Tetanus Antibody Production in Serum and Cerebrospinal Fluid in the Rabbit and Correlated Histopathological Features of the Central Nervous System

The histopathological features in the central nervous system (CNS) developing during the active phase of tetanus antibody formation in the cerebrospinal fluid (CSF) as induced in 15 rabbits were studied. The measurement of antibody titres in serum and CSF by electroimmunodiffusion and histological examination were done sequentially at the 1st, 3rd, 5th, 7th and 9th days after cisternal secondary inoculation with fluid tetanus toxoid. Tetanus antibodies appeared in serum after the 1st and in CSF after the 5th day. Decreasing values of CSF total protein were found. The meaning of an elevated Q ratio as observed in this situation of strong antibody formation in the CSF was enhanced. The histopathological features in the central nervous system consisted of perivascular inflammatory infiltration, at first polymorphic and then composed almost exclusively of mononuclear cells with a predominantly leptomeningeal and subpial localization, which might represent the origin of CSF tetanus antibodies. The localization was related to the contact zone between the antigen- and antibody-containing compartments, respectively the subarachnoid space and vascularized structures of the brain and spinal cord. Four control rabbits presented neither tetanus antibodies in the CSF nor perivascular inflammatory infiltration in the CNS. Similarity between the present experimental results and the immunopathological features of the primary demyelinating diseases provides some useful information about the immunological inflammatory events in these diseases.