Association between ATG16L1 rs2241880(T300A) and rs4663421 and ANCA­associated vasculitis in the Guangxi population of China: Propensity score matching analysis.

Antineutrophil cytoplasmic antibody-associated vasculitis (AAV) is a rare autoimmune disease with an unclear pathogenesis. The present study investigated the associations between autophagy-related protein 16-like 1 (ATG16L1) rs2241880(T300A) and rs4663421 and AAV. A total of 177 patients with AAV and 216 healthy controls were included. Propensity score matching was used to match the two groups of subjects in terms of sex, age and ethnicity. Analyses of the relationships between these genetic polymorphisms and AAV susceptibility, including comparisons of allele and genotype frequency distribution, linkage disequilibrium analysis and analysis of single nucleotide polymorphism (SNP) interactions between two loci were performed. The association between the loci and laboratory test results and renal pathology were also analysed. A total of 154 pairs of patients with AAV and healthy controls was successfully matched. Neither polymorphism was associated with AAV susceptibility. However, SNP interaction in the model constructed with the two loci was statistically significant (P=0.018), and the combination of the AA genotype of rs2241880(T300A) and GG genotype of rs4663421 was associated the highest disease risk. The differences in the Birmingham Vasculitis Activity Score (BVAS), C-reactive protein (CRP) levels and 24-h urine protein level between patients with the rs2241880(T300A) AA + AG genotypes and the GG genotype were statistically significant (P<0.05). Furthermore, significant differences in the severity of glomerulosclerosis and global sclerosis were detected between individuals with the AA + AG genotype and those with the GG genotype at the rs2241880(T300A) locus (P<0.05). Similarly, there were statistically significant differences in degree of segmental sclerosis between individuals with CC + CG genotypes and those with GG genotypes at the rs2243421 locus (P<0.05). In summary, the single gene polymorphisms of these loci were not associated with genetic susceptibility to AAV. However, SNP interactions may serve a role in the risk of AAV. The rs2241880(T300A) polymorphism may be associated with BVAS, CRP levels and 24-h urine protein level in AAV. These SNPs may be associated with glomerulosclerosis and segmental sclerosis.

Autoantibodies towards HFE and SYT5 in anti-neutrophil cytoplasm antibody-associated vasculitis relapse.

OBJECTIVE: Identification of those at high and low risk of disease relapse is a major unmet need in the management of patients with ANCA-associated vasculitis (AAV). Precise stratification would allow tailoring of immunosuppressive medication. We profiled the autoantibody repertoire of AAV patients in remission to identify novel autoantibodies associated with relapse risk. METHODS: Plasma samples collected from 246 AAV patients in remission were screened for novel autoantibodies using in-house generated protein arrays including 42 000 protein fragments representing 18 000 unique human proteins. Patients were categorized based on the occurrence and frequency of relapses. We modelled the association between these antibodies and relapse occurrence using descriptive and high dimensional regression approaches. RESULTS: We observed nine autoantibodies at higher frequency in samples from AAV patients experiencing multiple relapses compared with patients in long-term remission off therapy (LTROT). LASSO analysis identified six autoantibodies that exhibited an association with relapse occurrence after sample collection. Antibodies targeting HFE and SYT5 were identified as associated with relapse in both analyses. CONCLUSION: Through a broad protein array-based autoantibody screening, we identified two novel autoantibodies directed against HFE and SYT5 as candidate biomarkers of relapse in AAV.

Prognostic significance of tubulointerstitial macrophage density in MPO-ANCA-associated glomerulonephritis: implications for renal outcomes.

OBJECTIVE: This study aimed to evaluate the density of tubulointerstitial macrophages with renal outcomes in patients with myeloperoxidase (MPO)-ANCA associated glomerulonephritis (MPO-ANCA GN). METHODS: This study analyzed patients with MPO-ANCA GN who had renal biopsies at Jinling Hospital. It looked at the density of CD68+ macrophages in the tubulointerstitium and examined correlations with serum creatinine levels, urinary protein levels, treatment regimen, and renal histologic class. The study used KM curves to show the impact of these factors on renal prognosis and conducted multivariate analyses with Cox proportional hazards regression models. RESULTS: A total of 172 patients with MPO-ANCA GN (median age: 50 y, 43.6% male) were included. Stratification of the cohort into tertiles was based on tubulointerstitial macrophage density. Significant differences in serum creatinine levels, induction treatment regimen, the rates of ESKD, and renal histologic class were observed between the three groups. Correlation analysis showed that induction treatment regimen and renal histologic class were correlated with tubulointerstitial macrophage density. Kaplan-Meier curves illustrated patients with a lower presence of CD68+ macrophages in the tubulointerstitium experienced significantly better renal survival compared with those with a higher presence. The higher levels of CD68+ macrophage infiltration were significantly associated with adverse renal outcomes. This association persisted after adjusting for potential confounders including baseline serum creatinine, histopathological class, and induction therapy modalities. CONCLUSIONS: The results of our study provide insight into the prognostic significance of macrophage infiltration in the tubulointerstitium in MPO-ANCA GN.

Seven cases illustrating difficulties in the treatment of MPO-ANCA-positive refractory otitis media.

There are increasing reports of patients with refractory otitis media caused by anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV), especially myeloperoxidase (MPO)-ANCA-positive middle ear disease.　However, making a definitive diagnosis can be difficult, which can adversely affect the outcome of treatment.　We reviewed the diagnostic features of MPO-ANCA-positive middle ear disease and here discuss the difficulties of timely diagnosis and treatment.　Seven cases were eligible (6 women, 1 man;aged 57-83 years), and all were MPO-ANCA positive and proteinase 3 (PR3)-ANCA negative.　The patients were referred to our institution for management of intractable otitis media (2/7), progressive hearing loss (7/7) with facial palsy (1/7), and/or a high MPO-ANCA titer (5/7).　All patients underwent tapering steroid therapy and their MPO-ANCA titer was monitored.　Refractory MPO-ANCA-positive otitis media was noted:5 of 7 cases showed improvement with tapering steroid therapy but cure was not achieved in the remaining 2 cases.　This study demonstrates the difficulties in the diagnosis and treatment of localized AAV.　Early diagnosis and treatment can improve the prognosis of patients with AAV but global diagnostic criteria for ear disease have not been established.　Additional cases should be prospectively examined to establish a treatment for MPO-ANCA-positive middle ear disease.

The predictive performance of the ANCA renal risk score in patients over 65 years of age with renal ANCA-associated vasculitis.

Background: The anti-neutrophil cytoplasmic antibody (ANCA) renal risk score (ARRS) for predicting renal survival in ANCA-associated vasculitis (AAV) had not previously been validated in adults over 65 years of age and presenting impairments associated with an aging kidney, a high cardiovascular comorbidity burden and prevalent microscopic polyangiitis. Methods: We retrospectively studied a cohort of 192 patients over 65 years of age [median (interquartile range) age: 73 (68-78) years], including 17.2% with renal-limited vasculitis, 49.5% with microscopic polyangiitis and 33.3% with granulomatosis with polyangiitis, at six centres in northern France. The primary study endpoint was the cumulative incidence of end-stage kidney disease (ESKD, maintenance of dialysis for at least 3 months) at 12 months, with death considered as a competing event. Results: The median serum creatinine concentration at diagnosis was 300 (202-502) µmol/L, and 48 (25.0%) patients required dialysis at presentation. The ARRS was high in 43 (22.4%) patients, medium in 106 (55.2%) and low in 43 (22.4%). The cumulative incidence of ESKD at 12 months was 0% in the low-risk group, 13.0% (interquartile range 7.6-20.0) in the medium-risk group and 44.0% (29.0-58.0) in the high-risk group (P < .001). In the subgroup of 149 patients presenting a medium or high score, the ARRS had a C-index of 0.66 (0.58-0.74) for the prediction of ESKD at 12 months; this rose to 0.86 (0.80-0.90) when dialysis status at diagnosis was included. Conclusion: The ARRS was a poor predictor of kidney survival at 12 months among patients over 65 years of age with renal AAV involvement-especially in the high ARRS group. The addition of dialysis status at diagnosis as an additional clinical parameter might improve the predictive performance of the ARRS.

Assessment of cardiovascular risk in patients with ANCA-associated vasculitis: A systematic review and meta-analysis.

Background: Although many chronic inflammatory conditions are linked to elevated cardiovascular risk, the specific extent of this risk in ANCA-associated vasculitis (AAV) remains elusive, largely due to the disease's rarity. Our study sought to clarify the cardiovascular risks and mortality linked to AAV. Methods: A systematic literature review was conducted across multiple databases from their inception until April 2024 to identify studies comparing cardiovascular outcomes in patients with and without AAV. R Studio's meta package was used to pool risk ratios under the random-effects model, and statistical significance was set at p < 0.05. Results: Nine observational studies involving 45024 individuals were included in this analysis. Patients with AAV exhibited a significantly elevated risk of stroke (RR = 1.43, 95 % CI: 1.12-1.83, I2 = 62 %, p = 0.0048), myocardial infarction (RR = 1.49, 95 % CI: 1.25-1.79, I 2  = 0 %, p < 0.0001), ischemic heart disease (RR = 1.40, 95 % CI: 1.24-1.58, I 2  = 1 %, p < 0.0001), venous thromboembolism (RR = 2.57, 95 % CI: 1.70-3.90, I 2  = 74 %, p < 0.0001), and pulmonary embolism (RR = 3.53, 95 % CI: 2.82-4.42, I 2  = 9 %, p < 0.0001), deep vein thrombosis (RR: 4.21; 95 % CI: 2.00-8.86; p = 0.0002), heart failure (RR = 1.63, 95 % CI: 1.39-1.90, I 2  = 0 %, p < 0.0001), and cardiovascular disease-related mortality (RR = 1.79, 95 % CI: 1.07-3.00, I2 = 0 %, p = 0.0256) compared to patients without AAV. Conclusion: This meta-analysis underscores a notable increase in adverse cardiovascular events among patients with AAV, underscoring the need for comprehensive cardiovascular care and diligent monitoring in this patient cohort.

The incidence of vasculitides in Israel from 2007 to 2021 and during the COVID-19 pandemic.

Background: The incidence of various types of vasculitis conditions over time, specifically during coronavirus disease 2019 (COVID-19), is unknown. Objectives: We aimed to assess recent trends in vasculitides and the effect of the COVID-19 pandemic on these trends. Design: We conducted a retrospective analysis of Israel's largest Health Maintenance Organization, which covers over 4.7 million patients and represents 55% of the country. Methods: We calculated the age- and sex-adjusted incidence of giant cell arteritis (GCA), Takayasu, ANCA-associated vasculitis (AAV), IgA vasculitis, cryoglobulinemia, and Behcet's disease (BD) during 2007-2021. We analyzed associations of COVID-19 with the incidence of each of the examined conditions. Results: During 2007-2021, the adjusted annual incidence decreased from 7.9 (95% confidence interval (CI) 3.5-17.9) to 1.5 (95% CI 0.7-3.6) per 100,000 for GCA, from 5.2 (95% CI 2.7-11.1) to 1.5 (95% CI 0.7-3.3) per million for IgA vasculitis, and from 6.3 (95% CI 3.0-13.5) to 1.0 (0.5-2.5) per 100,000 for BD. The relative risks for these conditions decreased: 0.92 (95% CI 0.91-0.93), 0.93 (95% CI 0.89-0.98), and 0.90 (95% CI 0.85-0.94), respectively. The incidences of Takayasu, AAV, and cryoglobulinemia remained unchanged. The COVID-19 pandemic was not associated with changes in the incidence of any examined vasculitides. Conclusion: The incidences of GCA, IgA vasculitis, and BD decreased substantially in Israel during 15 years and were unaffected by the COVID-19 pandemic. Future studies should focus on possible environmental contributions to these findings.

Bowel and Small Joint Involvement in Granulomatosis With Polyangiitis: A Case Report.

We discuss the case of a 45-year-old male with complaints of abdominal pain, loose stools with on and off melena, and multiple joint pains bilaterally. The patient reported having similar episodes in the past, with slight variations in the symptoms and relief with short courses of steroids. Initially, a workup was done to identify an infectious etiology of the diarrhea. However, no such cause was identified. Similarly, an autoimmune profile was ordered to investigate the patient's joint complaints, albeit with no conclusive findings. His renal function tests and urinalysis showed findings indicative of an acute kidney injury. This prompted an antineutrophil cytoplasmic antibody (ANCA) profile, which was positive for c-ANCA. A diagnosis of granulomatosis with polyangiitis (GPA) was made, and the patient was started on pulse steroid and immunomodulator therapy with improvement in the patient's condition. This case is atypical due to its involvement of the gastrointestinal system, which is relatively rare, as well as polyarthritis of the small joints.

Renal-Limited Presentation of Hydralazine-Induced Anti-neutrophil Cytoplasmic Antibody Vasculitis: A Case Report.

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis is a rare multisystem autoimmune disease resulting from necrotizing inflammation of small vessels. Genetic predisposition and environmental factors are typically associated with its presentation, though rarely a drug-induced form has been reported. Here, we present a case of a 73-year-old female with a history of hypertension and chronic kidney disease who presented with acute kidney injury secondary to hydralazine-induced ANCA vasculitis. This report aims to highlight the rare association of hydralazine with vasculitis and the importance of pursuing a full initial workup in patients with acute kidney injury.

Microscopic polyangiitis presenting as idiopathic pulmonary fibrosis.

The most detectable form of pulmonary fibrosis in MPA (microscopic polyangiitis) is UIP (usual interstitial pneumonia), occurring in 48 % of MPA patients with pulmonary fibrosis. In some cases, ILD (interstitial lung disease) is the initial clinical manifestation of MPA (22 % of cases). Here, we describe a patient diagnosed with IPF (idiopathic pulmonary fibrosis) who later developed pulmonary infiltrates on CT and hemoptysis, found to have diffuse alveolar hemorrhage on bronchoscopy and ultimately was diagnosed with MPA. There are no guidelines recommending routine screening of vasculitis in cases of suspected IPF, which may result in more misdiagnoses of vasculitides.

A Case of Pleuritis Associated With Antineutrophil Cytoplasmic Antibody (ANCA)-Associated Vasculitis Diagnosed Through Medical Thoracoscopy.

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) includes eosinophilic granulomatosis with polyangiitis, granulomatosis with polyangiitis, and microscopic polyangiitis. Pulmonary involvements such as interstitial pneumonia and alveolar hemorrhage are common in AAV, but pleuritis is rare. Here, we report a case of pleuritis associated with AAV. A 68-year-old woman was referred to our hospital because of bilateral wrist and knee pain, Raynaud's phenomenon, and a sclerotic change in her extreme fingers with elevation of proteinase 3 ANCA (PR3-ANCA) and myeloperoxidase-ANCA (MPO-ANCA). From a skin biopsy of her forearms and fingers, we diagnosed that the patient had limited systemic sclerosis. After her first visit at 15 months, she complained of pain in the side of her chest. Her chest X-ray and computed tomography showed left pleural effusion, and local anesthetic thoracoscopy was performed. Histological examination of the pleural revealed granuloma and vasculitis. Based on her symptoms and histological findings, we diagnosed this case as ANCA-associated vasculitis (AAV) and treated it with steroids and intravenous cyclophosphamide successfully. Pleuritis is a rare pulmonary lesion of AAV, and thoracoscopy under local anesthesia is useful for the histological examination of vasculitis.

Acute Renal Failure and Generalized Weakness in a 75-Year-Old Male With Pauci-Immune Necrotizing Antineutrophil Cytoplasmic Antibody (ANCA)-Associated Vasculitis: A Case Report.

We describe a 75-year-old male who presented to the emergency department with generalized weakness and was ultimately diagnosed with acute renal failure secondary to pauci-immune necrotizing antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis. The patient's clinical course was complicated by a perforated gastric ulcer and severe malnutrition, necessitating involvement from multiple specialists. The case highlights the challenges of this rare vasculitis and the complications that can arise from the disease and its treatment. .

Skin, Heart, and CNS Involvement in Granulomatosis With Polyangiitis: A Case Report.

We discuss the case of a 60-year-old male who presented with ankle pain, a necrotic rash, and progressive weakness in both lower limbs and the right upper limb. An infectious workup of the skin lesions came back negative. Additionally, his kidney function tests indicated an acute kidney injury. This prompted investigations for vasculitis etiologies, which revealed a positive cytoplasmic antineutrophil cytoplasmic autoantibody (c-ANCA). His neurological deficits were also investigated, and imaging suggested embolic infarcts. Cardiac imaging showed valve vegetations and blood culture showed a lack of growth suggestive of a noninfective nature of these lesions. Based on all these findings, a kidney biopsy was obtained and demonstrated pauci-immune segmental vasculitis consistent with ANCA-associated glomerulonephritis. As such, the patient showed improvement with heavy pulse steroid and immunomodulator therapy. Although skin, heart, and CNS involvement have been previously reported with ANCA-associated vasculitis, it is rare, especially together, and can prove a diagnostic challenge. Therefore, it is important to consider vasculitis etiology in patients presenting similarly. In addition, this case highlights the overlapping clinical picture between infective endocarditis and vasculitis with valvular involvement, making differentiation between the two challenging.

ANCA-associated vasculitis and lung cancer: an immunological perspective.

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a severe autoimmune disease that often involves the upper and lower respiratory tracts. In recent years, numerous studies have found a significant increase in the incidence of cancer among AAV patients, but the association between lung cancer and AAV remains inconclusive, with relatively low clinical attention. This review summarizes the current literature on the risk of lung cancer in patients with ANCA-associated vasculitis (AAV), detailing the potential mechanisms by which AAV may contribute to lung cancer, and further elucidates the inherent carcinogenic risks of immunosuppressants.There is a correlation between AAV and lung cancer, which is related to T cell senescence and damage, as well as the abnormal expression of cytokines such as IL-6 and IL-10. In AAV patients, the use of cyclophosphamide and azathioprine (AZA) alone has a clear carcinogenic risk, with frequent use of CYC potentially posing a high risk for lung cancer. Although TNF inhibitors (TNFi) combined with CYC have carcinogenic risks, there is insufficient evidence to link them directly to an increased risk of lung cancer. For patients at high risk for lung cancer, the judicious use of immunosuppressants, timely computed tomography (CT), and lung cancer screening can reduce the risk of lung cancer in AAV patients.

Immunoadsorption and Plasma Exchange are Comparable in Anti-Neutrophil Cytoplasmic Antibodies or Anti-Glomerular Basement Membrane Removal Kinetics.

Introduction: Apheresis allows the fast removal of autoantibodies in anti-glomerular basement membrane (anti-GBM) disease, and in severe antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitis. The CINEVAS study tested whether immunoadsorption (IA) allowed a faster removal of ANCA and/or anti-GBM antibodies than plasma exchanges (PEx). Methods: CINEVAS was a prospective multicenter study comparing IA to PEx in consecutive patients with ANCA and/or anti-GBM vasculitides. The primary objective was the reduction rate in autoantibody titers between the beginning of the first and the end of the seventh apheresis session. Secondary objectives were number of sessions needed to obtain desired reduction rates; reduction rates of total Ig levels; tolerance of sessions; and patients' outcome. Results: The results of 38 patients (16 treated with IA and 22 with PEx), and 43 autoantibodies, were analyzed. There was no difference in the reduction rates in autoantibody titers between IA and PEx over 7 sessions (respectively 98% vs. 96%, P = 0.39). The numbers of sessions needed to obtain undetectable autoantibodies, or 50%, 75%, or 90% reductions, did not differ between techniques. Greater reduction rates of autoantibodies were observed when plasma was separated by filtration compared to centrifugation, with IA and PEx. IA allowed a greater reduction in total IgG levels, and better preservation of total IgA and IgM levels than PEx. PEx sessions required higher volumes of plasma, IA sessions higher volumes of citrate; IA sessions were longer. Conclusions: IA and PEx were comparable in ANCA or anti-GBM removal kinetics, despite a faster reduction in total IgG with IA.

Characteristic changes in the mRNA expression profile of plasma exosomes from patients with MPO-ANCA-associated vasculitis and its possible correlations with pathogenesis.

To explore the expression patterns and potential roles of mRNAs in exosomes from patients with myeloperoxidase-specific anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (MPO-AAV). Plasma exosomes were isolated from MPO-AAV patients and healthy controls (HCs) to screen for differential mRNA expression via exosomal mRNA sequencing. The differentially expressed mRNAs in exosomes from the 2 groups were comparatively explored by bioinformatics analysis. The six most differentially expressed mRNAs were selected and validated in larger groups of MPO-AAV patients and HCs by real-time quantitative polymerase chain reaction (RT‒qPCR). The relationships between these selected mRNAs and patient characteristics were statistically analyzed. Compared with HCs, a total of 1077 mRNAs in exosomes from MPO-AAV patients were found to be significantly upregulated, including DEPDC1B and TPST1, while NSUN4 and AK4 were significantly downregulated. Statistical analysis did not reveal any correlation between the six selected mRNAs and clinical indicators, including disease activity. GO enrichment analysis revealed that these differentially expressed genes participate in various enzyme activities, protein synthesis, etc. KEGG pathway analysis revealed that metabolic pathways, cell adhesion molecules, epithelial signaling, and mitogen-activated protein kinase (MAPK) signaling pathways were significantly enriched in the exosomal mRNAs. There were significant differences in the expression of exosomal mRNAs between MPO-AAV patients and HCs, which may be related to the occurrence and development of MPO-AAV. These findings provide clues for further investigations of MPO-AAV pathogenesis and the identification of new potential therapeutic targets.

Superiority of Avacopan and Mepolizumab to Glucocorticoid Tapering in the Treatment of Anti-neutrophil Cytoplasmic Antibody (ANCA)-Associated Vasculitis: A Systematic Review.

Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) comprises a spectrum of autoimmune diseases, including granulomatosis with polyangiitis (GPA), microscopic polyangiitis (MPA), and eosinophilic granulomatosis with polyangiitis (EGPA). Studies have shown that avacopan and mepolizumab are promising therapeutics for partial or complete replacement of glucocorticoids (GC), with sustained remission while completely weaning off GC. Avacopan inhibits C5aR in the complement pathway, preventing neutrophil migration, while mepolizumab targets IL-5R, reducing eosinophil activity. Additionally, complement inhibition has not only contributed to the recovery of renal function and alleviation of physical symptoms but has also enhanced patients' overall quality of life and mental well-being. This systematic review explores the pathogenesis of AAV, traditional treatments, and the potential of emerging complement and interleukin antagonist therapies such as avacopan and mepolizumab in revolutionizing AAV management.

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.

Myeloperoxidase Anti-Neutrophil Cytoplasmic Antibody (MPO-ANCA)-Associated Vasculitis With Rare Clinical Manifestations After SARS-CoV-2 Multisystem Inflammatory Syndrome in a 14-Year-Old Boy.

Myeloperoxidase antineutrophil cytoplasmic antibody (MPO-ANCA) microscopic polyangiitis is a rare but life-threatening small vessel vasculitis in childhood that affects multiple systems. Emerging clinical evidence suggests a possible association between SARS-CoV-2 infection or multisystem inflammatory syndrome in children (MIS-C) as well as the futuredevelopment of autoimmune diseases. A 14-year-old boy with a diagnosis of MIS-C two years prior to presentation was admitted to our hospital due to edema and left lower limb joint pain along with concomitant upper surface petechia. The patient had a positive higher SARS-CoV-2 IgG than MIS-C diagnosis titers and MPO-ANCA-positive antibody titers. Kidney biopsy favored a pauci-immune crescentic glomerulonephritis. Restrictive lung disease with concomitant diffusion abnormalities was also observed. Pancreatitis and gastrointestinal wall edema were additional clinical manifestations. SARS-CoV-2 breakthrough infection and MIS-C could contribute to the onset of autoimmune vasculitis through various immunological mechanisms. Further research is still needed to elucidate the role of SARS-CoV-2 in the pathophysiology of newly diagnosed autoimmune vasculitis.

Impact of Rituximab on Remission Rates in Granulomatosis With Polyangiitis: A Systematic Review.

This systematic review evaluates the efficacy of rituximab in inducing and maintaining remission in patients with granulomatosis with polyangiitis (GPA). We conducted a comprehensive search across multiple databases, identifying 81 studies, of which 11 met our inclusion criteria after rigorous screening and assessment for relevance and quality. Our analysis shows that rituximab, compared to traditional treatments such as cyclophosphamide and azathioprine, significantly improves remission rates and reduces relapse frequency in GPA patients. Notably, rituximab's benefits extend across various patient demographics, including pediatric groups, and are evident in different dosing regimens, highlighting its versatility and potential as a first-line therapy. The review also underscores the importance of personalized medicine approaches in managing GPA, as rituximab's effectiveness was particularly pronounced in patients with relapsing disease forms. Future research should focus on long-term outcomes, optimal dosing strategies, and the economic implications of widespread rituximab use in clinical practice. Our findings advocate for the integration of rituximab into standard treatment protocols for GPA, offering new hope for patients afflicted with this challenging autoimmune disorder.