
14.
15.
16.
17.
18.
Acknowledgments
19.
We wish to thank Mr. Anand Madhava Rao Bhat for his technical assistance. 20.
References 1. Mitelman F, Heim S, Mandhal N. Trisomy 21 in neoplastic cells. Am J Med Genet 1990;7(Suppl):S262eS266. 2. Cortes JE, Kantarjian H, O’Brien S, Keating M, Pierce S, Freireich EJ, et al. Clinical and prognostic significance of trisomy 21 in adult
21.
22.
801
patients with acute myelogenous leukaemia and myelodysplastic syndrome. Leukemia 1995;9:115e117. Wei CH, Yu IT, Tzeng CH, Fan FS, Hsieh RK, Chiou TJ, et al. Trisomy 21 in acute myeloid leukaemia. Cancer Genet Cytogenet 1996;86:177e180. Dewald GW, Diez-Martin JL, Steffen SL, Jenkins RB, Stupca PJ. Burgert EO Jr, Hematologic disorders in 13 patients with acquired trisomy 21 and 13 individuals with Down syndrome. Am J Med Genet 1990; 7(Suppl):S247eS250. Kondo H, Kobayashi A, Iwasaki H. Trisomy 21 as the sole acquired karyotypic abnormality in an adult patient with CD 7 positive acute myeloid leukaemia. Cancer Genet Cytogenet 2001;127:77e79. Yamamoto K, Nagata K, Hamaguchi H. A new case of CD 7 positive acute myeloblastic leukaemia with trisomy 21 as a sole acquired abnormality. Cancer Genet Cytogenet 2002;133:183e184. ISCN. An International System for Human Cytogenetic Nomenclature. In: Mitelman F, ed. Basel: S. Karger;2005. Sebastio G, Sperandeo MP, Panico M, de Franchis R, Kraus JP, Andria G. The molecular basis of homocysteinuria due to cystathionine beta-synthase deficiency in Italian families, and report of four novel mutations. Am J Human Genet 1995;56:1324e1333. Wan TSK, Au WY, Chan JCW, Chan LC, Ma SK. Trisomy 21 as the sole acquired karyotypic abnormality in acute myeloid leukaemia and myelodysplatic syndrome. Leuk Res 1999;23:1079e1083. Gallego M, Sole F, Acin P, Florensa L, Sans-Sabrafen J, Woessner S. A new case of trisomy 21 in a patient with an acute nonlymphocytic leukaemia (M5b). Cancer Genet Cytogenet 1996;95:213e214. Drexler HG, Thiel E, Ludwig WD. Acute myeloid leukemias expressing lymphoid-associated antigens: diagnostic incidence and prognostic significance. Leukemia 1993;7:489e498. Kita K, Miwa H, Nakase K, Kawakani K, Kobayashi T, Shirakawa S, et al. Clinical importance of CD 7 expression in acute myeloid leukaemia. Blood 1993;81:2399e2405. Bradstock K, Matthews J, Benson E, Page F, Bishop J. Prognostic value of immunophenotyping in acute myeloid leukemia. Australian Leukaemia Study Group. Blood 1994;84:1220e1225. Ball ED, Davis RB, Griffin JD, Mayer RJ, Davey FR, Arthur DC, et al. Prognostic value of lymphocytic markers in acute myeloid leukemia. Blood 1991;77:2242e2250. Schwarzinger I, Valent P, Koller U, Marosi C, Schneider B, Haas O, et al. Prognostic significance of surface marker expression on blasts of patients with de novo acute myeloblastic leukemia. J Clin Oncol 1990;8:423e430. Hurwitz CA, Raimondi CA, Head D, Krance R, Mirro J Jr, Kalwinsky DK, et al. Distinctive immunophenotypic features of t(8; 21)(q22;q22) acute myeloblastic leukemia in children. Blood 1992; 80:3182e3188. Ferrero D, Carlesso N, Gallo E, Pregno P, De Fabritiis P, Petti MC, Mandelli F. CD9 antigen on acute non-lymphoid leukemia cells: preferential expression by promyelocytic (M3) subtype. Leuk Res 1991; 15:457e461. Boucheix C, Benoit P, Frachet P, Billard M, Worthington RE, Gagnon J, et al. Molecular cloning of the CD9 antigen. a new family of cell surface proteins. J Biol Chem 1991;266:117e122. Heagy W, Duca K, Finberg RW. Enkephalins stimulate leukemia cell migration and surface expression of CD9. J Clin Invest 1995;96: 1366e1374. Saxena A, Sheridan DP, Card RT, McPeek AM, Mewdell CC, Skinnider LF. Biologic and clinical significance of CD7 expression in acute meloid leukemia. Am J Hematol 1998;58:278e284. Lauria F, Raspadori D, Ventura MA, Ronelli D, Tura S. CD 7 expression does not affect the prognosis in acute myeloid leukemia. Blood 1994;83:3097e3098. Taub JW, Huang X, Matherly LH, Stout ML, Buck SA, Massey GV, et al. Expression of chromosome 21-localised genes in acute myeloid
802
Udayakumar et al./ Archives of Medical Research 38 (2007) 797e802
leukemia: differences between Down syndrome and non-Down syndrome blast cells and relationship to in vitro sensitivity to cytosine arbinoside and daunorubicin. Blood 1999;94:1393e1400. 23. Ge Y, Jensen T, James SJ, Becton DL, Massey GV, Weinstein HJ, et al. High frequency of the 844ins68 cystathionine-beta-synthase gene var-
iant in Down syndrome children with acute myeloid leukemia. Leukemia 2002;16:2339e2341. 24. Ge Y, Jensen T, Matherly LH, Taub JW. Transcriptional regulation of the cystathion-beta-synthase gene in Down syndrome and non-Down syndrome megakaryocytic leukaemia cell lines. Blood 2003;101:1551e1557.