Role of TSP-1 and its receptor ITGB3 in the renal tubulointerstitial injury of focal segmental glomerulosclerosis.

Focal segmental glomerulosclerosis (FSGS), a common cause of primary glomerulonephritis, has a poor prognosis and is pathologically featured by tubulointerstitial injury. Thrombospondin-1 (TSP-1) is an extracellular matrix protein that acts in combination with different receptors in the kidney. Here, we analyzed the tubular expression of TSP-1 and its receptor integrin ß3 (ITGB3) in FSGS. Previously the renal interstitial chip analysis of FSGS patients with tubular interstitial injury showed that the expressions of TSP-1 and ITGB3 were up-regulated. We found that the level of TSP-1 and ITGB3 increased in the tubular cells of FSGS patients. The serum level of TSP-1 increased and was correlated to the degree of tubulointerstitial lesions in FSGS patients. THBS1/ITGB3 signaling induced renal tubular injury in HK-2 cells exposure to BSA and the ADR-induced nephropathy model. THBS1 knockout ameliorated tubular injury and renal fibrosis in ADR-treated mice. THBS1 knockdown decreased the expression of KIM-1 and caspase 3 in the HK-2 cells treated with BSA, while THBS1 overexpression could induce tubular injury. In vivo, we identified cyclo-RGDfK as an agent to block the binding of TSP-1 to ITGB3. Cyclo-RGDfK treatment could alleviate ADR-induced renal tubular injury and interstitial fibrosis in mice. Moreover, TSP-1 and ITGB3 were colocalized in tubular cells of FSGS patients and ADR-treated mice. Taken together, our data showed that TSP-1/ITGB3 signaling contributed to the development of renal tubulointerstitial injury in FSGS, potentially identifying a new therapeutic target for FSGS.

Risk factors for acute kidney injury and kidney relapse in patients with lupus podocytopathy.

Background: Patients with lupus podocytopathy show a high incidence of acute kidney injury (AKI) and relapse, but the risk factors and mechanisms were unclear. This study analysed the clinicopathological features and risk factors for AKI and relapse in lupus podocytopathy patients. Methods: The cohort of lupus podocytopathy was generated by screening the biopsies of patients with lupus nephritis (LN) from 2002 to 2022 and was divided into the mild glomerular lesion (MGL) and focal segmental glomerulosclerosis (FSGS) groups based on glomerular morphological characteristics. The acute (ATI) and chronic (CTI) tubulointerstitial lesions were semi-quantitatively scored. Logistic and Cox regressions were employed to identify the risk factors for AKI and relapse, respectively. Results: Among 6052 LN cases, 98 (1.6%) were diagnosed as lupus podocytopathy, with 71 in the MGL group and 27 in the FSGS group. All patients presented with nephrotic syndrome and 33 (34.7%) of them had AKI. Seventy-seven (78.6%) patients achieved complete renal response (CRR) within 12 weeks of induction treatment, in which there was no difference in the CRR rate between glucocorticoid monotherapy and combination therapy with glucocorticoids plus immunosuppressants. Compared with the MGL group, patients in the FSGS group had significantly higher incidences of hypertension and haematuria; in addition, they had higher Systemic Lupus Erythematosus Disease Activity Index 2000, ATI and CTI scores but a significantly lower CRR rate. Urinary protein ≥7.0 g/24 h and serum C3 ≤0.750 g/l were independent risk factors for AKI. During a median follow-up of 78 months, 57 cases (60.0%) had relapse and none reached the kidney endpoint. Failure to achieve CRR within 12 weeks, maintenance with glucocorticoid monotherapy and AKI at onset were independent risk factors for kidney relapse. Conclusions: In this study, histological subtypes of lupus podocytopathy were found to be associated with clinical features and treatment response. In addition, several risk factors associated with AKI occurrence and kidney relapse were identified.

Clinicopathological Characteristics of Light and Heavy Chain Deposition Disease: A Case Series.

RATIONALE & OBJECTIVE: Light and heavy chain deposition disease (LHCDD) is a rare form of monoclonal immunoglobulin (Ig) deposition disease, and limited clinical data are available characterizing this condition. Here we describe the clinicopathological characteristics and outcomes of LHCDD. STUDY DESIGN: Case series. SETTING & PARTICIPANTS: 13 patients with biopsy-proven LHCDD diagnosed between January 2008 and December 2022 at one of 2 Chinese medical centers. FINDINGS: Among the 13 patients described, 6 were men and 7 were women, with a mean age of 52.6±8.0 years. Patients presented with hypertension (76.9%), anemia (84.6%), increased serum creatinine concentrations (84.6%; median, 1.7mg/dL), proteinuria (100%; average urine protein, 3.0g/24h), nephrotic syndrome (30.8%), and microscopic hematuria (76.9%). Serum immunofixation electrophoresis showed monoclonal Ig for 11 patients (84.6%). Serum free light chain ratios were abnormal in 11 patients (84.6%), and heavy/light chain ratios were abnormal in 9 of 10 patients (90%) with available data. Five patients were diagnosed with multiple myeloma. A histological diagnosis of nodular mesangial sclerosis was made in 10 patients (76.9%). Immunofluorescence demonstrated deposits of IgG subclass in 7 patients (γ-κ, n=4; γ-λ, n=3) and IgA in 5 patients (α-κ, n=2; α-λ, n=3). Six patients underwent IgG subclass staining (γ1, n=3; γ2, n=2; γ3, n=1). The deposits of IgD-κ were confirmed by mass spectrometry in 1 patient. Among 12 patients for whom data were available during a median of 26.5 months, 11 received chemotherapy and 1 received conservative treatment. One patient died, and disease progressed to kidney failure in 3 (25%). Among the 9 patients evaluable for hematological and kidney disease progression, 5 (56%) had a hematologic response and 1 (11%) exhibited improvement in kidney disease. LIMITATIONS: Retrospective descriptive study, limited number of patients, urine protein electrophoresis or immunofixation electrophoresis test results missing for most patients. CONCLUSIONS: In this case series of LHCDD, light and heavy chain deposition in kidney tissues were most frequent with monoclonal IgG1-κ. Among patients with evaluable data, more than half had a hematologic response, but a kidney response was uncommon.

Artificial intelligence assists identification and pathologic classification of glomerular lesions in patients with diabetic nephropathy.

BACKGROUND: Glomerular lesions are the main injuries of diabetic nephropathy (DN) and are used as a crucial index for pathologic classification. Manual quantification of these morphologic features currently used is semi-quantitative and time-consuming. Automatically quantifying glomerular morphologic features is urgently needed. METHODS: A series of convolutional neural networks (CNN) were designed to identify and classify glomerular morphologic features in DN patients. Associations of these digital features with pathologic classification and prognosis were further analyzed. RESULTS: Our CNN-based model achieved a 0.928 F1-score for global glomerulosclerosis and 0.953 F1-score for Kimmelstiel-Wilson lesion, further obtained a dice of 0.870 for the mesangial area and F1-score beyond 0.839 for three glomerular intrinsic cells. As the pathologic classes increased, mesangial cell numbers and mesangial area increased, and podocyte numbers decreased (p for all < 0.001), while endothelial cell numbers remained stable (p = 0.431). Glomeruli with Kimmelstiel-Wilson lesion showed more severe podocyte deletion compared to those without (p < 0.001). Furthermore, CNN-based classifications showed moderate agreement with pathologists-based classification, the kappa value between the CNN model 3 and pathologists reached 0.624 (ranging from 0.529 to 0.688, p < 0.001). Notably, CNN-based classifications obtained equivalent performance to pathologists-based classifications on predicting baseline and long-term renal function. CONCLUSION: Our CNN-based model is promising in assisting the identification and pathologic classification of glomerular lesions in DN patients.

Advancing the application of the analytical renal pathology system in allograft IgA nephropathy patients.

BACKGROUND: The analytical renal pathology system (ARPS) based on convolutional neural networks has been used successfully in native IgA nephropathy (IgAN) patients. Considering the similarity of pathologic features, we aim to evaluate the performance of the ARPS in allograft IgAN patients and broaden its implementation. METHODS: Biopsy-proven allograft IgAN patients from two different centers were enrolled for internal and external validation. We implemented the ARPS to identify glomerular lesions and intrinsic glomerular cells, and then evaluated its performance. Consistency between the ARPS and pathologists was assessed using intraclass correlation coefficients. The association of digital pathological features with clinical and pathological data was measured. Kaplan-Meier survival curve and cox proportional hazards model were applied to investigate prognosis prediction. RESULTS: A total of 56 biopsy-proven allograft IgAN patients from the internal center and 17 biopsy-proven allograft IgAN patients from the external center were enrolled in this study. The ARPS was successfully applied to identify the glomerular lesions (F1-score, 0.696-0.959) and quantify intrinsic glomerular cells (F1-score, 0.888-0.968) in allograft IgAN patients rapidly and precisely. Furthermore, the mesangial hypercellularity score was positively correlated with all mesangial metrics provided by ARPS [Spearman's correlation coefficient (r), 0.439-0.472, and all p values < 0.001]. Besides, a higher allograft survival was noticed among patients in the high-level groups of the maximum and ratio of endothelial cells, as well as the maximum and density of podocytes. CONCLUSION: We propose that the ARPS could be implemented in future clinical practice with outstanding capability.

Deep learning model to predict lupus nephritis renal flare based on dynamic multivariable time-series data.

OBJECTIVES: To develop an interpretable deep learning model of lupus nephritis (LN) relapse prediction based on dynamic multivariable time-series data. DESIGN: A single-centre, retrospective cohort study in China. SETTING: A Chinese central tertiary hospital. PARTICIPANTS: The cohort study consisted of 1694 LN patients who had been registered in the Nanjing Glomerulonephritis Registry at the National Clinical Research Center of Kidney Diseases, Jinling Hospital from January 1985 to December 2010. METHODS: We developed a deep learning algorithm to predict LN relapse that consists of 59 features, including demographic, clinical, immunological, pathological and therapeutic characteristics that were collected for baseline analysis. A total of 32 227 data points were collected by the sliding window method and randomly divided into training (80%), validation (10%) and testing sets (10%). We developed a deep learning algorithm-based interpretable multivariable long short-term memory model for LN relapse risk prediction considering censored time-series data based on a cohort of 1694 LN patients. A mixture attention mechanism was deployed to capture variable interactions at different time points for estimating the temporal importance of the variables. Model performance was assessed according to C-index (concordance index). RESULTS: The median follow-up time since remission was 4.1 (IQR, 1.7-6.7) years. The interpretable deep learning model based on dynamic multivariable time-series data achieved the best performance, with a C-index of 0.897, among models using only variables at the point of remission or time-variant variables. The importance of urinary protein, serum albumin and serum C3 showed time dependency in the model, that is, their contributions to the risk prediction increased over time. CONCLUSIONS: Deep learning algorithms can effectively learn through time-series data to develop a predictive model for LN relapse. The model provides accurate predictions of LN relapse for different renal disease stages, which could be used in clinical practice to guide physicians on the management of LN patients.

Evaluation of the significance of complement-related genes mutations in atypical postinfectious glomerulonephritis: a pilot study.

BACKGROUND: Postinfectious glomerulonephritis with C3-dominant glomerular deposition (C3-PIGN) involves C3-dominant glomerular deposition without immunoglobulin. Atypical C3-PIGN involves persistent hypocomplementemia. We investigated the clinical features and explored complement-related gene mutations in atypical PIGN patients. METHODS: We enrolled atypical C3-PIGN patients and collected data regarding the clinical presentation and pathological characteristics and follow-up data. We measured the levels of complement associated antibodies and performed whole-exome sequencing (WES) to detect mutations in complement-related genes. RESULTS: The analysis included six atypical C3-PIGN patients. All patients were antistreptolysin-O (ASO) positive. All patients had varying degrees of hematuria, and four patients had proteinuria. None of the patients were positive for complement-related antibodies. All patients possessed mutations of genes related to the complement pathway, including alternative complement pathway genes-CFI, CFH, CFHR3, CFHR5; the lectin pathway gene-MASP2; and the common complement pathway gene-C8A. The rare variant of CFHR3 has been reported in C3 glomerulonephritis. During 56-73 months of follow-up, the levels of urine markers in three patients recovered within 6 months, and the remaining patients had abnormal urine test results over 12 months. Patients who received glucocorticoid therapy recovered faster. CONCLUSIONS: Our study suggested that complement-related gene mutations may be an important cause of persistent hypocomplementemia in atypical C3-PIGN patients. In addition to variations in alternate pathway-related genes, we also found variations in lectin pathway-related genes, especially MASP2 genes. Although the overall prognosis was good, atypical C3-PIGN patients exhibited a longer period for recovery. Our results suggested that atypical C3-PIGN patients should receive more medical attention and need testing for mutations in complement-related genes.

Docosahexaenoic acid (DHA) inhibits abdominal fat accumulation by promoting adipocyte apoptosis through PPARγ-LC3-BNIP3 pathway-mediated mitophagy.

Obesity has always been an overwhelming health concern worldwide. Docosahexaenoic acid (DHA) reduces abdominal fat accumulation by inducing adipocyte apoptosis, but the underlying mechanism remains unclear. Mitophagy, the process of maintaining mitochondrial homeostasis, has a double-edged sword effect that positively or negatively regulates apoptosis. In this study, grass carp (Ctenopharyngodon idellus) was used as an animal model to investigate the role of mitophagy in regulating apoptosis and the potential molecular mechanisms for DHA-induced mitophagy in vivo and in vitro. Firstly, we found that DHA induced the intrinsic apoptosis in grass carp adipocytes, accompanying by activating BNIP3/NIX-mediated mitophagy. Then, suppression of mitophagy alleviated apoptosis and eliminated the inhibition of lipid accumulation induced by DHA in vivo and in vitro. Mechanistically, the DHA-induced mitophagy was caused by activating PPARγ and its DNA binding capacity to the LC3 promoter, which promoted the interaction of BNIP3 (rather than NIX) with LC3. However, the inhibition of PPARγ in vitro significantly decreased the expression of autophagy-related genes (P < 0.05), reducing the colocalization of mitochondria and lysosomes while preventing BNIP3/NIX-mediated mitophagy-mediated apoptosis and subsequently alleviating the inhibition of lipid accumulation in adipocytes induced by DHA. For the first time, we demonstrated that DHA activates mitophagy by regulating the PPARγ-LC3-BNIP3 pathway, consequently inducing apoptosis, which decreases adipocytes, inhibiting lipid accumulation in grass carp. These findings provide new insight into the mechanism of DHA-induced apoptosis mediated by mitophagy as the potential therapeutic target of inhibiting abdominal fat accumulation in vertebrates.

Krüppel-like Factor 15 Suppresses Ferroptosis by Activating an NRF2/GPX4 Signal to Protect against Folic Acid-Induced Acute Kidney Injury.

Acute kidney injury (AKI) is a common and serious disease with high morbidity and mortality, and its pathophysiological mechanisms are not fully understood. Increasing evidence suggests an important role of ferroptosis in AKI. Krüppel-like factor 15 (KLF15) is a transcription factor involved in several metabolic diseases, but its role in AKI and ferroptosis remains unclear. In this study, we explored the potential role of KLF15 using a folic acid-induced AKI model. Our study showed that KLF15 expression was reduced in kidney tissues of AKI mice, and KLF15 knockout exacerbated folic acid-induced ferroptosis and kidney injury. In vitro studies revealed that the ferroptosis inducer erastin significantly suppressed KLF15 expression in human tubular epithelial cells. Notably, the overexpression of KLF15 attenuated ferroptosis, as evidenced by a decrease in the lipid peroxidation marker of malondialdehyde and the upregulation of glutathione peroxidase 4 (GPX4), while KLF15 knockdown with shRNA exerted the opposite effect. Mechanistically, KLF15 stabilized the protein of nuclear factor erythroid 2-related factor 2 (NRF2) and subsequently increased the GPX4 level. Collectively, KLF15 plays an important role in the modulation of ferroptosis in AKI and may be a potential therapeutic target for treating AKI.

Light chain only variant of proliferative glomerulonephritis with monoclonal immunoglobulin deposits: a clinicopathological study of three cases.

AIMS: To explore the clinical and pathological features of light chain only variant of proliferative glomerulonephritis with monoclonal immunoglobulin deposits (PGNMID-LC). METHODS: From January 2010 to December 2022, patients who were diagnosed with PGNMID-LC were selected, and their clinical and pathological features were retrospectively analysed. RESULTS: Three males aged 42-61 years old were enrolled. Hypertension was present in three patients, oedema in three patients, anaemia in two patients, proteinuria in three patients, nephrotic syndrome in one patient, microscopic haematuria in three patients, renal insufficiency in two patients and hypocomplementaemia of C3 in one patient. Elevated serum-free LC ratios and plasmacytosis on bone marrow smears were observed in three patients, and κ was identified by serum protein immunofixation electrophoresis in one patient. Renal biopsy showed membranoproliferative glomerulonephritis in two patients and endocapillary proliferative glomerulonephritis in one patient on light microscopy. Immunofluorescence indicated restricted κ LC and C3 distributed in glomeruli. By electron microscopy, electron-dense deposits without substructure were identified predominantly in the mesangial and subendothelial regions and were variable in the subepithelial region. Two patients were treated with plasma cell-directed chemotherapy and achieved haematological complete response or very good partial response, and one of them achieved a renal status of complete remission. One patient treated with immunosuppressive therapy only did not achieve haematological or renal remission. CONCLUSIONS: PGNMID-LC is a rare and uniform disease with a high frequency of a detectable pathogenic plasma cell clone and is characterised by glomerular deposition of restricted LC and C3 in renal pathology. Plasma cell-directed chemotherapy may improve haematological and renal prognosis.

The Spectrum of Biopsy-Proven Kidney Diseases, Causes, and Renal Outcomes in Acute Kidney Injury Patients.

INTRODUCTION: Acute kidney injury (AKI) is a group of highly heterogeneous, complicated clinical syndromes. Although kidney biopsy plays an irreplaceable role in evaluating complex AKI, a few studies have focused on the clinicopathology of AKI biopsies. This study analyzed the pathological disease spectrum, causes, and renal outcomes of biopsied AKI patients. METHODS: We retrospectively included 2,027 AKI patients who underwent kidney biopsies at a national clinical research center of kidney diseases from 2013 through 2018. To compare the biopsied AKI cases without and with coexisting glomerulopathy, patients were classified into acute tubular/tubulointerstitial nephropathy-associated AKI (ATIN-AKI) and glomerular disease-associated AKI (GD-AKI) groups. RESULTS: Of 2,027 biopsied AKI patients, 65.1% were male, with a median age of 43 years. A total of 1,590 (78.4%) patients had coexisting GD, while only 437 (21.6%) patients had ATIN alone. The AKI patients with GD mainly (53.5%) manifested as stage 1 AKI, while most ATIN-AKI patients (74.8%) had stage 3 AKI. In the ATIN-AKI group, 256 (58.6%) patients had acute interstitial nephritis (AIN), and 77 (17.6%) had acute tubular injury (ATI). ATIN-AKI was mainly caused by drugs in 85.5% of AIN and 63.6% of ATI cases, respectively. In AKI patients with coexisting GD, the leading pathological diagnoses in over 80% of patients were IgA nephropathy (IgAN, 22.5%), minimal change disease (MCD, 17.5%), focal segmental glomerulosclerosis (FSGS, 15.3%), lupus nephritis (LN, 11.9%), membranous nephropathy (MN, 10.2%), and ANCA-associated vasculitis (AAV, 4.7%). A total of 775 patients were followed up within 3 months after renal biopsy; ATIN-AKI patients achieved statistically higher complete renal recovery than the GD-AKI patients (83.5% vs. 70.5%, p < 0.001). CONCLUSIONS: Most biopsied AKI patients have coexisting GD, while ATIN alone is seen less frequently. ATIN-AKI is mainly caused by drugs. In GD-AKI patients, IgAN, MCD, FSGS, LN, MN, and AAV are the leading diagnoses. Compared to AKI patients without GD, patients with GD suffer from worse renal function recovery.

A mouse model for X-linked Alport syndrome induced by Del-ATGG in the Col4a5 gene.

Alport syndrome (AS) is an inherited glomerular basement membrane (GBM) disease leading to end-stage renal disease (ESRD). X-linked AS (XLAS) is caused by pathogenic variants in the COL4A5 gene. Many pathogenic variants causing AS have been detected, but the genetic modifications and pathological alterations leading to ESRD have not been fully characterized. In this study, a novel frameshift variant c.980_983del ATGG in the exon 17 of the COL4A5 gene detected in a patient with XLAS was introduced into a mouse model in by CRISPR/Cas9 system. Through biochemical urinalysis, histopathology, immunofluorescence, and transmission electron microscopy (TEM) detection, the clinical manifestations and pathological alterations of Del-ATGG mice were characterized. From 16 weeks of age, obvious proteinuria was observed and TEM showed typical alterations of XLAS. The pathological changes included glomerular atrophy, increased monocytes in renal interstitial, and the absence of type IV collagen α5. The expression of Col4a5 was significantly decreased in Del-ATGG mouse model. Transcriptomic analysis showed that differentially expressed genes (DEGs) accounted for 17.45% (4,188/24003) of all genes. GO terms indicated that the functions of identified DEGs were associated with cell adhesion, migration, and proliferation, while KEGG terms found enhanced the degradation of ECM, amino acid metabolism, helper T-cell differentiation, various receptor interactions, and several important pathways such as chemokine signaling pathway, NF-kappa B signaling pathway, JAK-STAT signaling pathway. In conclusion, a mouse model with a frameshift variant in the Col4a5 gene has been generated to demonstrate the biochemical, histological, and pathogenic alterations related to AS. Further gene expression profiling and transcriptomic analysis revealed DEGs and enriched pathways potentially related to the disease progression of AS. This Del-ATGG mouse model could be used to further define the genetic modifiers and potential therapeutic targets for XLAS treatment.

Polynucleotide phosphorylase protects against renal tubular injury via blocking mt-dsRNA-PKR-eIF2α axis.

Renal tubular atrophy is a hallmark of chronic kidney disease. The cause of tubular atrophy, however, remains elusive. Here we report that reduction of renal tubular cell polynucleotide phosphorylase (PNPT1) causes renal tubular translation arrest and atrophy. Analysis of tubular atrophic tissues from renal dysfunction patients and male mice with ischemia-reperfusion injuries (IRI) or unilateral ureteral obstruction (UUO) treatment shows that renal tubular PNPT1 is markedly downregulated under atrophic conditions. PNPT1 reduction leads to leakage of mitochondrial double-stranded RNA (mt-dsRNA) into the cytoplasm where it activates protein kinase R (PKR), followed by phosphorylation of eukaryotic initiation factor 2α (eIF2α) and protein translational termination. Increasing renal PNPT1 expression or inhibiting PKR activity largely rescues IRI- or UUO-induced mouse renal tubular injury. Moreover, tubular-specific PNPT1-knockout mice display Fanconi syndrome-like phenotypes with impaired reabsorption and significant renal tubular injury. Our results reveal that PNPT1 protects renal tubules by blocking the mt-dsRNA-PKR-eIF2α axis.

Efficacy of Immunomodulatory Drugs in Combination With Dexamethasone in Proliferative Glomerulonephritis With Monoclonal Immunoglobulin Deposits.

Introduction: Immunomodulatory drugs (IMiDs) plus dexamethasone are effective for plasma cell dyscrasias, but the treatment efficacy of IMiD in proliferative glomerulonephritis with monoclonal immunoglobulin deposits (PGNMID) has been rarely reported. Methods: We retrospectively analyzed the clinicopathologic data of 64 patients with PGNMID (steroid, IMiD, and bortezomib and dexamethasone/Rituximab [BD/RTX] groups) from January 1, 2010 to December 31, 2020, at the National Clinical Research Center of Kidney Disease in Nanjing. The prognosis of patients receiving different treatment regimens were compared. Factors potentially affecting renal prognosis and renal response were evaluated. Results: Twenty-eight, 26 and 10 PGNMID patients were divided into IMiD group, steroid group and BD/RTX group respectively. The rate of serum M protein detection was significantly lower in the steroid group than in the other 2 groups. Renal remission (P = 0.001 and P = 0.03, respectively) rates and renal complete remission (CR) (P = 0.001 and P = 0.01, respectively) rates were significantly higher in the IMiD and BD/RTX groups than in the steroid group at the last follow-up. Multivariate logistic analysis identified that hypertension and high serum creatinine (SCr) levels (>1.24 mg/dl) decreased renal remission, whereas low C3 levels, IMiD and BD/RTX treatments were positively associated with renal remission. Multivariate Cox analysis identified IgG3 in renal tissue and high SCr levels as poor renal prognostic indicators. Severe adverse events were more common in the IMiD and BD/RTX groups than in the steroid group (P = 0.072 and P = 0.035, respectively). Conclusion: Our results suggest that IMiDs plus dexamethasone is effective for achieving renal remission in PGNMID patients.

Efficacy of long-term repeated rituximab treatment in refractory phospholipase A2 receptor-antibody-related membranous nephropathy.

Aims: To evaluate the efficacy of long-term repeated rituximab treatment in refractory PLA2R-Ab-related membranous nephropathy (MN). Materials & methods: Rituximab was administered at a single dose of 375 mg/m2 and repeated if peripheral B-cell levels were >5/ul in 46 patients with refractory PLA2R-Ab-related MN. Results: The median frequency of rituximab treatment was 3 (IQR 2.0-4.0). A total of 32 (32/46) patients achieved remission (completed remission [CR] or partial remission [PR]) over a median time of 17.0 months, and 10 patients eventually progressed to CR. The proportion of serum PLA2R-Ab depletion was 73.91% (34/46) over a median time of 9 months. Antibody depletion preceded proteinuria remission. Conclusions: Long-term repeated rituximab treatment achieved high kidney and immunological response rates in refractory PLA2R-Ab related MN, and antibody depletion was a prerequisite for proteinuria remission.

Membranous nephropathy (MN) is the leading cause of proteinuria in adults and is mainly manifested as edema. Phospholipase 2 receptor (PLA2R) antibody is detected in 70­80% of patients with MN. Its main treatments are immunosuppressive therapies. The efficacy of traditional immunosuppressant drugs including steroids and alkylating and calcineurin inhibitors in reducing proteinuria have been confirmed; however, several adverse events such as diabetes mellitus, infections, cancer and kidney injury have been reported. Rituximab, a monoclonal antibody against CD20 on B cells, has been verified to be effective, safer and better tolerated in MN. However, the optimal rituximab regimen for MN has not yet been established. Here, we use B-cell-driven long-term repeated rituximab regimen and determine its exciting efficacy for refractory MN.

Treatment of Membranous Nephropathy by Disulfiram through Inhibition of Podocyte Pyroptosis.

Introduction: Membranous nephropathy (MN) is a common chronic kidney disease in adults and a major challenge of clinical practice for its treatment. Despite major advances, since the discovery of the phospholipase A2 receptor as the major autoantigen of podocytes in MN, the mechanisms leading to glomerular damage remain elusive. Pyroptosis, a newly discovered type of programed necrotic cell death mainly mediated by gasdermin, was found to be responsible for podocyte injury in MN in our recent work. Objectives: The aim of this study was to explore the therapeutic effect of an FDA-approved drug, disulfiram (DSF), in the treatment of MN by inhibiting pyroptosis. Methods and Results: DSF significantly alleviated C3a/C5a-induced podocyte injury in vitro and renal lesions in passive Heymann nephritis (PHN) rats, as reflected by the decreased percentage of propidium iodide staining podocytes, decreased lactate dehydrogenase release from cultured podocytes and improvement in 24-h urine protein, serum albumin, serum creatinine, abnormal alterations of podocyte injury markers Desmin and WT-1 and podocyte foot process fusion in PHN rats. The protective effect of DSF on podocyte injury in vitro and in vivo can be ascribed to its inhibition of the activation and membrane translocation of the pyroptosis executor gasdermin D (GSDMD) in podocytes. DSF also inhibited the increase and activation of the pyroptosis signaling pathway NLRP3-ASC-Caspase-1/IL-18/GSDMD in C3a/C5a-treated podocytes and renal tissue of PHN rats. Conclusion: DSF is a potential drug for MN treatment, and its clinical application needs to be further investigated.

Long-term follow-up of autologous peripheral blood hematopoietic stem cell transplantation for refractory lupus nephritis-a series study of 20 patients.

BACKGROUND: Autologous hematopoietic cell transplantation (ASCT) improves immunologic homeostasis in autoimmune diseases. ASCT-treated refractory lupus nephritis (LN) has been reported. Nevertheless, the long-term outcome of patients with refractory LN after ASCT remains unknown. This study reports the outcomes of 20 refractory lupus patients with 10-year of follow-up after receiving ASCT. METHODS: Twenty-two patients with LN refractory to immunosuppressive therapy were enrolled. Twenty patients were examined closely and two cases died within 100 days after ASCT. Hematopoietic cell mobilization with cyclophosphamide and granulocyte colony-stimulating factor (G-CSF) was followed by collection of CD34+ positively selected cells. The conditioning regimen consisted of intravenous cyclophosphamide, rabbit antithymocyte globulin, methylprednisolone, and G-CSF. All immunosuppressive therapies were discontinued at the start of mobilization and corticosteroids were tapered rapidly after ASCT. RESULTS: Data was collected from 22 patients with refractory LN treated by ASCT. 59% were female, duration of lupus before ASCT was 46 (33-71) months, and median duration of follow-up after ASCT was 89.5 (56-108) months. 20 long-term followed up patients had an average follow-up time of 92 months (63.25-109.5). Eighteen patients achieved complete remission, one patient reached partial remission, one patient without remission started peritoneal dialysis at month 12, and one patient received short-term renal replacement therapy before ASCT started hemodialysis at 84 months after transplantation. Nine patients relapsed 10 times during the follow-up, and three patients received rituximab. Two patients relapsed during pregnancy after complete response and the Apgar scores of infants were 9 and 10, respectively. All nine patients received glucocorticoids and immunosuppressive medication after relapse and responded again. The 10-year overall survival, 10-year disease-free survival rate, and 10-year renal survival were 100%, 35%, and 90%, respectively. The rate of relapse was 45%. Complications included hypocytosis, infection, B-type insulin resistance syndrome, and monoclonal immunoglobulinemia. CONCLUSION: This study suggests ASCT is effective and safety in treating refractory LN and is beneficial to improve their long-term outcomes.

Inhibition of HDAC6 With CAY10603 Ameliorates Diabetic Kidney Disease by Suppressing NLRP3 Inflammasome.

Background: Diabetic nephropathy (DN) is one of the leading causes of chronic kidney disease (CKD) worldwide, tubular injury is the driving force during the pathogenesis and progression of DN. Thus, we aim to utilize the connectivity map (CMap) with renal tubulointerstitial transcriptomic profiles of biopsy-proven DN to identify novel drugs for treating DN. Methods: We interrogated the CMap profile with tubulointerstitial transcriptomic data from renal biopsy-proven early- and late-stage DN patients to screen potential drugs for DN. Therapeutic effects of candidate drug were assessed in Murine model of diabetic kidney disease (STZ-induced CD-1 mice), and HK-2 cells and immortalized bone marrow-derived macrophages (iBMDMs). Results: We identified CAY10603, a specific inhibitor of histone deacetylase 6 (HDAC6), as a potential drug that could significantly reverse the altered genes in the tubulointerstitial component. In DN patients and mice, upregulation of HDAC6 was mainly observed in renal tubular cells and infiltrated macrophages surrounding the diluted tubules. In both early- and late-onset diabetic mice, daily CAY10603 administration effectively alleviated renal dysfunction and reduced macrophage infiltration, tubular injury and tubulointerstitial fibrosis. Mechanistically, CAY10603 suppressed NLRP3 activation in both HK-2 cells and iBMDMs. Conclusion: CAY10603 exhibited therapeutic potential for DN by suppressing NLRP3 inflammasome activation in both tubular cells and macrophages.

Unsupervised Tissue Segmentation via Deep Constrained Gaussian Network.

Tissue segmentation is the mainstay of pathological examination, whereas the manual delineation is unduly burdensome. To assist this time-consuming and subjective manual step, researchers have devised methods to automatically segment structures in pathological images. Recently, automated machine and deep learning based methods dominate tissue segmentation research studies. However, most machine and deep learning based approaches are supervised and developed using a large number of training samples, in which the pixel-wise annotations are expensive and sometimes can be impossible to obtain. This paper introduces a novel unsupervised learning paradigm by integrating an end-to-end deep mixture model with a constrained indicator to acquire accurate semantic tissue segmentation. This constraint aims to centralise the components of deep mixture models during the calculation of the optimisation function. In so doing, the redundant or empty class issues, which are common in current unsupervised learning methods, can be greatly reduced. By validation on both public and in-house datasets, the proposed deep constrained Gaussian network achieves significantly (Wilcoxon signed-rank test) better performance (with the average Dice scores of 0.737 and 0.735, respectively) on tissue segmentation with improved stability and robustness, compared to other existing unsupervised segmentation approaches. Furthermore, the proposed method presents a similar performance (p-value >0.05) compared to the fully supervised U-Net.