Association of Breg cells and Treg cells with the clinical effects of Infliximab in the treatment of Chinese patients with Crohn's disease

Abstract

Objective: To explore the associations of regulatory B cells (Breg cells) and regulatory T cells (Treg cells) with the clinical effect of Infliximab in the treatment of Chinese patients with Crohn's disease (CD). Methods: From January 2017 to June 2019, a total of 32 CD patients at active stage and 33 age and gender-matched healthy controls were collected from the Second Affiliated Hospital of Wenzhou Medical University in this study. Approximate 5 ml of peripheral fasting venous blood was obtained from every subject. Peripheral blood mononuclear cells (PBMCs) were isolated from whole blood. Then multi-color flow cytometry was applied to determine the proportion of Breg (CD3-CD19+IL-10+B cells) in B cells and the proportion of Treg (CD4+CD25+Foxp3+T cells) in CD4+T cells. Infliximab (5 mg/kg) was given intravenously at week 0, 2 and 6 to induce CD remission, and then maintained with the same dose of Infliximab every 8 weeks. And the proportions of Breg and Treg were examined at week 14 of Infliximab treatment, then compared with those of week 0. Simultaneously, C-reactive protein (CRP), leucocyte count, platelet count, erythrocyte sedimentation rate were detected in CD patients to assess the clinical effect at week 0 and 14 of Infliximab treatment. Results: Before infliximab treatment, compared with healthy controls, the proportion of Breg in B cells was significantly increased [(3.15±1.17)% vs (2.64±0.38)%, P=0.024)], and the proportion of Treg in CD4+T cells was significantly decreased [(2.15±0.49)% vs (4.25±0.41)%, P<0.001] in CD patients. And the proportion of Breg was positively related with the proportion of Treg in CD patients either at week 0 or week 14 of Infliximab treatment (r=0.628, P<0.001; r=0.749, P<0.001). At week 14 of Infliximab treatment, according to symptoms, Crohn's disease activity index (CDAI) and endoscopic mucosal healing, CD patients were classified as remission group (CDAI<150 and endoscopic mucosal healing, R group) and non-remission group (CDAI≥150 or mucosal non-healing group, N group). Compared with CD patients at week 0 of Infliximab treatment, both the proportion of Breg and Treg were significantly enhanced [(5.89±2.60)% vs (3.19±1.27)%, P<0.001; (4.59±0.72)% vs (2.08±0.47)%, P<0.001], whereas CDAI and CRP was significantly reduced [CDAI: (63.19±14.69) vs (195.62±58.13), P<0.001; CRP: (3.65±2.23) mg/L vs (29.80±30.06) mg/L, P<0.001] in R group at week 14 of Infliximab treatment. The proportions of Breg and Treg were negatively related with the CRP (r=-0.279, P=0.026; r=-0.406, P=0.001) and CDAI (r=-0.409, P=0.001; r=-0.708, P<0.001) in CD patients at week 0 and 14 of Infliximab treatment. At week 14 of Infliximab treatment, ROC curve analysis showed that the predictive value of "Breg+Treg" for the effect of Infliximab was higher than the other parameters (area under ROC: 0.782, cutoff value: 0.895 5, P=0.034). Conclusions: Breg cells and Treg cells are not only significantly correlated with CD disease activity, but the combined detection of the two types of immune cells has higher clinical value for predicting the effect of Infliximab in CD patients at active stage.