Clinical And Pathological Features Of Renal Damage In 19 Cases Of ANCA-Associated Systemic Vasculitis

Objective: To retrospectively analyze the clinical and renal pathological features of 19 patients with renal damage of antineutrophil cytoplasmic antibody(ANCA)-associated systemic vasculitis(AASV).Methods: Collect the clinical datas of 19 hospitalized patients,who were firstly diagnosed with AASV accompanying renal damage,and underwent renal biopsy in the fourth Hospital of Hebei Medical University from June 2013 to November 2018.Analyze retrospectively the clinicopathological changes of kidney,laboratory results,organ involvement,and their relationship with prognosis.Results: The average age of onset was(61.58±16.82)years old in 19 patients with AASV,the ratio of male to female was 1.37:1,17 cases of MPA and 2 cases of GPA.The initial symptoms of 19 patients were mostly non-specific.Serum ANCA showed that 17 cases were p-/MPO-ANCA positive,2 cases were c-/PR3-ANCA positive,94.12% of MPA patients were MPO-ANCA positive;Two patients with GPA,one recognized MPO,another recognized PR3.The damage of ANCA to extrarenal organs was as follows: lung involvement(52.63%),ear-nose involvement(31.58%),eye involvement(10.53%),skin involvement(5.26%).The main clinical manifestation of AASV with renal damage was acute nephritis syndrome(78.95%).Characteristics of renal pathology: our cohort found 8 cases of focal type,2 cases of crescentic type,9 cases of mixed type,and 0 cases of sclerotic type.94.74% of patients injured glomerulus,89.47% of them had crescent formation,36.84% had fibrin-like necrosis of capillary loop,57.89% had spherical sclerosis;Renal interstitial lymphatic monocyte infiltration,IF and TA accounted for 94.74%,73.68%,68.42%,respectively.63.16% of the patients were completely negative in immunofluorescence.Correlation analysis showed that,the proportion of total crescent had a significant negative correlation with baseline eGFR level;There was weak negative correlation between proportion of cellular crescent and baseline eGFR level.In this study,3 people died,all of them succumb to infection,and 5 people initiated maintenance hemodialysis.According to the end-point events,it was found that AASV patients with lung damage,low serum albumin and high renal interstitial lymphatic monocyte infiltration were more likely to die or need renal replacement therapy.Logistic regression model showed that lung involvement was an independent risk factor for prognosis.Conclusion: Most of the patients with AASV in our group were MPO-ANCA positive,MPA was more common,and patients were mostly over 60 years old.The kidney and lung were the most frequently affected organs.When AASV was accompanied by renal damage,patients present with acute nephritis syndrome,renal function deteriorated rapidly,some of them need emergency dialysis.Renal pathology was characterized by oligoimmunity,necrosis,crescentic glomerulonephritis,with involvement of tubules and interstitial.Patients with AASV had an increased risk of death or renal replacement therapy when combined with lung damage.