ANTIBODY REACTIVITY TO INDIVIDUAL STRUCTURAL PROTEINS OF MEASLES-VIRUS IN THE CSF OF SSPE AND MS PATIENTS

Background: Chronic progressive disorders of the central nervous syste m (CNS) impose diagnostic problems, particularly in younger patients. The demonstration of antibodies against measles virus (MV) in the cere brospinal fluid (CSF) plays a major role in the laboratory diagnosis o f subacute sclerosing panencephalitis (SSPE) as well as multiple scler osis (MS). Objectives: Because intrathecally synthesized antibodies ag ainst MV can be found in both diseases, it is necessary to establish e asy and reliable methods to improve the differential diagnosis. Study design: Seventy-one paired serum/CSF samples obtained from patients wi th the diagnosis of SSPE (n=23), MS (n=14), or acute postinfectious me asles encephalitis (APME, n=8) have been examined. The reactivity of i ntrathecally synthesized immunoglobulin to individual recombinant MV s tructural proteins was assessed using Western blot analysis, ELISA as well as isoelectric focusing (IEF). Results: All CSF samples obtained from patients suffering from SSPE showed a strong antibody response to MV-nucleocapsid (N) and phosphoprotein (P). Sera from 15 of the 23 SS PE patients were reactive to MV-fusion protein (F). Faint reactivity w as obtained against MV-matrix (M) or hemagglutinin protein (H) in the minority of samples (40 and 20%, respectively). CSF samples of MS pati ents only revealed a clear response to N, and in two cases to F. The o ther proteins were not recognized in the CSF samples of MS patients. I n contrast to SSPE, the IEF of CSF from MS patients revealed only few MV-specific oligoclonal bands. In the CSF samples from APME patients, intrathecal MV antibodies were not detected. Conclusions: This study s hows that discrimination between SSPE and MS can be achieved in doubtf ul cases by IEF using MV-N, P and F proteins.