J. Frappier et al., HOMOZYGOTE THIOPURINE METHYL TRANSFERASE DEFICIENCY - A CONTRAINDICATION TO AZATHIOPRINE IN KIDNEY-TRANSPLANT RECIPIENTS, La Presse medicale, 24(27), 1995, pp. 1257-1259
Azathioprine-induced myelosuppression is the mast important side effec
t observed in kidney transplantation. We report a case of severe neutr
openia after kidney transplantation due to a thiopurine methyltransfer
ase deficiency. This cause of azathioprine-induced myelotoxicity is ra
re, but its infectious consequences may be severe, Thiopurine methyltr
ansferase deficiency must therefore be suspected when early and severe
leukopenia occurs during azathiaprine therapy, Erythrocyte thiopurine
methyltransferase activity measurement confirms the diagnosis. Azathi
oprine and 6-mercaptopurine must afterwards be definitively avoided.