IL2 and tropical spastic paraparesis: Moreover, unlike mono-infected people with HIV-1 or HTLV-1, several studies on the impact of HIV-1/HTLV-1 co-infections indicated an increased production of the IL-2 and INFγ cytokines and the worsening of symptoms (thrombocytopenia, urinary tract infection, opportunistic infections), as well as the faster development and progression of the pathologies associated with HTLV-1, including TSP/HAM and ATLL [88,89,90].