Rev Esp Enferm Dig. 2021 Sep 14. doi: 10.17235/reed.2021.8175/2021. Online ahead of print.
Azathioprine is a drug widely used to treat patients with inflammatory bowel disease, with not an inconsiderable frequency of adverse events. Among these, myelotoxicity is one of the most serious. For some time, the existence of specific genetic variations of the gene encoding thiopurine-methyltransferase that affect enzymatic activity and produce alterations in thiopurine metabolism that translate into a higher frequency of adverse events in these patients has been known. It has recently been observed that patients carrying certain genetic variations in the nudix hydrolase gene also present a higher rate of adverse events induced by azathioprine, mainly related to leukopenia and alopecia, the latter behaving as an early clinical marker of myelotoxicity. These genetic variants are more common in the Asian population. We present the case of a European patient with azathioprine-induced alopecia and leukopenia whose genetic analysis confirmed that she had one of the genetic alterations associated with the appearance of these adverse events.