[Peripheral Neuropathy in Eosinophilic Granulomatosis with Polyangiitis].

Eosinophilic granulomatosis with polyangiitis (EGPA) is an antineutrophil cytoplasmic autoantibody-associated vasculitis secondary to inflammation of the small vessels. EGPA-induced neuropathy develops in approximately 90% of patients with peripheral blood eosinophilia and may lead to serious complications of the peripheral nervous system, necessitating emergency therapeutic intervention.

[Non-Eosinophilic Granulomatosis with Polyangiitis Vasculitic Neuropathy: An Overview].

Vasculitic neuropathy is commonly associated with systemic vasculitis, leading to ischemic damage to the peripheral nerves and axonal degeneration. The typical clinical manifestation of vasculitic neuropathy is a sensory-dominant multiple mononeuropathy often accompanied by pain. Although vasculitic neuropathy is caused by various systemic diseases, ANCA-associated vasculitis, secondary systemic vasculitis linked to various collagen diseases, and non-systemic vasculitic neuropathy hold particular significance. A comprehensive understanding of vasculitic neuropathy is crucial for its early diagnosis, contributing to an improved prognosis for this condition.

Clinical Characteristics of EGPA Patients in Comparison to GPA Subgroup with Increased Blood Eosinophilia from POLVAS Registry.

Objective: To characterize the eosinophilic granulomatosis with polyangiitis (EGPA) population from the POLVAS registry depending on ANCA status and diagnosis onset, including their comparison with the granulomatosis with polyangiitis (GPA) subset with elevated blood eosinophilia (min. 400/µl) (GPA HE) to develop a differentiating strategy. Methods: A retrospective analysis of the POLVAS registry. Results: The EGPA group comprised 111 patients. The ANCA-positive subset (n = 45 [40.54%]) did not differ from the ANCA-negative one in clinics. Nevertheless, cardiovascular manifestations were more common in ANCA-negative patients than in those with anti-myeloperoxidase (MPO) antibodies (46.97% vs. 26.92%, p = 0.045). Patients diagnosed before 2012 (n = 70 [63.06%]) were younger (median 41 vs. 49 years, p < 0.01), had higher blood eosinophilia at diagnosis (median 4,946 vs. 3,200/µl, p < 0.01), and more often ear/nose/throat (ENT) and cardiovascular involvement. GPA HE comprised 42 (13.00%) out of 323 GPA cases with reported blood eosinophil count. Both GPA subsets had a lower prevalence of respiratory, cardiovascular, and neurologic manifestations but more often renal and ocular involvement than EGPA. EGPA also had cutaneous and gastrointestinal signs more often than GPA with normal blood eosinophilia (GPA NE) but not GPA HE. The model differentiating EGPA from GPA HE, using ANCA status and clinical manifestations, had an AUC of 0.92, sensitivity of 96%, and specificity of 95%. Conclusion: Cardiovascular symptoms were more prevalent in the ANCA-negative subset than in the MPO-ANCA-positive one. Since EGPA and GPE HE share similarities in clinics, diagnostic misleading may result in an inappropriate therapeutic approach. Further studies are needed to optimize their differentiation and tailored therapy, including biologics.

[Clinical and electrophysiological characteristics and treatment outcomes of anti-neutrophil cytoplasmic antibody ANCA-associated vasculitic neuropathy].

Objective: To investigate the clinical and electrophysiological characteristics of ANCA-associated vasculitic neuropathy (VN) and analyze the predictors of treatment outcomes. Methods: Retrospective case series. In all, 652 consecutive patients with ANCA-associated vasculitis were admitted to the First Medical Center of the Chinese PLA General Hospital between January 2006 and December 2022. Peripheral neuropathy occurred in 91 patients. Patients were excluded if other known causes of neuropathy were present. Sixty-one patients were eventually enrolled, including 17 with eosinophilic granulomatosis with polyangiitis (EGPA), 11 with granulomatosis polyangiitis (GPA), and 33 with microscopic polyangiitis (MPA). Their clinical data were collected and clinical characteristics, VN manifestations, electrophysiological findings (including interside amplitude ratio [IAR]), and treatment outcomes were compared among the three subsets of AAV. Then, factors influencing the treatment outcomes were analyzed using multivariable logistic regression analysis. Results: Peripheral neuropathy occurred in 62.1%(18/29) of EGPA, 8.3%(15/180) of GPA, and 13.1%(58/443) of MPA patients. The age at onset and examination was higher in patients with MPA than those with EGPA or GPA (P<0.01). The occurrence of VN was later in patients with GPA than those with EGPA (P<0.01), and the GPA group had fewer affected nerves than the other two groups (P<0.016). The abnormal IARs of motor nerves in lower limbs were more detected in the EGPA than the MPA group (P<0.01). Logistic regression analysis suggested that higher Birmingham vasculitis activity score-version 3 (BVAS-V3) (OR=6.85, 95%CI 1.33-35.30) was associated with better treatment outcomes of VN. However, central nervous system involvement was a risk factor for poor treatment outcomes (OR=0.13, 95%CI 0.02-0.89). Conclusions: The clinical and electrophysiological characteristics of VN were slightly different among subsets of AAV. Patients with GPA often presented with polyneuropathy and had fewer nerves affected; mononeuritis multiplex was more common in EGPA than GPA and MPA. Higher BVAS-V3 and central nervous system involvement might predict the treatment outcome of VN.

[Modern Perspectives on Peripheral Neuropathology].

Recent advances in genetic and antibody testing have limited pathological examination of peripheral nerve specimens. However, when examining peripheral neuropathological findings from a modern perspective, there is often an opportunity to comprehend previously unnoticed observations upon re-examining the same specimen. For example, electron microscopy studies have suggested that the components that distinguish between nodal regions and internodes play a pivotal role in the behavior of macrophages that initiate myelin phagocytosis in the demyelinating form of Guillain-Barré syndrome and chronic inflammatory demyelinating polyneuropathy (CIDP). Conversely, some patients previously diagnosed with CIDP were found to possess distinctive mechanisms initiated by autoantibodies against paranodal junction proteins such as neurofascin 155 leading to the emergence of the concept of autoimmune nodopathy. In vasculitis, the roles of neutrophils in antineutrophil cytoplasmic antibody-associated vasculitis, eosinophils in eosinophilic granulomatosis with polyangiitis, and complements in nonsystemic vasculitic neuropathy in tissue damage have also been demonstrated when viewed from a modern perspective. Furthermore, mechanisms attributable to predominant small-fiber loss in hereditary transthyretin amyloidosis have been clarified at an ultrastructural level.

Granulomatosis with polyangiitis or its mimic? A case report.

Differentiation between granulomatosis with polyangiitis (GPA) limited to the upper airways and cocaine-induced midline destructive lesion (CIMDL) may be particularly difficult because of their common histopathologic features and antineutrophil cytoplasmic antibody (ANCA) profiles. We herein present a case involving a young woman with an initial diagnosis of GPA based on upper and lower airway manifestations and constitutional symptoms, histopathologic evidence of granulomas, a positive cytoplasmic ANCA indirect immunofluorescent test result, and proteinase 3 positivity by enzyme-linked immunosorbent assay (ELISA). CIMDL was confirmed based on the appearance of a hard palate perforation, positivity for methylecgonine on urine toxicology, a positive perinuclear ANCA indirect immunofluorescent test result, and subsequent human neutrophil elastase (HNE) ANCA positivity by ELISA. Finally, based on the coexistence of CIMDL, constitutional symptoms, and lower airway manifestations, the diagnosis was modified to cocaine-induced GPA mimic. Urine toxicology for cocaine and HNE ELISA are indicated in young patients with GPA who develop limited airway disease to check for the presence of CIMDL and cocaine-/levamisole-induced ANCA-associated vasculitis. Continued abstinence from cocaine is the first-choice therapy for both CIMDL and cocaine-induced GPA mimic.

Chemokine expression in sera of patients with microscopic polyangiitis and granulomatosis with polyangiitis.

We evaluated chemokine expression and its correlation with disease activity in patients with microscopic polyangiitis (MPA) and granulomatosis with polyangiitis (GPA) (MPA/GPA). Serum CCL2, CCL4, CCL19, CXCL1, CXCL2, and CX3CL1 level in 80 patients were analysed using multiple enzyme-linked immunosorbent assays. Correlations between variables were investigated using Pearson's correlation analysis, and receiver operator curve analysis was performed to identify optimal CX3CL1 values in determining active disease. Multivariate logistic regression analysis was done to evaluate predictors of active disease. CCL4 (r = 0.251, p = 0.025), CXCL1 (r = 0.270, p = 0.015), and CX3CL1 (r = 0.295, p = 0.008) significantly correlated with BVAS, while CX3CL1 was associated with five-factor score (r = - 0.290, p = 0.009). Correlations were revealed between CCL2 and CCL4 (r = 0.267, p = 0.017), CCL4 and CXCL1 (r = 0.368, p < 0.001), CCL4 and CXCL2 (r = 0.436, p < 0.001), and CXCL1 and CXCL2 (r = 0.518, p < 0.001). Multivariate analysis revealed serum CX3CL1 levels > 2408.92 pg/mL could predict active disease (odds ratio, 27.401, p < 0.001). Serum chemokine levels of CCL4, CXCL1, and CX3CL1 showed association with disease activity and especially, CX3CL1 > 2408.92 pg/mL showed potential in predicting active MPA/GPA.

The Joint Vasculitis Registry in German-speaking countries (GeVas): subgroup analysis of 266 AAV patients.

OBJECTIVES: Prospective long-term observational data on the disease course of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) were missing in Germany to date. Therefore, the Joint Vasculitis Registry in German-speaking countries (GeVas) has been established to follow the course of patients with AAV. The aim of this study is to present baseline data of patients with newly diagnosed and relapsing AAV enrolled in the GeVas registry. METHODS: GeVas is a prospective, web-based, multicentre, clinician-driven registry for the documentation of organ manifestations, damage, long-term outcomes, and therapy regimens in various types of vasculitis. Recruitment started in June 2019. RESULTS: Between June 2019 and October 2022, 266 patients with AAV were included in the GeVas registry: 173 (65%) with new-onset and 93 (35%) with relapsing AAV. One hundred and sixty-two (61%) patients were classified as granulomatosis with polyangiitis (GPA), 66 (25%) as microscopic polyangiitis (MPA), 36 (13%) as eosinophilic granulomatosis with polyangiitis (EGPA), and 2 (1%) as renal limited AAV. The median age was 59 years (51-70 years, IQR), 130 (51%) patients were female. Most patients were ANCA positive (177; 67%) and affected by general symptoms, pulmonary, ear nose throat (ENT), renal and neurological involvement. For induction of remission, the majority of patients received glucocorticoids (247, 93%) in combination with either rituximab (118, 45%) or cyclophosphamide (112, 42%). CONCLUSIONS: Demographic characteristics are comparable to those in other European countries. Differences were found regarding ANCA status, frequencies of organ manifestations, and therapeutic regimens. The GeVas registry will allow longitudinal observations and prospective outcome measures in AAV.

Proteinase 3-specific antineutrophil cytoplasmic antibody-associated vasculitis.

Proteinase 3 (PR3)-specific antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis is one of two major ANCA-associated vasculitis variants and is pathogenically linked to granulomatosis with polyangiitis (GPA). GPA is characterised by necrotising granulomatous inflammation that preferentially affects the respiratory tract. The small vessel vasculitis features of GPA are shared with microscopic polyangiitis. Necrotising granulomatous inflammation of GPA can lead to PR3-ANCA and small vessel vasculitis via activation of neutrophils and monocytes. B cells are central to the pathogenesis of PR3-ANCA-associated vasculitis. They are targeted successfully by remission induction and maintenance therapy with rituximab. Relapses of PR3-ANCA-associated vasculitis and toxicities associated with current standard therapy contribute substantially to remaining mortality and damage-associated morbidity. More effective and less toxic treatments are sought to address this unmet need. Advances with cellular and novel antigen-specific immunotherapies hold promise for application in autoimmune disease, including PR3-ANCA-associated vasculitis. This Series paper describes the inter-related histopathological and clinical features, pathophysiology, as well as current and future targeted treatments for PR3-ANCA-associated vasculitis.

Lung cancer in older patients with granulomatosis with polyangiitis: a report of three cases.

BACKGROUND: Granulomatosis with polyangiitis (GPA) is characterized by necrotizing granulomatous inflammation with necrotizing vasculitis predominantly affecting small to medium vessels. The survival rates have drastically improved; however, GPA can be lethal, with older patients having a worse prognosis and higher mortality than younger patients. Moreover, the incidence of various cancers has been reported to increase in patients with GPA. We aimed to discuss possible associations between GPA and lung cancer and emphasize the associated diagnostic challenges. CASE PRESENTATION: We encountered three older patients with chronic GPA who developed lung cancer during long-term follow-up. Two of the patients had a smoking history, with one having silicosis and the other having chronic obstructive pulmonary disease. Furthermore, all of them had radiation exposure from repeated radiography/computed tomography. All the patients had confirmed GPA, and vasculitis relapse was first suspected when new lung lesions were noted during follow-up. However, they had no new clinical symptoms, and serum ANCA titer increased only in one patient. All the patients received standard immunosuppressive treatment but eventually died. CONCLUSIONS: Lung cancer is uncommon in patients with GPA; however, the similarity between the imaging findings of lung cancer and GPA may pose a diagnostic challenge. Clinicians should be particularly vigilant when treating older patients with an increased risk of cancer, as they are often asymptomatic or have poorly apparent clinical features.

Unexpected discovery of renal mass in a patient with granulomatosis with polyangiitis: accidental or inevitable?

Granulomatosis with polyangiitis (GPA) is an uncommon disorder that mainly involves the upper and lower respiratory tract and kidney, presenting as sinusitis, saddle nose, otitis media, pulmonary nodule and cavity, rapidly progressive glomerulonephritis. It also affects skin, eye, heart, joint and nervous system. Renal involvement in GPA is commonly manifested as necrotising glomerulonephritis, while renal mass is very rare. We herein present two hospitalised cases with fever, pulmonary cavity and renal mass. Clinical course and examinations of the cases, from symptoms to diagnosis, will be discussed in detail, along with a relevant literature review of this unusual renal manifestation.

Investigating the concomitance of anti-neutrophil cytoplasmic antibody (ANCA) associated vasculitides and inflammatory bowel disease (IBD).

OBJECTIVE: To assess relationship between Anti-neutrophil cytoplasmic antibody (ANCA) associated vasculitis and inflammatory bowel disease (IBD). METHODS: This is a retrospective study design. The patients were identified using a preset criteria of patients who have the diagnosis of ANCA associated vasculitis including a diagnosis of granulomatosis with polyangiitis (GPA) or microscopic polyangiitis (MPA) or eosinophilic granulomatosis with polyangiitis (EGPA) with overlapping inflammatory bowel disease (Crohn's disease or ulcerative colitis) in the time period from 01/01/2020 to 08/03/2023. Subsequently data from each patient was collected that will include baseline demographics, disease characteristics, disease activity, treatment information, multiorgan involvement, and pathology findings which were then analyzed. RESULTS: 39 patients were identified that met criteria. 20 patients carried a diagnosis of GPA, 6 had MPA and 4 patients had EGPA. 20 patients with GPA had inflammatory bowel disease, 13 with ulcerative colitis and 6 with Crohn's disease while 1 GPA patient had unspecified inflammatory bowel disease. 4 patients with EGPA had inflammatory bowel disease, 2 with ulcerative colitis and 2 with Crohn's disease. 6 patients with MPA had inflammatory bowel disease, 4 with ulcerative colitis and 2 with Crohn's disease. IBD diagnosis preceded the diagnosis of ANCA vasculitis in 77.8 % of the cases. CONCLUSION: Objective observation and deductions from this study raise the concern for a possible pathogenic association of ANCA associated vasculitis and inflammatory bowel disease and more research is needed to identify any causal association or influence of the two systemic disease on each other.

APDS patients with immune-complex vasculitis and resolution with leniolisib.

Activated phosphoinositide 3-kinase delta syndrome (APDS) is an inborn error of immunity with heterogeneous clinical manifestations of infections, immune dysregulation, autoimmunity; lymphoproliferation; and malignancy. Immune complex-mediated vasculitides have not yet been described in APDS patients. Here we offer a case series of three patients with APDS who have refractory IgA vasculitis (also called Henoch-Schönlein purpura), a form of immune complex-mediated vasculitis that activates complement and attracts neutrophils, macrophages and eosinophils to cause local tissue injury. Leniolisib is an inhibitor of PI3K p110δ and an FDA-approved treatment for APDS. IgA vasculitis resolved upon treatment with leniolisib. Patients with immune dysregulation including IgA vasculitis should be screened for APDS.

Significance of clinical-immunological patterns and diagnostic yield of biopsies in microscopic polyangiitis and granulomatosis with polyangiitis.

BACKGROUND: Microscopic polyangiitis (MPA) and granulomatosis with polyangiitis (GPA) are the two major antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV). OBJECTIVES: To characterize a homogenous AAV cohort and to assess the impact of clinicopathological profiles and ANCA serotypes on clinical presentation and prognosis. Clinical differences in GPA patients according to ANCA serotype and the diagnostic yield for vasculitis of biopsies in different territories were also investigated. RESULTS: This retrospective study (2000-2021) included 152 patients with AAV (77 MPA/75 GPA). MPA patients (96.1% myeloperoxidase [MPO]-ANCA and 2.6% proteinase 3 [PR3]-ANCA) presented more often with weight loss, myalgia, renal involvement, interstitial lung disease (ILD), cutaneous purpura, and peripheral nerve involvement. Patients with GPA (44% PR3-ANCA, 33.3% MPO, and 22.7% negative/atypical ANCA) presented more commonly with ear, nose, and throat and eye/orbital manifestations, more relapses, and higher survival than patients with MPA. GPA was the only independent risk factor for relapse. Poor survival predictors were older age at diagnosis and peripheral nerve involvement. ANCA serotypes differentiated clinical features in a lesser degree than clinical phenotypes. A mean of 1.5 biopsies were performed in 93.4% of patients in different territories. Overall, vasculitis was identified in 80.3% (97.3% in MPA and 61.8% in GPA) of patients. CONCLUSIONS: The identification of GPA presentations associated with MPO-ANCA and awareness of risk factors for relapse and mortality are important to guide proper therapeutic strategies in AAV patients. Biopsies of different affected territories should be pursued in difficult-to-diagnose patients based on their significant diagnostic yield.

[ANCA-negative granulomatosis with polyangiitis: a case report].

We reported a case of 73-year-old male with multiple pulmonary nodules and cavities. The patient was admitted with a chief complaint of "dry cough with shortness of breath for 3 months". Chest CT showed multiple irregular masses, nodules, and patchy lesions in both lungs, accompanied by the formation of cavities. He also had anemia and renal dysfunction. Despite given empirical anti-infective and anti-tuberculosis treatments, the pulmonary nodules progressed, and the cavities enlarged. Anti-neutrophil cytoplasmic antibodies (ANCA) were negative twice. Bronchoscopic biopsy was performed. The mucosal pathology of the right middle lobe lesion showed little necrosis, focal granulomatous structure formation, and relevant vasculitis and remaining vessel wall structure in the necrosis lesions by elastic fiber staining. A clinical diagnosis of ANCA-negative necrotizing granulomatous polyangiitis was made and the patient was treated with glucocorticoids and cyclophosphamide. The nodules and cavities shrank, and some lesions were absorbed.

Epidemiology and treatment outcome of ANCA-associated vasculitis in South Korea: a nationwide, population-based cohort study.

OBJECTIVES: To investigate the epidemiological features of granulomatosis with polyangiitis (GPA) and microscopic polyangiitis (MPA) in South Korea. METHODS: We identified the index cases of GPA and MPA using the 2010-2018 Korean National Health Insurance Service database and the Rare Intractable Disease registry for the entire Korean population. Each disease's incidence and prevalence rates and trends over time were analysed. To assess the impact of disease on morbidity and mortality, a comparator group comprising the general population was established using nearest-neighbour matching by age, sex, income, and comorbidity index, at a 5:1 ratio. Morbidity outcomes included the initiation of renal replacement therapy and admission to the intensive care unit. RESULTS: We identified 546 and 795 patients with GPA and MPA, respectively. The incidence rates of both diseases increased with age, with peak incidence rates observed among patients aged ≥70 years. The incidence of MPA increased continuously over time, whereas that of GPA showed no significant changes. During the observation period, 132 (28.7%) and 277 (41.1%) patients in the GPA and MPA groups, respectively, died, which were significantly higher than that in the general population (standardised mortality ratio: 3.53 and 5.58, respectively) and comparator group (hazard ratio: 4.02 and 5.64, respectively). Higher mortality and morbidity rates were observed among patients with MPA than among those with GPA. CONCLUSIONS: In South Korea, the incidence of MPA has increased over time. Although both GPA and MPA had high rates of mortality and morbidity, MPA has a poorer prognosis than GPA.