Detection and clinical significance of IL-21R mRNA in peripheral blood mononuclear cells of patients with rheumatoid arthritis

Objective To establish a nested-real-time-PCR for the detection of IL-21R mRNA in peripheral blood mononuclear cells(PBMC)of patients with rheumatoid arthritis,and explore its clinical significance.Methods The outer primers of span intron and inner primers were designed for nested-real-time-PCR.To increase specific template,the concentration of primers and enzyme,cycle times were decreased in the first amplification,and the real-time fluorescent quantity assay was performed in the second amplification.The β-actin gene was used as internal reference,and the results were presented as the ratios of IL-21R mRNA to β-actin mRNA.Results IL-21R mRNA was detected in 60 patients with RA and 30 healthy controls.The expression of IL-21R mRNA gene in the patients with RA was increased,and the statistical analysis has significant differences(P0.01).According to the grades of joint function in RA patients,the expression of IL-21R mRNA has no significant differences between the grade I and grade II(P0.05),but a significant difference was found in the patients of grade III compared with those of grade I and II(P0.01).The expression levels of IL-21R mRNA in active patients was higher than those in non-active patients.After treatment,the expression of IL-21R mRNA was lower obviously,and the difference was significant(P0.01).Conclusions Nested-real-time-PCR is a simple,repeatable,high specific and sensitive method for the detection of IL-21R mRNA in human PBMC.The expression level of IL-21R mRNA may be valuable for diagnosis of RA and analysis of therapeutic effect.