Premature chromosome condensation in childhood acute lymphoblastic leukaemia: correlation of proliferative potential index in blood and marrow.

The proliferative potential index (PPI), which is the proportion of all GI cells which are in late GI, has been shown to reflect disease state in patients with acute leukaemia. We have determined PPI in paired blood and marrow samples from children with acute lymphoblastic leukaemia (ALL) at different stages of the disease, and found a close correlation between blood and marrow PPI irrespective of disease stage. Therefore blood PPI can replace marrow PPI for monitoring disease control in ALL.