The particulate (speckled-like thread) nuclear staining pattern: species and cellular distribution of Ro/SSA antigen

Anti-Ro/SSA antibodies are associated with a particulate (speckled-like thread) nuclear immunofluorescence (IF) staining pattern when human spleen imprints are employed as substrate. The present study was undertaken to determine if these antibodies would yield a similar IF pattern with splenic imprints from other species, and with other human cell lines. All splenic imprints (mammalian, avian, amphibian and fish origin) demonstrated a particulate nuclear pattern when treated with anti-Ro/SSA antibody positive serum samples. Cytospin preparations of a variety of peripheral blood cells also demonstrated this particulate pattern when treated with anti-Ro/SSA antibodies. Similar findings were noted when cytospin preparations of cultured keratinocyte cell lines were used as substrate. The antigen, associated with the particulate IF staining pattern when treated with anti-Ro/SSA antibody positive serum samples, is expressed in a variety of tissues and species.