[Clinical diagnostic value of potential polypeptides associated with rheumatoid arthritis].
OBJECTIVE
To obtain the mimotope recognized by anti-keratin antibody (AKA) by screening a phage random peptide library and evaluate its diagnostic value.


METHODS
IgG was purified from AKA positive pooled serum of rheumatoid arthritis (RA) patients by 33.3% (NH4)2SO4 (AKA measured with indirect immunofluorescence). Then the antibody was used as the ligand for biopanning of a 12-mer phage random peptide library. The serum of patients with RA, SLE and normal people were detected with the positive clone by indirect ELISA.


RESULTS
After 4 rounds of screening, the peptide of mimotope associated with RA was acquired. The diagnostic specificity, positive predictive value and Youden's index were 95.6%, 90% and 155.6% respectively. Its amino acid sequence was QSESAGPTTSRR. This sequence was similar to 137-148 amino acid sequence of human filaggrin.


CONCLUSIONS
The RA-associated peptide is acquired by screening a phage random peptide library using polyclonal AKA of RA patients. It may be a specific diagnostic tool of RA.
Luo
Hong
H
Department of Clinical Immunology & Microbiology, Dalian Medical University, Dalian 116044, China.
Yang
Guang
G
Liu
Hui
H
Liu
Yong-e
YE
D000293:Adolescent; D000328:Adult; D000368:Aged; D001172:Arthritis, Rheumatoid / Q000175:diagnosis*; D005260:Female; D000091344:Filaggrin Proteins; D006801:Humans; D008180:Lupus Erythematosus, Systemic / Q000175:diagnosis; D008297:Male; D008875:Middle Aged; D019151:Peptide Library; D010455:Peptides; D011237:Predictive Value of Tests; D012680:Sensitivity and Specificity; D055815:Young Adult
C000717249:FLG protein, human; D000091344:Filaggrin Proteins; D019151:Peptide Library; D010455:Peptides