Diagnostic Value of Antibodies against a Modified Citrullinated Vimentin in Rheumatoid Arthritis

Aim of Work: To investigate the value of the detection of antibodies against modified citrullinated vimentin antibodies (anti-MCV) in comparison with anti-CCP2-for the diagnosis of rheumatoid arthritis (RA). Patients and Methods: The study Included Forty patients with Rheumatoid arthritis (RA). They under went assessment by the disease activity score (DAS-28), visual analogue scale (VAS) and health assessment questionnaire (HAQ). Thirty healthy subjects matched for age and sex served as a control group. Blood samples were obtained from patients and controls for erythrocyte sedimentation rate (ESR), C reactive protein (CRP), rheumatoid factor (RF). Anti-CCP2 and anti-MCV were determined using ELISA technique. Results: Estimated serum levels of anti-CCP2 and anti-MCV were significantly higher in patients compared to controls (p 0.001). There were no significant correlations between anti-MCV levels and age, dis- ease duration, duration of morning stiffness, number of swollen and tender joints, HAQ or ESR in patients with RA, while serum levels correlates significantly with DAS28, VAS and CRP (p 0.05). Anti-CCP2 correlates significantly with DAS28, VAS and CRP and ANA (p 0.05). Serum anti-MCV and anti-CCP2 were significantly correlated with each other (r = 0.483;p The receiver operating characteristic (ROC) curve was drawn and it showed that anti-MCV had diagnostic specificity, sensitivity of 93.3%, 75.5%, respectively, while anti-CCP2 specificity, sensitivity of 98.1%, 85%, respectively. Conclusion: Serum anti-MCV as well as the anti-CCP-2 assay perform comparably well in the diagnosis of RA. In the high-specificity range, however, the anti-CCP2 assay appears to be superior to the anti-MCV test.

Increased IgG Rheumatoid Factor-Positivity in the Asian Rheumatoid Arthritis Patients Irrespective of Ethnicity

Aim of Work: Initial observations implied IgG rheumatoid factor (RF) to be common among Malaysian rheumatoid arthritis (RA) patients. We tested this hypothesis and used a multiethnic RA cohort (Malays, Chinese and Indians) to investigate whether the IgG RF predominance might be genetically or environmentally determined. Patients and Methods: 556 serum samples comprising 171 patients classified as RA according to the 1987 ACR criteria, 60 patients with other rheumatic diseases and 325 non-rheumatic controls were tested for IgG RF, IgM RF and anti-CCP by ELISA. The findings were then tested in a larger RA case-control cohort (n = 1844). Results: IgG RF predominated over IgM RF in all the investigated ethnic groups. The sensitivity, specificity, and diagnostic accuracy of IgG RF (55.6%, 91.2% and 80.2%, respectively) were superior compared to IgM RF, but comparable to anti-CCP. IgG RF was however, also increased in the Malaysian controls, but the IgG RF superiority over IgM RF was still apparent after cutoff adjustment according to the 1987 ACR criteria. Autoantibody levels did not differ between the three ethnic groups. The Receiver Operating Characteristics (ROC) curves showed larger areas under the curves for IgG RF (0.826) and for anti-CCP (0.867) than for IgM RF (0.737). Review of the literature showed consistently higher sensitivity for IgG RF in studies of Asian RA patients as compared to Caucasian and African-American studies. Conclusion: Increased frequency of IgG RF-positive in RA populations with different genetic background living in Malaysia argues for an environmental factor selectively amplifying the IgG RF response.

Changes in the gene expression of activation-induced cytidine deaminase in peripheral blood mononuclear cells in COVID-19 patients

Objective:To assess the changes in gene expression of activation-induced cytidine deaminase(AID)in COVID-19 patients and its relationship with the presence of autoantibodies in those ones.Methods:This retrospective study was carried out among COVID-19 patients’serum and peripheral blood mononuclear cells that were archived at the main COVID-19 referral centers in Iran from January to March 2022.The titer of autoantibodies in the serum of healthy and COVID-19 subjects was investigated by serological tests.Then,the AID gene expression in peripheral blood mononuclear cells in two groups was evaluated using the real-time polymerase chain reaction method.Results:100 patients were included.In total,8%and 1%of patients had a significant titer of anti-citrullinated protein antibody and antinuclear antibody autoantibodies,respectively,and those suffered from at least one comorbidity.No patient was positive for antiphospholipid autoantibody.Moreover,no significant changes were observed in the titer of autoantibodies between healthy subjects and patients.Furthermore,the increase in the expression of the AID gene was not significant in two groups.Conclusions:The presence of autoantibodies in COVID-19 patients might be linked to the previous underlying disease.