title: Anti-MBL autoantibodies in patients with rheumatoid arthritis: prevalence and clinical significance.
abstract: Occurrence of autoantibodies in patients' sera is the characteristic feature of autoimmune disorders. We assessed the presence of anti-mannose binding lectin (MBL) autoantibodies in the sera of 107 rheumatoid arthritis (RA) patients and 121 control subjects by enzyme immunoassay. Elevated levels of anti-MBL autoantibodies in the sera of RA patients (P<0.0001) was detected for the first time. The ratios of anti-MBL positive in RA patients and controls were respectively 60.7% and 1.65%. Experiments were then designed to understand the functional relevance of these autoantibodies. An inverse correlation of anti-MBL autoantibodies with serum MBL levels (P=0.001) and MBL complex activity (P=0.02) was observed without genetic association between MBL polymorphisms and anti-MBL autoantibody secretion. A significant increase (P=0.038) in the level of anti-MBL autoantibodies was observed in 23 synovial fluid samples in comparison to the serum samples. Moreover, the anti-MBL autoantibodies were found to be more often present in the sera of RA patients (60.75% sensitivity, 98.35% specificity and 0.913 area under the ROC curve) in comparison to the IgM and IgG isotypes of rheumatoid factors (RF). Anti-MBL autoantibodies were still positive in 25.23% RA patients when both the RF isotypes were negative. Also, in RA patients, at all stages of disease activity and joint deformity, anti-MBL autoantibodies were more often present than both the RF isotypes. Therefore, the significant presence of anti-MBL autoantibodies enunciates that anti-MBL autoantibodies might have a diagnostic value; however, more studies are needed to confirm the role of anti-MBL autoantibodies in the diagnosis of rheumatoid arthritis.
authors.affiliation: Institute of Genomics and Integrative Biology, Delhi University Campus, Mall Road, Delhi 110 007, India.
authors.forename: Bhawna
authors.initials: B
authors.lastname: Gupta
authors.forename: Sunil Kumar
authors.initials: SK
authors.lastname: Raghav
authors.forename: Charu
authors.initials: C
authors.lastname: Agrawal
authors.forename: Ved Prakash
authors.initials: VP
authors.lastname: Chaturvedi
authors.forename: Rakha Hari
authors.initials: RH
authors.lastname: Das
authors.forename: Hasi Rani
authors.initials: HR
authors.lastname: Das
mesh_terms: D000328:Adult; D001172:Arthritis, Rheumatoid / Q000097:blood* / Q000175:diagnosis* / Q000276:immunology; D001323:Autoantibodies / Q000097:blood*; D001324:Autoantigens / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006801:Humans; D007132:Immunoglobulin Isotypes / Q000097:blood / Q000276:immunology; D008297:Male; D037601:Mannose-Binding Lectin / Q000097:blood / Q000276:immunology*; D015995:Prevalence; D012372:ROC Curve; D012217:Rheumatoid Factor / Q000097:blood / Q000276:immunology; D012680:Sensitivity and Specificity; D013582:Synovial Fluid / Q000737:chemistry / Q000276:immunology
chemical_list: D001323:Autoantibodies; D001324:Autoantigens; D007132:Immunoglobulin Isotypes; D037601:Mannose-Binding Lectin; D012217:Rheumatoid Factor