The intrathecal synthesis of virus-specific oligoclonal IgG in multiple sclerosis.

A highly sensitive antigen-mediated capillary blot technique was developed for the detection of virus-specific oligoclonal IgG in paired CSF and serum samples from patients with various neurological diseases. In multiple sclerosis, intrathecal synthesis of oligoclonal antibodies was present against measles (70%), rubella (60%), varicella zoster (40%) and mumps (30%); in most cases (75%), such synthesis involved two or more viruses. In contrast, antibodies against a non-neurotropic virus (cytomegalovirus) were rarely produced in CSF from MS patients (5%). However, this 'polyspecific' reaction was not restricted to MS samples but was also observed in neurolupus and in the late phase of infectious diseases of the central nervous system. These anti-viral antibodies could be produced without de novo replication of the corresponding viral genome and are likely mere bystanders of an ongoing immune response.