Clinical features and prognosis of ANCA-associated vasculitis patients who were double-seropositive for myeloperoxidase-ANCA and proteinase 3-ANCA.

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) patients with dual positivity for proteinase 3-ANCA (PR3-ANCA) and myeloperoxidase-ANCA (MPO-ANCA) are uncommon. We aimed to investigate these idiopathic double-positive AAV patients' clinical features, histological characteristics, and prognosis. We reviewed all the electronic medical records of patients diagnosed with AAV to obtain clinical data and renal histological information from January 2010 to December 2020 in a large center in China. Patients were assigned to the MPO-AAV group or PR3-AAV group or idiopathic double-positive AAV group by ANCA specificity. We explored features of idiopathic double-positive AAV. Of the 340 patients who fulfilled the study inclusion criteria, 159 (46.76%) were female, with a mean age of 58.41 years at the time of AAV diagnosis. Similar to MPO-AAV, idiopathic double-positive AAV patients were older and had more severe anemia, lower Birmingham Vasculitis Activity Score (BVAS) and C-reactive protein (CRP) levels, less ear, nose, and throat (ENT) involvement, higher initial serum creatinine and a lower estimated glomerular filtration rate (eGFR) when compared with PR3-AAV (P < 0.05). The proportion of normal glomeruli of idiopathic double-positive AAV was the lowest among the three groups (P < 0.05). The idiopathic double-positive AAV patients had the worst remission rate (58.8%) among the three groups (P < 0.05). The relapse rate of double-positive AAV (40.0%) was comparable with PR3-AAV (44.8%) (P > 0.05). Although there was a trend toward a higher relapse rate of idiopathic double-positive AAV (40.0%) compared with MPO-AAV (23.5%), this did not reach statistical significance (P > 0.05). The proportion of patients who progressed to ESRD was 47.1% and 44.4% in the idiopathic double-positive AAV group and MPO-AAV group respectively, without statistical significance. Long-term patient survival also varied among the three groups (P < 0.05). Idiopathic double-positive AAV is a rare clinical entity with hybrid features of MPO-AAV and PR3-AAV. MPO-AAV is the "dominant" phenotype in idiopathic double-positive AAV.

Smith-specific regulatory T cells halt the progression of lupus nephritis.

Antigen-specific regulatory T cells (Tregs) suppress pathogenic autoreactivity and are potential therapeutic candidates for autoimmune diseases such as systemic lupus erythematosus (SLE). Lupus nephritis is associated with autoreactivity to the Smith (Sm) autoantigen and the human leucocyte antigen (HLA)-DR15 haplotype; hence, we investigated the potential of Sm-specific Tregs (Sm-Tregs) to suppress disease. Here we identify a HLA-DR15 restricted immunodominant Sm T cell epitope using biophysical affinity binding assays, then identify high-affinity Sm-specific T cell receptors (TCRs) using high-throughput single-cell sequencing. Using lentiviral vectors, we transduce our lead Sm-specific TCR into Tregs derived from patients with SLE who are anti-Sm and HLA-DR15 positive. Compared with polyclonal mock-transduced Tregs, Sm-Tregs potently suppress Sm-specific pro-inflammatory responses in vitro and suppress disease progression in a humanized mouse model of lupus nephritis. These results show that Sm-Tregs are a promising therapy for SLE.

[Preliminary Study on the Relationship between the Developmental Stage of Multiple Myeloma Disease and the Results of Bone Marrow Whole Exome Sequencing].

OBJECTIVE: To investigate the genetic results of whole exome sequencing of bone marrow from new onset multiple myeloma (MM) patients to analyze the process of genetic clonal evolution in MM patients. METHODS: Genomic DNA was extracted from bone marrow samples of 15 MM patients and the whole exomes sequencing was performed using next generation sequencing technology. Using own buccal cells as germline controls, combinated with clinical information, the mutation profile of genes from high-risk asymptomatic myeloma to symptomatic myeloma were analyzed, and genes that may be associated with the efficacy and side effects of bortezomib were screened. RESULTS: Except for two patients in whom no peripheral neuropathy was observed after a short treatment period, other patients peripheral neuropathy developed of various degrees during treatment with bortezomib containing chemotherapy, and the vast majority of patients achieved remission after receiving this bortezomib-related chemotherapy regimen. All patients had comparable levels of the inherited mutations number, but the somatic mutations was correlated with disease evolution. CONCLUSION: different gene "mutational spectra" exist in myeloma patients at different stages and are associated with progression through all stages of the disease.

Single-cell transcriptomics uncover hub genes and cell-cell crosstalk in patients with hypertensive nephropathy.

Hypertensive nephropathy (HTN) is one of the leading causes of end-stage renal disease, yet the molecular mechanisms are still unknown. To explore novel mechanisms and gene targets for HTN, the gene expression profiles of renal biopsy samples obtained from 2 healthy living donor controls and 5 HTN patients were determined by single-cell RNA sequencing. Key hub genes expression were validated by the Nephroseq v5 platform. The HTN endothelium upregulated cellular adhesion genes (ICAM2 and CEACAM1), inflammatory genes (ETS2 and IFI6) and apoptosis related genes (CNN3). Proximal tubules in HTN highly expressed hub genes including BBOX1, TPM1, TMSB10, SDC4, and NUP58, which might be potential novel targets for proximal tubular injury. The upregulated genes in tubules of HTN were mainly participating in inflammatory signatures including IFN-γ signature, NF-κB signaling, IL-12 signaling and Wnt signaling pathway. Receptor-ligand interaction analysis indicated potential cell-cell crosstalk between endothelial cells or mesangial cells with other renal resident cells in HTN. Together, our data identify a distinct cell-specific gene expression profile, pathogenic inflammatory signaling and potential cell-cell communications between endothelial cells or mesangial cells with other renal resident cells in HTN. These findings may provide a promising novel landscape for mechanisms and treatment of human HTN.

Sex disparities in clinicopathological features and outcomes of patients with myeloperoxidase-ANCA-associated vasculitis: a retrospective study of 366 cases in a single Chinese center.

There are a few studies that reported sex disparities in clinical features, pathological features and outcomes among ANCA-associated vasculitis (AAV) patients, but studies focusing on sex-specific differences of myeloperoxidase (MPO)-AAV patients are scarce. Therefore, the purpose of this study was to analyze sex differences in clinicopathological features and outcomes of MPO-AAV. Patients diagnosed with MPO-AAV in Xiangya Hospital from January 2010 to June 2021 were included in the study and separated into female and male groups. The differences in clinical manifestations, laboratory parameters, pathological features and prognosis between the two groups were retrospectively analyzed. Three hundred and sixty-six patients were included and divided into female group (n = 176) and male group (n = 190). The age of the male group was 62.41 ± 10.49 years, significantly higher than that of the female group (58.69 ± 16.39, p = 0.011). Compared with the female group, the male group had a shorter duration of disease, higher levels of hemoglobin, eosinophil count, proteinuria, serum C4, and lower levels of serum globulin, serum IgG and serum IgM (p < 0.05). No significant differences in kidney pathological features were observed between the two groups. During a median follow-up of 37.6 months, there was no significant difference in renal survival and patient survival between the two groups, but male patients had a worse composite outcome of renal and patient survival compared with the female patients (p = 0.044). This study found that male patients with MPO-AAV had a higher age of onset, shorter duration of disease, higher levels of hemoglobin, eosinophil count, proteinuria, serum C4, and lower levels of serum globulin, serum IgG and serum IgM. Male patients fared worse than female patients in terms of the composite outcome of renal and patient survival.

Single-cell RNA sequencing reveals the transcriptomic landscape of kidneys in patients with ischemic acute kidney injury.

BACKGROUND: Ischemic acute kidney injury (AKI) is a common syndrome associated with considerable mortality and healthcare costs. Up to now, the underlying pathogenesis of ischemic AKI remains incompletely understood, and specific strategies for early diagnosis and treatment of ischemic AKI are still lacking. Here, this study aimed to define the transcriptomic landscape of AKI patients through single-cell RNA sequencing (scRNA-seq) analysis in kidneys. METHODS: In this study, scRNA-seq technology was applied to kidneys from two ischemic AKI patients, and three human public scRNA-seq datasets were collected as controls. Differentially expressed genes (DEGs) and cell clusters of kidneys were determined. Gene ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis, as well as the ligand-receptor interaction between cells, were performed. We also validated several DEGs expression in kidneys from human ischemic AKI and ischemia/reperfusion (I/R) injury induced AKI mice through immunohistochemistry staining. RESULTS: 15 distinct cell clusters were determined in kidney from subjects of ischemic AKI and control. The injured proximal tubules (PT) displayed a proapoptotic and proinflammatory phenotype. PT cells of ischemic AKI had up-regulation of novel pro-apoptotic genes including USP47 , RASSF4 , EBAG9 , IER3 , SASH1 , SEPTIN7 , and NUB1 , which have not been reported in ischemic AKI previously. Several hub genes were validated in kidneys from human AKI and renal I/R injury mice, respectively. Furthermore, PT highly expressed DEGs enriched in endoplasmic reticulum stress, autophagy, and retinoic acid-inducible gene I (RIG-I) signaling. DEGs overexpressed in other tubular cells were primarily enriched in nucleotide-binding and oligomerization domain (NOD)-like receptor signaling, estrogen signaling, interleukin (IL)-12 signaling, and IL-17 signaling. Overexpressed genes in kidney-resident immune cells including macrophages, natural killer T (NKT) cells, monocytes, and dendritic cells were associated with leukocyte activation, chemotaxis, cell adhesion, and complement activation. In addition, the ligand-receptor interactions analysis revealed prominent communications between macrophages and monocytes with other cells in the process of ischemic AKI. CONCLUSION: Together, this study reveals distinct cell-specific transcriptomic atlas of kidney in ischemic AKI patients, altered signaling pathways, and potential cell-cell crosstalk in the development of AKI. These data reveal new insights into the pathogenesis and potential therapeutic strategies in ischemic AKI.

The effect of discontinuation of maintenance therapy in Chinese patients with MPO-ANCA associated vasculitis who were in long-term stable remission.

There is a consensus that maintenance therapy should be used to prevent relapse of myeloperoxidase-anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (MPO-AAV), but there is a debate about the optimal duration of maintenance therapy. Therefore, the purpose of this study was to determine whether discontinuation of maintenance therapy in MPO-AAV patients who were in long-term stable remission affects relapse, renal survival and patient survival. Seventy-nine patients with MPO-AAV diagnosed at Xiangya hospital from June 2010 to June 2019 who were in stable remission for at least 18 months following maintenance therapy were included. Patient records were retrospectively reviewed, and based on whether patients discontinued maintenance therapy 18 months after commencing maintenance therapy, patients were assigned into either the withdrawal group (n = 26) or maintenance group (n = 53). The endpoint was the percentage of relapse, relapse-free survival, renal survival and patient survival during follow-up. Ten relapses (38.5%) occurred in the withdrawal group (n = 26) and 8 relapses (15.1%) occurred in the maintenance group (n = 53) (p = 0.020). Compared to the withdrawal group, the maintenance group had similar relapse-free survival (log-rank test p = 0.099). But maintenance group had a better renal survival (p = 0.035), with no difference in patient survival or adverse events. This study suggests that discontinuing maintenance therapy at 18 months following induction of sustained remission leads to a significant increase in the percentage of relapse, and decreases renal survival in patients with MPO-AAV, but does not decrease relapse-free survival or patient survival.

Coexistence of antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) and IgA nephropathy.

Co-occurrence of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) and IgA nephropathy (IgAN) is extremely uncommon. To date, only a few case reports have described such patients. Here, we describe the clinical presentation, pathologic features, treatment response, and outcome data of five patients with the rare form of co-existing AAV and IgAN and compared the characteristics of these patients to AAV patients with pauci-immune glomerulonephritis (n = 10) and IgAN patients (n = 10) that were selected as controls by stratified random sampling. In addition, we summarize all the previously reported cases of AAV and IgAN. In total, including the current study, 16 AAV/IgAN overlap cases were reported. Our five patients with the coexistence of AAV and IgAN were younger than the ten AAV patients with pauci-immune glomerulonephritis (22.6 ± 8.2 years versus 48.9 ± 15.7 years, respectively, P = 0.004). Histologically, they had a significantly lower percentage of glomeruli with fibrous crescents compared with AAV patients (0.0% versus 4.0%, P = 0.038). Compared with ten IgAN patients, our five AAV/IgAN patients had higher levels of ESR (P = 0.032) and CRP (P = 0.031). After accepting treatment with a combination of steroid and immunosuppressants, all patients showed a positive response to therapy, except for one patient in our cohort and another previously reported patient. We described the clinical presentation, pathologic features, treatment response, and outcome data of five patients with overlapping AAV and IgAN. They had mild glomerular pathological lesions and a positive response to aggressive immunosuppressive therapy. They were quite similar to pauci-immune AAV patients in clinical features, except for younger age. They had a lower percentage of glomeruli with fibrous crescents compared with AAV patients. In contrast to IgAN patients, they had higher levels of ESR and CRP. The mechanism of the coexistence of IgAN and AAV needs further study.

Clinical features and prognosis of MPO-ANCA and anti-GBM double-seropositive patients.

Background: Several lines of evidence implicate that there are distinct differences between patients with myeloperoxidase (MPO)-antineutrophil cytoplasmic antibody (ANCA) and anti-glomerular basement membrane (GBM) antibody double-seropositive patients (DPPs) and single-positive patients. Hence, we conducted a retrospective study from a single center in China to analyze the clinical and pathological features, and prognosis of DPPs. Methods: 109 patients with MPO-ANCA-associated vasculitis (MPO-AAV), 20 DPPs and 23 patients diagnosed with anti-GBM disease from a large center in China were included in this study. The ratio of patients with renal biopsy in three groups were 100%, 50% and 100%, respectively. Their clinical and pathological characteristics, and outcomes were analyzed. The intensity of immune deposits in the kidney at diagnosis was detected by immunofluorescence (IF). Furthermore, multivariate Cox hazard model analysis was used to assess the clinical and histological predictors of end-stage renal disease (ESRD) and death for DPPs. Results: In our study, we found that patients in the DPPs group were older than the other two groups (p = 0.007, MPO-AAV vs. DPPs; p < 0.001, DPPs vs. anti-GBM). The DPPs group had a higher value of serum creatinine (p = 0.041) and lower estimated glomerular filtration rate (eGFR) (p = 0.032) compared with MPO-AAV patients. On the contrary, the DPPs group had a lower serum creatinine (p = 0.003) compared with patients with anti-GBM group. The proportion of patients with cardiac system involvement in the DPPs group was higher than anti-GBM patients (p = 0.014). Cellular crescents could be generally observed in renal biopsy of DPPs and patients with anti-GBM glomerulonephritis. In addition, Bowman's capsule rupture was more common in DPPs than MPO-AAV patients (p = 0.001). MPO-AAV had a better renal and overall survival outcome than DPPs (p < 0.001). There was no significant difference of renal and overall survival outcome between DPPs and patients with anti-GBM disease. The incidence of ESRD in DPPs was negatively associated with lymphocyte count (HR 0.153, 95% CI 0.027 to 0.872, p = 0.034) and eGFR (HR 0.847, 95% CI 0.726 to 0.989, p = 0.036). Elevated serum creatinine was confirmed as a risk factor of both renal (HR 1.003, 95% CI 1.000 to 1.005, p = 0.019) and patient survival in DPPs (HR1.461, 95% CI 1.050 to 2.033, p = 0.024). Conclusion: In summary, compared with anti-GBM disease, DPPs tended to involve multi-organ damage rather than limited to the kidney. It is highlighted that serologic DPPs have a worse renal and patient prognosis than MPO-AAV. Moreover, we found that the risk factors of renal survival of DPPs include low lymphocyte count, elevated serum creatinine and reduced eGFR, and serum creatinine can predict patient survival.

Intrarenal Single-Cell Sequencing of Hepatitis B Virus Associated Membranous Nephropathy.

To date, the pathogenesis of hepatitis B virus (HBV)-associated membranous nephropathy (MN) remains elusive. This study aimed to decipher the etiopathogenesis of HBV-associated MN by performing single-cell RNA sequencing (scRNA-seq) of kidney biopsy specimens from a patient with HBV-associated MN and two healthy individuals. We generated 4,114 intrarenal single-cell transcriptomes from the HBV-associated MN patient by scRNA-seq. Compared to healthy individuals, podocytes in the HBV-associated MN patient showed an increased expression of extracellular matrix formation-related genes, including HSPA5, CTGF, and EDIL3. Kidney endothelial cells (ECs) in the HBV-associated MN were enriched in inflammatory pathways, including NF-kappa B signaling, IL-17 signaling, TNF signaling and NOD-like receptor signaling. Gene ontology (GO) functional enrichment analysis and Gene Set Variation Analysis (GSVA) further revealed that differentially expressed genes (DEGs) of ECs from the HBV-associated MN patients were enriched in apoptotic signaling pathway, response to cytokine and leukocyte cell-cell adhesion. The up-regulated DEGs in glomerular ECs of HBV-associated MN patients were involved in biological processes such as viral gene expression, and protein targeting to endoplasmic reticulum. We further verified that the overexpressed genes in ECs from HBV-associated MN were mainly enriched in regulation of protein targeting to endoplasmic reticulum, exocytosis, viral gene expression, IL-6 and IL-1 secretion when compared with anti-phospholipase A2 receptor (PLA2R)-positive idiopathic membranous nephropathy (IMN). The receptor-ligand crosstalk analysis revealed potential interactions between endothelial cells and other cells in HBV-associated-MN. These results offer new insight into the pathogenesis of HBV-associated MN and may identify new therapeutic targets for HBV-associated MN.

High levels of platelet-to-lymphocyte ratio may predict reduced risk of end stage of renal disease in Chinese patients with MPO-ANCA associated vasculitis. / 血小板/淋巴细胞比率比值升高可能预示中国MPO-ANCAç›¸å ³æ€§è¡€ç®¡ç‚Žæ‚£è€ è¿›å±•è‡³ç»ˆæœ«æœŸè‚¾ç— çš„é£Žé™©è¾ƒä½Ž.

OBJECTIVES: Platelet-to-lymphocyte ratio (PLR) has recently been investigated as a new inflammatory marker in many inflammatory diseases, including systemic lupus erythematosus and immunoglobulin A vasculitis. However, there were very few reports regarding the clinical role of PLR in patients with anti-neutrophil cytoplasmic antibody (ANCA) associated vasculitis. This study was thus undertaken to investigate the relationship between inflammatory response and disease activity in Chinese patients with myeloperoxidase-anti-neutrophil cytoplasmic antibody (MPO-ANCA) associated vasculitis. Furthermore, we evaluated whether PLR predicts the progression of end stage of renal disease (ESRD) and all-cause mortality. METHODS: The clinical, laboratory and pathological data, and the outcomes of MPO-ANCA associated vasculitis patients were collected. The Spearman correlation coefficient was computed to examine the association between 2 continuous variables. Cox regression analysis was used to estimate the association between PLR and ESRD or all-cause mortality. RESULTS: A total of 190 consecutive patients with MPO-ANCA associated vasculitis were included in this study. Baseline PLR was positively correlated with CRP (r=0.333, P<0.001) and ESR (r=0.218, P=0.003). PLR had no obvious correlation with Birmingham Vasculitis Activity Score (BVAS). Patients having PLR≥330 exhibited better cumulative renal survival rates than those having PLR<330 (P=0.017). However, there was no significant difference in the cumulative patient survival rates between patients with PLR≥330 and those with PLR<330 at diagnosis (P>0.05). In multivariate analysis, PLR is associated with the decreased risk of ESRD (P=0.038, HR=0.518, 95% CI 0.278 to 0.963). We did not find an association between PLR with all-cause mortality using multivariate analysis (HR=1.081, 95% CI 0.591 to 1.976, P=0.801). CONCLUSIONS: PLR is positively correlated with CRP and ESR. Furthermore, PLR may independently predict the risk of ESRD.

Clinical features and outcomes of anti-neutrophil cytoplasmic autoantibody-associated vasculitis in Chinese childhood-onset patients.

Data on anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV) are limited in children. This study is to determine the clinical features and outcomes of childhood-onset AAV. A retrospective study was performed on patients who were diagnosed with AAV before 18 years old in Xiangya Hospital. Their medical records were analyzed by retrospective review. Sixteen patients were diagnosed with AAV before 18 years old in the past 9 years, with an average age of 13.3 ± 3.3 years and 13 of them were female. There were 15 patients with microscopic polyangiitis (MPA) and 1 with Wegener's granulomatosis. The interval between onset of disease and diagnosis of AAV was 2 (1.5-3) months. Most patients (15/16, 93.8%) had multi-organ involvement, and all patients had renal involvement with 7 (43.8%) patients requiring dialysis at presentation. Eleven patients underwent a renal biopsy, of which mixed class and sclerotic class were the most two common histological types. All patients received immunosuppressive therapy for induction therapy including intravenous administrations of methylprednisolone (MP) pulse therapy for 8 patients. 8 patients (50%) achieved remission after induction therapy. After a median follow-up of 46.3 ± 36.1 months, nine (56.3%) patients progressed to end-stage renal disease (ESRD) and 5 (31.3%) patients died. Childhood-onset AAV showed similar clinical and pathological features compared to those of adults, except that it usually occurs in girls. The most commonly involved organ was the kidney, and it had a high risk of progression to ESRD. Early diagnosis and initiation of appropriate immunomodulatory therapy would be important to improve outcomes.

Serum Sortilin Is Associated with Coronary Artery Calcification and Cardiovascular and Cerebrovascular Events in Maintenance Hemodialysis Patients.

OBJECTIVE: To analyze the role of serum sortilin in coronary artery calcification (CAC) and cardiovascular and cerebrovascular events (CCE) in maintenance hemodialysis (MHD) patients. METHODS: One hundred eleven patients with MHD ≥3 months were included in this study. The general data, clinical features, hematological data, and medication history of the patients were recorded. Eighty-five cases were examined by vascular color Doppler ultrasound, cardiac color Doppler ultrasound, lateral lumbar radiography, and coronary artery calcification score. The patients were followed up for a median time of 45 months. The primary endpoint was CCE or death from a vascular event, and the role of sortilin in this process was analyzed. RESULTS: Among 85 MHD patients, 51 cases (60.00%) had different degrees of CAC. There were significant differences in diabetes, dialysis time, serum phosphorus, calcium-phosphorus product, medical history of phosphate binders, sortilin, and carotid artery plaque between 4 different degrees of calcification groups (p < 0.05). Logistic regression analysis showed that diabetes (OR = 5.475; 95% CI: 1.794-16.71, p = 0.003), calcium-phosphorus product (OR = 2.953; 95% CI: 1.198-7.279, p = 0.019), and sortilin (OR = 1.475 per 100 pg/mL; 95% CI: 1.170-1.858, p = 0.001) were independent risk factors for CAC. During the follow-up, 28 cases of 111 patients (25.23%) suffered from CCE. There were significant differences in CCE between mild, moderate, and severe CAC groups and noncalcification groups (p < 0.05). Cox regression analysis showed that diabetes mellitus (HR 3.424; 95% CI: 1.348-8.701, p = 0.010), CAC (HR 5.210; 95% CI: 1.093-24.83, p = 0.038), and serum sortilin (HR = 8.588; 95% CI: 1.919-38.43, p = 0.005) were independent risk factors for CCE. Besides, we proposed a cutoff value of 418 pg/mL for serum sortilin level, which was able to predict the occurrence of CCE with 75.0% sensitivity and 71.9% specificity. The area under the curve was 0.778 (95% CI: 0.673-0.883). CONCLUSION: Sortilin is newly found to be independently associated with CAC and CCE in MHD patients.

Single-Cell Profiling Reveals Transcriptional Signatures and Cell-Cell Crosstalk in Anti-PLA2R Positive Idiopathic Membranous Nephropathy Patients.

Idiopathic membranous nephropathy (IMN) is an organ-specific autoimmune disease of the kidney glomerulus. It may gradually progress to end-stage renal disease (ESRD) characterized by increased proteinuria, which leads to serious consequences. Although substantial advances have been made in the understanding of the molecular bases of IMN in the last 10 years, certain questions remain largely unanswered. To define the transcriptomic landscape at single-cell resolution, we analyzed kidney samples from 6 patients with anti-PLA2R positive IMN and 2 healthy control subjects using single-cell RNA sequencing. We then identified distinct cell clusters through unsupervised clustering analysis of kidney specimens. Identification of the differentially expressed genes (DEGs) and enrichment analysis as well as the interaction between cells were also performed. Based on transcriptional expression patterns, we identified all previously described cell types in the kidney. The DEGs in most kidney parenchymal cells were primarily enriched in genes involved in the regulation of inflammation and immune response including IL-17 signaling, TNF signaling, NOD-like receptor signaling, and MAPK signaling. Moreover, cell-cell crosstalk highlighted the extensive communication of mesangial cells, which infers great importance in IMN. IMN with massive proteinuria displayed elevated expression of genes participating in inflammatory signaling pathways that may be involved in the pathogenesis of the progression of IMN. Overall, we applied single-cell RNA sequencing to IMN to uncover intercellular interactions, elucidate key pathways underlying the pathogenesis, and identify novel therapeutic targets of anti-PLA2R positive IMN.

A Partial Picture of the Single-Cell Transcriptomics of Human IgA Nephropathy.

The molecular mechanisms underlying renal damage of IgA nephropathy (IgAN) remain incompletely defined. Here, single-cell RNA sequencing (scRNA-seq) was applied to kidney biopsies from IgAN and control subjects to define the transcriptomic landscape at single-cell resolution. We presented a comprehensive scRNA-seq analysis of human renal biopsies from IgAN. We showed for the first time that IgAN mesangial cells displayed increased expression of several novel genes including MALAT1, GADD45B, SOX4, and EDIL3, which were related to cell proliferation and matrix accumulation. The overexpressed genes in tubule cells of IgAN were mainly enriched in inflammatory pathways including TNF signaling, IL-17 signaling, and NOD-like receptor signaling. Furthermore, we compared the results of 4 IgAN patients with the published scRNA-Seq data of healthy kidney tissues of three human donors in order to further validate the findings in our study. The results also verified that the overexpressed genes in tubule cells from IgAN patients were mainly enriched in inflammatory pathways including TNF signaling, IL-17 signaling, and NOD-like receptor signaling. The receptor-ligand crosstalk analysis revealed potential interactions between mesangial cells and other cells in IgAN. IgAN patients with overt proteinuria displayed elevated genes participating in several signaling pathways compared with microproteinuria group. It needs to be mentioned that based on number of mesangial cells and other kidney cells analyzed in this study, the results of our study are preliminary and needs to be confirmed on larger number of cells from larger number of patients and controls in future studies. Therefore, these results offer new insight into pathogenesis and identify new therapeutic targets for IgAN.

Glomerular Immune Deposition in MPO-ANCA Associated Glomerulonephritis Is Associated With Poor Renal Survival.

Background: Rapidly progressive glomerulonephritis caused by antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is typically characterized as pauci-immune glomerulonephritis. However, immune complex (IC) deposition in the glomerulus has been reported in a growing number of studies. Here, we assess the presence of glomerular immune deposits alongside renal outcome in myeloperoxidase (MPO)-ANCA associated glomerulonephritis (MPO-ANCA GN). Methods: Clinical and histopathologic characteristics of 97 patients with MPO-ANCA GN classified by renal biopsy from January 2008 to December 2019 were extracted retrospectively from electronic medical records. The extent of immune deposits in the kidney (C3, C4, C1q, IgA, IgG, IgM) at diagnosis were analyzed by immunofluorescence (IF). Patients were followed up for a median period of 15 months. The response to treatment and outcomes of renal and histological lesion changes were also assessed. Results: In our study, 41% (40/97) of patients showed positive IF (≥2+) for at least one of the six immunoglobulin or complement components tested. Patients with IC deposits showed higher levels of serum creatinine (p=0.025), lower platelet counts (p=0.009), lower serum complement C3 (sC3) (≤790 ml/L) (p=0.013) and serum IgG (p=0.018) than patients with pauci-immune (PI) deposition at diagnosis. End-stage renal disease was negatively associated with eGFR (HR 0.885, 95% CI 0.837 to 0.935, p<0.0001), platelet count (HR 0.996, 95% CI 0.992 to 1.000, p=0.046) and serum globulin (HR 0.905, 95% CI 0.854 to 0.959, p=0.001). Patients with lower sC3 levels showed a worse renal outcome than the patients with normal sC3 at diagnosis (p=0.003). Analysis of the components of the renal deposits found that patients with IgG deposits exhibited a poorer renal outcome compared to patients that were IgG negative (p=0.028). Moreover, Bowman's capsule rupture occurred less frequently in patients with IgM deposition compared with IgM negative counterparts (p=0.028). Vascular lesions and granuloma-like lesions had been seen more frequently in cases with IgA deposition than those without IgA deposition (p=0.03 and 0.015, respectively). Conclusion: In conclusion, patients with immune complex deposits in the kidney showed less platelet count, lower sC3 and sIgG levels, and higher serum creatinine levels. Patients with low sC3 at initial and with continued low sC3 during the treatment displayed a trend toward poorer kidney survival. Moreover, the IC group showed a worse renal outcome than the PI group, further enforcing the present strategy of introducing complement targeted therapies in AAV.

Differences between myeloperoxidase-antineutrophil cytoplasmic autoantibody (ANCA) and proteinase 3-ANCA associated vasculitis: A retrospective study from a single center in China.

In antineutrophil cytoplasmic autoantibody (ANCA)-associated vasculitides (AAV), the two major target antigens of ANCA are proteinase 3 (PR3) and myeloperoxidase (MPO). Evidence is accumulating that there are distinct differences between patients with PR3-AAV and those with MPO-AAV. In the present study, the clinicopathological features and prognosis of patients with PR3-AAV and MPO-AAV from a single center in China were retrospectively analyzed. A total of 212 Chinese patients with AAV were recruited in the present study; 189/212 (89.15%) patients were classified as having MPO-AAV and 23/212 (10.85%) patients as having PR3-AAV. Compared with those in the PR3-AAV group, patients in the MPO-AAV group were older and less frequently had ear, nose and throat or ophthalmic involvement. MPO-AAV patients had higher levels of serum creatinine and proteinuria at baseline. No significant difference was observed with regard to the pathological changes of the glomeruli and tubulointerstitium between the two groups. The probability of developing end-stage renal disease was significantly higher in patients with MPO-AAV compared with that in patients with PR3-AAV. There was no significant difference in the one-year patient survival rate between the two groups. However, differences in certain clinical characteristics and outcomes were observed between MPO-AAV and PR3-AAV patients. A large national investigation of AAV is required to confirm the concept that PR3-AAV and MPO-AAV are distinct disease entities.

Breakpoint mapping of a t(9;22;12) chronic myeloid leukaemia patient with e14a3 BCR-ABL1 transcript using Nanopore sequencing.

BACKGROUND: The genetic changes in chronic myeloid leukaemia (CML) have been well established, although challenges persist in cases with rare fusion transcripts or complex variant translocations. Here, we present a CML patient with e14a3 BCR-ABL1 transcript and t(9;22;12) variant Philadelphia (Ph) chromosome. METHODS: Cytogenetic analysis and fluorescence in situ hybridization (FISH) was performed to identify the chromosomal aberrations and gene fusions. Rare fusion transcript was verified by a reverse transcription-polymerase chain reaction (RT-PCR). Breakpoints were characterized and validated using Oxford Nanopore Technologies (ONT) (Oxford, UK) and Sanger sequencing, respectively. RESULTS: The karyotype showed the translocation t(9;22;12)(q34;q11.2;q24) [20] and FISH indicated 40% positive BCR-ABL1 fusion signals. The RT-PCR suggested e14a3 type fusion transcript. The ONT sequencing analysis identified specific positions of translocation breakpoints: chr22:23633040-chr9:133729579, chr12:121567595-chr22:24701405, which were confirmed using Sanger sequencing. The patient achieved molecular remission 3 months after imatinib therapy. CONCLUSIONS: The present study indicates Nanopore sequencing as a valid strategy, which can characterize breakpoints precisely in special clinical cases with atypical structural variations. CML patients with e14a3 transcripts may have good clinical course in the tyrosine kinase inhibitor era, as reviewed here.

The association of neutrophil-to-lymphocyte ratio with all-cause mortality in Chinese patients with MPO-ANCA associated vasculitis.

Neutrophil-to-lymphocyte ratio (NLR) has been recently reported to be a promising inflammatory marker to assess systemic inflammation in many disorders. However, there are only a few studies looking at NLR in patients with myeloperoxidase (MPO)-anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). This study was thus undertaken to explore the relationship between NLR at diagnosis with inflammatory response and disease activity among MPO-AAV patients in a single Chinese center. Furthermore, we evaluated whether NLR could predict the renal prognosis and patient outcome. 188 patients with MPO-AAV were included in this study. Baseline NLR was positively correlated with CRP (r = 0.404, P < 0.001) and negatively with serum levels of C3 (r = - 0.163, P = 0.035), but it had no obvious correlation with Birmingham Vasculitis Activity Score (BVAS). Patients with MPO-AAV having NLR ≥ 9.53 exhibited higher risk for all-cause mortality than those having NLR < 9.53 (P < 0.0001). However, no significant difference was found in the kidney survival between patients having NLR ≥ 9.53 and those NLR < 9.53 at diagnosis. In multivariate analysis, NLR was positively associated with all-cause mortality (P = 0.037, HR = 1.98, 95% CI 1.04-3.78). There was no association between NLR with ESRD observed using univariate analysis or multivariate analysis. This large retrospective study of MPO-AAV patients in a single Chinese center demonstrates that NLR positively correlates with CRP and negatively correlates with serum levels of C3 in Chinese patients with MPO-AAV. Importantly, higher NLR predicts increased mortality and is, therefore, a useful independent prognostic in MPO-AAV.

Risk factors for treatment resistance and relapse of Chinese patients with MPO-ANCA-associated vasculitis.

Identification of risk factors for treatment resistance and relapse would be crucial to personalization therapy in patients with myeloperoxidase (MPO)-anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (MPO-AAV). Current evidence with regard to the risk factors for treatment resistance and relapse remains limited and inconclusive. We aimed to assess the predictors for treatment resistance and relapse in a single-center cohort of Chinese patients with MPO-AAV in this study. In total, 184 patients with MPO-AAV were included. Treatment resistance occurred in 64 (34.9%) of 184 patients and was positively associated with lung involvement (odds ratio [OR] 3.581, 95% CI 1.137-11.278, p = 0.029) and the initial serum creatinine level (OR 1.004, 95% CI 1.001-1.007, p = 0.010) and was negatively associated with platelet (OR 0.992, 95% CI 0.987-0.998, p = 0.007) and serum C3 levels (OR 0.998, 95% CI 0.996-0.999, p = 0.004). Relapse occurred in 29 (24.17%) of 120 patients in whom remission was achieved and was independently associated with lung involvement (hazard ratio [HR] 4.595, 95% CI 1.272-16.599, p = 0.020) and cardiovascular involvement (HR 3.689, 95% CI 1.237-11, p = 0.019,). The serum globulin was demonstrated to be negatively associated with relapse independently (HR 0.876; 95% CI 0.806-0.953; p = 0.002). This retrospective study of MPO-AAV patients in a single Chinese center suggests that treatment resistance was positively associated with lung involvement and the initial serum creatinine level and was negatively associated with platelet and serum C3 levels. Lung involvement and cardiovascular involvement were associated with an increased risk of relapse, while the higher serum globulin was demonstrated to be in association with a decreased risk of relapse.