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 system (CNS) impose diagnostic problems, particularly in younger patients. The demonstration of antibodies against measles virus (MV) in the cerebrospinal fluid (CSF) plays a major role in the laboratory diagnosis of subacute sclerosing panencephalitis (SSPE) as well as multiple sclerosis (MS).

OBJECTIVES

Because intrathecally synthesized antibodies against MV can be found in both diseases, it is necessary to establish easy and reliable methods to improve the differential diagnosis.

STUDY

DESIGN

Seventy-one paired serum/CSF samples obtained from patients with the diagnosis of SSPE (n = 23), MS (n = 14), or acute postinfectious measles encephalitis (APME, n = 8) have been examined. The reactivity of intrathecally synthesized immunoglobulin to individual recombinant MV structural 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 SSPE patients were reactive to MV-fusion protein (F). Faint reactivity was obtained against MV-matrix (M) or hemagglutinin protein (H) in the minority of samples (40 and 20%, respectively). CSF samples of MS patients only revealed a clear response to N, and in two cases to F. The other proteins were not recognized in the CSF samples of MS patients. In 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 shows that discrimination between SSPE and MS can be achieved in doubtful cases by IEF using MV-N, P and F proteins.