Melatonin receptor 1b polymorphisms in women with Systemic Lupus Erythematosus.

AIM: The pineal hormone melatonin could exert an important influence on the immune system and autoimmunity. Its effect on the immunocompetent cells might be mediated at least partially through specific melatonin receptors. However, the role of melatonin - melatonin receptor 1B (MTNR1B) interrelations in human autoimmune diseases is still unknown. Therefore, the present study aimed to investigate the possible influence of the MTNR1B gene polymorphisms for the development and clinical expression of systemic lupus erythematosus (SLE). METHODS: 109 female SLE patients and 101 healthy women were genotyped for the MTNR1B rs1562444, rs10830962 and rs10830963 polymorphisms. RESULTS: No genotype distribution differences were found between patients and controls. The presence of MTNR1B rs10830963 C/C genotype was related to increased prevalence of leucopenia compared to genotypes C/G and G/G after Bonferroni correction for multiple comparisons [36.5% vs. 14.5%, p=0.014]. Moreover, the rs10830963 G/G carriers had lower number of lupus criteria in comparison to patients with C/C genotype. CONCLUSIONS: The present data suggested that MTNR1B polymorphisms could influence the clinical features in lupus patients, and especially the susceptibility to leucopenia.