Monitoring of inosine monophosphate dehydrogenase activity in mononuclear cells of children with acute lymphoblastic leukemia: enzymological and clinical aspects.

Background: Inosine 5'-monophosphate dehydrogenase (IMPDH; EC1.1.1.

Thiopurine methyltransferase in acute lymphoblastic leukaemia: biochemical and molecular biological aspects.

Thiopurine S-methyltransferase (TPMT) is a cytosolic enzyme, catalysing S-methylation of aromatic and heterocyclic sulphhydryl compounds. TPMT activities and genotypes have been determined in patients with acute lymphoblastic leukaemia (ALL) and in control children. Median red blood cell (RBC) TPMT activity in ALL patients at diagnosis was significantly lower than in controls (median 11.