Relationship between deoxycytidine kinase (DCK) genotypic variants and fludarabine toxicity in patients with follicular lymphoma.

DCK catalyzes the intracellular phosphorylation of fludarabine. The promoter and coding region of the DCK gene were analyzed in 74 follicular lymphoma (FL) patients receiving a therapeutic regimen that included fludarabine. DCK mRNA expression was quantified in a cohort of healthy donors. Four previously described genotypic variants, -360C>G, -201C>T (rs2306744), C28624T (rs11544786) and c.91+37G>C (rs9997790), as well as the new variant, -12C>G, were identified. Variant C28624T showed a lower risk of lymphopenia (P=0.04), but a higher risk of neutropenia (P=0.04). Statistical significance was found in bivariate logistic regression between lymphopenia and infectious episodes in the induction period (odds ratio 3.85, P=0.04).