Antibodies to extractable nuclear antigen polypeptides: detection and its clinical significance]

Using immunoblotting technique (IBT) and saline extracts of rabbit thymus powder as antigen, we detected seven autoantibodies i.e. anti-Sm, anti-RNP, anti-SSA, anti-SSB, anti-Scl-70, anti-Jo-1 and anti-ribosome with only a strip of blot. Comparison of IBT and counter-immunoelectrophoresis (CIE) showed that the antibodies against Sm in SLE could be detected more sensitively by IBT than by CIE (P < 0.01). And the antibodies against ribosome by IBT were much specific for SLE (P < 0.01). So the detection of antibodies against ENA polypeptides by IBT was helpful in the diagnosis of SLE. In rheumatic diseases, the antibodies against SSB could be detected more sensitively by IBT than by CIE (P < 0.05), while the antibodies against SSA could be detected more sensitively by CIE than by IBT (P < 0.01). The antibodies against Scl-70 and Jo-1 by IBT were much specific for PSS and PM/DM respectively (P < 0.01).