Analysis of clinical, pathological features and prognosis of microscopic polyangiitis / 中国医师进修杂志

ABSTRACT

Objectives:To analyze the clinical features of microscopic polyangiitis (MPA), and observe the clinical outcomes of different pathological types.Methods:The clinical data of 61 patients with MPA in Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine from January 2010 to December 2019 were analyzed retrospectively. According to age, the patients were divided into ≥ 60 years old group (46 cases) and<60 years old group (15 cases). According to the initial serum creatinine, the patients were divided into ≥ 500 μmol/L group (18 cases) and<500 μmol/L group (43 cases). The basic data and laboratory examination results of the patients were recorded, and the disease activity was evaluated by Birmingham systemic vasculitis activity score (BVAS). Twenty-three patients with complete pathological data were pathologically classified and followed up to assess their clinical outcomes. The progression to end-stage renal disease (ESRD) or death was defined as the endpoint.Results:Ferritin in ≥60 years old group was significantly higher than that in<60 years old group 452 (289, 792) μg/L vs. 210 (119, 451) μg/L, and there was statistical difference ( P<0.05). The fever rate, hemoglobin and platelets in creatinine ≥ 500 μmol/L group were significantly lower than those in creatinine<500 μmol/L group 3/18 vs. 48.8% (21/43), 77.5 (62.8, 86.0) g/L vs. 85.0 (77.0, 104.0) g/L and 192 (147, 234) × 10 9/L vs. 257 (208, 365) × 10 9/L, the gastrointestinal involvement and BVAS in creatinine ≥ 500 μmol/L group were significantly higher than those in creatinine<500 μmol/L group 16/18 vs. 25.6% (11/43) and 20.0 (16.0, 23.3) scores vs. 15.0 (12.0, 19.0) scores, and there were statistical differences ( P<0.05 or<0.01). Pearson correlation analysis result showed that BVAS was positively correlated with creatinine ( r = 0.42, P<0.01), negatively correlated with hemoglobin ( r = -0.42, P<0.01), but it had no correlation with erythrocyte sedimentation rate and platelets ( r = 0.05 and 0.04, P>0.05). Among the 23 patients with completed the clinical outcome statistics, endpoint events occurred in 5 of 6 patients with crescent renal pathology, and in 7 of 12 patients with severe renal interstitial injury. Kaplan-Meier survival curve analysis result showed that the average survival time in ESRD MPA patients was significantly shorter than that in non ESRD MPA patients (41.2 months vs. 63.5 months), and there was statistical difference ( χ2 = 0.48, P = 0.028). Conclusions:The clinical manifestations of elderly MPA patients are similar to those of young MPA patients. Creatinine≥500 μmol/L or anemia at initial onset indicate higher vasculitis activity in MPA. The prognosis of MPA patients with pathological manifestations of crescent or severe interstitial injury is poor, and the survival rate of ESRD is lower than that of non ESRD patients.