Importance of detection of SS-A/Ro autoantibody in screening immunofluorescence tests for autoantibodies to nuclear antigens.

SS-A/Ro autoantibodies are related to Sjögren's syndrome and to several clinical subsets of lupus erythematosus. The most widely used laboratory procedure for ANA screening is the indirect immunofluorescence test (IF-ANA); the laboratory detection of anti-SS-A/Ro requires implementation and adherence to several technical and quality assurance recommendations. Using appropriate substrate cells containing the SS-A/Ro antigen, many so-called "ANA-negative" lupus erythematosus patients will demonstrate a positive IF-ANA.