Antibody profiles of sera giving different nuclear staining patterns

Antibodies to three major antigens of the non-histone or saline-extractable nuclear antigen (ENA) complex were sought by counterimmunoelectrophoresis (CEP) in three groups of sera which gave different patterns in the immunofluorescence test for antinuclear antibodies (ANA). Precipitins, mainly anti RNP and anti SS-B, were found most commonly (61%) in 70 sera with a speckled ANA pattern but were less frequent (8%) in 61 sera with a homogeneous ANA pattern and exceptional (1%) in 72 sera which showed fibrillar ANA staining. Rim staining was an insensitive indicator of nDNA antibody. An enzyme immunoassay (EIA), specific for anti-SS-B was more sensitive than CEP and identified this antibody in 28 sera, compared with 18 for CEP.