Relevance of HTLV-1 proviral load in asymptomatic and symptomatic patients living in endemic and non-endemic areas of Argentina

Abstract

HTLV-1 proviral load (pVL) in peripheral blood mononuclear cell (PBMCs) is proposed as a marker of disease progression but its role still remains controversial. The aim of this study was to evaluate the levels of HTLV-1 pVL in symptomatic patients and asymptomatic HTLV-1 carriers. In this cross-sectional study the pVL was measured by Real Time PCR in 102 asymptomatic carriers and 22 symptomatic patients (5ATLL, 15 TSP and 2 uveitis). We observed that the HTLV-1 pVL was significantly higher in symptomatic patients (median = 4.99 log10 HTLV-1 copies /106 PBMCs) compared to asymptomatic HTLV-1 carriers (median = 4.38 log10 HTLV-1 copies /106 PBMCs; p = 0.0030). A wide variation on the HTLV-1 pVL levels among asymptomatic HTLV-1 carriers was observed with some pVL as high as those observed in symptomatic patients. The asymptomatic HTLV-1 carriers were divided according to the place of birth and the highest levels of pVL were detected among patients from endemics areas from the North of Argentina. Our results reinforce the usefulness of the proviral load would be a prognostic marker of HTLV-1 disease progression. Moreover, host, viral or socio-environmental factors cannot be excluded as determinant of high proviral load.

BoLA-DRB3 Polymorphism is Associated with Differential Susceptibility to Bovine Leukemia Virus-Induced Lymphoma and Proviral Load

“…Contrarily, the sporadic inconsistency between PVL and terminal diseases might be a common phenomenon, due to host genetic polymorphisms during different infectious viral diseases. Indeed, partial inconsistency between PVL and the related symptoms was also observed in HTLV-1-infected patients [48]. As BLV is closely related to HTLV-1, the consistency between the susceptibility of host genetic polymorphisms with PVL and HTLV-1-related symptoms is worth confirming.…”

Association of the rs4143815 polymorphism of PDL1 gene with HTLV‐1 infection and proviral load in asymptomatic blood donors in northeast Iran

“…This polymorphism can increase the load of the virus by increasing the expression of PDL1 and escaping immune system responses. Previous studies have shown that the proviral load is higher in patients with ATL and HAM/TSP than in asymptomatic carriers 5,28 . Aggressive subtypes of ATL had a many copy number of PD‐L1 compared with indolent subtypes 29 .…”

“…Infection with HTLV‐1 virus can progress to two serious diseases: adult T‐cell leukemia/lymphoma (ATL) and HTLV‐1‐associated myelopathy/tropical spastic paraparesis (HAM/TSP) 4 . The HTLV‐1 proviral load is significantly higher in symptomatic patients than in asymptomatic HTLV‐1 carriers (ACs) 5 . High levels of proviral load can predict the progression of the HTLV‐1 disease, so polymorphisms that impress the proviral load of HTLV‐1 virus can affect the progression of disease and new therapy targets.…”

Case Report: Relevance of an Accurate Diagnosis and Monitoring of Infective Dermatitis Associated With Human T-Lymphotropic Virus Type 1 in Childhood

“…This factor represents a great risk for both diseases, IDH and ATLL. High PVL values have been associated with an increased risk of progression to HAM/TSP (19)(20)(21). However, in children with IDH, it has been documented that high PVL is not indicative of progression to HAM/TSP and that PVL values do not decrease after IDH remission.…”