Rapid and sensitive detection of anti-Ro (SS-A) antibodies by indirect immunofluorescence of 60kDa Ro HEp-2 transfectants

Abstract

Anti-Ro (SS-A) antibodies are important diagnostic markers for primary Sjögren's syndrome and systemic lupus erythematosus, but their detection by indirect immunofluorescence (IF) in the diagnostic laboratory is hindered by the low cellular abundance of 60kDa Ro protein (Ro60). The approach we used to overcome this problem was to transfect and over-express the Ro60 gene into HEp-2 cells. In this study we have used a mixture of Ro60 transfectants and untransfected HEp-2 cells (HEp-Ro60) as a substrate for IF-antinuciear antibody (ANA) testing in a hospital laboratory. Screening of 240 routine serum specimens identified 14 Ro transfectant-positive sera which were confirmed by counterimmunoelec..