The importance of cell size and surface marker analysis in childhood acutemyeloblastic leukemia

In order to evaluate the prognostic significance of cell size and surface m arker expression, we evaluated 33 children with newly diagnosed acute myelo blastic leukemia by flow cytometry. We determined: the percentage of small, middle and large cells; large to small cell ratios (LS); large plus middle to small cell ratios (LMS); the percentage of surface markers expressed by each group of cell; the ratios of surface marker percentages expressed by the large blasts to that expressed by small blasts (LS for surface markers) ; and large plus middle blasts to that by small blasts (LMS for surface mar kers). For 'early prognosis', patients who could and could not achieve remi ssion (n = 23 and 10) and for late prognosis, the patients who deceased or relapsed within the first 12 months of the treatment (n = 24) and who survi ved for more than 12 months (n = 9) were compared, in two classifications. CD3 percentages of the small cells of alive patients were significantly hig her than that of dead or relapsed patients. LMS for CD3 and CD20 and LS for CD20 were higher in dead-relapsed patients than that of alive patients. Th e total percentage of CD14 was significantly higher in dead-relapsed patien ts than it was in the alive patients and CD3 was significantly higher in th e group of patients who achieved remission than that of the patients who co uld not achieve remission. It was striking that, expression of CD3, CD7, CD 22, CD33, CD14, CD15, CD34 increased or decreased as to cell. size, whateve r the prognosis. CD10, CD20 and CD13 were expressed on the large cells of t he patients who could not achieve remission or died-relapsed. We showed tha t, the blast cell size, individually does not have any prognostic significa nce in childhood AML and the prognostic significance of surface markers not only depends on their presence or absence but also on their relative confi guration of expression by the blasts with different size. (C) 1999 Elsevier Science Ltd. All rights reserved.