TROPICAL SPASTIC PARAPARESIS HTLV-I-ASSOCIATED MYELOPATHY ETIOLOGY AND CLINICAL SPECTRUM

In 1985 we had the first indication that human T-cell lymphotropic vir us (HTLV-I) was the possible etiological agent of a chronic myelopathy that seemed to be peculiar to the tropics and that is now known as en demic tropical spastic paraparesis (TSP). IgG antibodies to HTLV-I wer e found in serum and cerebrospinal fluid of patients from Jamaica, Col ombia, Martinique, and shortly after in southern Japan, where the dise ase is called HTLV-I-associated myelopathy (HAM). The HTLV-I seroposit ivity was first determined by enzyme-linked immunoassay and confirmed by western immunoblot and in the cerebrospinal fluid specific IgG olig oclonal bands to HTLV-I were found in cerebrospinal fluid and not in s erum. These laboratory findings indicated that HTLV-I could be neuropa thogenic and for the first time a single etiological agent was identif ied in patients from different countries. Thus, in less than a decade a century of research and speculation was seemingly resolved when this disease, which was thought to occur only in blacks of poor socieconom ic status in tropical countries, was shown to occur in all ethnic grou ps of varying socioeconomic status in temperate, subtropical, and trop ical climates.