Distribution of IgG subclass antibodies anti-ENA (extractable nuclear antigens) in systemic rheumatic diseases.

The subclass distribution of anti-ENA antibodies was investigated in the serum of patients with systemic rheumatic diseases, using an ELISA technique. All the sera studied were previously detected positive for anti-ENA antibodies by other technique (gel precipitation). The patients were classified according to the enzymatic sensitivity of the antigen against the antibodies. There was no subclass restriction for antibodies against Ribonuclease-sensitive ENA antigen or other ENA antigens. Progressive studies showed that a single pattern of subclass distribution for each serum was maintained.