Presence of cross-reactive antibodies to HTLV-1 and absence of antigens in patients with multiple sclerosis.

Antibodies to HTLV-1, as determined by ELISA, were highly elevated in the serum samples of four out of four (100%) patients with TSP, moderately elevated in four out of four (100%) HTLV-1 carriers, slightly elevated in 12 out of 34 (35%) patients with MS, and absent from the serum samples of 34 normal subjects. Western blot analysis showed that the antibodies to HTLV-1 antigens in MS serum were heterogeneous. Cultivation of peripheral blood lymphocytes (PBLs) from patients with MS or normal subjects did not generate HTLV-1 core p19 antigen in the supernatant of culture medium, whereas cultivation of PBLs from patients with TSP and carriers of HTLV-1 generated core p19 antigen after 3 days for up to 28 days of cultivation. HTLV-1 antigens were also expressed on the surface of PBLs in three out of four patients with TSP and in two out of four HTLV-1 carriers on days 14 and 28 of cultivation, as measured by indirect immunofluorescence or alkaline phosphatase staining, but were not found in PBLs of any of 34 patients with MS or 34 normal subjects. The data indicate that although cross-reacting antibodies appear in the serum of some patients with MS, not enough evidence exists to suggest that HTLV-1 antigen is being produced in MS or that HTLV-1 plays a role in the pathogenesis of this disease.