Immunohistochemical localisation of neuron-binding antibodies in rheumatic heart disease

Neuron-binding antibodies and heart-reactive antibodies (HRA) have been investigated in the sera of patients with acute rheumatic fever (ARF) and chronic valvular rheumatic heart disease (both active and inactive by means of immunoperoxidase technique. The incidence of neuron-binding antibodies was highest in ARF (61.1%) in comparison with 54.2% in active chronic valvular disease with activity and 21.1% in inactive chronic valvular disease. In active chronic valvular disease the labelling of neurons was commoner than labelling of myofibres (p less than 0.01). In the other two groups (ARF and inactive chronic valvular disease) no difference in staining of neurons and myofibres was observed. Morphological localisation of binding sites of antibodies in the caudate nucleus neurons showed a definite pattern, which varied from a peripheral crescentic to a diffuse staining within the neuronal cytoplasm, often extending into the dendritic processes. Antibodies binding to caudate nucleus neurons were significantly commoner in ARF and active chronic valvular disease than in inactive chronic valvular disease (p less than 0.05).