DIASEASES ASSOCIATED TO HUMAN T CELL LYMPHOTROPIC VIRUS TYPE 1 (HTLV-1) INFECTION IN ARGENTINA

DUCASA N; BERINI C; BIGLIONE M; BENENCIO P

Lima

Conferencia; The 19th International Conference on Human Retrovirology: HTLV and Related Viruses,; 2019

HTLV-1 is the causative agent of Adult T Cell leukemia/lymphoma (ATLL) and HTLV-1 Associated Myelopathy/Tropical Spastic Paraparesis (HAM/TSP). It is estimated that 2-5% of infected individuals will develop either one of them. HTLV-1 has also been associated to infective dermatitis in children and disseminated strongyloidiasis. In Argentina, this retrovirus is endemic in the Northeastern region, particularly in Salta and Jujuy.ObjetiveThe aim of this study was to retrospectively analyze samples processed for HTLV-1 diagnosis in Argentina in order to determine the epidemiological characteristics, circulating strains, proviral load and genetic background of patients with HTLV-1 associated diseases. MethodsThe database of samples received at the INBIRS for HTLV-1/2 diagnosis from January 1997 to June 2018 was analyzed. The proviral load was determined by qPCR (Syber Green). Phylogenetic analysis and HLA-A/B/C typing was performed by amplifying and sequencing the LTR and HLA-A, B and C, respectively. ResultsFrom a total of 2736 samples, 575 cases were positive for HTLV-1 (21.02%, 95% CI: 19.47-22.56). Among them, 20 had ATLL, 37 HAM/TSP, 2 Strongyloidiasis and one infective dermatitis. Of the 20 ATLL, 11 were classified as acute, 5 as lymphomas and one favorable chronic leukemia. Among the 60 patients with pathologies, 24 were related from endemic areas. The phylogenetic studies identified the Cosmopolitan subtype, Transcontinental subgroup (Aa) in cases with pathologies and reaffirms this strains as the major one in Argentina. The proviral load and alleles of HLA-A/B and C revealed that HLA-B*35 (p=0,040) and HLA-C*07 (p=0,001) were significantly higher in individuals with pathologies compared to asymptomatics, suggesting susceptibility to disease. HLA-A*02 carriers presented significantly lower proviral load compared to other alleles, especially A*31. ConclusionSince 2006 the detection of anti-HTLV-1/2 is mandatory in Argentine blood donors and cases of pathologies associated with HTLV-1 infection have been identified both in endemic and non-endemic areas. These results highlight the importance of performing a complete surveillance and including these retroviruses in a National Program in the Public Health setting with the aim of implementing measures of prevention, surveillance and training of professionals to give the right information in relation to primary health care and follow up of infected patients.