New Onset of Eosinophilic Granulomatosis with Polyangiitis Following mRNA-Based COVID-19 Vaccine

Unexpected hypereosinophilia after Sinopharm vaccination: a case report

BACKGROUND

COVID-19 vaccines have been pivotal in the management of the recent pandemic. However, despite their safety and efficacy, apprehension regarding possible adverse effects has always been raised. Most of the vaccine-related side effects are mild. However, serious complications like anaphylaxis and thromboembolic events have also been reported. Various hematological disorders, including hypereosinophilia, have been reported following COVID-19 vaccination, the exact mechanisms of which remain unclear.

CASE PRESENTATION

We report a 66-year-old male who developed hypereosinophilia (absolute eosinophil count: 4063 cells/µL) and lymphadenopathy two months after receiving the third dose of the BBIBP-CorV (Sinopharm) COVID-19 vaccine. Extensive investigations failed to identify an alternative cause for these findings.

CONCLUSIONS

This case report underscores the potential for unexpected hematological adverse events following COVID-19 vaccination, even with inactivated vaccines. While a definitive causal relationship cannot be established, the temporal association between vaccination and symptom onset warrants further investigation. This case emphasizes the importance of continued surveillance for rare adverse events and additional research to elucidate the potential mechanisms underlying vaccine-associated eosinophilia.

Eosinophils and COVID-19: Insights into immune complexity and vaccine safety

BACKGROUND

COVID-19 exhibits a variety of symptoms and may lead to multi-organ failure and death. This clinical complexity is exacerbated by significant immune dysregulation affecting nearly all cells of the innate and adaptive immune system. Granulocytes, including eosinophils, are affected by SARS-CoV-2.

OBJECTIVES

Eosinophil responses remain poorly understood despite early recognition of eosinopenia as a hallmark feature of COVID-19 severity.

RESULTS

The heterogeneous nature of eosinophil responses categorizes them as dual-function cells with contradictory effects. Eosinophil activation can suppress virus-induced inflammation by releasing type 2 cytokines like IL-13 and granular proteins with antiviral action such as eosinophil-derived neurotoxins and eosinophil cationic protein, and also by acting as antigen-presenting cells. In contrast, eosinophil accumulation in the lungs can induce tissue damage triggered by cytokines or hormones like IFN-γ and leptin. Additionally, they can affect adaptive immune functions by interacting with T cells through direct formation of membrane complexes or soluble mediator action. Individuals with allergic disorders who have elevated levels of eosinophils in tissues and blood, such as asthma, do not appear to be at an increased risk of developing severe COVID-19 following SARS-CoV-2 infection. However, the SARS-CoV-2 vaccine appears to be associated with complications and eosinophilic infiltrate-induced immunopathogenicity, which can be mitigated by corticosteroid, anti-histamines and anti-IL-5 therapy and avoided by modifying adjuvants or excipients.

CONCLUSION

This review highlights the importance of eosinophils in COVID-19 and contributes to a better understanding of their role during natural infection and vaccination.

COVID-19 vaccine adverse events: Evaluating the pathophysiology with an emphasis on sulfur metabolism and endotheliopathy

In this narrative review, we assess the pathophysiology of severe adverse events that presented after vaccination with DNA and mRNA vaccines against COVID-19. The focus is on the perspective of an undersulfated and degraded glycocalyx, considering its impact on immunomodulation, inflammatory responses, coagulation and oxidative stress. The paper explores various factors that lead to glutathione and inorganic sulfate depletion and their subsequent effect on glycocalyx sulfation and other metabolites, including hormones. Components of COVID-19 vaccines, such as DNA and mRNA material, spike protein antigen and lipid nanoparticles, are involved in possible cytotoxic effects. The common thread connecting these adverse events is endotheliopathy or glycocalyx degradation, caused by depleted glutathione and inorganic sulfate levels, shear stress from circulating nanoparticles, aggregation and formation of protein coronas; leading to imbalanced immune responses and chronic release of pro-inflammatory cytokines, ultimately resulting in oxidative stress and systemic inflammatory response syndrome. By understanding the underlying pathophysiology of severe adverse events, better treatment options can be explored.

New-onset of rheumatic diseases following COVID-19 vaccination: the report of three cases and a literature review

Vaccines against coronavirus disease 2019 (COVID-19) have been distributed in most countries for the prevention of onset and aggravation of COVID-19. Recently, there have been increasing numbers of reports on new-onset autoimmune and autoinflammatory diseases following COVID-19 vaccination, however, only little information is available on the long-term safety of these vaccines. Here, we experienced three cases of new-onset rheumatic diseases following COVID-19 vaccination, one case each of rheumatoid arthritis (RA), anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) and systemic lupus erythematosus (SLE). The symptom onset ranged from one day to a few days following vaccination. The patients of AAV and SLE were treated successfully with glucocorticoid therapy, and the patient of RA died due to COVID-19. In the literature review of new-onset rheumatic diseases following COVID-19 vaccination, which including seven cases of RA, 37 cases of AAV and 18 cases of SLE, the mean time from vaccination to onset was approximately 11 to 12 days. Most cases improved with glucocorticoid, immunosuppressive drugs and biologic agents. Although such adverse effects are rare, and vaccines are useful in prevent onset and severity of infections, continued accumulation of similar cases is important in terms of examining the long-term safety and understanding pathogenic mechanism of rheumatic diseases.

COVID-19 vaccine-associated vasculitis: A systematic review

Objectives

Post-COVID-19 vaccine-associated vasculitis stands as one of the most serious side effects attributed to COVID-19 vaccines. This complication encompasses diverse manifestations which vary in presentation and severity. Moreover, it can impact patients across all age groups, with a notably elevated incidence in the elderly. This systematic review seeks to review and evaluate the spectrum of vasculitis manifestations linked to COVID-19 vaccination.

Methods

A systematic review of the literature was done by searching through PubMed, Google Scholar, and Scopus up to October 2022. Articles including data about sex, age at diagnosis, vasculitis clinical manifestations, type of vaccination, most commonly used investigations, comorbid medical conditions, treatments, and clinical outcomes were included in the final analysis. Furthermore, vasculitis flare-ups post-vaccination were considered part of this review.

Results

A total number of 117 studies describing 158 patients developing vasculitis following COVID-19 vaccination were included in the final analysis. Among the patients who developed vasculitis, the most administered type of vaccination was the mRNA vaccine subtype (n = 103), followed by the viral vector vaccines (n = 42) and inactivated viral vaccines (n = 10). On the other hand, about 38% of vasculitis-related symptoms occurred after the administration of the first dose of the vaccine and 37% occurred after taking the second dose. The skin (60.7%) and the kidneys (27.8%) were the most affected organs and complete remission was achieved in 111 patients (70%), while partial remission occurred in 11% of the patient population.

Conclusion

COVID-19 vaccine-induced vasculitis is a rare occurrence associated with COVID-19 vaccines. It generally presents a favorable prognosis and outcomes for the vast majority of patients, ultimately leading to full remission within days. This review emphasizes the notion that the advantages of COVID-19 vaccines outweigh the potential risks, particularly for individuals with compromised immune systems.

Central Retinal Artery Occlusion Leading to Diagnosis of Eosinophilic Granulomatous Polyangiitis After Adenovirus Vector COVID-19 Vaccination

Purpose: To present a case of central retinal artery occlusion (CRAO) leading to the diagnosis of eosinophilic granulomatosis with polyangiitis (Churg-Strauss syndrome) within 1 week of an adenovirus vector COVID-19 vaccination. Methods: A case was reviewed. Results: A 50-year-old man with atopic dermatitis and asthma presented with acute painless vision loss in 1 eye. An examination and imaging findings showed CRAO. Further evaluation found eosinophilia and elevated inflammatory markers. A workup for vasculitis showed elevated cytoplasmic-antineutrophil cytoplasmic antibody, perinuclear-antineutrophil cytoplasmic antibody, myeloperoxidase antibody, rheumatoid factor, and total immunoglobulin E. Skin biopsies were consistent with eosinophilic granulomatosis with polyangiitis. Steroids, cyclophosphamide, and mepolizumab were initiated. At 1 year, the patient's systemic symptoms had improved but his vision had not. Conclusions: Few reports exist of CRAO associated with eosinophilic granulomatosis with polyangiitis, with no other instances related to an adenovirus vector COVID-19 vaccination. Treating a systemic vasculitis early can be vision saving in the fellow eye and prevent systemic life-threatening complications.

COVID-19 vaccine-associated lymphadenopathy: a review

Following the introduction of RNA-based vaccines, COVID-19 vaccine-associated clinical lymphadenopathy (C19-LAP) has been reported as a side effect. Moreover, subclinical lymphadenopathy detected on imaging (SLDI) has also been observed, mainly as incidental findings while performing screening tests on oncological patients. In these cases, surgical lymphadenectomy, fine-needle aspiration cytology (FNAC) and core needle biopsy (CNB) have been used as a valuable diagnostic tool for SLDI and C19-LAP. In this review the clinical, histologic and cytologic features of SLDI and C19-LAP have been investigated. A search for studies that reported on C19-LAP and SLDI histopathology and cytopathology was performed on PubMed and Google Scholar, on 11 January 2023. Thirty-one reports on SLDI and C19-LAP were retrieved and included in a pooled analysis. In total, we included 54 patients with a median age of 47 years. In our research, surgical excision, CNB and/or FNAC of C19-LAP or SLDI enlarged lymph nodes have been performed in 54 cases. Of all cases, only two metastases were diagnosed and one case was diagnosed as reactive hyperplasia with atypical follicles. The remaining cases were reactive lymphadenopathy (28 cases), follicular hyperplasia (13 cases), Kikuchi-Fujimoto disease (6 cases), granulomatous lymphadenitis (2 cases), eosinophilic lymph node abscesses (1 case), Langherans cell histiocytosis (1 case), Rosai-Dorfman disease (1 case). SLDI and C19-LAP have represented a diagnostic dilemma, especially in oncologic patients. The role of different diagnostic tools for SLDI and C19-LAP has been discussed.

New-onset severe eosinophilic granulomatosis with polyangiitis following the third dose of mRNA COVID-19 vaccine: A case report

Eosinophilic granulomatosis with polyangiitis (EGPA) is a complex multifactorial disease that results in multisystemic inflammation of the small- and medium-sized arteries. The exact pathogenesis of this syndrome is poorly understood, but it is postulated to result from a combination of eosinophilic dysfunction, genetic predisposition, and the development of autoantibodies after exposure to an unknown stimulus. We describe a case of new-onset EGPA following the third dose of the Pfizer-BioNTech mRNA vaccine in an infection-naive middle-aged man with a background history of allergic respiratory symptoms. The patient developed acute onset of mononeuritis multiplex, pauci-immune glomerulonephritis, and leucocytoclastic vasculitis 10 days after receiving the booster dose. His laboratory markers including eosinophil count, antineutrophil cytoplasmic antibodies, and renal function tests improved markedly after the initiation of pulse steroid therapy and rituximab infusion. However, his peripheral muscle weakness and neuropathic pain did not respond to the initial therapy but improved later with intravenous cyclophosphamide and intravenous immunoglobulin. To the best of our knowledge, this is the fourth case report of post-coronavirus disease 2019 vaccination precipitation of EGPA. All reported cases including our report were in patients with previous allergic manifestations who received mRNA-based coronavirus disease 2019 vaccines, and all the patients developed mononeuritis multiplex at presentation. Despite the few reported cases of post-vaccination autoimmune phenomena, the temporal association between vaccination administration and disease onset does not indicate causality, given the mass vaccination programmes employed. However, the novel use of the mRNA platform in vaccine delivery necessitates vigilant monitoring by the scientific committee.

Eosinophilic Granulomatosis With Polyangiitis Following COVID-19 Vaccination: A Case Report

The current emergence of the coronavirus disease 2019 (COVID-19) pandemic and the possible side effects of COVID-19 mRNA vaccination remain worrisome. Few cases of vaccination-related side effects, such as vasculitis, have been reported. Eosinophilic granulomatosis with polyangiitis (EGPA), also known as Churg-Strauss syndrome, is a type of vasculitis characterized by the histological richness of eosinophils, asthma, polyneuropathy, sinusitis, and skin or lung involvement. Here, we report the first case of new onset EGPA following COVID-19 vaccination in Korea. A 71-year old woman developed a skin rash and presented with progressive weakness of the upper and lower extremities after the BNT162b2 vaccination (Pfizer-BioNTech). She was diagnosed with EGPA and her symptoms improved after systemic steroid and immunosuppressant therapy. Although it is very rare, clinicians should be aware that EGPA may occur after COVID-19 vaccination.

Eosinophilic granulomatosis with polyangiitis following flu guard influenza vaccination: A case report

Key Clinical Message

This case highlights a potential association between influenza vaccination and the development of eosinophilic granulomatosis with polyangiitis (EGPA), prompting the need for increased vigilance regarding vaccine-related autoimmune reactions. While causality remains unclear, clinicians should consider this possibility in patients presenting with EGPA-like symptoms shortly after vaccination.

Abstract

Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare systemic vasculitis characterized by tissue infiltration by eosinophils and hyper eosinophilia. We present a case of EGPA in a middle-aged man following influenza vaccination. The patient developed respiratory symptoms, skin lesions, joint pain, and neurological deficits. Diagnostic tests revealed eosinophilia, positive anti-neutrophil cytoplasmic antibodies, and elevated acute phase reactants. This report highlights a potential association between influenza vaccination and EGPA.

New insights of antineutrophil cytoplasmic antibody-associated vasculitis from the perspective of COVID-19 vaccination

The occurrence of antineutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV) has been reported since the coronavirus disease 2019 (COVID-19) vaccination, but whether there is a causal relationship or coincidence remains to be verified. We combined the term COVID-19 vaccination with each word of AAV to search for case reports and case series published in PubMed, EMBASE, and Web of Science databases before 13 March 2023. A total of 56 patients who developed AAV after COVID-19 vaccination were identified from 44 research centers. Of the 56 subjects, 43 (76.7%) were vaccinated with the mRNA vaccine, followed by the adenovirus vaccine (14.3%) and inactivated vaccine (9.0%) (P = 0.015). Compared with relapsed AAV, new-onset AAV patients had at least two other diseases previously (P < 0.001). Twenty-five (44.6%) patients presented symptoms after the first injection, and the medium onset time was 12 (1-77) days, while Twenty-eight (50.0%) patients developed symptoms after the second dose, and their medium period was 14 (1-60) days. Forty-four (78.5%) patients achieved remission after immunosuppressive agents, plasma exchange, and hemodialysis. One (1.8%) patient died from progressive respiratory failure and nine (16.1%) did not recover, leaving five patients permanently dependent on hemodialysis. Pathogenic ANCA may be activated by enhanced immune response and epitope spreading after COVID-19 vaccination and induced the occurrence of AAV, especially in genetically susceptible populations.

New-Onset Rheumatic Immune-Mediated Inflammatory Diseases Following SARS-CoV-2 Vaccinations until May 2023: A Systematic Review

A comprehensive, up-to-date systematic review (SR) of the new-onset rheumatic immune-mediated inflammatory diseases (R-IMIDs) following COVID-19 vaccinations is lacking. Therefore, we investigated the demographics, management, and prognosis of new R-IMIDs in adults following SARS-CoV-2 vaccinations. A systematic literature search of Medline, Embase, Google Scholar, LitCovid, and Cochrane was conducted. We included any English-language study that reported new-onset R-IMID in adults following the post-COVID-19 vaccination. A total of 271 cases were reported from 39 countries between January 2021 and May 2023. The mean age of patients was 56 (range 18-90), and most were females (170, 62.5%). Most (153, 56.5%) received the Pfizer BioNTech COVID-19 vaccine. Nearly 50% of patients developed R-IMID after the second dose of the vaccine. Vasculitis was the most prevalent clinical presentation (86, 31.7%), followed by connective tissue disease (66, 24.3%). The mean duration between the vaccine's 'trigger' dose and R-IMID was 11 days. Most (220, 81.2%) received corticosteroids; however, 42% (115) received DMARDs such as methotrexate, cyclophosphamide, tocilizumab, anakinra, IV immunoglobulins, plasma exchange, or rituximab. Complete remission was achieved in 75 patients (27.7%), and 137 (50.6%) improved following the treatment. Two patients died due to myositis. This SR highlights that SARS-CoV-2 vaccines may trigger R-IMID; however, further epidemiology studies are required.

COVID-19 post-vaccination lymphadenopathy: A review of the use of fine needle aspiration cytology

COVID-19 vaccine-associated clinical lymphadenopathy (C19-LAP) and subclinical lymphadenopathy (SLDI), which are mainly detected by 18F-FDG PET-CT, have been observed after the introduction of RNA-based vaccines during the pandemic. Lymph node (LN) fine needle aspiration cytology (FNAC) has been used to diagnose single cases or small series of SLDI and C19-LAP. In this review, clinical and LN-FNAC features of SLDI and C19-LAP are reported and compared to non-Covid (NC)-LAP. A search for studies on C19-LAP and SLDI histopathology and cytopathology was performed on PubMed and Google Scholar, on 11 January 2023. Reports on LN-FNAC of C19-LAP were retrieved. A total of 14 reports, plus one unpublished case of C19-LAP observed in our institution, diagnosed by LN-FNAC were included in a pooled analysis and compared to the corresponding histopathological reports. In total, 26 cases were included in this review, with a mean age of 50.5 years. Twenty-one lymphadenopathies assessed by LN-FNAC were diagnosed as benign, and three cases as atypical lymphoid hyperplasia; the latter were subsequently confirmed as benign (one by repetition of LN-FNAC, two by histological control). One case of mediastinal lymphadenopathy in a patient suffering from melanoma was reported as reactive granulomatous inflammation, while one unsuspected case was diagnosed as metastasis from melanoma. In all cases, the cytological diagnoses were confirmed by follow-up or excisional biopsy. The high diagnostic value of LN-FNAC in excluding malignant processes was extremely useful in this context and may be particularly valuable when CNB or histological excisions are difficult to perform, as was the case during Covid lockdowns.

Eosinophilic Granulomatosis with Polyangiitis after mRNA-1273 SARS-CoV-2 Vaccine

During one of the worst global health crises, millions of people were vaccinated against SARS-CoV-2. In rare cases, new onset systemic inflammatory diseases were reported with temporal coincidence to the vaccination. We describe a case of severe Eosinophilic Granulomatosis with Polyangiitis (EGPA) in a young asthmatic woman, occurring after a second dose of the mRNA-1273 vaccine. She presented with multisystem EGPA with cardiac and central nervous system involvement, complicated by secondary immune thrombocytopenia (ITP). We review the reported cases of EGPA coinciding with SARS-CoV-2 mRNA vaccination. All potentially vaccine-related EGPA cases reported so far occurred within 14 days from immunization. EGPA is very rare with an incidence of 1:1,000,000 inhabitants, and the number of reported post-vaccination EGPA cases lies within the expected incidence rate for the period. While we cannot prove a causal relationship between the vaccine and EGPA onset, the temporal relationship with the vaccine immune stimulation is intriguing, in a disease occurring almost always in adults with asthma and/or chronic rhinosinusitis and driven by an aberrant Th2 lymphocyte activation with hypereosinophilia; nevertheless, cases of inflammatory diseases (IMIDs) emerging in the context of vaccination remain rare and the benefits of preventing severe COVID presentations with SARS-CoV-2 mRNA vaccines remain unquestionable.

Eosinophilic granulomatosis with polyangiitis - Advances in pathogenesis, diagnosis, and treatment

Eosinophilic granulomatosis with polyangiitis (EGPA) is a rare disease characterized by eosinophil-rich granulomatous inflammation and necrotizing vasculitis, pre-dominantly affecting small-to-medium-sized vessels. It is categorized as a primary antineutrophil cytoplasmic antibody (ANCA)-associated vasculitides (AAVs) but also shares features of hypereosinophilic syndrome (HES); therefore, both vessel inflammation and eosinophilic infiltration are suggested to cause organ damage. This dual nature of the disease causes variable clinical presentation. As a result, careful differentiation from mimicking conditions is needed, especially from HES, given the overlapping clinical, radiologic, and histologic features, and biomarker profile. EGPA also remains a diagnostic challenge, in part because of asthma, which may pre-dominate for years, and often requires chronic corticosteroids (CS), which can mask other disease features. The pathogenesis is still not fully understood, however, the interaction between eosinophils and lymphocytes B and T seems to play an important role. Furthermore, the role of ANCA is not clear, and only up to 40% of patients are ANCA-positive. Moreover, two ANCA-dependent clinically and genetically distinct subgroups have been identified. However, a gold standard test for establishing a diagnosis is not available. In practice, the disease is mainly diagnosed based on the clinical symptoms and results of non-invasive tests. The unmet needs include uniform diagnostic criteria and biomarkers to help distinguish EGPA from HESs. Despite its rarity, notable progress has been made in understanding the disease and in its management. A better understanding of the pathophysiology has provided new insights into the pathogenesis and therapeutic targets, which are reflected in novel biological agents. However, there remains an ongoing reliance on corticosteroid therapy. Therefore, there is a significant need for more effective and better-tolerated steroid-sparing treatment schemes.

A Case of Takotsubo Cardiomyopathy Triggered by Asthma Exacerbation After mRNA-based Vaccination for COVID-19

It is recommended to get the multiple coronavirus disease 2019 (COVID-19) vaccinations for almost all people including asthma patients. A 70-year-old Japanese woman with asthma experienced worsening of respiratory symptoms after the second dose of the mRNA-based COVID-19 vaccine BNT162b2. The patient had hypercapnic respiratory failure and cardiac-apex ballooning and was diagnosed with takotsubo cardiomyopathy induced by asthma exacerbation. Therapies for asthma exacerbation resulted in prompt improvement of respiratory failure and cardiac-apex ballooning. Our findings suggest that asthma patients are prone to exacerbations after receiving the COVID-19 vaccination; therefore, stratification of the patients at risk is required.

COVID-19-Induced Eosinophilic Lower Airway Inflammation in Those With Multiple COVID-19 Vaccinations

A 29-year-old woman was admitted with a diagnosis of ischemic enteritis. She had a coronavirus disease 2019 (COVID-19) infection four weeks before this visit and continued to experience a cough. Four months before, she received the third COVID-19 vaccine. Chest computer tomography revealed scattered ground-glass opacities in both upper lobes. Based on abnormalities in chest imaging, eosinophilia, and a high level of fractional exhaled nitric oxide, she was diagnosed with eosinophilic lower airway inflammation due to COVID-19. Since the visit, the patient had an intermittent fever and no radiological improvement, so systemic corticosteroid treatment was initiated, and the symptoms and clinical findings improved. Clinicians should know the potential association between COVID-19 and eosinophilic lower airway inflammation, which may still occur despite multiple vaccinations.

Colitis with Hypereosinophilia following the Second Dose of the BNT162b2 mRNA COVID-19 Vaccine: A Case Report with a Literature Review

A 61-year-old man presented with a 7-day history of watery diarrhea and loss of appetite after receiving the second dose of the Pfizer-BioNTech COVID-19 vaccine. Laboratory studies showed significant eosinophilia and an elevated IgE level (white cell count, 18.4×10⁹/L; eosinophil count, 9.5×10⁹/L; and IgE level, 540 IU/L). Symptoms resolved 10 days after vaccination without any steroids or antiallergic medications, and the eosinophil count had also returned to within normal limits 2 months later. Several cases of eosinophilic disorders following receipt of any type of injectable COVID-19 vaccine have been reported, so the etiology should be examined.

Gastrointestinal Eosinophilic Granulomatosis with Polyangiitis following a Clostridium difficile Infection

Eosinophilic granulomatosis with polyangiitis (EGPA), historically named Churg-Strauss syndrome, is a rare vasculitis affecting small- and medium-sized blood vessels. The disease has a predilection for numerous organs including the lungs, sinuses, kidneys, heart, nerves, and gastrointestinal tract but is prominently associated with asthma, rhinosinusitis, and eosinophilia. Gastrointestinal involvement is common; however, a gastrointestinal manifestation as the cardinal symptom following an infection is atypical. Here, we present a case of a 61-year-old male who presented with persistent diarrhea following a toxigenic Clostridium difficile infection despite multiple antibiotic courses. Repeat testing confirmed eradication of the infection, and further evaluation with colon biopsy revealed small and medium-sized vasculitis with eosinophilic infiltration and granulomas. Treatment with prednisone and cyclophosphamide resulted in rapid improvement of his diarrhea. Gastrointestinal symptoms in EGPA are associated with worse prognosis, so prompt identification and treatment of the disease is crucial. EGPA is rarely documented in histopathological samples from the gastrointestinal tract as endoscopic biopsies are typically too superficial to sample the submucosal layer containing the affected vessels. Additionally, the link between EGPA and infections as a potential trigger has not been clearly established, but gastrointestinal EGPA manifesting after a colonic infection raises concerns that this may have been a triggering event. Ultimately, further study is needed to understand, diagnose, and treat gastrointestinal and postinfection EGPA.

Infections and systemic vasculitis

Infections and systemic vasculitis (SV) are characterized by mutual influence, which increases the risk of occurrence, aggravates the course and outcome of the disease. The review considers the issues related to both the trigger role of infections in the development of SV and comorbid infections (CI) that complicate the course of the disease. Recognition of the infectious etiology of SV is of great importance, since it requires a comprehensive examination and, if necessary, early and complete etiotropic treatment. Since SV per se and the use of both induction and maintenance immunosuppressive therapy are significant risk factors for secondary CIs, special attention should be paid to the prevention of the latter, including vaccination, primarily against influenza and pneumococcal infections.