Leukemia Research Vol. 4, No. 9, pp. 82~824, 1990. Printed in Great Britain.

0145-2126/90 $3.00 + .00 Pergamon Press plc

LETTER TO THE EDITORS

N E U T R O P H I L FUNCTIONS IN CHRONIC MYELOID L E U K E M I A

The aggregation [9] was measured in a platelet aggregometer (Aggrecoder PA-3210, Menarini S.p.A., Florence, Italy). P H A was used at final concentrations ranging from 60 to 120 ~tg/ml. This agent was added (50 ~tl) to a cellular volume of 250 ~tl containing 2.5 × 106 neutrophils, after 2 min of preheating at 37°C. The aggregation curves were registered up to 5 min, in duplicate. Quantitation of granulocyte aggregation during the initial 5 min was made using a compensating polar planimeter (Mod. 236, Salmoiraghi S.p.A., Milan, Italy), and the results were expressed in square centimetres (cm2). Aggregation was verified by using phase contrast microscopy. Five patients, who had been treated with r-alpha2a-interferon or hydroxyurea, presented a defective aggregating behaviour similar to that of patients in chronic phase (cm 2 3 3 . 8 4 +- 3.16; N.V., n = 14, 43.19 - 2.99; means -+ S.D.), while three subjects treated with busulfan or hydroxyurea showed normal aggregation (cm 2 43.1 -+ 1.08). Preincubation with neuraminidase (0.1 U/ml for 15 min at 37°; purified from Clostridium perfrigens, Sigma Chemical Company) corrected the aggregating abnormality and led to a normal neutrophil aggregation (cm 2 45.62 -+ 3.16). Other tests were carried out with four normal subjects. In these cases, neuraminidase treatment did not cause any aspecific effect, since aggregation with suboptimal PHA concentrations (60 ~tg/ml) was not affected by neuraminidase preincubation (cm 2 30.25 -+ 1.19 vs 29.28 -+ 1.71). Therefore, lectin receptors masking may also be present in neutrophils (or in a part of them) from CML patients treated with chemotherapy and in haematological remission, and this anomaly may be responsible for defective neutrophil functions. Studies aimed to clarify this biological aspect may lead to interesting acquisitions.

THE INTERESTINGpaper by Naik et al. [1], which has recently been published, reported defective PMN chemotaxis in chronic myeloid leukemia in haematological remission (i.e. after chemotherapy with busulfan or hydroxyurea). The authors commented on their results by hypothesizing that the circulating PMN in CML patients might contain a mixture of normal and abnormal cells, and that an altered chemotactic peptide receptor interaction or an alteration in the motile apparatus of the cells might be responsible for defective chemotaxis. One important property displayed by neutrophils from CML patients is represented by aberrant sialylation on membranes due to increased activity of a specific sialyltransferase [2-4]. This property is able to lead to the masking of neutrophil surface lectinbinding sites [5] and to a reduced accessibility of functional receptors of fMLP [6]. In addition, neutrophil adherence to nylon wool appears to be affected by increased membrane sialyation [5]. Although it was reported [2] that busulfan-treated CML patients presented a normal neutrophil membrane sialylation, the possibility that, in CML patients in remission, aberrant clones may produce neutrophils with membrane properties similar to untreated CML should be taken into account. Previous observations [7] showed that neutrophils from CML in chronic phase presented decreased aggregating capacity after stimulation with phytohemagglutinin (PHA). In an attempt to understand the mechanism(s) involved, we carried out aggregation tests with neutrophils from patients with CML who had achieved haematological remission after chemotherapy with bulsulfan or hydroxyurea or ralpha-2a-interferon, using PHA as aggregating agent. Eight patients suffering from CML and in haematological remission, and four healthy volunteers were studied. Circulating neutrophils were obtained as previously described [8], with minor modifications, and suspended in PBS supplemented with bovine serum albumin (BSA) 0.25%. The neutrophil viability was always greater than 98%, and platelet, monocyte, lymphocyte, eosinophil and metamyelocyte contamination was less than 1%.

REFERENCES 1. Naik N. K., Advani S. H. & Bhisey A N. (1989) PMN cells from chronic myeloid leukemia (CML) patients 823

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Letter to the Editors

show defective chemotaxis in remission. Leukemia Res. 13, 959. 2. Baker M. A., Taub R. N., Whelton C. H. & Hindenburg A. (1984) Aberrant sialylation of granulocyte membranes in chronic myelogenous leukemia. Blood 63, 1194.

3. Taub R. N., Hindenburg A. A. & Baker M. A. (1895) Regeneration of membrane sialic acid after neuraminidase treatment of leukemic granulocytes. Leukemia Res. 9, 507. 4. Baker M. A., Taub R. N., Kanani A., Brockhausen I. & Hindenburg A. (1985) Increased activity of a specific sialyltransferase in chronic myelogenous leukemia. Blood 66, 1068. 5. Taub R. N., Baker M. A. & Madyastha K. R. (1980) Masking of neutrophil surface lectin-binding sites in chronic myelogenous leukemia (CML). Blood 55, 294. 6. Baker M. A., Whelton C. H., Hindenburg A. A. & Taub R. N. (1982) Hypersialylation of CML neutrophils reduces accessibility of functional receptors for FMLP. Blood 60, (Suppl. 1), 60a (abstract). 7. Carulli G., Baicchi U., Marini A., Vaglini F., Grassi B. & Ambrogi F. (1990) Phytohemagglutinin-induced

neutrophil aggregation in patients affected by myeloproliferative diseases. Haematologia (in press). 8. Carulli G., Marini A., Azzarh A., Petrini M., Ruocco L. & Ambrogi F. (1985) Modifications in the phagocytosis of human neutrophils induced by vinblastine and cytochalasin B: the effects of lithium. Acta Haemat. 74, 81. 9. Carulli G., Vaglini F. & Marini A. (1989) Phytohemagglutinin-induced human neutrophil aggregation. Medicina Riv. E.M.L 9, 177. GIOVANNI CARULLI ANTONIO AZZARA FEDERICO PAPINESCHI ANGELA RIZZUT1 BRUNO GRASSI and FABIO AMBROGI Clinica Medica 1 Unith Operativa di Ematologia University of Pisa 56100 Pisa Italy

Neutrophil functions in chronic myeloid leukemia.

Leukemia Research Vol. 4, No. 9, pp. 82~824, 1990. Printed in Great Britain. 0145-2126/90 $3.00 + .00 Pergamon Press plc LETTER TO THE EDITORS N E...
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