Abstract:

ABSTRACT  Objective: To investigate the clinical and renal pathological characteristics of patients with ANCA associated vasculitis (AAV), and to explore the clinical feature of patients with complement deposition in renal pathology.  Methodology: From Jan, 2006 to Jan, 2012, ninety six patients diagnosed as AAV were collected and their clinical and pathological data were retrospectively analyzed.  Results: They were 53 males and 43 females (ratio 1.2:1) with an age 58.4±16.6 (ranged from 15~83) years old, and older than 65 years old in 42.3%. The median duration of disease was 57 days from 30 to 115 days. Their clinical manifestations were diverse and complicated. The most commonly involved organs were kidney in 84 cases (87.5%),and lung in 61 (63.5%). In renal pathology: 51 of 96 patients were performed renal biopsy. The histological examinations showed crescent formation in 86.3%, fibrinoid necrosis of glomeruli in 54.9%, global sclerosis in 64.7% and tubular interstitial fibrosis in 62.7%. According to the degree of glomerular pathological change assessed by light microscopy, 44 cases with pathological diagnosis of AAV were classified as four general categories: Focal (15), Crescentic (7), Mixed (12) and Sclerotic (10 cases). The patients of focal subtype presented with significantly lower serum creatinine than that the other three subtypes (Pd2<0.01、Pb1<0.05、and Pc1<0.05). After the immunosuppressive therapy, the patients of crescentic subtype had a bigger decrease of serum creatine, compared with those who presented with other subtypes (Pa2<0.01、Pb2<0.01、Pc1<0.05). ESRD developed in one of 15 patients with focal, 2 of 7 patients with crescentic, 2 of 12 patients with mixed, and 3 of 10 patients with sclerotic subtype vasculitis during the follow-up period. The patients with complement deposition (n=22) had a higher level of erythrocyte sedimentation rate (ESR) (P=0.023), higher initial serum creatinine (P=0.021) and serum ureanitrogen(P=0.012), lower eGFR (P=0.033) and serum C3 (P=0.005) at presentation, compared with those without complement deposition (n=17). In renal histology, the patients with complement deposition had a notably higher percentage in fibrous crescents (P=0.009) and global sclerosis (P=0.028) but a lower percentage of normal glomeruli (P=0.016).  Conclusion: The most common involved organs were kidney and lung in our patients. The patients with focal presented with relatively preserved renal function; with crescentic responded well to treatment; and with sclerotic subtype had the highest percentage of developing ESRD and a poor prognosis. The complement deposition in glomeruli was not rare in patients with ANCA-associated glomerulonephritis, which was associated with more severe renal injury.

Key words: ANCA, vasculitis, clinical, pathology