Rituximab or Cyclosporine in the Treatment of Membranous Nephropathy.

BACKGROUND: B-cell anomalies play a role in the pathogenesis of membranous nephropathy. B-cell depletion with rituximab may therefore be noninferior to treatment with cyclosporine for inducing and maintaining a complete or partial remission of proteinuria in patients with this condition. METHODS: We randomly assigned patients who had membranous nephropathy, proteinuria of at least 5 g per 24 hours, and a quantified creatinine clearance of at least 40 ml per minute per 1.73 m2 of body-surface area and had been receiving angiotensin-system blockade for at least 3 months to receive intravenous rituximab (two infusions, 1000 mg each, administered 14 days apart; repeated at 6 months in case of partial response) or oral cyclosporine (starting at a dose of 3.5 mg per kilogram of body weight per day for 12 months). Patients were followed for 24 months. The primary outcome was a composite of complete or partial remission of proteinuria at 24 months. Laboratory variables and safety were also assessed. RESULTS: A total of 130 patients underwent randomization. At 12 months, 39 of 65 patients (60%) in the rituximab group and 34 of 65 (52%) in the cyclosporine group had a complete or partial remission (risk difference, 8 percentage points; 95% confidence interval [CI], -9 to 25; P = 0.004 for noninferiority). At 24 months, 39 patients (60%) in the rituximab group and 13 (20%) in the cyclosporine group had a complete or partial remission (risk difference, 40 percentage points; 95% CI, 25 to 55; P<0.001 for both noninferiority and superiority). Among patients in remission who tested positive for anti-phospholipase A2 receptor (PLA2R) antibodies, the decline in autoantibodies to anti-PLA2R was faster and of greater magnitude and duration in the rituximab group than in the cyclosporine group. Serious adverse events occurred in 11 patients (17%) in the rituximab group and in 20 (31%) in the cyclosporine group (P = 0.06). CONCLUSIONS: Rituximab was noninferior to cyclosporine in inducing complete or partial remission of proteinuria at 12 months and was superior in maintaining proteinuria remission up to 24 months. (Funded by Genentech and the Fulk Family Foundation; MENTOR ClinicalTrials.gov number, NCT01180036.).

Characteristics and Outcomes of Patients with Anti-Glomerular Basement Membrane Antibody Disease and Anti-Neutrophil Cytoplasmic Antibodies.

BACKGROUND: It is unclear whether patients with Anti-Glomerular Basement Membrane (GBM) disease and Anti-Neutrophil Cytoplasmic Antibodies (ANCA), so called "Double-Positive" (DP), have a different clinical presentation and outcome compared to patients with anti-GBM antibody disease alone. This study describes the clinical and histologic characteristics as well as the patient and renal outcomes of DP patients at the University of Washington compared to patients with anti-GBM antibody disease alone. METHODS: Adults admitted to the University of Washington and Harborview Medical Centers from 2000 to 2016 who had a kidney biopsy showing anti-GBM disease characterized by crescentic glomerulonephritis with strong linear staining of glomerular basement membranes for IgG by immunofluorescence were included. Subjects were classified into anti-GBM or DP based on serologic testing. Information on demographics, clinical presentation, biopsy findings, initial treatment, and rates of relapse and patient and renal survival were collected. Continuous and categorical variables were analyzed using the Mann-Whitney U and Fisher's exact tests, respectively. RESULTS: There were 6 anti-GBM and 7 DP patients. Two patients were lost to follow-up after one year. There was no significant difference in clinical presentation or outcomes between the two groups. Two DP patients had greater than 50% global glomerulosclerosis. All the subjects developed ESRD. Two DP patients had a relapse while off immunosuppression. Two patients in each group died within 5 years of diagnosis. CONCLUSION: Two DP patients in our cohort had a relapse within 5 years of diagnosis. Multicenter studies are needed to determine whether DP patients have a higher relapse rate and need prolonged immunosuppression.

Plasma C4d+ Endothelial Microvesicles Increase in Acute Antibody-Mediated Rejection.

BACKGROUND: Antibody-mediated rejection (AMR) is a major cause of kidney allograft loss. Currently, AMR diagnosis relies on biopsy which is an invasive procedure. A noninvasive biomarker of acute AMR could lead to early diagnosis and treatment of this condition and improve allograft outcome. Microvesicles are membrane-bound vesicles released from the cell surface after injury. We hypothesized that because AMR is associated with allograft endothelial injury and C4d deposition, plasma microvesicles positive for endothelial (CD144) marker and C4d are increased in this condition. METHODS: We studied microvesicle concentration in the plasma of 95 kidney transplant patients with allograft dysfunction and compared with 23 healthy volunteers. Biopsy diagnosis and scoring was performed using Banff classification. RESULTS: In the 28 subjects with AMR, the density of C4d+/CD144+ microvesicles was on average 11-fold (P = 0.002) higher than transplant recipients with no AMR and 24-fold (P = 0.008) than healthy volunteers. Densities of C4d+ and C4d+/annexin V+ (C4d+/AVB+) microvesicles were also increased in AMR patients compared with no AMR and healthy subjects. C4d+/AVB+ microvesicles correlated with AMR biopsy severity. Nine patients with acute AMR that received treatment showed a mean 72% decrease (P = 0.01) in C4d+/CD144+ microvesicle concentration compared with pretreatment values. CONCLUSIONS: Quantification of plasma C4d+ microvesicles provides information about presence of AMR, its severity and response to treatment in transplant patients.

Urinary Podocyte Loss Is Increased in Patients with Fabry Disease and Correlates with Clinical Severity of Fabry Nephropathy.

Chronic kidney disease is a major complication of Fabry disease. Podocytes accumulate globotriaosylceramide inclusions more than other kidney cell types in Fabry patients. Podocyte injury occurs early in age, and is progressive. Since injured podocytes detach into the urine (podocyturia), we hypothesized that podocyturia would increase in Fabry patients and correlate with clinical severity of Fabry nephropathy. Urine specimens from 39 Fabry patients and 24 healthy subjects were evaluated for podocyturia. Most of the Fabry patients and many healthy subjects had podocyturia. The number of podocytes per gram of urine creatinine (UPodo/g Cr) was 3.6 fold greater in Fabry patients (3,741 ± 2796; p = 0.001) than healthy subjects (1,040 ± 972). Fabry patients with normoalbuminuria and normoproteinuria had over 2-fold greater UPodo/g Cr than healthy subjects (p = 0.048). UPodo/gCr was inversely related to eGFR in male patients (r = -0.69, p = 0.003). UPodo/gCr was directly related to urine protein creatinine ratio (r = 0.33; p = 0.04) in all Fabry patients. These studies confirm increased podocyturia in Fabry disease, even when proteinuria and albuminuria are absent. Podocyturia correlates with clinical severity of Fabry nephropathy, and potentially may be of prognostic value.

Higher levels of leflunomide are associated with hemolysis and are not superior to lower levels for BK virus clearance in renal transplant patients.

BACKGROUND AND OBJECTIVES: Leflunomide use in renal transplantation has been increasing. Outcome correlation and safety data are still to be refined. The goals of this study were to report one center's experience with leflunomide, specifically the correlation of leflunomide levels with the outcomes of BK nephropathy and the observed toxic effects during the treatment with leflunomide. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Leflunomide was used in 21 patients with BK nephropathy. These patients were divided into two groups on the basis of the leflunomide levels achieved: Low-level group (<40 microg/ml) and high-level group (>40 microg/ml). RESULTS: During 13 mo of follow-up, there was no difference in the rate of serum BK viral clearance between the groups. There were three graft losses in the low-level group and one in the high-level group; however, creatinine levels were higher at the time of starting leflunomide in the low-level group. Leflunomide was also used in six patients with chronic allograft injury. No graft loss was observed during the follow-up period of 16 mo. Treatment with leflunomide seemed to be associated with a new toxicity, hemolysis, seen in four of the 27 patients so treated. Patients with hemolysis had high leflunomide levels (81.4 +/- 14 microg/ml) and worsening allograft function. Two patients had histologic evidence of thrombotic microangiopathy, which led to graft loss in one patient. CONCLUSIONS: The clinical correlation between leflunomide levels and outcomes needs to be further refined. This study described a possible association of leflunomide with thrombotic microangiopathy, especially at higher levels.