Thiopurine methyltransferase activity in a sample population of black subjects in Florida.
Thiopurine methyltransferase (TPMT), is an enzyme detected in the human red blood cell that catalyzes the S-methylation of thiopurine drugs and is known to exist as a genetic polymorphism in white subjects. Investigations in this laboratory of red blood cell TPMT showed interethnic differences also existed in North American black subjects. A sample group of black subjects in Florida had a mean activity of 8.64 +/- 3.47 U/ml red blood cells and an antimode of 6.5 units, which represented values significantly lower than those obtained for both the mean activity and the antimode in other populations. The findings of this study suggest the possibility that TPMT activity may be under genetic control in North American black subjects and that this ethnic group may be at greater risk of experiencing thiopurine-induced toxicity caused by the lower overall mean activity of the enzyme.
Jones
C D
CD
Clinical Pharmacology Research Unit, College of Pharmacy and Pharmaceutical Sciences, Florida Agricultural and Mechanical University, Tallahassee 32307.
Smart
C
C
Titus
A
A
Blyden
G
G
Dorvil
M
M
Nwadike
N
N
D000293:Adolescent; D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D044383:Black People; D004912:Erythrocytes / Q000201:enzymology*; D005260:Female; D005431:Florida; D006801:Humans; D016014:Linear Models; D008297:Male; D008780:Methyltransferases / Q000097:blood*; D008875:Middle Aged; D001741:Black or African American
D008780:Methyltransferases; C022745:thiopurine methyltransferase