Association of IL-17A rs2275913, IL-23R rs11209026 polymorphisms and serum level of IL-17A with rheumatoid arthritis in Egyptian patients.

Several studies have reported genetic polymorphisms at the IL-23/IL-17 axis linked to rheumatoid arthritis (RA) in many populations. We aimed to investigate the association of IL-17A rs2275913 and IL-23R rs11209026 polymorphisms with susceptibility to RA and, disease clinical features and the serum level of IL-17A in Egyptian patients. This case-control study included 94 RA cases and 74 controls. TaqMan genotyping assays were used for detection of gene polymorphism and the enzyme-linked immunosorbent assay was used to quantify IL-17A serum level. There was significant difference between RA patients and controls in genotypic distribution and allelic frequency of IL-17A rs 2275913 (p < 0.0001). The GG genotype had 7 times higher risk for RA development (OR=7.04: 95% CI 2.11:23.46, p value= 0.001). Also, GG genotype was associated with higher level of serum IL-17 A compared to GA and AA genotypes (p < 0.0001). Moreover, patients carrying the GG genotype had higher disease activity score 28 (DAS28) score (4.99±0.84) compared to patients with GA (2.73±0.52, p < 0.0001) and patients with AA genotypes (2.67±0.41, p < 0.0001). Genotypic distribution of IL-23R rs11209026 was significantly different between RA patients and controls (p < 0.0001), but there was no difference between the allelic frequency in both groups (p=0.08). IL-23R rs11209026 SNP was not a risk for RA development. However, DAS28 was lower in AA genotype than AG and GG genotypes (p=0.002, p=0.009 respectively). The mean serum IL-17A level was higher among the RA patients (39.07±10.47 pg./ mL) compared to controls (15.23±1.88 pg/ mL; p < 0.0001). Also, there was a positive correlation between IL-17A serum level and DAS28 score (Spearman r = 0.42; p value < 0.0001). We concluded that the variant IL-17A (rs2275913) genotype could be a risk factor for RA in our population and IL-17A may play a crucial role in the development and pathogenesis of RA.

Diagnostic and prognostic value of anti-CarP antibodies in a sample of Egyptian rheumatoid arthritis patients.

INTRODUCTION: Detection of autoantibodies in sera of rheumatoid arthritis (RA) patients has an important role in diagnosis and management strategies. Recently, another type of autoantibodies has been detected with activity against carbamylated proteins (anti-CarP) which may play an important role in the diagnosis of RA. The aim of this study was to raise knowledge about the diagnostic and prognostic value of anti-CarP antibodies in RA. MATERIALS AND METHODS: Seventy RA patients and thirty-four controls were included in this study. DAS28 was used to evaluate disease activity. Joint erosions were assessed by Larsen score using plain X-ray of involved joints of hands and feet. Serum samples were analyzed for anti-CarP antibody titer using the ELISA technique. RESULTS: Out of 70 patients, 35.7% were positive for anti-CarP and only 5.88% of controls had high titer above the cut-off value. A total of 24.29% of the patients were RF-negative and 30% were ACPA-negative. Five patients (29.41%) of the negative RF group were positive for anti-CarP. Four patients (19%) of the ACPA-negative group were positive for anti-CarP, and three patients (4.28%) of the total number of patients were triple negative and seventeen (24.28%) were triple positive. There was a significant correlation between anti-CarP titer and both DAS28 and Larsen scores only in the positive anti-CarP group. In addition, there was a strong association between anti-CarP antibody titer and joint erosions at both baseline and after 1-year follow-up. CONCLUSION: Presence of the anti-CarP antibodies in sera of RA patients may have a prognostic value as it correlates with the disease activity and joint erosions; moreover, it may have a diagnostic value in rheumatoid arthritis especially in RF- and ACPA-negative patients. Key Points • This study was carried out to raise our knowledge about the importance of anti-CarP antibodies in predicting the prognosis of RA. • This study was carried out to assess the correlation between anti-CarP antibodies, disease activity, and joint erosions. • This study was carried out to state the extent to which we can rely on the anti-CarP antibodies as a biomarker for prediction of RA.