RESUMO
BACKGROUND Erythema nodosum leprosum (ENL) is an acute and systemic inflammatory reaction of leprosy characterised by painful nodules and involvement of various organs. Thalidomide is an immunomodulatory and anti-inflammatory drug currently used to treat this condition. Cereblon (CRBN) protein is the primary target of thalidomide, and it has been pointed out as necessary for the efficacy of this drug in others therapeutics settings. OBJECTIVES In this study, we aimed to evaluate the influence of CRBN gene variants on the dose of thalidomide as well as its adverse effects during treatment of ENL. METHODS A total of 103 ENL patients in treatment with thalidomide were included in this study. DNA samples were obtained from saliva and molecular analysis of CRBN gene were performed to investigate the variants rs1620675, rs1672770 and rs4183. Different genotypes of CRBN variants were evaluated in relation to their influence on the dose of thalidomide and on the occurrence of adverse effects. FINDINGS No association was found between CRBN variants and thalidomide dose variation. However, the genotypes of rs1672770 showed association with gastrointestinal effects (p = 0.040). Moreover, the haplotype DEL/C/T (rs4183/rs1672770/rs1620675) was also associated with gastrointestinal adverse effects (p = 0.015). MAIN CONCLUSIONS Our results show that CRBN variants affect the treatment of ENH with thalidomide, especially on the adverse effects related to the drug.