Mediators go together: High production of CXCL9, CXCL10, IFN-γ and TNF-α in HAM/TSP.

HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is a chronic demyelinating and disabling syndrome caused by HTLV-1. Although the pathogenic mechanisms that lead to HAM/TSP outcome have not been elucidated, genetic and immunological factors may be involved in the myelopathy occurrence. The present study aimed to compare cytokines, chemokines and nitric oxide levels in asymptomatic and HAM/TSP HTLV-1 infected patients. The study group consisted of 21 HAM/TSP and 48 asymptomatic HTLV-1 patients. Chemokines (CCL5, CCL2, CXCL8, CXCL9 and CXCL10) and cytokines (IL-2, IFN-γ, TNF-α, IL-4, IL-6 and IL-10) were measured using CBA while nitric oxide (NO) production was measured after reaction of supernatants with nitrate reduction solution. CXCL9 and CXCL10 chemokines levels were found to be higher in HAM/TSP group. CXCL9 was also strongly correlated with CXCL10 and both CXCL9 as well as CXCL10 were moderately correlated with CCL2 and CCL5 levels, in both HAM/TSP and asymptomatic groups. There was no significant difference related to NO, IL-4, IL-6 and IL-10 levels between the clinical groups but TNF-α and IFN-γ levels were increased in HAM/TSP patients. Thus, factors such as CXCL9, CXCL10, TNF-α and IFN-γ could be good prognostic biomarkers candidates, and further studies may help to clarify their association with HAM/TSP immunopathogenesis.