An inverse correlation of HTLV-I viral load in CSF and intrathecal synthesis of HTLV-I antibodies in TSP/HAM.

The authors measured human T-cell lymphotrophic virus type I (HTLV-I) proviral load and intrathecal synthesis of antibodies to HTLV-I in CSF of 13 Brazilian patients with tropical spastic paraparesis/ HTLV-I-associated myelopathy (HAM). The authors also measured HTLV-I proviral load in peripheral blood mononuclear cells of five of these patients and found that it was 10- to 100-fold higher than that in CSF cells. The combination of HTLV-I proviral load and intrathecal synthesis of antibodies to HTLV-I appears to be a useful marker of disease progression. Patients with high viral load and no intrathecal synthesis of antibodies to HTLV-I had more rapidly progressing, serious clinical disease.