“…Much of this interest is due to the facts that measles virus is considered as an etiological agent of SSPE (Connolly et al ., 1967;Horta-Barbosa et al, 1969;Payne et al, 1969), and that there is circumstantial evidence linking measles virus infection to multiple sclerosis (Salmi et al, 1972;Norrby et al ., 1974). Thus, radioimmunoassay (RIA) has been applied to the detection of measles antibodies by several investigators (Arstila et al, 1977;Kiessling et al, 1977;Vuorimaa et al, 1978). In the present study, we developed an indirect RIA technique for detection of measles antibody using HeLa cells persistently infected with measles virus as solid-phase antigen and applied the technique to the detection of measles antibody in the sera and CSF of patients with SSPE and multiple sclerosis.…”