Pauci-immune Glomerulonephritis Research Articles

The clinical course of SARS-CoV-2 infection in patients with glomerular diseases and evaluation of the subsequent risk of relapse.

This study aimed to describe the clinical course of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection in patients with glomerular diseases (GDs) and its impact on the probability of relapse. Patients with biopsy-proven GD and positive PCR test for SARS-CoV-2 from glomerular clinics across Greece were studied retrospectively. Those who received the GD diagnosis after the SARS-CoV-2 vaccination or coronavirus disease 2019 (COVID-19) or ended in ESKD prior to infection were excluded. Demographics, histopathological diagnoses, past medical history, immunosuppression, and GD activity status were recorded. A total of 219 patients with GDs and documented SARS-CoV-2 infection were included. The mean time from the diagnostic kidney biopsy to SARS-CoV-2 infection was 67.6 ( ± 59.3) months. Among the participants, 82.5% had been vaccinated against SARS-CoV-2 with three doses (range: 2.5-3) without subsequent GD reactivation in 96.2% of them. Twenty-two patients (10%) were hospitalized for COVID-19 and one (0.5%) required mechanical ventilation. Four (1.8%) died due to COVID-19 and one (0.5%) had long COVID-19 symptoms. Among patients in remission prior to SARS-CoV-2 infection, 22 (11.2%) experienced a GD relapse within 2.2 (range: 1.5-3.7) months from the diagnostic test. The relapse-free survival after COVID-19 was significantly shorter for patients with minimal change disease, pauci-immune glomerulonephritis, and focal segmental glomerulosclerosis. No difference was observed in the relapse-free survival post-COVID-19 based on the history of SARS-CoV-2 vaccination. SARS-CoV-2 infection appears to have a symptomatic but uncomplicated sequence in vaccinated patients with GDs, with a significant impact on the clinical course of GD, associated with an increased probability of relapse in certain histopathological types.

HHV8-related Castleman disease presenting with nephrotic syndrome and pauci-immune glomerulonephritis.

HHV8-related Castleman disease presenting with nephrotic syndrome and pauci-immune glomerulonephritis.

Clinical Presentation and Outcomes of SARS-CoV-2 Infection in Patients with Pauci-Immune Glomerulonephritis

Clinical Presentation and Outcomes of SARS-CoV-2 Infection in Patients with Pauci-Immune Glomerulonephritis

Pauci-Immune Glomerulonephritis (GN) in a Patient with Scleroderma: Importance of Urine Sediment and Kidney Biopsy

Pauci-Immune Glomerulonephritis (GN) in a Patient with Scleroderma: Importance of Urine Sediment and Kidney Biopsy

Uncommon Presentation of Pauci-Immune Crescentic Glomerulonephritis in a Young Adult with Normal Kidney Function

Uncommon Presentation of Pauci-Immune Crescentic Glomerulonephritis in a Young Adult with Normal Kidney Function

I ANCA Kidding: ANCA-Associated, Pauci-Immune Crescentic Glomerulonephritis with Normal Kidney Function Presenting with Transverse Myelitis

I ANCA Kidding: ANCA-Associated, Pauci-Immune Crescentic Glomerulonephritis with Normal Kidney Function Presenting with Transverse Myelitis

Etiology, clinical profile, and outcomes of crescentic glomerulonephritis in children: a systematic review.

Crescentic glomerulonephritis, if not managed promptly, is associated with unsatisfactory outcomes. There are limited studies reporting the outcomes of crescentic glomerulonephritis in children. This systematic review is aimed at synthesizing the data on etiology, clinical profile, and outcomes of crescentic glomerulonephritis in children. We performed a literature search using PubMed, Embase, and Web of Science from inception to January 2024 without language or geographic restrictions. Cohort and cross-sectional studies with at least 10 participants reporting etiology, clinical features, and outcomes on crescentic glomerulonephritis in children were considered eligible. Children aged less than 18years with crescentic glomerulonephritis. We used a tool by Hoy et al. for assessing the quality of studies. We calculated pooled estimates using random effect meta-analyses. Primary outcome was the pooled proportion of patients progressing to kidney failure. From 1706 records, we included 36 studies (1548 participants) from 16 countries. Etiology was immune-complex glomerulonephritis in 76% (95% CI 67 to 85), pauci-immune in 19% (13 to 25), and anti-GBM disease in 5% (3 to 7) of patients. Gross hematuria, oliguria, edema, and hypertension were observed in 63% (41 to 82), 57% (34 to 79), 79% (65 to 90), and 64% (49 to 77), respectively. In-hospital mortality, reported in 11 studies, was 7% (4 to 11). Progression to kidney failure and chronic kidney disease was reported in 27% (21 to 33) and 50% (29 to 71) ofpatients, respectively. Risk factors for kidney failure included oliguria, dialysis requirement at onset, estimated GFR, proportion of fibrous crescents, and pauci-immune glomerulonephritis as the underlying etiology. High heterogeneity in pooled estimates of the outcomes. Immune-complex glomerulonephritis is the most common etiology in children, with edema, hypertension, gross hematuria, and oliguria being the chief presenting manifestations. Almost one in every four patients with crescentic glomerulonephritis progressed to kidney failure. PROSPERO registration number CRD42024500515.

ANCA-negative Crescentric Pauci-immune Glomerulonephritis Associated with Allergic Bronchopulmonary Aspergillosis: A Rare Entity

We present an unusual case of a 23-year-old male presenting with dyspnea, anasarca, and high-colored urine and simultaneously diagnosed as a case of allergic bronchopulmonary Aspergillosis. On detailed investigations, his serologies for vasculitis turned out to be all negative. Renal biopsy revealed pauci-immune crescentic glomerulonephritis. This rare report explains that the underlying immunological response to Aspergillus antigen can be the cause for casual association between the two entities.

A case of ANCA-negative pauci-immune crescentic glomerulonephritis with lung adenocarcinoma with mediastinal involvement successfully treated by corticosteroid and radiation therapy.

Pauci-immune crescentic glomerulonephritis (PICGN) is one of the pathologies causing rapidly progressive glomerulonephritis, often associated with anti-neutrophil cytoplasmic antibody (ANCA); however, in 10-30% of cases, ANCAs are negative. While a relatively large number of cases of ANCA-positive PICGN complicated with malignancy have been previously reported, the number of cases of ANCA-negative PICGN with malignancy is limited. The prognosis for such cases was poor, and many patients died within a relatively short period. Here, we report the case of ANCA-negative PICGN complicated with malignancy successfully treated by corticosteroid and radiation therapy. A 63-year-old Japanese man was admitted to our hospital due to spiking fevers in the previous 3months. Based on the findings of imaging and pathological tests, he was diagnosed with locally advanced lung adenocarcinoma with mediastinal involvement. After admission, his renal function rapidly deteriorated, and urinalysis showed heavy proteinuria. In serological tests, serology for autoantibodies, including ANCAs, was negative. The kidney biopsy revealed PICGN with prominent endocapillary proliferation. We administered corticosteroid therapy for glomerulonephritis and subsequent radiation therapy for lung carcinoma, both of which were effective. He has been alive without progression of malignancy or kidney disease for 5 years after discharge. In patients with malignancy presenting with acute deterioration of kidney function, although infrequent, one of the conceivable pathological conditions to consider is ANCA-negative PICGN associated with malignancy. In such cases, even with negative antibodies such as ANCA, pathological examination is warranted, and a combination of anti-tumor therapy and immunosuppressive therapy is expected to be effective.

Kidney Failure in Pauci-immune Crescentic Glomerulonephritis: Rationale for Immunosuppression to Improve Kidney Outcome.

Pauci-immune crescentic glomerulonephritis is the hallmark finding in ANCA-associated vasculitis (AAV) when the kidneys are affected. The rationale for immunosuppression in AAV is based on the underlying autoimmune nature of the disease. Overall remission rates, kidney outcomes, and the burden of disease have greatly improved since the discovery of various immunosuppressive therapies, but relapses remain common, and a significant proportion of patients continue to progress to end-stage kidney disease. Here, we review the role of immunosuppressive therapies for the treatment of pauci-immune crescentic glomerulonephritis. Besides the recognized role of B and T cells in the pathogenies of AAV, the focus on the contribution of inflammatory cytokines, neutrophil extracellular traps (NETs), and the complement system allowed the discovery of new therapies. Specifically, the C5a receptor blocker (avacopan) has been approved as a glucocorticoid-sparing agent. Additionally, based on observational data, more clinicians are now using combination therapies during the induction phase. There is also an evolving understanding of the role of plasma exchange in removing ANCA antibodies. Furthermore, the recent development of risk score systems provides physicians with valuable prognostic information that can influence decisions on immunosuppression, although future validation from larger cohorts is needed. The over-activation of various immune pathways plays a significant role in the pathogenesis of pauci-immune crescentic glomerulonephritis in AAV. Immunosuppression is, therefore, an important strategy to halt disease progression and improve overall outcomes. Relapse prevention while minimizing adverse events of immunosuppression is a major long-term goal in AAV management.

Clinical Presentation and Treatment Outcomes of Renal Medullary Angiitis in Antineutrophil Cytoplasmic Antibody-Associated Vasculitis: A Single-Center Case Series.

Antineutrophil cytoplasmic antibody-associated vasculitis (AAV) with renal involvement primarily affects the renal cortex and presents with key histopathologic findings of a pauci-immune necrotizing and crescentic glomerulonephritis. Infrequently reported and poorly characterized is renal medullary angiitis (RMA), a pathologic variant of AAV primarily involving the renal medulla. This study seeks to describe the presentation and treatment outcomes of RMA. In this single-center cohort, renal pathology samples classified as AAV with renal involvement underwent secondary review to determine if they met histopathologic criteria for RMA. Demographic, clinical, and laboratory data were obtained via electronic medical record review. Descriptive statistical analysis was performed on key variables. Of the 136 kidney biopsy samples classified as AAV with renal involvement, histopathologic features of RMA were present in 13 cases. The mean (SD) age at the time of RMA diagnosis was 65 (19) years, and 54% were female. Most cases presented with extrarenal manifestations of disease. Initial median (IQR) estimated glomerular filtration rate and proteinuria on presentation were 16 (10-19) mL/min/1.73 m2 and 1,100 (687-2,437) mg, respectively. The primary histologic features were high degrees of interstitial inflammation comprised leukocytes, neutrophils, plasma cells, and eosinophils along with either interstitial hemorrhage or necrosis. All patients were treated with glucocorticoids in combination with either cyclophosphamide, rituximab, or mycophenolate. All patients achieved disease remission. During a median (IQR) follow-up of 42 (14-68) months, 1 patient reached ESKD and 1 patient died. In this single-center case series, we identified the presence of RMA in 9.5% of AAV samples that underwent secondary review. RMA presented with severe impairment in renal function and multisystem disease. Standard of care immunosuppression for AAV was effective for remission induction in RMA. It remains unclear whether standard prognostication tools are useful in this population.

Outcomes of Covid-19 Vaccine-Associated Glomerular Diseases (CVAGD) – A Case Series from India

Background Several cases of glomerular diseases following Covid-19 vaccination, especially mRNA vaccines, have been reported. However, there is little data on glomerular diseases associated with the two vaccines widely available in India (Covaxin and Covishield) and their long-term outcomes. Materials and Methods This was a prospective observational study conducted between May 2021 and May 2023. Patients with new-onset or relapse of proteinuria, hematuria, or renal failure within 30 days of Covid-19 vaccination were included. Data on pre-existing renal disease, vaccine type, symptomatology, laboratory reports, kidney biopsy findings, and treatment details were collected. The clinical course and long-term renal outcomes were studied. Results Sixteen patients with Covid-19 vaccine associated glomerular disease (CVAGD) were studied. The median age was 28 years (IQR 20.5–40) and median time of symptom onset was 14 days (IQR 10–16.5) after vaccination. Renal syndromes at presentation were nephrotic syndrome in seven patients (43.75%), nephritic syndrome in seven patients (43.75%), and rapidly progressive renal failure in two patients (12.5%). Kidney biopsy revealed minimal change disease in five patients (31.2%); IgA nephropathy in four patients (25%); C3 glomerulopathy, lupus nephritis, and focal segmental glomerulosclerosis in two patients each (12.5%); and pauci-immune glomerulonephritis (ANCA-associated vasculitis) in one patient (6.25%). Eleven patients were treated with immunosuppressive drugs. Median duration of follow-up was 20 months (IQR 18–21). At last follow-up, 11 patients had complete recovery of renal failure and proteinuria and 4 patients had partial recovery. Conclusion The most common lesions in this series were minimal change disease and IgA nephropathy. The overall long-term outcome of CVAGD appears good.

Diagnostic accuracy of ANCA serology in ANCA-associated vasculitis with renal involvement.

Pauci-immune glomerulonephritis (GN) due to antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a common cause of crescentic GN. Despite advances in treatment, rates of mortality and progression to end-stage kidney disease remain high. Renal involvement is diagnosed by histological examination of kidney tissue. Serum ANCAs play a significant role in AAV; however, the value of serum ANCA quantification to predict renal involvement is not well-established. We aimed to evaluate the diagnostic accuracy of serum ANCA titres in diagnosing AAV with renal involvement. We conducted a retrospective study of consecutive native kidney biopsies reported at our centre from 2016 to 2021. We included all adults who had both a kidney biopsy and ANCA serology. ANCA serology was tested using indirect immunofluorescence with reporting of titres. Antibodies to proteinase 3 and myeloperoxidase were measured using a chemiluminescent immunoassay. Eight hundred and forty-eight native kidney biopsies were reported during the study period. Five hundred and seven cases were included. The biopsy prevalence of pauci-immune GN in paired samples was 41/507 (8.1%). Most of the cohort had haematuria (66.6%), proteinuria (93.4%) and/or acute kidney injury (65.0%). A positive ANCA at any titre demonstrated a sensitivity of 97.6% and a specificity of 71.2% for a diagnosis of pauci-immune GN. The area under the curve for the receiver operator characteristic was 0.93 (95% confidence interval [CI]: 0.89-0.97). A cutoff ANCA titre of 1:160 provided the optimum balance between a sensitivity of 75.6% (95% CI: 59.7%-87.6%) and a specificity of 94.0% (95% CI: 91.6%-96.0%). ANCA titres are highly predictive of pauci-immune GN in the appropriate context. While serum ANCA quantitation may not replace renal biopsy, reporting will assist in the decision to start treatment early for patients with organ or life-threatening disease.

Crescentic Glomerulonephritis in Human Immunodeficiency Virus Infection

The spectrum of kidney disease among human immunodeficiency virus (HIV) infected patients is extensive. We describe a young male who was recently detected with HIV infection and antineutrophil cytoplasmic antibody (ANCA) negative pauci-immune crescentic glomerulonephritis. The patient had no extrarenal vasculitis involvement. Patient was successfully managed with highly active antiretroviral therapy (HAART) and oral steroids. In our case report, we have also reviewed the literature of crescentic glomerulonnephritis in HIV infection.

Deciphering the association between biopsy-confirmed systemic small vessel vasculitis and Epstein-Barr virus-positive polymorphic B-cell lymphoproliferation.

The Epstein-Barr virus (EBV) is associated with various lymphoproliferative disorders (LPD). Additionally, EBV infection has correlated with diverse autoimmune diseases. However, the association between EBV and systemic small vessel vasculitis (SVV) remains controversial. Here, we report a case of SVV with pauci-immune glomerulonephritis accompanied by an EBV-positive polymorphic B-cell LPD, not otherwise specified. The intricate distinction between EBV-positive B-cell LPD and SVV was difficult, as both diseases demonstrated similar clinical presentations. Lymph node and kidney biopsies facilitated the accurate diagnosis of these two conditions. The administration of high-dose prednisolone, combined with rituximab, proved efficacious, with no instances of relapse over the subsequent 2-year period. This case indicates an association between EBV-positive B-cell LPD and SVV. The diligent execution of biopsies is a crucial diagnostic and interpretive strategy, generating precise comprehension of this condition and guiding its appropriate therapeutic management.

#1782 Clinicopathological study of renal limited pauci-immune vasculitis and its short-term outcome: a single centre observational study

Abstract Background and Aims Pauci immune crescentic glomerulonephritis, is a leading cause of RPGN. The majority of patients with PICGN have glomerular diseases as a part of a systemic small vessel vasculitis, a minority may present as renal-limited vasculitis. In north-east India, there are still no major studies in this group of patients. Therefore, our study involving north-east Indian population constitutes an effort to prospectively study the clinico-pathological feature of patients with PICGN and assess the short-term outcome. Method This single-centre, prospective, observational, study was conducted over 12 months at the Department of Nephrology, Gauhati Medical College. All renal biopsy-proven patients with pauci-immune renal vasculitis were included, excluding those with secondary vasculitis. Baseline characteristics and laboratory data were recorded, and disease activity was assessed using the Birmingham Vasculitis Activity Score. The ANCA tests were performed using a standardised essay for both indirect immunofluorescence assay and antigen-specific ELISA. The renal biopsy specimen obtained was evaluated by light microscopy and direct immunofluorescence. The sample size was calculated based on the prevalence of pauci-immune glomerulonephritis, and data were analysed using SPSS. Results The study involved 24 patients, predominantly females (70.83%), aged 14-65 years, presenting predominantly with pedal oedema and oliguria. Laboratory findings showed varying levels of haemoglobin, total count, platelet count, creatinine, and 24-hour urine protein. 50% of the patients were (MPO) positive, 33.3% were (PR3) positive while 16% were ANCA negative. Renal biopsy analysis showed a majority with mixed class according to the Berden classification. Treatment involved induction with Methylprednisolone and Cyclophosphamide, with dialysis administered to 58.3% of patients. At six months, 36.3% had a stable GFR, and 50% were on maintenance hemodialysis. Factors predicting renal loss included oliguria, dialysis at presentation, and fibrous/fibrocellular crescents. The best predictor of renal outcome was serum creatinine at presentation. Conclusion Pauci-immune CrGN is a severe disease affecting a wide age range. Early diagnosis and treatment initiation are crucial for better outcomes, including lower ESRD risk and relapse rates. Prognostic factors include baseline serum creatinine levels and fibrous crescents. Optimising treatment regimens may improves outcomes.

Myeloperoxidase-Associated Membranous Nephropathy in Antineutrophil Cytoplasmic Antibody-Associated Glomerulonephritis

IntroductionAnti-neutrophil cytoplasmic antibody (ANCA)–associated glomerulonephritis (GN) is characterized by pauci-immune crescentic GN. Although myeloperoxidase ANCA-associated GN (MPO-ANCA GN) with membranous nephropathy (MN), where bright granular capillary myeloperoxidase (MPO) and immunoglobulin G (IgG) staining along the glomerular basement membrane (GBM) is present, has been reported; however, its clinicopathological features remain unclear. MethodsWe investigated 7 MPO-ANCA GN with MN and 11 control cases (6 MPO-ANCA GN and 5 primary MN cases). Proteomics of laser microdissected glomeruli followed by immunohistochemical analysis was performed to identify causal antigens in MPO-ANCA GN with MN. We described the clinicopathological features of MPO-associated MN compared with those of MPO-ANCA GN and primary MN. ResultsWe detected proteomic MPO and granular capillary MPO deposits in all MPO-ANCA GN with MN cases. Confocal microscopy revealed MPO and IgG co-localization along the GBM. MPO-associated MN clinicopathological features include greater proteinuria, a higher fibrous crescent rate, and a lower MPO-ANCA titer than MPO-ANCA GN. The estimated glomerular filtration rate and urinary protein excretion were lower in MPO-associated MN than in primary MN. ConclusionMPO-associated MN, a unique type of secondary MN where MPO serves as the causal antigen, is a subset of MPO-ANCA GN with MN. Prolonged periods of MPO-ANCA GN and a low MPO-ANCA titer might be related to MPO-associated MN development.

Glomerulonephritis following COVID-19 infection or vaccination: a multicenter study in South Korea.

Despite the widespread impact of the severe acute respiratory syndrome coronavirus 2 (coronavirus disease 2019, COVID-19) and vaccination in South Korea, our understanding of kidney diseases following these events remains limited. We aimed to address this gap by investigating the characteristics of glomerular diseases following the COVID-19 infection and vaccination in South Korea. Data from multiple centers were used to identify de novo glomerulonephritis (GN) cases with suspected onset following COVID-19 infection or vaccination. Retrospective surveys were used to determine the COVID-19-related histories of patients who were initially not implicated. Bayesian structural time series and autoregressive integrated moving average models were used to determine causality. Glomerular diseases occurred shortly after the infection or vaccination. The most prevalent postinfection GN was podocytopathy (42.9%), comprising primary focal segmental glomerulosclerosis and minimal change disease, whereas postvaccination GN mainly included immunoglobulin A nephropathy (IgAN; 57.9%) and Henoch-Schönlein purpura nephritis (HSP; 15.8%). No patient progressed to end-stage kidney disease. Among the patients who were initially not implicated, nine patients with IgAN/HSP were recently vaccinated against COVID-19. The proportion of glomerular diseases changed during the pandemic in South Korea, with an increase in acute interstitial nephritis and a decrease in pauci-immune crescentic GN. This study showed the characteristics of GNs following COVID-19 infection or vaccination in South Korea. Understanding these associations is crucial for developing effective patient management and vaccination strategies. Further investigation is required to fully comprehend COVID-19's impact on GN.

Identification of inflammatory biomarkers in IgA nephropathy using the NanoString technology: a validation study in Caucasians

Objective and designImmunoglobulin A nephropathy (IgAN) is a kidney disease characterized by the accumulation of IgA deposits in the glomeruli of the kidney, leading to inflammation and damage to the kidney. The inflammatory markers involved in IgAN remain to be defined. Gene expression analysis platforms, such as the NanoString nCounter system, are promising screening and diagnostic tools, especially in oncology. Still, their role as a diagnostic and prognostic tool in IgAN remains scarce. In this study, we aimed to validate the use of NanoString technology to identify potential inflammatory biomarkers involved in the progression of IgAN.SubjectsA total of 30 patients with biopsy-proven IgAN and 7 cases of antineutrophil cytoplasmic antibody (ANCA)-associated pauci-immune glomerulonephritis were included for gene expression measurement. For the immunofluorescence validation experiments, a total of 6 IgAN patients and 3 controls were included.MethodsTotal RNA was extracted from formalin-fixed paraffin-embedded kidney biopsy specimens, and a customized 48-plex human gene CodeSet was used to study 29 genes implicated in different biological pathways. Comparisons in gene expression were made between IgAN and ANCA-associated pauci-immune glomerulonephritis patients to delineate an expression profile specific to IgAN. Gene expression was compared between patients with low and moderate risk of progression. Genes for which RNA expression was associated with disease progression were analyzed for protein expression by immunofluorescence and compared with controls.ResultsIgAN patients had a distinct gene expression profile with decreased expression in genes IL-6, INFG, and C1QB compared to ANCA patients. C3 and TNFRSF1B were identified as potential biomarkers for IgAN progression in patients early in their disease course. Protein expression for those 2 candidate genes was upregulated in IgAN patients compared to controls. Expression of genes implicated in fibrosis (PTEN, CASPASE 3, TGM2, TGFB1, IL2, and TNFRSF1B) was more pronounced in IgAN patients with severe fibrosis compared to those with none.ConclusionsOur findings validate our NanoString mRNA profiling by examining protein expression levels of two candidate genes, C3 and TNFRSF1B, in IgAN patients and controls. We also identified several upregulated mRNA transcripts implicated in the development of fibrosis that may be considered fibrotic markers within IgAN patients.

Renal Limited Anti-Neutrophil Cytoplasmic Antibody Associated Vasculitis: A Case Report

Background: Renal Limited Vasculitis (RLV) is a localized autoimmune vascular inflammatory disorder that is part of the Pauci Immune Glomerulonephritis (PIGN) spectrum. Over 90% of PIGN patients have circulating Anti-Neutrophil Cytoplasmic Antibodies (ANCA Ab). Anti-Neutrophil Cytoplasmic Antibody (ANCA) associated vasculitides are a heterogeneous group of multisystemic autoimmune disorders with distinct pathological findings. They are characterized by widespread inflammation of vessels according to their size, their location, and their serotypes based on the presence or absence of ANCA antibodies, namely Myeloperoxidase (MPO-ANCA), Proteinase-3 (PR3-ANCA) or simply ANCA negative, if no antibodies are found. RLV is characterized by antibody positivity to myeloperoxidase in the majority of cases. Case Report: A 77-year-old Caucasian female was admitted with altered mental status and laboratory evidence of renal function compromise consistent with non-oliguric acute renal failure. Imaging and renal biopsy resulted in a diagnosis of pauci-immune glomerulonephritis consistent with MPO-ANCA vasculitis with a subtype that was associated with necrotizing arteritis, a severe form of the disease. She was placed on hemodialysis, intravenous cyclophosphamide, and oral prednisone, and entered remission. Conclusion: A high level of suspicion and familiarity with clinical signs and symptoms are critical in distinguishing primary RPGN subtypes from other types of ANCA-associated small vessel vasculitis. If left untreated, renal limited vasculitis can progress to widespread systemic involvement and become fatal.