Determinants of renal and patient outcomes in a Spanish cohort of patients with ANCA-associated vasculitis and renal involvement.

The classification of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) remains controversial. The main objective of this study was to define the respective values of ANCA serotype-based classification, clinicopathological classification, and histopathological classification in predicting patient and renal outcomes in a Spanish cohort of patients with ANCA with specificity for myeloperoxidase, MPO-ANCA, versus ANCA with specificity for proteinase 3, PR3-ANCA. Two hundred and forty-five patients with ANCA-AAV and biopsy-proven renal involvement diagnosed between 2000 and 2104 were recruited in 12 nephrology services. Clinical and histologic data, renal outcomes, and mortality were analyzed. We applied the Chapel Hill Consensus Conference definition with categories for granulomatosis with the polyangiitis (GPA) and microscopic polyangiitis (MPA), the classification based on ANCA specificity, and the histopathological classification proposed in 2010. Eighty-two percent were MPO-ANCA positive and 18.0% PR3-ANCA positive. Altogether, 82.9% had MPA and 17.1% GPA. The median follow-up was 43.2 months (0.1-169.3). Neither ANCA-based serological nor clinical classification was predictive of renal outcomes or patient survival on bivariate or multivariate Cox regression analysis. Histopathological classification was found to predict development of end-stage renal disease (p = 0.005) in Kaplan-Meier analysis. ANCA specificity was more predictive of relapse than clinicopathological classification in multivariate analysis (HR 2.086; 95% CI 1.046-4.158; p = 0.037). In our Spanish cohort, a majority of patients had an MPO-ANCA-AAV. A classification based on ANCA specificity has a higher predictive value for relapse occurrence and could be used for decision-making with respect to induction treatment and maintenance therapies.

Use of mycophenolate in ANCA-associated renal vasculitis: 13 years of experience at a university hospital.

INTRODUCTION: Standard therapy with corticosteroids (CS) and cyclophosphamide (CYC) followed by azathioprine has been shown to improve renal and patient survival in ANCA-associated renal vasculitis (rAAV). Mycophenolate mofetil (MF) has been progressively introduced for the treatment of rAAV in the last years because of its immunosuppressive efficacy combined with a lower toxicity profile. In this study, we retrospectively analyse the results of the introduction of MF for maintenance and induction therapy in rAAV in our institution from 2001 to 2013. RESULTS: We reported 67 patients treated with MF as a maintenance treatment, divided by baseline serum creatinine (>500 µmol/L: Group 1 and <500 µmol/L: Group 2) and treatment schedule. Twenty-nine of the 67 patients were also treated with MF as induction treatment, mostly in Group 2. During the follow-up (2 years after the diagnosis) creatinine levels for serum glomerular filtration rate, ANCA titres, C-reactive protein and percentage of haematuria decreased in all groups. In Group 2, parameters and also relapse rates were similar at 24 months in patients treated with CYC or MF as an induction treatment (Subgroups 2a and 2b, respectively). Median dose of MF in maintenance treatment was 1000 mg daily and prednisone dose was tapered to 10 mg daily from Month 3. After 24 months, 82% of patients remained on MF therapy, 18% had discontinued the treatment, seven of them due to medical indication and two because of gastrointestinal intolerance. The percentage of patients that started renal replacement therapy was irregular in Group 1 depending on the subgroup (25-100%), and 10% in Group 2. Adverse effects, such as neutropenia, infections and neoplasia, were more prevalent in groups treated with CYC. CONCLUSION: In conclusion, in our patients with rAAV, MF demonstrated to be an effective and well-tolerated option for maintenance treatment. As an induction treatment, MF seems to be similar to CYC for patients with moderate renal failure in the diagnosis.