Gender difference in red blood cell thiopurine methyltransferase activity

Klemetsdal B, Wist E, Aarbakke J. Gender difference in red blood cell thiopurine methyltransferase activity. Scand J Clin Lab Invest 1993; 53: 747-749.High red blood cell (RBC) thiopurine methyltransferase (TPMT) activity is associated with a higher relapse rate in children with acute lymphoblastic leukaemia on 6-mercaptopurine therapy. RBC TPMT activity is subject to genetic polymorphism and interethnic variation. Higher TPMT activity in male subjects has previously been reported in RBC and liver tissue, but only in non-healthy subjects. In this healthy, drug-free study group the gender difference in the RBC TPMT high activity subgroup was confirmed with 8.3% higher TPMT activity in male subjects (n = 105).