Abstract

A semiquantitative assessment of blast cell acid phosphatase activity, expressed as a score, was made in 41 unselected children with newly diagnosed and untreated non-T acute lymphoblastic leukaemia (ALL). Despite a wide range of enzyme activity in both sexes boys had significantly higher scores than girls, and, in view of the known association between males and T ALL on the one hand, and between acid phosphatase and T ALL on the other, these findings raise the possibility that boys may have a predisposition to a type of pre-T ALL which could contribute to the as yet unexplained difference in prognosis between the sexes.