Ciclosporin in HTLV-1 Associated Myelopathy/ Tropical Spastic Paraparesis (HAM/TSP)

HAM/TSP is a chronic disease of the spinal cord, caused by a virus called HTLV-I. Worldwide approximately 20 million persons are infected.Infection with HTLV-I is lifelong, and about 3% of infected persons will develop this chronic debilitating disease, of which half will become wheelchair dependent. We, and others, have shown a strong and persistent immune response to HTLV-I in carriers and patients with HAM/TSP, but this fails to clear the virus. However, carriers with a low burden of virus in the blood have a low risk of developing disease. The immune response in these carriers seems better able to kill infected cells. A less efficient response is associated with a higher viral burden that drives the immune response with a resultant release of chemicals by the immune cells that inadvertently cause harm, most especially to cells in the spinal cord. Our understanding of HAM/TSP suggests that targeting the immune response should improve the health of our patients especially if the disease is diagnosed early. To identify the best type of treatment we are planning a series of studies of drugs that target the immune response in different ways. Each has been used in other inflammatory conditions but never before studied in HAM/TSP. We aim to study the extent and duration of the clinical response and to associate this with the different effects that the therapies have on the immune response and on the number of HTLV-I infected cells in the blood. This in turn will improve our knowledge and understanding of the disease and should lead to better therapy. This application is in relation to the first study - to explore that therapeutic benefit of ciclosporin in patients with HAM/TSP.