Early Renal Recovery after the First Flare of Pauci-Immune Glomerulonephritis.

INTRODUCTION: Renal involvement is a severe manifestation of antineutrophil cytoplasmic antibody-associated vasculitis. Patients often progress to end-stage renal disease. The potential for renal recovery after the first flare has seldom been studied. Our objectives were to describe the evolution of the estimated glomerular filtration rate (eGFR) and identify factors associated with the change in the eGFR between diagnosis and the follow-up at 3 months (ΔeGFRM0-M3). METHODS: This was a retrospective study over the period 2003-2018 of incident patients in the Nord-Pas-de-Calais (France). The primary outcome was the ΔeGFRM0-M3. RESULTS: One hundred and seventy-seven patients were included. The eGFR at 3 months was significantly higher than at diagnosis (mean ± standard deviation, 40 ± 24 vs. 28 ± 26 mL/min/1.73 m2, p < 0.001), with a ΔeGFRM0-M3 of 12 ± 19 mL/min/1.73 m2. The eGFR at 12 months was higher than at 3 months (44 ± 13 vs. 40 ± 24 mL/min/1.73 m2, p = 0.003). The factors significantly associated with the ΔeGFRM0-M3 in multivariate analysis were the percentage of cellular crescents and neurological involvement. The mean increase in the eGFR was 2.90 ± 0.06 mL/min/1.73 m2 for every 10-point gain in the percentage of cellular crescents. CONCLUSIONS: Early renal recovery after the first flare of pauci-immune glomerulonephritis occurred mainly in the first 3 months of treatment. The percentage of cellular crescents was the main independent predictor of early renal recovery.

Organ Transplantation in Hereditary Fibrinogen A α-Chain Amyloidosis: A Case Series of French Patients.

RATIONALE & OBJECTIVE: Fibrinogen A α-chain amyloidosis (AFib amyloidosis) is a form of amyloidosis resulting from mutations in the fibrinogen A α-chain gene (FGA), causing progressive kidney disease leading to kidney failure. Treatment may include kidney transplantation (KT) or liver-kidney transplantation (LKT), but it is not clear what factors should guide this decision. The aim of this study was to characterize the natural history and long-term outcomes of this disease, with and without organ transplantation, among patients with AFib amyloidosis and various FGA variants. STUDY DESIGN: Case series. SETTING & PARTICIPANTS: 32 patients with AFib amyloidosis diagnosed by genetic testing in France between 1983 and 2014, with a median follow-up of 93 (range, 4-192) months, were included. RESULTS: Median age at diagnosis was 51.5 (range, 12-77) years. Clinical presentation consisted of proteinuria (93%), hypertension (83%), and kidney failure (68%). Manifestations of kidney disease appeared on average at age 57 (range, 36-77) years in patients with the E526V variant, at age 45 (range, 12-59) years in those with the R554L variant (P<0.001), and at age 24.5 (range, 12-31) years in those with frameshift variants (P<0.001). KT was performed in 15 patients and LKT was performed in 4. In KT patients with the E526V variant, recurrence of AFib amyloidosis in the kidney graft was less common than with a non-E526V (R554L or frameshift) variant (22% vs 83%; P=0.03) and led to graft loss less frequently (33% vs 100%). Amyloid recurrence was not observed in patients after LKT. LIMITATIONS: Analyses were based on clinically available historical data. Small number of patients with non-E526V and frameshift variants. CONCLUSIONS: Our study suggests phenotypic variability in the natural history of AFib amyloidosis, depending on the FGA mutation type. KT appears to be a viable option for patients with the most common E526V variant, whereas LKT may be a preferred option for patients with frameshift variants.

Microvascular inflammation and acute tubular necrosis are major histologic features of hantavirus nephropathy.

Hantavirus nephropathy (HVN) is an uncommon etiology of acute renal failure due to hantavirus infection. Pathological features suggestive of HVN historically reported are medullary interstitial hemorrhages in a background of acute interstitial nephritis (AIN). However, interstitial hemorrhages may be lacking because of medullary sampling error. This emphasizes that other pathological criteria may be of interest. We performed a retrospective clinicopathological study of 17 serologically proven HVN cases with renal biopsy from 2 nephrology centers in northern France. Histologic analysis was completed by immunohistochemistry with anti-CD3, anti-CD68, and anti-CD34 antibodies. Three control groups were not related to hantavirus infection: acute tubular necrosis (ATN) of ischemic or toxic etiology and AIN were used for comparison. Renal biopsy analysis showed that almost all HVN cases with medullary sampling (9/10) displayed interstitial hemorrhages, whereas focal hemorrhages were detected in 2 of the 7 "cortex-only" specimens. ATN was common, as it was present in 15 (88.2%) of 17 HVN cases. By contrast, interstitial inflammation was scarce with no inflammation or only slight inflammation, representing 15 (88.2%) of 17 cases. Moreover, HVN showed inflammation of renal microvessels with cortical peritubular capillaritis and medullary vasa recta inflammation; peritubular capillaritis was significantly higher in HVN after comparison with ischemic and toxic ATN controls (P = .0001 and P = .003, respectively), but not with AIN controls. Immunohistochemical studies highlighted the involvement of T cells and macrophages in renal microvascular inflammation related to HVN. Our study showed that microvascular inflammation, especially cortical peritubular capillaritis, and ATN are important histologic features of HVN.