ABSTRACT
@#Introduction: Rheumatoid arthritis is diagnosed based on the 2010 Rheumatoid Arthritis Classification Criteria whereby rheumatoid factor and anti-citrullinated protein antibody are the serological markers included in these criteria. Anti-RA33 antibody has the potential to provide additional diagnostic value in rheumatoid arthritis. The aim of this study is to determine the diagnostic performance of anti-RA33 antibody as a serological marker for rheumatoid arthritis. Material and methods: Thirtyfour patients with rheumatoid arthritis and 34 non-rheumatoid arthritis individuals were included in this cross-sectional study. Anti-RA33 antibody and rheumatoid factor were performed on all samples. Results: The sensitivity, specificity, positive and negative predictive value for anti-RA33 antibody and rheumatoid factor were 41.1%, 97.1%, 93.3%, 62.3% and 64.7%, 79.4%, 75.9%, 69.2% respectively. The overall sensitivity and specificity if either anti-RA33 antibody or rheumatoid factor are positive were 79.4% and 76.47% respectively. Conclusion: Anti-RA33 antibody showed good specificity and positive predictive value and could be considered as a potential serological marker for rheumatoid arthritis diagnosis.
ABSTRACT
Objective To investigate the application value of combined detection of antikeratin (AKA) antibody,anti-cyclic citrullinated peptide(anti-CCP) antibody,anti-RA33 antibody,RF and ESR in the diagnosis of rheumatoid arthritis(RA).Methods One hundred cases of RA and 60 cases of suspected RA in our hospital from June 2014 to May 2015 were collected.One hundred and twenty cases of non-RA other autoimmune diseases served as the control group.The indirect immunofluorescence assay (IFA) was used to detect anti-KA antibody,anti-CCP antibody and anti-RA33 antibody were detected by using ELISA.The rate scatter turbid assay was used to detect RF.The Westergren method was used to detect ESR.The diagnostic performance of each diagnostic indicator was evaluated.Results The detection rates of anti-KA antibody,anti-CCP antibody,anti-RA33 antibody,RF and ESR in the RA group were in turn 64%,75%,44%,84% and 51% respectively,the detection rate(sensitivity) of 5-indicator parallel detection were 97%, the specificity of 5-indicator series detection was 89.2%;in the suspected RA group,the detection rates of 5-indicator were in turn 16.7%, 31.7%,13.3%,20%,15% respectively,which in the control group were in turn 0.8%,2.5%,1.7%,0.8% and 5.8% respectively.The detection rates of 5-indicator in the RA group was significantly higher than that in the suspected RA group,showing extremely significant difference (P<0.001),the detection rate of 5-indicator had extremely significant difference between the suspected RA group and control group (P<0.001),the sensitivity of five-indicator parallel detection was 97%,which was significantly higher than that of single indicator detection (P<0.05),the detection specificity of 5-indicator series detection was up to 100%,which was also significantly higher than that of single indicator detection (P<0.05),the missed diagnosis rate of parallel detection was minimal,while the negative predictive value was highest,the misdiagnosis rate of series detection was lowest,the positive predictive value was highest,the Youden index of parallel detection was largest.Conclusion The single detection of anti-CCP antibody and RF have good sensitivity and specificity, but 5-indicator combined detection has higher sensitivity and specificity,which can better reduce the missed diagnosis rate and misdiagnosis rate,can greatly improve the efficiency of diagnosis,and has an important clinical significance for the early diagnosis of RA.