Zahra Meshkat - Antimicrobial Resistance Research Center, Mashhad University of Medical Sciences, Mashhad, Iran
Mona Fani - Department of Virology, Faculty of Medicine, Ahvaz Jundishapur University of Medical Sciences, Ahvaz, Iran

Human T-lymphotropic virus type- 1 (HTLV-1) is a retrovirus that infects from 15 to 25 million people worldwide and is associated with tropical spastic paraparesis/ HTLV-1-associated myelopathy (TSP/HAM). TSP/HAM as a neurological disorder is associated with bladder and sphincter disturbances and minimal sensory loss. On the other hand, TSP/HAM involves faster women than men and is characterizedby demyelinisation of the white and grey matter and meningo-myelitis of the lower thoracic cord. HTLV-1 can transmit to blood brain barrier (BBB) and enter into cells of the central nervous system (CNS). Consequently, this virus can infect lymphocytes produce pro-inflammatorycytokines, Interleukin 1 beta and interleukin 6, that disrupts the BBB. In addition, infiltration of perivascular T-lymphocyte into CNS was reported. Actually, presence of T and macrophages cells in TSP/HAM spinal cord material and also, the up-regulation of HLAand cytokine molecules indicate that such an increase in immunologic activity in the CNS may be related to the pathogenesis of TSP/HAM. Conclusion: Generally, the most important factors to progress TSP/HAM are sex hormones and proviral load. IgG specific anti HTLV-Iantibody in the serum and cerebrospinal fluid is one of others factor for detection of HTLV-1. The aim of current study is to present the complexities of HTLV-1 associated neurological disorders.