association of single nucleotide polymorphism of interleukin-21 gene and serum interleukin-21 levels with systemic lupus erythematosus

Background: Systemic lupus erythematosus [SLE] is a common autoimmune disorder which commonly results from the combined effects of a large number of genes. Variations in the DNA sequence in the Interleukin-21 [IL-21] gene may lead to altered IL-21 production and/or activity which can affect an individual's susceptibility to SLE. IL-21 is a novel class I cytokine produced by activated CD4+ T cells, natural killer T cells and T helper [Th] cells. There is increasing evidence that IL-21 contributes to the pathogenesis of SLE due to its biological activity

Aim of the study: To investigate the association between single nucleotide polymorphism [SNP] of IL-21 rs2221903 gene and serum IL-21 levels with SLE and to detect the possible association between IL-21 serum levels and the pathogenesis of the disease

Subjects and methods: This study was conducted on 30 SLE patients and 20 age and sex matched healthy controls. Serum IL-21 levels were measured using enzyme-linked immunosorbent assay [ELISA] technique and SNP of IL-21 rs2221903 gene was detected by genotyping assay, using real time polymerase chain reaction[RT-PCR]

Results: Serum 11-21 levels were significantly higher in patients compared with controls [p < 0.001]

Patients with high activity index of SLE had significantly higher levels of serum IL-21 [p value < 0.001]

A statistically significant association was found between the T allele of SNP rs2221903 and SLE, whereas; no association between SNP of IL-21 rs2221903 genotypes and SLE or serum IL-21 levels could be detected

Conclusion: IL-21 plays an important role in the immune-pathogenesis of SLE and could be used as a possible target for novel immunotherapy. The T allele of SNP rs2221903 suggests that the IL-21 gene may contribute to an inherited predisposition to SLE

MicroRNA-146a expression as a potential biomarker for rheumatoid arthritis in Egypt

Background: MicroRNAs [miRNAs] are small non-coding RNAs, whose role in regulating diverse immune functions, suggests they might play a role as biomarkers for immune medi-ated disorders. Studies showed that miRNA-146a [miR-146a] expression is increased by proinflammatory cytokines and is an important modulator of differentiation and function of cells of innate and adaptive immunity

Aim of the work: The current study aimed to evaluate the expression of miR-146a as a potential biomarker for diagnosis of rheumatoid arthritis [RA] and to explore its association with disease activity

Subjects and methods: The study enrolled 50 Egyptian subjects divided into a patient group, which comprised 25 RA patients, and a control group which comprised 25 healthy individuals

The disease activity for the patients' group was determined by simplified disease activity index. Relative quantification of miR-146a expression in whole blood was determined using reverse tran-scriptase quantitative real time polymerase chain reaction

Results: There were highly significant statistical differences between patients and healthy controls as regards miR-146a relative expression, erythrocyte sedimentation rate [ESR] and anti-cyclic citrullinated peptide [anti-CCP] [p < 0.001]. Highly significant statistical differences [p < 0.001] were also found between different patients' subgroups as regards miR-146a relative expression and ESR. rm'R-146a levels correlated positively with those of ESR, C-reactive protein and anti-CCP [p < 0.001]

miR-146a illustrated best performance in diagnosing RA, showing the highest sensitivity and specificity [96% and 100%, respectively] [AUC: 0.992 at a cut off value of >/=2.16] compared to anti-CCP [sensitivity: 68%, specificity: 100% and AUC: 0.87 at a cut off value of >/= 22 U/ml] and RF [sensitivity: 56%, specificity: 80% and AUC: 0.992 at a cut off value of >/=13 U/ml]

Conclusion: This study demonstrated that miR-146a expression was highly significantly elevated in whole blood of patients with RA. Its diagnostic performance was better than anti-CCP and RF and its level of expression correlates with disease activity