[Quantitative determination of serum anti ribosomal-P protein antibody by enzyme immunoassay].
An enzyme immunoassay for serum anti-ribosomal P protein antibodies (anti-P) is developed, using highly purified synthetic ribosomal P peptides of the carboxyl terminal 22 amino acid sequence conjugated to human serum albumin (HSA) as an antigen. Anti-P levels were determined by subtracting the nonspecific binding activities to HSA. The concentration of anti-P which produced half of the maximal absorbance at 492 nm (OD492) given by saturating concentrations of anti-P in the ELISA plate was defined as 1 U/ml. The anti-P values in the samples were determined by referring to a standard curve made from a standard serum containing anti-P. Serum anti-P levels in 34 normal individuals were 5.52 +/- 8.39 U/ml (mean +/- SD). Anti-P in sera from 45 patients with systemic lupus erythematosus (SLE), 24 patients with rheumatoid arthritis (RA) and 27 patients with Behçet's disease were also analyzed. The values for serum anti-P in SLE, RA and Behçet's disease groups were 251.04 +/- 843.07 U/ml, 5.97 +/- 15.18 U/ml, and 2.62 +/- 3.35 U/ml (mean +/- SD) respectively. The positive ratio for serum anti-P in SLE patients was significantly higher than that in patients with RA or Behçet's disease (p < 0.05 as determined by chi-square test). These results indicate that quantitative determination of serum anti-P by our enzyme immunoassay is a successful tool for the diagnosis of SLE.
Isshi
K
K
Department of Internal Medicine, Teikyo University School of Medicine, Tokyo.
Kikuchi
H
H
Kojima
H
H
Kawai
M
M
Suda
H
H
Hirohata
S
S
D000328:Adult; D000368:Aged; D001323:Autoantibodies / Q000032:analysis*; D004797:Enzyme-Linked Immunosorbent Assay; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000276:immunology; D008875:Middle Aged; D015800:Protozoan Proteins; D012269:Ribosomal Proteins / Q000276:immunology*
D001323:Autoantibodies; C064601:L12E protein, Trypanosoma cruzi; D015800:Protozoan Proteins; D012269:Ribosomal Proteins