the impact of immune response on htlv-i in htlv-i-associated myelopathy/tropical spastic paraparesis (ham/tsp)

human t lymphotropic virus type i (htlv-i) is a retrovirus which is associated with adult t cells leukaemia (atl) and htlv-i-associated myelopathy/tropical spastic paraparesis (ham/tsp) in a minority of htlv-i-infected individuals. it is not clear why a minority of htlv-i-infected individuals develop ham/tsp and majority remains lifelong carriers. it seems that the interaction between the virus and the immune response plays an important role in htlv-i-associated diseases. although the role of the immune response in htlv-i pathogenesis is not fully understood, however it seems that the efficacy of the immune response which is involved in controlling or limiting of viral persistence determines the outcome of htlv-i-associated diseases. here we discuss the role of innate and adaptive immune response and also the risk factors contribute to the observed differences between ham/tsp patients and asymptomatic htlv-i carriers.