Expression of intercellular adhesion molecule 1 (ICAM-1) in childhood acute lymphoblastic leukaemia: correlation with clinical features and outcome.

To investigate whether expression of intercellular adhesion molecule 1 (ICAM-1, CD54) in childhood acute lymphoblastic leukaemia (ALL) has an 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. The 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 detected in T-ALL (12.2%). A significant positive correlation could be demonstrated 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, CD54 expression was a favourable but not independent prognostic factor. Event-free survival estimate at 4.5 years was 86% for CD54+ patients (n = 463), compared with 78% for CD54- patients (n = 241) (P < 0.01). These findings demonstrate that CD54 expression has an impact on dissemination patterns and outcome of childhood ALL, and emphasizes the potential relevance of adhesion mechanisms in influencing clinical characteristics and prognosis of haematological malignancies.