Clinical Features and Prognosis in ANCA Associated Vasculitis Patients with Acute Kidney Injury

Background: Renal involvement in patients with anti-neutrophil cytoplasmic antibody (ANCA) associated vasculitis (AAV) often presents as acute kidney injury (AKI), which is closely related to the prognosis of critically ill patients. Nevertheless, there are few researches on the subgroup of AVV patients with AKI. The study aimed to explore clinical features and prognosis in AAV patients with AKI. Methods: A retrospective analysis of AAV patients was conducted. The enrolled patients were grouped according to whether AKI on admission occurred or not. Demographic, clinical data and follow-up records were gathered from medical histories. Survival rates of AAV patients with AKI and risk factors of all AAV patients were studied. Results: (1) In the AKI group, the levels of hemoglobin, evaluated glomerular filtration rate (eGFR), serum albumin and complement 3 were significantly lower (P < 0.05); the proportions of microscopic polyangiitis (MPA) and levels of serum creatinine (SCr) on admission, red blood cell (RBC) counts in urine, 24-hour urine protein excretion (UPE) and Birmingham Vasculitis Activity Score (BVAS) were significantly higher (P < 0.05). There was a significantly lower incidence of otorhinolaryngologic involvement in the AKI group (P < 0.05). (2) There were significantly lower survival rates and renal survival rates in the AKI group (P < 0.05). (3) Higher creatinine and AKI were risk factors for poor prognosis in AAV patients. Conclusion: AAV patients with AKI have more severe kidney damage, higher disease activity and worse prognosis. More attention should be to AAV with AKI for both remission induction and infection