Clinicopathological characteristics and outcome predictors of anti-glomerular basement membrane glomerulonephritis

Clinical characteristics and outcome of double-seropositive patients with anti-glomerular basement membrane antibodies and anti-neutrophil cytoplasmic antibodies

OBJECTIVE

To explore the clinical characteristics of double-seropositive patients (DPPs) with anti-glomerular basement membrane (Anti-GBM) antibodies and anti-neutrophil cytoplasmic antibodies (ANCA).

METHODS

We collected patients with both ANCA and anti-GBM positive glomerulonephritis who were hospitalized in the Department of Nephrology at the First Affiliated Hospital of Nanjing Medical University from January 2010 to August 2022. Retrospective analysis of the baseline clinical characteristics of patients and follow-up to explore relevant factors affecting renal and patient survival.

RESULTS

A total of 386 patients, including 69 ANCA negative anti-GBM glomerulonephritis patients, 296 anti-GBM negative ANCA associated vasculitis (AAV) patients, and 21 DPPs were enrolled in this study. Among the 21 DPPs aged 68.0 years (59.5, 74.0), there were 11 males and 10 females. The median serum creatinine at diagnosis was 629.0 (343.85, 788.75) μmol/L, and the median eGFR (CKD-EPI) was 7.58 (4.74, 13.77) mL/min. Fifteen cases (71.4 %) underwent initial RRT. After a follow-up of 40.0 (11.0, 73.0) months, 13 out of 21 DPPs (61.9 %) received maintenance RRT, while 49 out of 69 (71.0 %) ANCA negative anti-GBM-GN patients and 124 out of 296 (41.9 %) anti-GBM negative AAV patients received maintenance RRT (P < 0.001). Kaplan-Meier survival analysis showed that DPPs and ANCA negative anti-GBM-GN patients were more likely to progress to ESRD than anti-GBM negative AAV patients (P = 0.001). Among the 21 patients with DPPs, renal survival was significantly better in patients with better initial renal function, including those who did not receive initial RRT (P = 0.003), with lower serum creatinine levels (Cr < 629.0 μmol/L, P = 0.004) and higher eGFR levels (eGFR ≥ 7.60 ml/min, P = 0.005) than those with poor initial renal function. At the end of follow-up, 14 out of 21 DPPs (66.7 %) survived. Survival analysis showed no significant difference among patients in DPPs group, ANCA negative anti-GBM-GN group, and anti-GBM negative AAV group.

CONCLUSIONS

DPPs and ANCA negative anti-GBM-GN patients were more likely to progress to ESRD than anti-GBM negative AAV patients. In DPPs, the poor renal function at diagnosis might be a risk factor associated with poor renal survival.

Bioinspired Gradient Covalent Organic Framework Membranes for Ultrafast and Asymmetric Solvent Transport

Gradients play a pivotal role in membrane technologies, e.g., osmotic energy conversion, desalination, biomimetic actuation, selective separation, and more. In these applications, the compositional gradients are of great relevance for successful function implementation, ranging from solvent separation to smart devices; However, the construction of functional gradient in membranes is still challenging both in scale and directions. Inspired by the specific function-related, graded porous structures in glomerular filtration membranes, a general approach for constructing gradient covalent organic framework membranes (GCOMx) applying poly (ionic liquid)s (PILs) as template is reported here. With graded distribution of highly porous covalent organic framework (COF) crystals along the membrane, GCOMx exhibts an unprecedented asymmetric solvent transport when applying different membrane sides as the solvent feed surface during filtration, leading to a much-enhanced flux (10-18 times) of the "large-to-small" pore flow comparing to the reverse direction, verified by hydromechanical theoretical calculations. Upon systematic experiments, GCOMx achieves superior permeance in nonpolar (hexane ≈260.45 LMH bar-1) and polar (methanol ≈175.93 LMH bar-1) solvents, together with narrow molecular weight cut-off (MWCO, 472 g mol-1) and molecular weight retention onset (MWRO, <182 g mol-1). Interestingly, GCOMx shows significant filtration performance in simulated kidney dialysis, revealing great potential of GCOMx in bionic applications.

Epidemiology, clinical features, risk factors, and outcomes in anti-glomerular basement membrane disease: A systematic review and meta-analysis

Anti-glomerular basement membrane (GBM) disease is a small-vessel vasculitis that represents the most aggressive form of autoimmune glomerulonephritis. The study aimed to investigate the prevalence, clinical characteristics, risk factors, and outcomes of anti-GBM disease through a systematic review and meta-analysis involving 47 studies with 2830 patients. The overall incidence of anti-GBM disease ranged from 0.60 to 1.79 per million population per annum. In rapidly progressive glomerulonephritis and crescentic glomerulonephritis, the pooled incidence rates were 8.0% and 12.8%, respectively. The pooled prevalence rates of anti-GBM antibodies, antineutrophil cytoplasmic antibodies (ANCA), and lung hemorrhage were 88.8%, 27.4%, and 32.6%, respectively. Patients with combined ANCA positivity demonstrated a prognosis comparable to those patients with only anti-GBM antibodies, though with differing clinical features. The pooled one-year patient and kidney survival rates were 76.2% and 30.2%, respectively. Kidney function on diagnosis and normal glomeruli percentage were identified as strong prognostic factors. This study represents the first comprehensive meta-analysis on anti-GBM disease, providing insights into its management. However, caution is warranted in interpreting some results due to the observational nature of the included studies and high heterogeneity.