Antibody response to the human stress protein BiP in rheumatoid arthritis.
OBJECTIVE
The human stress protein BiP (immunoglobulin binding protein) has been implicated in the pathogenesis of rheumatoid arthritis (RA) since BiP was found to stimulate synovial T-cell proliferation and anti-BiP antibodies are present in the serum of RA patients. The aim of this study was the development of a rapid and reproducible enzyme-linked immunosorbent assay (ELISA) to determine the specificity and sensitivity of anti-BiP antibodies in RA.


METHODS
An ELISA was developed that detected antibodies to BiP. The prevalence of anti-BiP antibodies was determined in sera from patients with early and established RA, sera antedating the onset of RA and sera from patients with other inflammatory and autoimmune diseases and healthy controls.


RESULTS
We have confirmed the increased prevalence of antibodies to BiP in the sera of a large cohort of patients with established RA (specificity 71% and sensitivity 73%) and early RA (specificity 65% and sensitivity 66%). In pre-disease sera, median 2.5 yr (interquartile range 1.1-4.7) before symptoms of joint disease, the sensitivity for anti-BiP antibodies was 45% and the specificity was 65% for the development of RA.


CONCLUSIONS
Antibodies to BiP are found in the sera of patients with RA and in sera antedating the onset of RA.
Bodman-Smith
M D
MD
Department of Rheumatology, GKT School of Medicine, King's College London, Guy's Hospital, London, UK. mbodmans@sghms.ac.uk
Corrigall
V M
VM
Berglin
E
E
Cornell
H R
HR
Tzioufas
A G
AG
Mavragani
C P
CP
Chan
C
C
Rantapää-Dahlqvist
S
S
Panayi
G S
GS
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000906:Antibodies / Q000032:analysis; D000917:Antibody Formation / Q000276:immunology*; D000918:Antibody Specificity / Q000276:immunology; D001172:Arthritis, Rheumatoid / Q000276:immunology*; D000091342:Endoplasmic Reticulum Chaperone BiP; D004797:Enzyme-Linked Immunosorbent Assay / Q000379:methods; D005260:Female; D006360:Heat-Shock Proteins / Q000276:immunology*; D006801:Humans; D007592:Joint Diseases / Q000276:immunology; D008297:Male; D008875:Middle Aged; D018832:Molecular Chaperones / Q000276:immunology*
D000906:Antibodies; D000091342:Endoplasmic Reticulum Chaperone BiP; D006360:Heat-Shock Proteins; D018832:Molecular Chaperones