Myeloperoxidase–anti-neutrophil cytoplasmic antibody positivity and disease characteristics, treatment, and prognosis in eosinophilic granulomatosis with polyangiitis

Objectives: To evaluate the relationship between anti-neutrophil cytoplasmic antibody (ANCA) positivity and the disease characteristics, treatment, and prognosis of eosinophilic granulomatosis with polyangiitis (EGPA). Method: We conducted a retrospective cohort study of patients with new-onset or severely relapsing ANCA-associated vasculitis, enrolled in the J-CANVAS registry. The clinical characteristics at baseline, treatments, and prognoses of ANCA-positive and ANCA-negative patients were assessed. Results: Three patients with positive proteinase-3 ANCA were excluded, and 166 patients with EGPA (new onset, 159; severe relapse, seven) were included. Sixty-two patients were myeloperoxidase (MPO)-ANCA positive and 104 patients were negative. No differences in age or sex were observed between the two groups. The MPO-ANCA-positive group had significantly more frequent mucous membrane and eye involvement, more frequent renal involvement, higher total Birmingham Vasculitis Activity Score, higher neutrophil counts, and higher C-reactive protein levels at baseline. Although rituximab was administered more frequently in the MPO-ANCA-positive group, no other differences in treatment were found. Both groups had comparable estimated glomerular filtration rates and prednisolone doses at weeks 24 and 48. The incidence rates of severe relapse, minor relapse, and serious infectious diseases were comparable. Cox regression analysis revealed that MPO-ANCA positivity was not a significant factor in serious infectious diseases and relapse. Conclusion: Patients with MPO-ANCA-positive EGPA demonstrated different baseline clinical characteristics from MPO-ANCA-negative patients. However, subsequent relapses and serious infectious diseases were comparable.

研究目的：评估抗中性粒细胞胞浆抗体（anti-neutrophil cytoplasmic antibody, ANCA）阳性与嗜酸性肉芽肿性多血管炎（eosinophilic granulomatosis with polyangiitis, EGPA）的疾病特征、治疗方案及预后之间的关联。
研究方法：本研究针对纳入J-CANVAS登记库的新发或重度复发ANCA相关性血管炎患者开展回顾性队列研究，对比分析ANCA阳性与ANCA阴性患者的基线临床特征、治疗方案及预后情况。
研究结果：本研究排除3例蛋白酶3（proteinase-3, PR3）ANCA阳性患者，最终纳入166例EGPA患者（其中新发159例，重度复发7例）。62例患者为髓过氧化物酶（myeloperoxidase, MPO）-ANCA阳性，104例为阴性。两组患者的年龄与性别分布无显著差异。MPO-ANCA阳性组患者基线时黏膜与眼部受累比例更高，肾脏受累比例更高，伯明翰血管炎活动量表总评分更高，中性粒细胞计数及C反应蛋白水平也显著升高。尽管利妥昔单抗在MPO-ANCA阳性组中的使用频率更高，但其余治疗方案无组间差异。在第24周与第48周时，两组患者的估算肾小球滤过率及泼尼松剂量均无显著差异。重度复发、轻度复发及严重感染的发生率组间无统计学差异。Cox回归分析显示，MPO-ANCA阳性并非严重感染与疾病复发的独立影响因素。
研究结论：MPO-ANCA阳性EGPA患者的基线临床特征与MPO-ANCA阴性患者存在显著差异，但后续疾病复发及严重感染的发生风险并无显著不同。