Clinical-pathological Characteristics Of Different Types Of ANCA-associated Glomerulonephritis And Their Correlation With The Prognosis

Part 1 Comparison of clinical-pathological characteristics and prognosis of different types of ANCA-associated glomerulonephritisObjectives: To retrospectively investigate the clinical and histological features and outcomes of ANCA associated glomerulonephritis(AAGN)with different ANCA serotypes.Method: A total of 467 AAGN patients were divided into MPO-AAGN(MPO)and PR3-AAGN(PR3)groups according to ANCA serotype.Clinical and histological features and renal outcomes were compared.Results: In this study,429(91.9%)patients tested positive for MPO-ANCA,and 38(8.1%)for PR3-ANCA.The median age at diagnosis(P = 0.017)and proportion of females(P = 0.003)were higher in the MPO group.Joint(P < 0.001),ENT(P =0.000),skin(P = 0.007)and eye(P = 0.014)involvements were more common in the PR3 group.Compared with that in the PR3-group,a higher proportion of patients in the MPO group had microscopic polyangiitis(P = 0.000),and a lower proportion of exhibited granulomatosis with polyangiitis(P = 0.000).Patients in the MPO group also exhibited lower BVAS scores(P = 0.003)and higher serum albumin levels(P =0.009).Histologically,a lower proportion of MPO patients had crescentic glomerulonephritis(P = 0.028)and acute tubule-interstitial lesion scores(P = 0.007),but a higher proportion of these patients exhibited mixed class glomerulonephritis(P= 0.032)than in the PR3 group.The relapse rate was lower(P = 0.020),and the5-year relapse-free survival rate(P = 0.003)was higher in the MPO group than in the PR3 group.However,the 5-year renal survival rates(P = 0.106)were not significantly different.Conclusions: MPO-ANCA was predominant in Chinese patients with ANCA-associated vasculitis and renal disease.The epidemiological characteristics,extra-renal involvement,histopathological classes and outcomes were different between MPO positive and PR3 positive patients,implying that they might be two different disease entities.Part 2 Podocyte injury in ANCA-associated glomerulonephritis and its correlation with clinical features and prognosisObjective: To retrospectively study the clinicopathological features,therapeutic effect and long-term prognosis of systemic vasculitis patients with podocyte damage.Methodology: 180 cases of AAGN confirmed by renal biopsy were examined podocyte fusion by electron microscopy.They were divided into severe group(the fusion area of the process exceeded 50% of the glomerular capillary loop area)and mild group(the fusion area of the process was less than 50% of the glomerular capillary loop area).Follow-up to end-stage renal failure(ESRD)or to April 2017.The clinical,pathological and prognostic differences between the two groups were compared.Results: There were 73 cases(40.6%)in severe group and 107 cases(59.4%)in mild group.Age of onset(median age 54 years vs 57 years,P < 0.01),lung involvement ratio(61.6% vs 77.6%,P < 0.05),hemoglobin(84.7±16.6 g/L vs 92.1±22.6 g/L,P <0.05),serum albumin(33.0±5.0 g/L vs 35.6±5.2 g/L,P < 0.01),focal type ratio(4.1%vs 26.2%,P < 0.01)in severe group were significantly lower than those in mild group.While the proportion of anemia(98.6% vs 90.7%,P < 0.05),nephrotic syndrome(41.1% vs 5.6%,P < 0.01),urinary protein(3.3±2.4 g/24 h vs 1.8±1.2 g/24 h,P < 0.01),naked hematuria(31.5% vs 16.8%,P < 0.05),mixed type(57.5% vs 37.4%,P < 0.05),renal replacement therapy(38.4% vs 19.6%,P < 0.01)were higher than those of mild group.There were no significant differences i n clinical classification,tubulointerstitial pathology,remission rate and recurrence rate between two groups.The 5-year renal survival rate in severe group was lower than that in mild group(49.2% vs 61.3%,P > 0.05).Conclusions: Nearly half of AAGN had severe podocyte damage.AAGN with severepodocyte lesions had early onset,severe renal damage and poor prognosis.