Association Study Of Interleukin-22and Its Receptors With Systemic Lupus Erythematosus

Background Interleukin-22(interleukin-22,IL-22) is mainly produced by Th22cells,which plays an important role in autoimmune diseases. Interleukin-22has tworeceptors,which are IL-22R1and IL-22BP. At present, few studies have focused on thepotential association between IL-22and SLE.Objective1To investigate the association of the serum level of IL-22BP with SLE.2To investigate the association of IL-22R and IL-22R1gene single nucleotidepolymorphism (SNP) rs1179251(A/G) and IL-22R1gene rs3795299(C/G) with SLEand its clinical features.Methods This study of SLE patients from the first affiliated hospital of anhui medicaluniversity and appointed hospital outpatient and hospitalized patients in anhui province.According to the American College of Rheumatology (ACR)1997Revised Criteria forthe classification of SLE.The frist study used enzyme linked immunosorbent assaytechnology.84cases of SLE patients and83controls (including the healthy controls,33cases,RA20examples, SS19examples, SSc11examples) were enrolled.The secondstudy used ABI7300polymerase chain reaction (PCR). A total of733SLE patientsfrom Anhui Provincial Hospital and the First Affiliated Hospital of Anhui MedicalUniversity were recruited in this study.696healthy controls were enrolled. The generalinformation and clinical data of subjects were collected by using self-designedquestionnaire. Genotypes of IL-22gene rs1179251(A/G) and IL-22R1gene rs3795299(C/G) were detected by TaqMan SNP allelic discrimination using ABI7300polymerasechain reaction (PCR). Frequencies of allele and genotype were compared betweenpatients and controls. Meanwhile, allellic and genotypic distribution were also analyzedbetween SLE patients with different clinical phenotypes. Results (1) Our study found no statistical difference between SLE patients and thecontrol groups in the serum level of IL-22BP (P>0.05)(2) For IL-22gene rs1179251, allelic frequencies for A and G were64.2%,35.9%inSLE patients and67.0%,33.0%in controls. There was no significant differencebetween patients and controls (2=2.42, P=0.120). Genotypic frequencies for AA, AGand GG were40.9%,46.5%,12.6%in SLE patients and45.1%,43.7%,11.2%incontrols. We failed to find any significant association between this polymorphism andSLE risk either at dominant or recessive model.For IL-22R1gene rs3795299(C/G), allelic frequencies for C and G were69.2%,30.8%)in SLE patients and70.5%and29.5%in controls with no statistical significance(2<0.001, P=0.971). Genotypic frequencies for GG, GC, and CC were10.0%,42.5%,47.5%in SLE patients and10.0%,42.4%,47.6%in controls. We found no statisticalsignificance difference between SLE cases and controls (P>0.05).(3) IL-22gene rs1179251and IL-22R1gene rs3795299) associated with lupusnephritis (P <0.001)(4) IL-22gene rs1179251(A/G) and IL-22BP gene rs3795299(C/G) might confersusceptibility to SLE. Additionally, it also associated with the clinical fetures oral ulcer,cheek rash and discoid lupus in SLE patients.Conclusions The serum level of IL-22BP has no association with SLE susceptibility;IL-22gene rs1179251and IL-22gene rs3795299R1associated with lupus nephritis andassociated with some major clinical symptoms.