Interleukin 21 as a diagnostic marker of rheumatoid arthritis.
To investigate the role of IL-21 as diagnostic marker in diagnosis of rheumatoid arthritis. Study Design: Cross sectional study. Setting: Department of Physiology and Orthopedic Gujranwala Medical College, Gujranwala. Period: October 2017 to October 2018 in one year duration. Materials and Methods: A total of 150 patients were included in the study, main variables assessed in this study were positive predictive value negative predictive value, sensitivity, specificity and accuracy of IL-21 in diagnosis of rheumatoid arthritis. SPSS version 23 was used to analyze the data. P value less than or equal to 0.05 was taken as significant. Study was started after permission from hospital ethical committee and patients were informed in detail about disease and procedure to be done. Non probability consecutive sampling was used. Results: The estimated sensitivity was 93.6%. The estimated specificity was 50%. Positive predictive value was 96.3% and negative predictive value was 35.7%. The overall accuracy was 90.6% for diagnosing rheumatoid arthritis. Conclusion: IL-21 induces MMP3 in rheumatoid arthritis patients, identification of IL-21 from synovium of patients indicates the presence of rheumatoid arthritis. We observed 90.6% diagnostic accuracy of IL-21 for rheumatoid patients taking RA factor as gold standard of diagnostic tool.