Single nucleotide polymorphisms in immune system genes and their association with clinical symptoms persistence in dengue-infected persons

This study was undertaken to determine the prevalence of dengue clinical symptom persistence during 60 days of disease follow up, in patients of Espirito Santo state (ES)-Brazil and to evaluate the relation of single nucleotide polymorphisms (SNPs) in Fc gamma RIIa, CD209, VDR, TNF-alpha, IL-4, IL-6 and IFN-gamma genes with symptom persistence. During 2012-2013, 96 blood samples from individuals diagnosed with symptomatic dengue were collected. Clinical symptom persistence in 60 days of follow-up was assessed by a clinical and epidemiological questionnaire filled in 4 interviews. SNP genotyping was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). In two months of monitoring the dengue infection, we observed that symptoms persisted in 38.5% (37/96) of dengue patients at the end of the first month (D30) and in 11.5% (11/96) of dengue patients at the end of the second month (D60). Our results show an association between Fc gamma RIIa, TNF-alpha, and IL-6 gene SNPs and symptom persistence and an association trend with CD209, IL-4 and IFN-gamma gene SNPs. Our findings may increase the knowledge on the pathophysiological mechanisms of persistent symptoms of infection with the dengue virus (DENV) and thus help the clinical management of patients. (C) 2015 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.