Expression Of TNFR2 On Treg Cells Of Sarcoidosis:Relation To Clinical Features And Inflammation

Background and ObjectiveSarcoidosis is a systemic granulomatous disease of unkown origin that predominantly affects the lung and lymphatic system. Treg cells play a key role in the pathogenesis of various infectious and autoimmune diseases, such as autoimmune arthritis, psoriasis, inflammatory bowel disease (IBD) and systemic lupus erythematosus (SLE). Recently, more and more researches have identified that Treg cells are malfunction on sarcoidosis. TNFα is a very important inflammatory mediator.TNFα exerts its effect by binding to two types of TNF receptors, TNFR1 and TNFR2. And the TNFR can be cleaved from cell surface and form the solube type. It had been reported that the expression of TNFR2 on CD4+ cells and sTNFR2 had some relationships with the process and prognosis of sarcoidosis. But the expression of TNFR2 on Treg cells has not been analyzed. Besides, the relationship between sTNFR2 and sarcoidosis was only fragmentary analyzed. The aim of our study is to assess the expression of TNFR2 on Treg cells and sTNFR2, then to determine the levels with clinical features and inflammation.MethodsWe collected PBMC and BALF samples from the Out-Patient Department of Respiratory at Peking Union Medical College Hospital (PUMCH) and retrieved clinical information from outpatient database. We measured the expression of TNFR2 on Treg cells of PBMC and BALF, and sTNFR2 levels of plasma and BALF. At last, we analyzed the results according to clinical features and inflammation to find the relationship between them.ResultsWe enrolled 64 subjects with 47 females and 17 males, and the average age is 52.08±9.55.13 healthy controls (HCs) were recruited from volunteers, and the average age is 46.38±11.40. We analyzed the expression of TNFR2 on Treg cells of 41 patients and 10 healthy controls. The expression is a little higher than healthy controls, but it is nonsignificant (P=0.0568). After the analysis of subgroups, we found that the patients of phase 0+I, not treated with glucocorticoids, no extrapulmonary lesions, and normal bronchoscopic performance had higher expression. As to the inflammation, the subgroups with high CD4/CD8, hsCRP and ESR had high expression. All the enrolled patients had been measured the sTNFR2. The sarcoidosis group was significantly higher than healthy controls (P<0.01). After the analysis of subgroups, we found that the patients of phase 0+I, not treated with glucocorticoids, no extrapulmonary lesions, and normal bronchoscopic performance had higher level. As to the inflammation, the subgroups with high CD4/CD8, hsCRP and ESR had higher level.ConclusionsThe evaluation of TNFR2 on Treg cells and sTNFR2 has some relationships with clinical features and inflammation.