Prognostic factors in renal and patient survival in anti-neutrophil cytoplasmic antibody associated vasculitis

Abstract Background and Aims The most important determinant of renal and patient survival in anti-neutrophil cytoplasmic antibody (ANCA) associated vasculitis (AAV) is early initiation immunosuppressive (IS) therapy. Other factors associated with survival are age and renal function and/or renal involvement at diagnosis. The prognosis is poor in patients with AAV who do not receive IS treatment. The effect of plasma exchange (PE). in patients who underwent plasmapheresis with IS treatment has been questioned in recent studies. Renal histology is a predictor of long-term risk of renal failure in patients with crescentic glomerulonephritis, and prognostic histological scorings have been developed. In this study, we investigated clinical and pathological risk factors that may affect patient and renal survival in patients with AAV. Method Data of 225 AAV patients diagnosed by renal biopsy in the age range of 16-85 years in 30 centers were used which were obtained from the Turkish Society of Nephrology Glomerular Diseases (TSN-GOLD) Working Group database. Patients who did not have regular follow-up for at least 3 months, patients with immunocomplex glomerulonephritis, and patients with rapidly progressive glomerulonephritis who were positive for anti-GBM antibodies were excluded from the study. Patients with negative ANCA (n: 17) and unknown ANCA results (n: 28) were included in the study according to their renal biopsy findings. Results The mean age of the study population was 52,1±15,2 years and 126 (56%) were male. After renal biopsy, 154 patients (85.1%) received only cyclophosphamide and steroid treatment as initial IS treatment, 23 patients (12.6%) also received PE. When the clinical results of the patients were evaluated, end-stage renal disease (ESRD) was detected in 50 (22.2%) patients, while 36 (16%) patients died. When the factors affecting the development of ESRD were evaluated with the logistic regression analysis model, it was shown that the low albumin level of the patients at the time of diagnosis and the percentage of interstitial fibrosis (IF) >25% in renal pathology were more effective for the development of ESRD (p = 0.02, p = 0.01). When the factors affecting the survival of the patients were evaluated with the logistic regression analysis model, we demonstrated that there was no significant effect of PE and IF >25% in renal pathology; age [HR = 1.035 (1.001-1.069)] and patients with lower albumin value [HR = 0.488 (0.241-0.987)] were found to be more risky in terms of death (p = 0.041, p = 0.046) (Table 1). Conclusion In this study, the serum albumin level of the patient at the time of biopsy was determinant in renal and patient survival in AAV. IF >25% in renal pathology was effective in renal survival, but it was not found to be effective in patient survival. Plasma exchange did not provide additional benefit to standard treatment. Prospective and multicenter studies with a larger number of patients are needed to confirm our findings.