DOES SLC11A2 GENE MUTATION ASSOCIATE WITH IRON-REFRACTORY IRON-DEFICIENCY ANEMIA AFTER BARIATRIC SURGERY?

ABSTRACT - BACKGROUND: After bariatric surgery, if there is iron-refractory iron-deficiency anemia (IRIDA) and does not respond to supplemental iron therapy, excluding other possible etiologies, genetic changes involved in iron metabolism should be considered. AIM: This study aimed to investigate the association of both mutations 1285G-C and 1246C-T, in the SLC11A2 gene, and the etiopathogenesis of anemia refractory to iron supplementation in patients undergoing bariatric surgery using Roux-en-Y gastric bypass (RYGB). METHODS: A case-control study was conducted, in which 100 patients were evaluated as Cases Group [subdivided into (i) with Anemia and (ii) without Anemia] and 100 individuals as Controls, comprising both sexes. Inherited and acquired causes of IRIDA were excluded. DNA was extracted from leukocytes of peripheral blood, and the regions that cover both mutations have been amplified by the molecular techniques such as polymerase chain reaction/restriction fragment length polymorphism. RESULTS: The 1285G-C mutation was not determined in any of the 400 alleles analyzed. Regarding the 1246C-T mutation, the wild CC genotype was found with a higher prevalence in the Control Group (34%) (OR 0.5475; 95%CI 0.2920-1.027; p=0.0827). The mutant TT genotype was found only in the Cases Group I (with Anemia) (13%). CONCLUSION: The results show the association between 1246C-T mutation, in the SLC11A2 gene, and the etiopathogenesis of IRIDA to iron supplementation in the evaluated sample. There are differences, at the molecular level, in patients with and without IRIDA after bariatric surgery using RYGB. RESUMO - RACIONAL: Após cirurgia bariátrica, se houver anemia por deficiência de ferro e não responder à terapia de ferro suplementar, excluindo-se outras possíveis etiologias, alterações genéticas envolvidas no metabolismo férrico devem ser consideradas. OBJETIVO: Investigar a associação das mutações 1285G-C e 1246C-T, no gene SLC11A2, e a etiopatogênese da anemia refratária à suplementação de ferro em pacientes submetidos à cirurgia bariátrica pela técnica de derivação gástrica em Y-de-Roux. MÉTODOS: Estudo de caso-controle, no qual forma avaliados 100 pacientes em Grupos de Casos (subdividido em Grupo I - com Anemia e Grupo II - sem Anemia) e 100 indivíduos como Controles, de ambos os sexos. Causas hereditárias e adquiridas de anemia ferropriva refratária ao ferro, foram excluídas. O DNA foi extraído de leucócitos de sangue periférico e as regiões que abrange