Abstract
BACKGROUND: Detection of specific immune responses against cancer/testis antigen NY-ESO-1 was recently reported in patients with adult T-cell leukemia/lymphoma (ATL) and human T-cell leukemia virus type 1 (HTLV-1)-infected asymptomatic carriers (ACs). However, the relationship of the responses with the HTLV-1 proviral load (PVL) and the levels of viral gene expression remain unclear. FINDINGS: We measured plasma levels of autoantibodies to NY-ESO-1 immunogenic tumor antigen in HTLV-1-infected individuals with different clinical status, and in healthy controls. Data were compared to tax and HBZ mRNA levels, and PVL. Plasma anti-NY-ESO-1 antibody was detectable in 13.7% (7/51) of ACs, 29.2% (38/130) of patients with HTLV-1 associated myelopathy/tropical spastic paraparesis (HAM/TSP), and 18.9% (10/53) of patients with ATL. Anti-NY-ESO-1 plasma levels were significantly higher in patients with HAM/TSP than in patients with ATL or ACs. Anti-NY-ESO-1 levels were not associated with PVL or the expression levels of tax and HBZ mRNA among HTLV-1-infected individuals, regardless of clinical status. CONCLUSIONS: The present results indicate the strong humoral immune response against NY-ESO-1 in natural HTLV-1 infection, irrespective of the clinical status. The higher immunoreactivity against NY-ESO-1 is not simply associated with the levels of both HTLV-1 gene expression and the number of infected cells in vivo. Rather, it might reflect chronic and generalized immune activation in infected individuals.