EXPRESSION OF INTERCELLULAR-ADHESION MOLECULE-1 (ICAM-1) IN CHILDHOODACUTE LYMPHOBLASTIC-LEUKEMIA - CORRELATION WITH CLINICAL-FEATURES ANDOUTCOME

To investigate whether expression of intercellular adhesion molecule 1 (ICAM-1, CD54) in childhood acute lymphoblastic leukaemia (ALL) has a n impact on the biological behaviour of the disease, we evaluated 751 children of the ALL-BFM 90 trial with B-cell precursor- (n = 677) or T -cell-ALL, (n = 74) for CD54 expression within immunological subgroups , its correlation to certain clinical features, and therapy outcome. T he highest percentage of patients expressing CD54 was found in common- and pre-B-ALL (76.1% and 61.4%, respectively). There was intermediate expression in pre-pre-B-ALL (47.8%), and the lowest expression was de tected in T-ALL (12.2%). A significant positive correlation could be d emonstrated between low CD54 expression (<20% stained blasts) and high peripheral leucocyte counts, central nervous system (CNS) involvement , and splenomegaly at the time of diagnosis (P < 0.01), In addition, C D54 expression was a favourable but not independent prognostic factor. Event-free survival estimate at 4.5 years was 86% for CD54(+) patient s (n = 463), compared with 78% for CD54(-) patients (n = 241) (P < 0.0 1). These findings demonstrate that CD54 expression has an impact on d issemination patterns and outcome of childhood ALL, and emphasizes the potential relevance of adhesion mechanisms in influencing clinical ch aracteristics and prognosis of haematological malignancies.