- Evaluation of anti-Tax antibodies in HTLV-1 Symptomatic and Asymptomatic carriers from Brazilian and Argentinean cohorts: a biomarker of disease development?.

ROCHA, AS; FRANCO,GM; GALLEGO S; BLANCO S; FRUTOS, MC; BALANGERO M; EDEL F. BARBOSA-STANCIOLI

Congreso; XXIII Congreso Latinoamericano de Microbiología y XIV Congreso Argentino de Microbiología. ALAM-AAM.; 2016

HTLV‐1 infects millions of people around the world and induces myelopathy (HAM/TSP), adult T‐cell leukemia and other inflammatory andrheumatologic diseases. Infection with HTLV‐1 is lifelong and the dynamic virus‐host interaction is complex, leading 1‐5% asymptomatic carriersto develop HAM/TSP. HTLV‐1 Tax protein is a key regulator of cellular and viral gene expression, exerting essential roles in viral transcription,viral persistence and cellular transformation. Tax is highly immunogenic being the first viral protein detected in cells expressing HTLV‐1 antigensand the major protein recognized by cytotoxic T lymphocytes in HTLV‐1 carriers. Several studies have suggested that anti‐Tax antibodies areinvolved in the pathogenesis of HAM/TSP. The presence of anti‐Tax antibodies has been also associated with higher risk of mother‐to‐child virustransmission. The aim of this study was to evaluate the anti‐Tax‐IgG reactivity in HTLV‐1 infected individuals from a Brazilian and Argentineancohorts (from endemic and non‐endemic zones) and to correlate the levels of anti‐Tax antibodies with symptomatic and asymptomatic clinicalcondition. A total of 154 individual were enrolled from Brazilian cohort: 34 seronegative (SN‐Br), 48 HTLV‐1 asymptomatic carriers (AC‐Br) and47 with HAM/TSP (HT‐Br); and 25 from Argentinean cohort: 10 symptomatic from endemic zone (Jujuy; Sym‐Ar) and 15 asymptomatic fromnon‐endemic zone (Cordoba; AC‐Ar). Anti‐Tax‐IgG reactivity was assessed in plasma samples using in house ELISA based on a prokaryoticrecombinant C‐terminal Tax. The Brazilian group with HAM/TSP showed the greatest reactivity for Tax recombinant protein, with the highestO.D mean, followed by the symptomatic group from Argentina (Mean O.D: HT‐Br 1.335> Sym‐Ar 1.091 > AC‐Ar 0.824 > AC‐Br 0.6742). It isinteresting to highlight that the difference between mean O.D for individuals asymptomatic and symptomatic from Brazilian cohort wassignificant (p