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.

Comparison of characteristics of muscle magnetic resonance imaging findings in patients with antineutrophilic cytoplasmic antibody-associated vasculitis and polyarteritis nodosa

AIM

This study aimed to analyze the muscle magnetic resonance imaging (MRI) findings of patients with antineutrophilic cytoplasmic antibody-associated vasculitis (AAV) and polyarteritis nodosa (PAN) presenting with clinical symptoms in the extremities.

METHODS

Retrospective analysis was conducted on short tau inversion recovery MRI findings, with a focus on intramuscular vessels displaying abnormal perivascular signals, in 22 and eight patients with AAV and PAN, respectively. The number per unit area (4 cm2) and diameter of abnormal vessels on muscle MRI were compared between patients with AAV and those with PAN. Cut-off values, clinical sensitivity, and specificity for these indices were calculated from the receiver operating characteristic curves to distinguish between AAV and PAN, and the relationship between the indices and clinical findings in AAV was analyzed.

RESULTS

The number of abnormal vessels per unit area was significantly higher in AAV compared to PAN (p < .05). Additionally, the diameter of the abnormal vessels was significantly higher in PAN than in AAV (p < .05). The presence of >6.44 abnormal vessels per unit area or ≤3.61 mm diameter of abnormal vessels was able to predict AAV (sensitivity, 0.955; specificity, 0.625). AAV patients with peripheral neuropathy exhibited a significantly higher number of abnormal vessels per unit area than those without peripheral neuropathy (p < .05).

CONCLUSIONS

Muscle MRI can detect small- to medium-vessel vasculitis and be a valuable tool for distinguishing between patients with AAV and PAN experiencing clinical symptoms in the extremities.

Granulomatosis with polyangiitis mimicking COVID-19 pneumonia: A case report

Granulomatosis with polyangiitis (GPA), formerly known as Wegener's granulomatosis, is a necrotizing vasculitis characterized by small-to-medium-sized vessel involvement and the presence of antineutrophil cytoplasmic antibodies (ANCA). We present a case of a 26-year-old Asian woman who was transferred to our center from a nearby hospital, where she presented with shortness of breath, tested positive for COVID-19, and was being managed for COVID-19 pneumonia. She also had hemoptysis, skin lesions, and left foot numbness. Serological markers and VATS-guided lung biopsy confirmed the diagnosis. Treatment with methylprednisolone and rituximab led to stabilization, despite complications of subcutaneous emphysema and lower extremity neuropathic symptoms. Early recognition and appropriate management of GPA are crucial for optimal outcomes.

ANCA-associated vasculitis with scleritis, corneal melt, and perforation rescued by rituximab: Case report and literature review

Key Clinical Message

Patients with antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis, specifically with myeloperoxidase (MPO)-ANCA, would have a risk for developing corneal melt and perforation abruptly in a short period. It is desirable to have a team of collaboration of rheumatologists and other specialties.

Abstract

An 80-year old man who had been diagnosed 5.5 years previously as ANCA-associated vasculitis by temporal artery biopsy developed corneal melt and perforation with scleritis in both eyes. He underwent successful cataract surgery and retained ambulatory vision with the aid of intravenous rituximab. Two additional patients with similar manifestations were found in the literature.

The confused puzzles in antineutrophil cytoplasmic antibody-associated vasculitis activity evaluation: A case report

Antineutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) is a group of chronic multisystem autoimmune diseases with substantial mortality and morbidity and frequent relapses. The complexity of the disease condition and treatment-related adverse reactions as well as infections play important roles in the poor outcomes. Unfortunately, the subjective symptoms and objective indicators are not fully parallel, and manifestations between disease activity and treatment-related adverse reactions are often similar. Here, we describe a case of pulmonary mucormycosis in an old female patient with AAV to highlight these challenges.

Sequential development of ANCA-associated vasculitis and anti-GBM disease: A report of two cases

In case of AAV with kidney involvement, physicians should explore anti-GBM antibodies and be aware of the possible sequential development of AAV, especially with MPO-ANCA, and anti-GBM glomerulonephritis. This sequential disease history is associated with a poor renal outcome, highlighting the need for urgent diagnosis and management.

Tocilizumab monotherapy uncovered the role of the CCL22/17-CCR4+ Treg axis during remission of crescentic glomerulonephritis

Objectives

Tocilizumab (TCZ) is a humanised anti‐interleukin (IL)‐6 receptor (IL‐6R) monoclonal antibody that is a promising agent to treat various autoimmune diseases. However, the mechanism of TCZ efficacy is unclear. This study aims to elucidate the relationship between Tregs and IL‐6R blockade in autoimmunity‐mediated renal disease based on a TCZ‐treated cohort of patients with anti‐neutrophil cytoplasmic antibody (ANCA)‐associated vasculitis (AAV) and in an experimental model of crescentic glomerulonephritis (cGN).

Methods

We examined multiple serum levels of cytokines and chemokines and peripheral blood mononuclear cells in patients with AAV who received TCZ monotherapy and achieved drug‐free remission. Moreover, we investigated the mechanistic role of IL‐6R blockade in accelerated cGN model to analyse the local sites of inflammation.

Results

Serum chemokines CCL22 and CCL17, in addition to the CCR4⁺Foxp3⁺ Treg population, increased in patients who demonstrated drug‐free remission after the cessation of TCZ. In the cGN model, IL‐6R blockade ameliorated the disease, elevated CCL22/17 in CD206⁺CD11b⁺CD11c⁺ kidney M2‐like type macrophages, and increased the migration of Tregs into the kidney and regional lymph nodes. The local administration of CCL22 in the kidney facilitated Treg accumulation and reduced glomerular crescent formation.

Conclusions

This study revealed a new mechanism whereby effector Tregs migrate into the inflammatory kidney via the CCL22/17–CCR4 axis that is facilitated by M2‐like type macrophages that are induced by IL‐6R blockade.