Invasive aspergillosis related with azathioprine-induced leucopenia without mutant allele of thioprine methyltransferase in a patient with rheumatoid arthritis.

摘要

Azathioprine (AZA) may induce bone marrow suppression, especially leucopenia. AZA-induced leucopenia is caused by excessive accumulation of intracellular 6-thioguanine nucleotides (6-TGN) during AZA metabolism [1]. This abnormality is often associated with mutations of enzyme thioprine methyltransferase (TPMT) gene, which catalyzes S-methylation of AZA. Severe leucopenia is estimated to occur in about 3% of cases of AZA treatment for rheumatoid arthritis (RA) and is often life threatening in this context [2]. The overall incidence of adverse reactions to AZA is relatively high, even in patients with the wild-type TPMT genotype [3].