The Expression Of P2X₇Receptors On PBMC In Patients With Primary Sj（o|¨）Gren’s Syndrome And Its Correlation With Anxiety And Depression

Objective: To study the surface expression of P2X₇receptors （P2X₇R） on peripheral bloodmononuclear cells （PBMC） in patients with primary sj gren’s syndrome （pSS） and its correlationwith anxiety and/or depression.Methods: Hamilton Anxiety and Depression Scale （HAMA and HAMD） were used to assess31patients with primary sj gren’s syndrome. PBMC were isolated and harvested by Ficoll-Hypaque density gradient centrifugation. The expression of P2X₇receptors on the surface ofCD14+PBMC and CD14-PBMC with or without ATP stimulation was measured by flowcytometry （FCM）.The levels of interleukin （IL）-1β and IL-6in blood plasma and supernatants afterATP stimulation were measured by enzyme-linked immunosorbent assay （ELISA）.19patientswith rheumatoid arthritis,18patients only with anxiety and/or depression and20cases of healthypersons were as controls.Results: The expression of P2X₇R can be detected in all subjects. Compared to no ATPstimulation, a significant up-regulation of P2X₇R expression on CD14+PBMC （monocytes） wasobserved after ATP stimulation only in pSS group （（5.63±2.48）%vs.（3.98±1.68）%）（t=3.647,P=0.001）; while on CD14-PBMC（mostly lymphocytes） it had a significant up-regulation in bothpSS group （（16.92±9.25）%vs.（10.06±4.35）%）（t=4.908, P<0.001） and anxiety/depression group（（12.68±8.15）%vs.（8.07±5.05）%）（t=3.412, P=0.003）. After ATP stimulation, P2X₇Rexpression on CD14+PBMC in pSS group was significantly higher than RA group （（5.63±2.48）%vs.（4.15±2.20）%）（P=0.044）, anxiety/depression group （（5.63±2.48）%vs.（3.35±1.80）%）（P=0.004） and healthy controls （（5.63±2.48）%vs.（3.25±2.05）%）（P=0.002）, however P2X₇Rexpression on CD14-PBMC in pSS group was significantly higher than RA group （（16.92±9.25）%vs.（11.40±8.71）%）（P=0.039）and healthy controls （（16.92±9.25）%vs.（6.51±3.98）%）（P<0.001），but had no statistics significance with anxiety/depression group （（16.92±9.25）%vs.（12.68±8.15）%）（P=0.126）. Meanwhile, in pSS group the supernatants levels of IL-1β weresignificantly higher than RA group （（18.39±13.99）%vs.（9.23±6.25）%）（Z=-2.560, P=0.010）,anxiety/depression group （（18.39±13.99）%vs.（9.44±5.56）%）（Z=-2.109, P=0.035） and healthycontrols （（18.39±13.99）%vs.（9.93±6.77）%）（Z=-2.244, P=0.025） and were significantly positively correlated to P2X₇R expression on CD14+PBMC （r=0.447, P=0.025）. The supernatantslevels of IL-6after ATP stimulation were significantly higher than the blood plasma without ATPstimulation in all groups （Z=-6.793, P<0.001）. There were45.2%（14/31） patients with anxiety and32.3%（10/31） with depression in pSS group. No matter whether there was ATP stimulus or not,P2X₇R expression on CD14-PBMC in the pSS patients with anxiety and depression wassignificantly higher than without anxiety or depression （PATP=0.003; PNOATP=0.009）. Theexpression of P2X₇R on CD14-PBMC was significantly positively correlated to the scores ofanxiety （r=0.344, P=0.030） and depression （r=0.319, P=0.045） after ATP stimulation. While therewere no significant correlations between P2X₇R expression on PBMC, IL-6, ESR, CRP andimmunoglobulins in pSS group.Conclusion: The surface expression of P2X₇R on PBMC in patients with pSS wassignificantly higher than controls, and it may have correlation to pSS patients with anxiety and/ordepression. It indicated that P2X₇R may contribute to the complex pathogenesis of pSS andinvolve in the mechanism of those patients with anxiety and/or depression by regulating pro-inflammatory cytokines, especially IL-1β.