High frequency of antibody activity against ribosomal protein S10 in anti-Sm sera from patients with systemic lupus erythematosus

This study was carried out to clarify the frequency of detection of antibod y activity to ribosomal protein S10 (anti-S10) in patients with systemic lu pus erythematosus (SLE) with anti-Sm antibodies (anti-Sm). and clinical dif ferences between anti-Sm-positive SLE patients with and without anti-S10. T wenty-seven of 31 serum samples containing anti-Sm reacted with ribosomal p rotein S10 along with Sm core proteins B/B' and D (87.1%). Four serum sampl es containing anti-Sm against only B/B' but not D did not react with S10 (1 2.9%). Patients who had both anti-Sm and anti-S10 showed lower serum comple ments levels, high frequency of skin lesion and anti-double-stranded DNA an tibody. Many anti-Sm antibodies may recognize B/B', D, and S10 simultaneous ly, and such antibodies may appear in active disease.