Differentiation of the humoral immune response in herpes simplex encephalitis

Six patients with herpes simplex encephalitis were investigated. Antibody activities against different viral antigens were determined in serum and cerebrospinal fluid with an enzyme-linked immunosorbent assay after adjusting both fluids to identical immunoglobulin G concentrations. In serum, the strength of the antiviral reaction remained low and no qualitative changes became detectable. In cerebrospinal fluid, at first locally synthesized antibodies were directed against the same antigens as in serum. Ten days later, the intrathecal reaction increased with additional antibodies against at least two antigens. Once established, this expanded heterogeneity remained stable during the course of the disease.