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LABELLED GRANULOCYTES FOR DIAGNOSIS OF SUPPURATION
852 exudates from patients with established cancer diagnosis and the puzzling presence of Reed-Sternberg cells in pleural exudates, which in reality represent efferent lymph from Hodgkin nodes. In cases of malignant lymphoma I have repeatedly been impressed by the sudden disappearance of a pleural effusion soon after the start of radiotherapy to the upper part of the ipsilateral lung hilus. In the case described by Bitram et al. the pleural effusion may or may not have been an example of lymph leakage, but in any case I would hesitate to accept leukaemic infiltration of the pleural wall as the direct cause of unilateral pleural effu-
vessels and the important reticuloendothelial organs in the atdominal cavity. With improvements (more efficient labelling and a better method of detection) this method should be evemore successful.
sion. Department, University Hospital,
NILS SÖDERSTRÖM
S-22185 Lund, Sweden
LABELLED GRANULOCYTES FOR DIAGNOSIS OF SUPPURATION
SIR,—It is often difficult to obtain an early clinical diagnosis of profound suppuration. One method, using labelled polymorphonuclear cells (P.M.N.), seems to resolve this problem. Experiments on laboratory animals have shown this method to be safe, accurate, and dependable,’ and we have now tried it clini-
cally. RESULTS OF TECHNETIUM-LABELLED P.M.N. SCANS
* False negative. P.M.N. are
labelled
using a physiological
property
(phagocy-
tosis of colloidal sulphur particles labelled with technetium-99m). This method does not alter the essential functions of these cells (chemotaxis and phagocytic index).2 P.M.N. are isolated from blood using the buffy-coat method.2 They are labelled by incubation at 370C with labelled colloidal sulphur particles. The excess of non-phagocytosed radioactivity is eliminated by washing. 3 x 107 P.M.N., having a radioactivity of 1-3 mCi, are re-injected intravenously. Focal suppuration is identified by scintillation scanning camera 3-8 h after re-injection. Fifteen patients have been studied (see table). All results except one (case 10) have been correct. The reliability and the stability of this labelling method have been proved in animal work’ which showed that the results were not due to free pertechnetate excess or non-phagocytosed colloid. The method was accurate in cases of osteoarticular and cerebral sepsis, but in cases of abdominal sepsis the results are difficult to interpret because of the large size of the
2.
R. LE NET
ENZYME-MULTIPLIED IMMUNOASSAY
Medical
1
J. CH. AUVERGNAT J. SIMON
Departments of Infectious Diseases and Nuclear Medicine, C.H.U. Toulouse 31052, France
Auvergnat, J.Ch., Simon, J., le Net, R., Guiraud, R., Armengaud, Biol clin. 1975, 33, 359. English, D., Andersen, B. J nucl. Med. 1975, 6, 5.
M. Ann.
SIR Your editorial (Aug. 21, p. 406) on ELISA linked immunosorbent assay) did not mention ’EMIT’
(enzyme(enzymemultiplied immunoassay technique [Syva Corporation, Palo Alto, California]). The advantage of EMIT is that it is a homogeneous immunoassay requiring no -separation of free and bound labelled material, so it is suitable for automation on currently available enzyme analysers. This method is precise and accurate for the determination of anticonvulsant-drug levels, digoxin, and thyroxine (T4).l2 We have modified an EMIT-T4 assay on our five ’AutoChemist’ instruments (LKB, Sweden), discrete multichannel analysers that perform 135 patient profiles/h. T4 is now part of a 23-test biochemical
screening profile. Serum-T4 is the single test of choice in screening for thyroid dysfunction or in monitoring patients with hyperthyroidisim. Thyroid dysfunction is common and often goes undiagnosed. None of the routine biochemical profiling tests detect thyroid disease. The diagnostic work-up for thyroid diseases is straightforward and relatively inexpensive, and treatment is often simple and inexpensive. About half the physicians ordering our autochemist biochemical profile also asked for T by radio-immunoassay (R.I.A.). Adding the T4-EMIT assay to the profile decreased reagent cost, saved on technical labour, avoided some sample handling, improved positive sample identification, facilitated data transfer, eliminated the need for automated pipettmg stations, centrifuges, and gamma counters, and eliminated entirely the radiation hazard and monitoring requirements of R.I.A. procedures. EMIT is a precise and accurate method for T4 analysis on the autochemist.4 Furthermore, it is more convenient and economical than R.I.A. and improves the diagnostic utility of the multi test biochemical profile. EMIT permits, for the first time, total automation of an immunoassay on a multichannel instrument. More importantly, this is the first time that a thyroid-function test has been included in a biochemical screening profile with a single instrument. This method is suitable for a variety of single-channel and mutuchannel enzyme analysers. In the U.S.A., digoxin and thyroxine constitute well over 50% of all
R.I.A. tests.
These
two
assays
can now
be done enzv-
therefore, challenge Professor Ekms’ matically. criticism (Sept. 11, p. 569) of your editorial, when he stated "that you misrepresent the situation and point too unequivocally to trends which are by no means certain". In contrast to Ekins’ closing remarks, we feel your readers can "anticipate the dawn of a new age in the measurement of biologically important substances." We agree with Dr Watson (Sept. 11, p. 570) that "the time required to establish change in clinical laboratory practice is almost alw avs underestimated". It was at the Ninth International Congress on Clinical Chemistry held in Toronto, July, 1975, that the first T4 enzyme immunoassay was described. We hoped to mtroduce this assay in January, 1976. Unfortunately, it was September before the EMIT-T4 became another routine test on our autochemist profile. We are now reporting 3000 such proWe must,
S. L., Cooreman, W. M., Bloome, W. Chem. 1976, 22, 733. 2. Wisdom, G B. ibid. 1976, 22, 1243. 3. Galen, R. S., Forman, D. W. ibid. (in the press). 4. Ullman, E. F., and others ibid. 1975, 21, 1011. 1.
Scharpe,
J., Laekman,
G, M.
Clin.
vessels and the important reticuloendothelial organs in the atdominal cavity. With improvements (more efficient labelling and a better method of detection) this method should be evemore successful.
sion. Department, University Hospital,
NILS SÖDERSTRÖM
S-22185 Lund, Sweden
LABELLED GRANULOCYTES FOR DIAGNOSIS OF SUPPURATION
SIR,—It is often difficult to obtain an early clinical diagnosis of profound suppuration. One method, using labelled polymorphonuclear cells (P.M.N.), seems to resolve this problem. Experiments on laboratory animals have shown this method to be safe, accurate, and dependable,’ and we have now tried it clini-
cally. RESULTS OF TECHNETIUM-LABELLED P.M.N. SCANS
* False negative. P.M.N. are
labelled
using a physiological
property
(phagocy-
tosis of colloidal sulphur particles labelled with technetium-99m). This method does not alter the essential functions of these cells (chemotaxis and phagocytic index).2 P.M.N. are isolated from blood using the buffy-coat method.2 They are labelled by incubation at 370C with labelled colloidal sulphur particles. The excess of non-phagocytosed radioactivity is eliminated by washing. 3 x 107 P.M.N., having a radioactivity of 1-3 mCi, are re-injected intravenously. Focal suppuration is identified by scintillation scanning camera 3-8 h after re-injection. Fifteen patients have been studied (see table). All results except one (case 10) have been correct. The reliability and the stability of this labelling method have been proved in animal work’ which showed that the results were not due to free pertechnetate excess or non-phagocytosed colloid. The method was accurate in cases of osteoarticular and cerebral sepsis, but in cases of abdominal sepsis the results are difficult to interpret because of the large size of the
2.
R. LE NET
ENZYME-MULTIPLIED IMMUNOASSAY
Medical
1
J. CH. AUVERGNAT J. SIMON
Departments of Infectious Diseases and Nuclear Medicine, C.H.U. Toulouse 31052, France
Auvergnat, J.Ch., Simon, J., le Net, R., Guiraud, R., Armengaud, Biol clin. 1975, 33, 359. English, D., Andersen, B. J nucl. Med. 1975, 6, 5.
M. Ann.
SIR Your editorial (Aug. 21, p. 406) on ELISA linked immunosorbent assay) did not mention ’EMIT’
(enzyme(enzymemultiplied immunoassay technique [Syva Corporation, Palo Alto, California]). The advantage of EMIT is that it is a homogeneous immunoassay requiring no -separation of free and bound labelled material, so it is suitable for automation on currently available enzyme analysers. This method is precise and accurate for the determination of anticonvulsant-drug levels, digoxin, and thyroxine (T4).l2 We have modified an EMIT-T4 assay on our five ’AutoChemist’ instruments (LKB, Sweden), discrete multichannel analysers that perform 135 patient profiles/h. T4 is now part of a 23-test biochemical
screening profile. Serum-T4 is the single test of choice in screening for thyroid dysfunction or in monitoring patients with hyperthyroidisim. Thyroid dysfunction is common and often goes undiagnosed. None of the routine biochemical profiling tests detect thyroid disease. The diagnostic work-up for thyroid diseases is straightforward and relatively inexpensive, and treatment is often simple and inexpensive. About half the physicians ordering our autochemist biochemical profile also asked for T by radio-immunoassay (R.I.A.). Adding the T4-EMIT assay to the profile decreased reagent cost, saved on technical labour, avoided some sample handling, improved positive sample identification, facilitated data transfer, eliminated the need for automated pipettmg stations, centrifuges, and gamma counters, and eliminated entirely the radiation hazard and monitoring requirements of R.I.A. procedures. EMIT is a precise and accurate method for T4 analysis on the autochemist.4 Furthermore, it is more convenient and economical than R.I.A. and improves the diagnostic utility of the multi test biochemical profile. EMIT permits, for the first time, total automation of an immunoassay on a multichannel instrument. More importantly, this is the first time that a thyroid-function test has been included in a biochemical screening profile with a single instrument. This method is suitable for a variety of single-channel and mutuchannel enzyme analysers. In the U.S.A., digoxin and thyroxine constitute well over 50% of all
R.I.A. tests.
These
two
assays
can now
be done enzv-
therefore, challenge Professor Ekms’ matically. criticism (Sept. 11, p. 569) of your editorial, when he stated "that you misrepresent the situation and point too unequivocally to trends which are by no means certain". In contrast to Ekins’ closing remarks, we feel your readers can "anticipate the dawn of a new age in the measurement of biologically important substances." We agree with Dr Watson (Sept. 11, p. 570) that "the time required to establish change in clinical laboratory practice is almost alw avs underestimated". It was at the Ninth International Congress on Clinical Chemistry held in Toronto, July, 1975, that the first T4 enzyme immunoassay was described. We hoped to mtroduce this assay in January, 1976. Unfortunately, it was September before the EMIT-T4 became another routine test on our autochemist profile. We are now reporting 3000 such proWe must,
S. L., Cooreman, W. M., Bloome, W. Chem. 1976, 22, 733. 2. Wisdom, G B. ibid. 1976, 22, 1243. 3. Galen, R. S., Forman, D. W. ibid. (in the press). 4. Ullman, E. F., and others ibid. 1975, 21, 1011. 1.
Scharpe,
J., Laekman,
G, M.
Clin.