Proviral load and the balance of serum cytocines in HTLV-1-asymptomatic infection and in HTLV-1-associated myelopathy/tropical spastic paraparesis (HAM/TSP)

► The proviral load and the seric TNF-α pro-inflammatory cytokine profile may be independent events in the peripheral blood of HAM/TSP individuals. ► Immunological factors that influence clinical evolution of HAM/TSP was studied. ► Immune features of HTLV-1-aymptomatic infection and HAM/TSP were compared. ► HTLV-1-proviral load regulates for anti-inflammation in asymptomatic infection. ► Imbalance of pro-inflammatory/regulatory cytokines occurs in HAM/TSP. ► Balance of pro-inflammatory/regulatory cytokines occurs in asymptomatic infection.