Manifestações clínicas e resposta imune em uma coorte de indivíduos infectados pelo HTLV-1 com alta carga proviral e sem evidência de mielopatia

Abstract

Introduction. Human T-cell lymphotropic virus type 1 (HTLV-1)-associated myelopathy (HAM/TSP) is the main neurological disease caused by HTLV-1, but other clinical manifestations associated with the virus are documented in more than 50% of individuals. infected. A high proviral load (CPV) is an important risk factor for HAM/TSP, but there is a lack of prospective studies evaluating whether HTLV-1 carriers with a high proviral load are at risk of developing HAM/TSP or other HAM/TSP-related diseases. HTLV-1. In this study, we compared the incidence of clinical manifestations and cytokine concentrations in individuals with HTLV-1 with high and low proviral load. Methods. This is a cohort study in which 30 HTLV-1 carriers with high CPV (> 50,000 copies / 106 cells) and an equal number of subjects with CPV lower than 50,000 copies / 106 cells, matched by sex and age, participated in the study. (± 5 years). They were followed for 2 to 16 years (median 11 years). CPV was measured by real-time PCR and the production of IFN-γ, TNF and IL-10 was quantified by ELISA in supernatants from unstimulated mononuclear cells. Abnormalities in neurological examination, development of HAM/TSP, urinary dysfunction, periodontal disease, erectile dysfunction and the appearance of dry syndrome were recorded annually. Results. Among the self-reported symptoms in the initial assessment, only the presence of paresthesias in the hands was more frequent in the group of individuals with high CPV when compared to the control group (p 0.04). During follow-up, there was no difference in the occurrence of erectile or urinary dysfunction, periodontal disease, dry syndrome, neurological signs between the two groups and none of the patients developed HAM/TSP. The production of IFN-γ was higher in the group with high CPV (median 1,308 versus 686pg/ml, p <0.011) when compared to the control group in the first evaluation. During follow-up there was a decrease in proviral load only among cases. Conclusion. Individuals with high proviral load followed for a long period did not progress to HAM/TSP, nor did they develop other clinical manifestations related to HTVL-1, indicating that factors other than proviral load are involved in the passage of HTLV-1-infected cells from the blood to the central nervous system.