The Clinical Significance And Expression Of Peripheral Blood Mononuclear Cell Surface Of The P2X7Purinergic Receptor In Patients With New-Oneset Systemic Lupus Erythematosus

Objective analyze the expression of the P2X7R on different lymphocyte subsets andits correlations with inflammatory cytokines in order to investigate their clinicalsignificance in patients with SLE.Methods The study was performed on29patients with SLE (27females and2males,age range18～57yrs, mean age33.83±10.77yrs) who met at least4of11revisedclassified criteria of the American College of Rheumatology (ACR) in1997and28ex-and age-matched healthy controls without autoimmune disease (26females and2males,age range18～59yrs, mean age28.64±8.88yrs). They all didn’t havebacteria,viruses,and tubercuosis infection in the near two weeks. SLE disease activitywas assessed by the SLE disease activity index (SLEDAI), and29patients had the score9~25(an average of13.96±55.55). All subjects received informed consent in this study.According to different clinical features, SLE patients were divided into differentpositive and negative groups：fever group(≥38.5℃), arthritis group(≥2peripheraljoint pain), rsah group(with cheek erythema), anti-beta2glycoprotein Ⅰantibody-positive group, Raynaud’s phenomenon group, lupus nephretisgroup(proteinuia＞3+or24-hour urine protein＞0.5g), neuropsychiatric lupus(NPSLE) group and all of the negative groups, The peripheral blood mononuclear cell（PBMC） were purified using Ficoll density gradient. PBMC layer was collected, anddivided into5tubes. The first one was set as blank. Anti-P2X7R-FITC (9μL), anti-CD19-PE(2μL), and anti-CD4-APC(2μL) were added another three tubes,respectively. P2X7R-FITC (9μL)，anti-anti-CD19-PE(2μL) and anti-CD4-APC(2μL)were added into the fifth tube.After incubatting the samples with antibodies for30minat4°C in dark. The cells were washed with PBS solution (2mL) twice. Resuspendedlabeled cells were collected and analyzed by FACSCalibur flow cytometer(FACSealibur system,BD).Serum were stored at-80℃. IL-6、TNF-α、IL-1βwas detected with ELISA.winmdi software analysis P2X7R expression level differences between29patients withSLE and28healthy volunteer.Compare the P2X7R expression levels of differentclinical characteristics in SLE patients and analysis the correlation of P2X7R andIL-6,TNF-α,IL-1β.Result SLE patients had significantly higher expression of P2X7R on lymphocytes,CD4+, CD19+cell surface (lymphocytes:1.85(5.75)vs1.19(0.74), p=0.082; CD4+cells:2.21(3.55) vs0.89(1.15) p=0.015; CD19+cells:11.53(20.01) vs6.66(6.27), p=0.037)compared to controls; The positive correlation was found between P2X7R expression inPBMC and the serum IL-6,TNF-α,IL-1βlevel in control groups; In patients, theexpression on PBMC was found positively correlated with the IL-6（r=0.449，p=0.015）；The patients with arthritis showed significantly higher expression of P2X7Ron lymphocytes(p=0.006) compared to patiens without arthritis;.The expression ofP2X7R on lymphocytes and CD19+cell was significantly positively correlated with theSLEDAI score; positive correlation with anti-β2GP1in lymphocytes was also found;Serum IL-6level was positively correlated with urinary protein in SLE；positivecorrelation between IL-6, IL-1βwith SLEDAI was also found.The serum of SLEpatients had significantly higher level of IL-6,TNF-α,IL-1βcompared to control;TheNeuropsychiatric lupus (NPSLE) patients had a significantly higher expression ofP2X7R on CD19+cell than nonneuropsychiatric lupus group; Conclusion P2X7R may be involved in pathogenesis of SLE through the release ofinflammatory cytokines, and may contribute in arthritis, lupus nephritis and NPSLEactivity in SLE patients.