A preliminary study on the change and significance of CD35 expression on the neutrophils of per-ipheral blood from patient with myeloperoxidase-antineutrophil cytoplasmic antibody associated vas culitis / 中华风湿病学杂志

ABSTRACT

Objective To investigate the change of CD35 expression on neutrophils in the peripheral blood and the relationship between the change and disease activity in patient with myeloperoxidase antineutrophil cytoplasmic antibody-associated vasculitis (MPO-AAV).Methods Forty untreated patients with active MPO-AAV(patient group)and forty healthy volunteers (control group) were enrolled into this study,and Bermingham vasculitis activity score (BVAS) for every patient was recorded.Flow cytometry (FCM) was employed to detect the CD35 and MPO expression on the neurtrophil,and enzyme linked immunosorbent assay (ELISA) was taken to test the levels of autoantibody against MPO-Antineutrophil cytoplasmic antibody (MPO-ANCA),fragment a from the activated complement factor B (Ba) and MPO in peripheral blood from both group.All test results were compared between the 2 groups by t test,Non-parametric test,Spearman correlation analysis.In addition,the relations among the laboratory results and the relationship between BVAS and the laboratory results were analyzed respectively.Results Compared with the control group,the expression level,which was represented as mean flourscence indensity (MFI),of CD35 and neutrophil membrane MPO on peripheral blood neutrophils was significantly increased [(2 014±968) vs (1 454±511),t=3.024,P=0.002 and (709±244) vs (580±158),t=2.806,P＜0.01,respectively],and the MPO expression level in neutrophils was significantly lower [(1 525±1 033) vs (3 196±2 126),t=-4.468,P＜0.01].Ba and MPO levels in serum of the patient group was significantly higher than that in the control group [37.89(26.17,63.14) μg/L vs 27.99(18.64,46.52) μg/L,Z=-2.521,P=0.012 and 546.16(450.55,729.96) U/L vs 327.93(279.02,365.10) U/L,Z=7.121,P＜0.01,respectively].In patient group,the expression level of CD35 had a significant positive relationship with peripheral blood neutrophil count (r=0.573,P＜0.01),serum Ba (r=0.433,P=0.005) and BVAS (r=0.368,P=0.020),respectively,whereas,there was a negative correlation between the MPO expressed on the neutrophils and that in the neutrophils (r=-0.458,P=0.003),and a positive relationship between MPO-ANCA and BVAS (r=0.351,P=0.026).Conclusion There is significant increased expression of CD35 on the neutrophil of patient with MPO-AAV,which might protect the neutrophil from destruction by the activated complement alternative pathway,and more neutrophils consequently contribute to the MPO-AAV pathogenesis.Inhibition of CD35 expression might become one of the potential new pathways for the treatment of MPO-AAV.