anti-GBM Nephritis Research Articles

Effective management of necrotizing crescentic glomerulonephritis using an aggressive combination therapy including avacopan in a patient double-seropositive for anti-GBM antibodies and ANCA: a case report.

The prognosis of anti-glomerular basement membrane (anti-GBM) nephritis, often accompanied by the presence of antineutrophil cytoplasmic antibodies (ANCA), is poor, and even with aggressive therapeutic approaches, kidney replacement therapy (KRT) is typically required. Here, we present a case of necrotizing crescentic glomerulonephritis in a patient double-seropositive for anti-GBM antibodies and ANCA who successfully achieved dialysis independence following aggressive treatment, including avacopan. The patient was a 77-year-old woman with rapidly progressive glomerulonephritis and double seropositivity for myeloperoxidase-ANCA and anti-GBM antibodies. A kidney biopsy revealed diffuse cellular crescents with necrosis and immunoglobin (Ig)G1 and IgG3 positivity on immunofluorescence staining, leading to a histological diagnosis of anti-glomerular basement membrane nephritis. Our treatment approach involved a novel combination of glucocorticoids, rituximab, low-dose cyclophosphamide, and plasma exchange complemented by avacopan. Temporary hemodialysis was required, and the patient successfully discontinued dialysis after 12 sessions despite a poor histological prognosis. This case underscores the significance of considering aggressive therapeutic strategies, including avacopan, for severe anti-GBM nephritis, even in the absence of lung involvement, to avert the need for KRT.

USP25 attenuates anti-GBM nephritis in mice by negative feedback regulation of Th17 cell differentiation

Purpose This study aimed to elucidate the role of USP25 in a mouse model of anti-glomerular basement membrane glomerulonephritis (anti-GBM GN). Methods USP25-deficient anti-GBM GN mice were generated, and their nephritis progression was monitored. Naïve CD4+ T cells were isolated from spleen lymphocytes and stimulated to differentiate into Th1, Th2, and Th17 cells. This approach was used to investigate the impact of USP25 on CD4+ T lymphocyte differentiation in vitro. Furthermore, changes in USP25 expression were monitored during Th17 differentiation, both in vivo and in vitro. Results USP25−/− mice with anti-GBM GN exhibited accelerated renal function deterioration, increased infiltration of Th1 and Th17 cells, and elevated RORγt transcription. In vitro experiments demonstrated that USP25−/− CD4+ T lymphocytes had a higher proportion for Th17 cell differentiation and exhibited higher RORγt levels upon stimulation. Wild-type mice with anti-GBM GN showed higher USP25 levels compared to healthy mice, and a positive correlation was observed between USP25 levels and Th17 cell counts. Similar trends were observed in vitro. Conclusion USP25 plays a crucial role in mitigating renal histopathological and functional damage during anti-GBM GN in mice. This protective effect is primarily attributed to USP25’s ability to inhibit the differentiation of naïve CD4+ T cells into Th17 cells. The underlying mechanism may involve the downregulation of RORγt. Additionally, during increased inflammatory responses or Th17 cell differentiation, USP25 expression is activated, forming a negative feedback regulatory loop that attenuates immune activation.

Short-chain fatty acids ameliorate experimental anti-glomerular basement membrane disease

BackgroundShort-chain fatty acids (SCFAs), as the link between gut microbiota and the immune system, had been reported to be protective in many autoimmune diseases by the modulation of T cell differentiation. The pathogenic role of autoreactive Th1 and Th17 cells and the protective role of Treg cells in the pathogenesis of anti-GBM disease have been fully demonstrated. Thus, the present study aimed to investigate the therapeutic effects of SCFAs in a rat model of anti-GBM disease. Materials and methodsExperimental anti-GBM disease was constructed by immunizing Wistar Kyoto rats with a nephrogenic T cell epitope α3127–148, and intervened by sodium acetate, sodium propionate, or sodium butyrate, 150 mM in the drinking water from day 0 to 42. Kidney injury was accessed by the biochemical analyzer, immunofluorescence, and immunohistochemistry. Antibody response was detected by ELISA. T cell clustering and proliferation were detected by flow cytometry. Human kidney 2 (HK2) cells were stimulated in vitro and cytokines were assessed by quantitative real-time PCR. ResultsTreatment with sodium acetate, sodium propionate, or sodium butyrate ameliorated the severity of kidney impairment in rats with anti-GBM glomerulonephritis. In the sodium butyrate-treated rats, the urinary protein, serum creatinine, and blood urea nitrogen levels were significantly lower; the percentage of crescent formation in glomeruli was significantly reduced; and the kidneys showed reduced IgG deposition, complement activation, T cell, and macrophage infiltration as well as the level of circulating antibodies against anti-α3(IV)NC1. The treatment of sodium butyrate reduced the α3127–148-specific T cell activation and increased the Treg cells differentiation and the intestinal beneficial bacteria flora. It also alleviated the damage of HK2 cells treated with inflammatory factors and complement. ConclusionTreatment with SCFAs, especially butyrate, alleviated anti-GBM nephritis in rat model, indicating its potential therapeutic effects in clinical usage.

Atypical Anti-Glomerular Basement Membrane Nephritis: A Case Series From the French Nephropathology Group

Rationale & ObjectiveAtypical anti-glomerular basement membrane (GBM) nephritis is characterized by a bright linear immunoglobulin staining along the GBM by immunofluorescence without a diffuse crescentic glomerulonephritis nor serum anti-GBM antibodies by conventional ELISA. We characterized a series of patients with atypical anti-GBM disease. Study DesignCase series. Setting & ParticipantsPatients were identified by the French Nephropathology Group as having atypical anti-GBM nephritis between 2003 and 2022. FindingsAmong 38 potential cases, 25 were included. 14 (56%) were female and 23 (92%) had hematuria. Median [interquartile range (IQR)] serum creatinine at diagnosis was 150 [102-203] μmol/L and median [IQR] urine protein to creatinine ratio was 2.4 [1.3-5.2] g/g. 9 (36%) patients had endocapillary proliferative glomerulonephritis (GN), 4 (16%) had mesangial proliferative GN, 4 (16%) had membranoproliferative GN, 2 (8%) had pure and focal crescentic GN, 1 (4%) had focal segmental glomerulosclerosis, and 5 had glomeruli that were unremarkable on histopathology. Nine patients (36%) had crescents, involving a median of 9% of glomeruli. Bright linear staining for IgG was seen in 22 cases (88%) and for IgA in 3 cases (12%). The nine patients (38%) who had a monotypic staining pattern tended to be older with less proteinuria and rarely had crescents. Kidney survival rate at one year was 83% and did not appear to be associated with the light chain restriction. LimitationsRetrospective case series with a limited number of biopsies including electron microscopy. ConclusionsCompared to typical anti-GBM disease, atypical anti-GBM nephritis frequently presents with endocapillary or mesangial proliferative glomerulonephritis pattern and appears to have slower disease progression. Further studies are needed to fully characterize its pathophysiology and associated clinical outcomes.

Recurrent atypical antiglomerular basement membrane nephritis in the kidney transplant

Atypical antiglomerular basement membrane (anti-GBM) nephritis can be defined as linear GBM staining for monotypic or polytypic immunoglobulin (Ig) by immunofluorescence (IF) without a diffuse crescentic pattern. We describe the clinicopathologic features of 6 patients (18 biopsies) in this first series of recurrent atypical anti-GBM nephritis after kidney transplantation. Recurrent glomerulonephritis occurred at a mean of 3.8 months posttransplant (range 1-7 months). Three index biopsies were for clinical indication, and 3 were protocol biopsies. Glomerular histologic changes were mild, with 2 showing segmental endocapillary hypercellularity, 1 focal glomerular microangiopathy, and the others no significant glomerular histologic changes. All 6 allografts showed monotypic linear glomerular Ig staining by IF: IgG kappa (n = 2), IgG lambda, IgA kappa, IgA lambda, and IgM lambda. Follow-up biopsies were available for 5 patients and showed similar histologic and IF findings without evidence of significant progression. No patients had detectable serum anti-GBM antibody or monoclonal proteins. The mean serum creatinine level on follow-up (24-62 months posttransplant) was 1.8 (range 0.93-2.77) mg/dL; no grafts were lost to recurrent disease. This series demonstrates that monotypic atypical anti-GBM recurs in the allograft and supports the idea that this disease is due to a circulating monoclonal protein.

The Association of Class I and II Human Leukocyte Antigen Serotypes With End-Stage Kidney Disease Due to Membranoproliferative Glomerulonephritis and Dense Deposit Disease

Membranoproliferative glomerulonephritis (MPGN), encompassing several distinct diseases, is a rare but significant cause of kidney failure in the United States. The potential etiologies of MPGN are unclear, but prior studies have suggested dysregulation of the alternative complement pathway and, recently, autoimmunity as potential mechanisms driving MPGN pathogenesis. In this study, we examined HLA associations with end-stage kidney disease (ESKD) due to MPGN and dense deposit disease (DDD) in a large racially and ethnically diverse US-based cohort. Case-control study. Using US Renal Data System (USRDS) and United Network for Organ Sharing (UNOS) data, we identified 3,424 patients with kidney failure due to MPGN and 263 due to DDD. We matched patients to kidney donor controls on designated race and ethnicity in a 1:15 ratio. 58 class I and II HLA serotypes. Case-control status. For each disease cohort, univariable and multivariable logistic regression analyses were used to investigate associations between the disease and 58 HLA serotypes. In subgroup analyses, we investigated HLA associations in White and Black patients. We also studied antiglomerular basement membrane (anti-GBM) nephritis as a positive-control outcome. We applied a Bonferroni correction to account for multiple comparisons. Eighteen serotypes were significantly associated with the odds of having MPGN in univariable analyses, with DR17 having the strongest association (odds ratio [OR], 1.55 [95% CI, 1.44-1.68], P=4.33e-28). No significant associations were found between any HLA serotype and DDD. Designated race-specific analyses showed comparable findings. We recapitulated known HLA associations in anti-GBM nephritis. Reliance on HLA serotypes (rather than genotype), lack of biopsy-confirmed diagnoses. HLA-DR17 is associated with ESKD due to MPGN in a racially and ethnically diverse cohort. The strength of association was similar in White and Black patients, suggesting a role in the pathogenesis of MPGN. No HLA associations were observed in patients with DDD. Prior studies have suggested dysregulation of the alternative complement pathway as a potential etiology of membranoproliferative glomerulonephritis (MPGN), but recent evidence from a British White population has implicated an autoimmune mechanism in MPGN pathogenesis. We investigated HLA associations between MPGN and dense deposit disease (DDD) in a large racially and ethnically diverse cohort of patients. We found that HLA-DR17 is associated with end-stage kidney disease (ESKD) due to MPGN in both White and Black patients. By contrast, no significant HLA associations with ESKD due to DDD were identified. These results suggest a role for autoimmunity in some cases of MPGN and highlight differences in the disease etiology of MPGN compared with DDD.

A Case Report Study at the Miangul Abdul Haq Jahanzeb Kidney Hospital in Swat Found Glomerular Basement Membrane Antibody Disease with Normal Renal Function.

Background: Anti-glomerular basement membrane (GBM) antibody disease is a rare autoimmune condition causing rapidly progressive glomerulonephritis, typically affecting adults. We present an unusual case of anti-GBM nephritis in a 7-year-old child, initially identified through a routine school urine screening. This young patient displayed no overt signs of renal impairment but testing revealed the atypical presence of GBM antibodies.. Objective: The purpose of this case report is to draw attention to the uncommon occurrence of anti-GBM disease in pediatric populations presenting with normal renal function. Diagnosis and management in such cases poses challenges given our understanding of anti-GBM nephritis derives mainly from adult patients. This anomaly prompts consideration of alternate screening and treatment approaches for younger patients who may manifest the disease atypically compared to older populations. Study design: A Case Report Study. Place and duration of study: department of nephrology at the MiangulAbdul Haq Jahanzeb Kidney Hospital From January 2021 to July 2021 Methods: This Case Report study was conducted in the department of nephrology at the MiangulAbdul Haq Jahanzeb Kidney Hospital From January 2021 to July 2021 after ethical clearance for hospital administration of this study. Results: (anti-GBM) illness in infants with intact renal function is uncommon. For this reason, professionals must carefully pick an appropriate therapy for youngsters since the prognosis is grim. Conclusion: Figures 1 to 3 show that things are true of (anti-GBM) illness. (anti-GBM) infection was suspected eventhough her kidneys were in good shape. A VUR might have caused this with a bladder issue as a secondary conditionsource. As an (anti-GBM) medication, DFPP works well for those with normal renal function. Keywords: Anti-GBM, Pediatrics, Normal renal function, School urine screening programmed, case report

Double-Positive Anti-Glomerular Basement Membrane Antibody and Myeloperoxidase Antineutrophil Cytoplasmic Autoantibody-Associated Glomerulonephritis Post COVID-19 mRNA vaccine: A Case Series of 4 Patients.

Vaccines remain central to the management of COVID-19 pandemic, including the need for repeat doses of vaccines to boost immunity. There has been an accumulating case count of glomerulopathies temporally associated with COVID-19 vaccination. This case series presents 4 patients who developed double-positive anti-glomerular basement membrane antibody (anti-GBM) and myeloperoxidase (MPO) antineutrophil cytoplasmic autoantibody (ANCA)-associated glomerulonephritis after COVID-19 mRNA vaccination. This report contributes to our collective knowledge about the pathophysiology and clinical outcomes associated with this rare complication. Four patients developed nephritic syndrome within 1 to 6 weeks after receiving a COVID-19 mRNA vaccine (3 post Pfizer-BioNTech and 1 post Moderna vaccination). Three of the 4 patients also had hemoptysis. Three of the 4 patients had double-positive serology, whereas the fourth patient had renal biopsy findings consistent with double-positive disease, although anti-GBM serology was negative. All patients had renal biopsy findings consistent with double-positive anti-GBM and ANCA-associated glomerulonephritis. All 4 patients were treated with pulse steroids, cyclophosphamide, and plasmapheresis. Of the 4 patients, 1 demonstrated complete remission, 2 remained dialysis-dependent, and the fourth is deceased. Of the 2 patients who received repeat vaccination with COVID-19 mRNA vaccine, 1 patient had second serologic flare of anti-GBM in response to the vaccine. This case series reinforces growing evidence that COVID-19 mRNA vaccine-induced glomerulonephritis is a rare but real phenomenon. Dual ANCA and anti-GBM nephritis can present after the first dose of COVID-19 mRNA vaccine or after several administrations of the vaccine. We are the first to report cases of double-positive MPO ANCA and anti-GBM nephritis after Pfizer-BioNTech vaccination. To our knowledge, we are also the first to report outcomes of repeat COVID-19 vaccination in patients with de novo flare of ANCA and anti-GBM nephritis temporally associated with COVID-19 vaccination.

Hydroxychloroquine suppresses anti-GBM nephritis via inhibition of JNK/p38 MAPK signaling.

Anti-glomerular basement membrane (anti-GBM) nephritis, characterized by glomerular crescent formation, requires early treatment because of poor prognosis. Hydroxychloroquine (HCQ) is an antimalarial drug with known immunomodulatory, anti-inflammatory, and autophagy inhibitory effects; it is recognized in the treatment of autoimmune diseases such as systemic lupus erythematosus. However, its effect on anti-GBM nephritis remains unknown. In this study, we investigated the effect of HCQ on anti-GBM nephritis in rats. Seven-weeks-old male WKY rats were administered anti-GBM serum to induce anti-GBM nephritis. Either HCQ or vehicle control was administered from day 0 to day 7 after the induction of nephritis. Renal function was assessed by measuring serum creatinine, proteinuria, and hematuria. Renal histological changes were assessed by PAS staining and Masson trichrome staining, and infiltration of macrophages was assessed by ED-1 staining. Mitogen-activated protein kinase (MAPK) was evaluated by western blotting, while chemokine and inflammatory cytokines were evaluated by enzyme-linked immunosorbent assay using urine sample. HCQ treatment suppressed the decline in renal function. Histologically, extracapillary and intracapillary proliferations were observed from day 1, while fibrinoid necrosis and ED-1 positive cells were observed from day 3. Rats with anti-GBM nephritis showed high levels of monocyte chemotactic protein-1 and tumor necrosis factor-α. These changes were significantly suppressed following HCQ treatment. In addition, HCQ suppressed JNK/p38 MAPK phosphorylation. HCQ attenuates anti-GBM nephritis by exerting its anti-inflammatory effects via the inhibition of JNK/p38 MAPK activation, indicating its therapeutic potential against anti-GBM nephritis.

Targeting Multiple End Organs in Lupus and Other Systemic Rheumatic Diseases by Inhibiting Bruton's Tyrosine Kinase.

Bruton tyrosine kinase (Btk) plays a vital role in activating and differentiating B-cells and regulating signaling in myeloid cells. Indeed, the potential use of Btk inhibitors in preventing lupus has been reported. Here, we extend these observations to 4 additional models of end-organ inflammation: (a) BWF1 lupus nephritis mice, (b) anti-GBM nephritis, (c) bleomycin-induced systemic sclerosis like skin disease, and (d) bleomycin-induced lung disease. In agreement with the previous studies, BTK inhibitor (BTKB66) treatment was effective in treating lupus nephritis in terms of reducing renal damage both functionally and histologically, accompanied by significant decrease in proteinuria. Both low-dose and high-dose BTKB66 profoundly blocked renal disease in the anti-GBM nephritis model, with efficacy that was comparable to that seen with dexamethasone. This study provides the first evidence that BTK inhibition has both therapeutic and preventative effects in bleomycin-induced SSc-like disease, in terms of reducing skin thickness, fibrosis, collagen deposition, and inflammation. Likewise, significantly lower lung inflammatory cell infiltration was observed after treatment with BTKB66. Therapeutic benefit was associated with lower numbers of macrophages, proliferating macrophages and activated T-cells in the respective injured organs. The observation that these immune cells play key roles in driving end organ inflammation in multiple systemic rheumatic diseases have broad implications for the use of BTKB66 in managing patients with systemic rheumatic diseases where multiple end organs are afflicted, including lupus and systemic sclerosis.

Plasmapheresis for systemic vasculitis.

Systemic vasculitides include a variety of, and numerous diseases. In 2012, the International CHAPEL HILL Consensus Conference (CHCC2012) led to a major reorganization of the classification of vasculitis, and this is still in wide use today. Although the results of plasmapheresis for individual diseases have been sometimes shown, there are few systematic reviews that discuss the effects along with vasculitis classification. Therefore, we will discuss the efficacy and the latest evidence for each vasculitis according to the CHCC 2012 classification in this review. This review provides a comprehensive overview of the estimation of plasmapheresis in each of the vasculitides, with a particular focus on small vasculitides, which have recently discussed frequently. For some time now, plasma exchange therapy (PEX) has been frequently used and is expected to be effective in some diseases, most of which are included in small vessel vasculitides. In particular, data showing efficacy have been accumulated for immune complex vasculitis, and the recommendation seems to be high. For instance, anti‐GBM nephritis, concomitant use of PEX is essential and strongly recommended. On the other hand, for ANCA‐related vasculitis among small vessel vasculitis, RCTs have recently shown negative results. In particular, the PEXIVAS trial statistically showed that PEX has no potential to reduce the mortality and renal death in AAV, but the ASFA, ACR, and KDIGO guidelines following this trial all regard PEX as salvage therapy or selective treatment for severe cases. As plasmapheresis is often performed in combination with other therapies, it is difficult to evaluate to clarify its efficacy on its own, and this predisposition may be pronounced in vasculitis, a rare disease. Although statistically significant differences are not apparent, the diseases that show a trend toward efficacy may possibly include treatment‐sensitive subgroups. Further analysis is expected in the future.

Successful treatment with intense immunosuppressive therapy in an initially 100% crescentic lesion of anti-GBM nephritis

Anti-glomerular basement membrane (anti-GBM) nephritis is uncommon glomerular disease caused by autoantibodies targeting the capillary beds of the kidney. The clinical presentation of the disease is a variable nephritic syndrome, rapidly progressing to glomerulonephritis. Treatment outcomes are dependent on predictors at first diagnosis. We presented a case of 58-year-old man who did not have underlying disease presented with marked abdominal distension and acute kidney injury. He had no evidence of chronic renal disease before admission however, laboratory test showed microscopic haematuria (RBC 30-50 per high-powered field), proteinuria (2.9 g/d), and renal failure (serum creatinine 610 µmol/L) compatible with rapidly progressive glomerulonephritis; hence, a renal biopsy was conducted. The pathology showed 100% crescentic glomerulonephritis with IgG deposits in a linear pattern at the GBM. The initial serum anti-GBM titre was 105.59 RU/mL. This patient had poor renal prognosis factors for treatment response. After a discussion regarding treatment option with the patient, we decided to give intensive immunosuppressive therapy and plasmapheresis due to his good baseline functional status. The patient achieved partial remission and is not dialysis dependent. In conclusion, despite a poor renal prognosis with 100% crescents and serum creatinine ≥ 600 µmol/L, the treated patient had a good survival status and did not become dialysis-dependent. However, immunosuppressive treatment should be performed along with careful monitoring for infection to avoid infection-related morbidity and mortality.

Effects of Perfusion Pressures on Podocyte Loss in the Isolated Perfused Mouse Kidney.

Podocytes are lost in most glomerular diseases, leading to glomerulosclerosis and progressive kidney disease. It is generally assumed, that podocytes are exposed to the filtration flow and thus to significant shear forces driving their detachment from the glomerular basement membrane (GBM). In this context, foot process effacement has been proposed as potential adaptive response to increase adhesion of podocytes to the GBM. We have tested these hypotheses using optical clearing and high-resolution 3-dimensional morphometric analysis in the isolated perfused murine kidney. We investigated the dynamics of podocyte detachment at different perfusion pressures (50, 300 and more than 450 mmHg) in healthy young or old mice (20 vs. 71 weeks of age), or mice injected with anti-GBM serum to induce global foot process effacement. Results show that healthy podocytes in young mice are tightly attached onto the GBM and even supramaximal pressures did not cause significant detachment. Compared to young mice, in aged mice and mice with anti-GBM nephritis and foot process effacement, gradual progressive loss of podocytes had occurred already before perfusion. High perfusion pressures resulted in a relatively minor additional loss of podocytes in aged mice. In mice with anti-GBM nephritis significant additional podocyte loss occurred at this early time point when increasing perfusion pressures to 300 mmHg or higher. This work provides the first experimental evidence that podocytes are extraordinarily resistant to acutely increased perfusion pressures in an ex vivo isolated kidney perfusion model. Only in glomerular disease, significant numbers of injured podocytes detached following acute increases in perfusion pressure.

Heightened Crescentic Glomerulonephritis in Immune Challenged 129sv Mice Is TGF-β/Smad3 Dependent.

The 129sv mouse strain is particularly sensitive to experimental immune-mediated nephritis. Previous studies have indicated that transforming growth factor-β (TGF-β) plays a critical role in both immune modulation and tissue fibrogenesis in various diseases and that its biological activities are exerted via the SMAD family. In this study, we aimed to determine whether TGF-β/SMAD signaling is essential for the development of immune-mediated nephritis in 129sv mice. Relative to C57BL/6J control mice with anti-glomeruli basement membrane (GBM) nephritis, 129sv mice with anti-GBM nephritis exhibited increased renal collagen deposition. Additionally, higher mRNA levels of pro-collagen and collagen IV, higher serum levels of active and total TGF-β1, and increased TGF-β1, TGF-βIIR, and phosphorylated SMAD expression were detected in these mice. Deletion of Smad3 in 129sv mice ameliorated anti-GBM induced nephritis, including crescentic glomerulonephritis. Collectively, these findings indicate that the heightened experimental nephritis and fibrotic disease in the 129sv strain of mice are regulated by SMAD3, which could be a potential therapeutic target for immune-mediated nephritis.

Disease activity prediction and prognosis of anti-GBM nephritis based on T lymphocyte subset ratios.

IntroductionCell-mediated autoimmunity, especially the autoreactivity of T cells, is known to underlie the initiation of anti-glomerular basement membrane disease. However, the T lymphocyte subsets that determine the disease activity, renal fibrosis, and prognosis of anti-GBM disease have not been clearly elucidated.MethodsThe T lymphocyte subsets (CD4+ and CD8+) were examined on peripheral blood and renal biopsy tissues from 65 patients with biopsy proven anti-GBM disease. Patients were divided into the high ratio group and low ratio group according to the cutoff values in the receiver operating characteristic curve analysis. The correlations of T lymphocyte subsets with clinical, pathological data, and renal outcome were analyzed.ResultsBy the end of follow-up, 45 patients (69.2%) developed end-stage renal disease (ESRD). In peripheral blood, the CD4+/CD8+ ratio showed a predictive ability with a sensitivity and specificity of 91.3% and 52.9%, respectively, which gave rise to a cutoff value of 0.89. There was a significant difference in the activity index between these two groups (3.91 ± 1.38 vs. 2.89 ± 1.13, p = 0.007). In the renal tissues, the CD4+/CD8+ ratio had the optimal cutoff point of 0.82 with a sensitivity of 57.8% and specificity of 85%. The renal activity index was higher for the renal tissues with high CD4+/CD8+ ratios than that of tissues with low CD4+/CD8+ ratios (4.32 ± 1.55 vs. 3.37 ± 1.41, p = 0.016). Peripheral blood CD4+/CD8+ ratios of ≥0.89 or renal tissue CD4+/CD8+ ratios of < 0.82 positively correlated with poor renal prognosis in patients with anti-GBM nephritis.ConclusionsThe CD4+/CD8+ ratio was associated with renal activity index both in peripheral blood and renal tissue and predicts the renal prognosis of patients with anti-GBM nephritis.

Clinicopathological and Immunological Features of Patients With New Onset Kidney Disease After Inactivated SARS-CoV-2 Vaccination: An Observational Cohort Study

Background: The onset of various kidney diseases have been reported after COVID-19 vaccination. However, detailed clinical and pathological examination of kidney injury in patients receiving inactivated vaccines are lacking.Methods: We screened and analyzed patients with newly diagnosed kidney diseases after inactivated SARS-CoV-2 vaccination in Peking University First Hospital from January 2021 to August 2021. We obtained samples of blood, urine, and renal biopsy tissues. Clinical and laboratory information, as well as light microscopy, immunostaining and ultrastructural observation were described. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) Spike protein and Nucleoprotein were stained using immune-fluorescence technique in the kidney biopsy samples. SARS-CoV-2 specific antibodies were tested using magnetic particle chemiluminescence immunoassay.Findings: The study group included 17 patients, including immune complex mediated kidney diseases (IgA nephropathy, membranous nephropathy and lupus nephritis), podocytopathy (minimal change disease and focal segmental glomerulosclerosis) and others (antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis, anti-GBM nephritis, acute tubulointerstitial nephritis, and thrombotic microangiopathy). Seven patients (41.18%) developed renal disease after the first dose and 10 (58.82%) after the second dose. We found no definitive evidence of SARS-CoV-2 Spike protein or Nucleoprotein deposition in the kidney biopsy samples. Serological markers implicated abnormal immune responses in predisposed individuals. Treatment and follow-up (median = 86 days) showed that biopsy diagnosis informed treatment and prognosis in all patients.Interpretation: We observed various kidney diseases following inactivated SARS-CoV-2 vaccine administration. Our findings provide an evidence against direct vaccine protein deposition as the major pathomechanism, but implicate abnormal immune responses in predisposed individuals. These findings expand our understanding of inactivated SARS-CoV-2 vaccine renal safety.Funding: This study was funded by National Natural Science Foundation of China (91742205, 82170711, 81800636, 82070733, 81625004), Clinical Medicine Plus X—Young Scholars Project of Peking University (PKU2021LCXQ017), the Fundamental Research Funds for the Central Universities, CAMS Innovation Fund for Medical Sciences (2019-I2M-5-046), Yunnan Provincial Science and Technology Department (202102AA100051 and 202003AC100010, China), and Beijing Young Scientist Program (BJJWZYJH01201910001006).Declaration of Interest: The authors declare no competing interests.Ethical Approval: This study was approved by the institutional review board of Peking University First Hospital (2021-352) and the Committee on Human Subject Research and Ethics of Yunnan University (CHSRE2021020). Written Informed Consent Form was obtained from each participant.

Recurrent, atypical anti-glomerular basement membrane disease

Anti-glomerular basement membrane disease (GBM) (Goodpasture's disease) typically presents with acute manifestations of rapidly progressive glomerulonephritis often accompanied by lung haemorrhage. Anti-GBM disease is usually monophasic. However, atypical presentations with indolent renal involvement are being increasingly recognized. Herein we report a patient who presented with lung haemorrhage, minimal renal involvement, and negative result for serum anti-GBM antibody, while immunofluorescence examination of the renal biopsy provided the diagnosis leading to the institution right treatment with excellent response. Interestingly, he had presented 10 years earlier with lung hemorrhage, more significant renal involvement clinically and histologically, with positive serum anti-GBM antibody. The present case is intended to increase our awareness regarding the variable presentations of anti-GBM disease, such as with negative serology and recurrence of anti-GBM disease. The presentation of anti-GBM nephritis with non-proliferative, non-crescentic glomerulonephritis is also highlighted. The possible explanations for negative serum anti-GBM antibody are explored with a brief review of literature.

The development of rapidly progressive glomerulonephritis associated with both antineutrophil cytoplasmic antibody-associated vasculitis and anti-glomerular basement membrane nephritis in the course of nontuberculous mycobacterium infection: a case report

BackgroundAntineutrophil cytoplasmic antibodies (ANCA) and Anti-glomerular basement membrane (GBM) antibodies often induce rapidly progressive glomerulonephritis (RPGN). Some reports have demonstrated RPGN with the sequential appearance of ANCA then anti-GBM antibodies, suggesting that ANCA may induce the development of anti-GBM antibodies. Whereas, many reports have shown that the development of ANCA is associated with various infectious diseases, such as non-tuberculous mycobacterial infection.Case presentationA 65-year-old woman with pulmonary non-tuberculous mycobacterial (NTM) infection was monitored without treatment. One year later, serum myeloperoxidase (MPO)- ANCA were elevated (14.1 U/mL (normal value < 3.0 U/ml)). A high fever and RPGN appeared 1 year later, and serum MPO-ANCAs were 94.1 U/mL. Anti-GBM antibodies were also detected. A renal biopsy revealed crescentic glomerulonephritis with linear deposits of IgG and C3c along the GBM and interstitial inflammation with endarteritis of arterioles. The diagnosis was RPGN associated with anti-GBM nephritis and ANCA-associated vasculitis.ConclusionThis report shows that preceding NTM infection may have induced ANCA and anti-GBM antibodies and caused the development of RPGN.

SUCCESSFUL TREATMENT WITH PLASMAPHERESIS AND IMMUNOSUPPRESSANTS IN ANCA-NEGATIVE GOOD PASTURE SYNDROME: A RARE CASE REPORT

SESSION TITLE: Medical Student/Resident Diffuse Lung Disease SESSION TYPE: Med Student/Res Case Rep Postr PRESENTED ON: October 18-21, 2020 INTRODUCTION: Goodpasture syndrome (GPS), or Anti-glomerular basement membrane disease is a rare autoimmune disease with an annual incidence of 0.5-1.6 cases per million [1]. We report a case of cytoplasmic antineutrophil cytoplasmic antibodies (C-ANCA) negative GPS disease where combined immunosuppressant and plasmapheresis treatment resulted in significant improvement of both hemoptysis and renal function. CASE PRESENTATION: A 19-year-old female with past medical history of obesity, asthma and chronic cough presented with shortness of breath, and hemoptysis of two week duration despite being treated with several courses of antibiotics for presumed recurrent pneumonia. She was found to be hypertensive on arrival (BP 163/95 mmHg). Work up revealed elevated creatinine, significant hematuria and proteinuria. CT chest demonstrated bilateral multifocal patchy infiltrates suspicious for pneumo-renal syndrome. She was empirically started on pulse dose methylprednisolone. Autoimmune workup revealed positive anti-glomerular basement membrane (anti-GBM) antibodies (36U ; normal value <20U) and negative C-ANCA. Renal biopsy showed acute necrotizing fibrocellular crescents involving more than two third of the glomeruli and linear GBM staining for IgG suggestive of anti-GBM nephritis confirming the diagnosis of GPS. Treatment with five rounds of plasmapheresis and immunosuppressive therapy with cyclophosphamide followed by extended release prednisone taper resulted in significant clinical improvement. DISCUSSION: GPS is characterized by auto reactivity to antigens in type IV collagen chains present in the glomeruli and alveolar basement membrane capillaries resulting in crescentic glomerulonephritis and diffuse pulmonary alveolar hemorrhage[2]. Additionally, ANCA is associated with GBM in 20-60% of the cases. The current treatment includes plasma exchange(PE) which involves removal of circulating anti-GBM antibodies and other mediators of inflammation, and immunosuppressants that minimize new antibody formation[3]. Although PE is effective in the treatment of GPS, the efficacy of combined immunosuppressant with PE is not well established. Our case is unique that the combined treatment with immunosuppressants and plasmapheresis resulted in a significant improvement of both hemoptysis and renal function in a ANCA negative good pasture’s disease. As GPS is associated with irreversible renal damage and high mortality rate, early and appropriate treatment may reverse the kidney damage and prevent the need for hemodialysis[2]. However, further multi-center clinical trials are required to establish its efficacy in the treatment of GBM. CONCLUSIONS: Our case highlights that PE in combination with cyclophosphamide resulted in significant improvement when compared to treatment with PE alone as reported in the literature. Early diagnosis and treatment can result in favorable outcomes in patients with GPS. Reference #1: Marques, C., et al., Prognostic Factors in Anti-glomerular Basement Membrane Disease: A Multicenter Study of 119 Patients. Front Immunol, 2019. 10: p. 1665. Reference #2: Apaydin, S., The treatment of ANCA-associated rapidly-progressive glomerulonephritis and Goodpasture syndrome with therapeutic apheresis. Transfus Apher Sci, 2018. 57(1): p. 8-12. Reference #3: Prendecki, M. and C. Pusey, Plasma exchange in anti-glomerular basement membrane disease. Presse Med, 2019. 48(11 Pt 2): p. 328-337. DISCLOSURES: No relevant relationships by Ioana Amzuta, source=Web Response No relevant relationships by Anupama B K, source=Web Response No relevant relationships by Japjot Chahal, source=Web Response No relevant relationships by Christopher Ramos, source=Web Response No relevant relationships by Akhila sunkara, source=Web Response

Growth Differentiation Factor 15 Ameliorates Anti-Glomerular Basement Membrane Glomerulonephritis in Mice.

Growth differentiation factor 15 (GDF15) is a member of the transforming growth factor-β (TGF-β) cytokine family and an inflammation-associated protein. Here, we investigated the role of GDF15 in murine anti-glomerular basement membrane (GBM) glomerulonephritis. Glomerulonephritis induction in mice induced systemic expression of GDF15. Moreover, we demonstrate the protective effects for GDF15, as GDF15-deficient mice exhibited increased proteinuria with an aggravated crescent formation and mesangial expansion in anti-GBM nephritis. Herein, GDF15 was required for the regulation of T-cell chemotactic chemokines in the kidney. In addition, we found the upregulation of the CXCR3 receptor in activated T-cells in GDF15-deficient mice. These data indicate that CXCL10/CXCR3-dependent-signaling promotes the infiltration of T cells into the organ during acute inflammation controlled by GDF15. Together, these results reveal a novel mechanism limiting the migration of lymphocytes to the site of inflammation during glomerulonephritis.