Comparison of five methods for the detection of antiribosomal P protein antibody.
1. We have compared the sensitivity and specificity of immunofluorescence, counterimmunoelectrophoresis, immunodiffusion, Western blotting and ELISA for the detection of antiribosomal P protein antibodies using 153 lupus sera. 2. Western blotting and ELISA were the 2 most sensitive and specific techniques for the detection of these antibodies. In contrast, cytoplasmic immunofluorescence was observed in only one third of the anti-P-positive patients. Immunodiffusion and counterimmunoelectrophoresis, although highly specific, detecting 14% and 29% of all anti-P-positive sera by Western blotting, were the least sensitive tests. 3. The frequency of anti-P in lupus patients, as detected by Western blotting analysis was 18%. The most frequently observed antibody in anti-P sera was anti-Ro/SSA (39%). Anti-P antibodies were also detected in the sera of 3 patients with negative nuclear immunofluorescence. 4. Anti-P is an additional serological marker for systemic lupus erythematosus and Western blotting is the method of choice for detecting this antibody due to the limited availability of the fusion protein in Brazil.
Bonfa
E
E
Departamento de Clínica Médica, Faculdade de Medicina, Universidade de São Paulo, Brasil.
Gaburo Júnior
N
N
Tavares
A V
AV
Cossermelli
W
W
D001323:Autoantibodies / Q000032:analysis*; D015415:Biomarkers / Q000032:analysis; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000276:immunology*; D012269:Ribosomal Proteins / Q000276:immunology*; D012680:Sensitivity and Specificity
D001323:Autoantibodies; D015415:Biomarkers; D012269:Ribosomal Proteins