Pathogenesis-based new perspectives of management of ANCA-associated vasculitis

Thrombosis in vasculitis: An updated review of etiology, pathophysiology, and treatment

Introduction

Thromboembolic disease is a complication of many vasculitides. A common observation is that thromboembolic events coincide with the period of vasculitic disease, but the mechanism by which this occurs remains unclear. Inflammatory thrombosis is now recognized as a symptom of arteritis rheumatic, and vasculitides such as Behçet's syndrome (BS), and anti-neutrophil cytoplasmic antibodies (ANCA)-associated vasculitis (AAV) or giant cell arteritis (GCA). This systematic review aimed to explain recent findings related to etiology, pathophysiology, and treatment methods for BS, AAV, and medium/large-vessel vasculitis.

Methods

A comprehensive literature search on English sources from PubMed, Scopus, MEDLINE, Science Direct, ProQuest, AIM, CINAHIL, and ELDIS databases was used to find the relevant articles and reports. The relevant papers (having full text) were obtained until June 2023. Two independent reviewers screened the titles and abstracts of the obtained articles, and a third arbitrator resolved disputes between the reviewers.

Results and conclusion

It is becoming increasingly clear that certain systemic inflammatory diseases, like vasculitis, are linked to a higher risk of both venous and arterial thrombosis. An increased incidence of thromboembolic disease in AAV has been noted, particularly during times of active disease. Growing evidence supports the use of immunosuppression in the management of venous thrombosis in vasculitis. These patients also have a higher risk of developing ischemic disease.

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.

Efficacy of protein A immunoadsorption and therapeutic plasma exchange in ANCA-associated vasculitis with severe renal involvement: a retrospective study

BACKGROUND

Severe renal impairment is a common complication of anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis (AAV) and is associated with poor prognosis and shorter survival. It is urgent to find effective treatments to improve the prognosis of AAV patients. This study was designed to assess the efficacy and safety of protein A immunoadsorption (PAIA) and therapeutic plasma exchange (TPE) for AAV with severe renal involvement.

METHODS

A total of 48 AAV patients with renal involvement admitted to the Second Xiangya Hospital from January 2018 to February 2021 were selected. Clinical data, myeloperoxidase anti-neutrophil cytoplasmic antibody (MPO-ANCA), remission at 6 months, and outcomes were evaluated. The primary outcomes of interest were death and renal survival as defined by the occurrence of end-stage renal disease (ESRD).

RESULTS

PAIA was effective in the removal of MPO-ANCA and IgG, and showed superior over TPE in the clearance of MPO-ANCA within 1 month after treatment. After a median follow-up of 14.5 months, PAIA therapy showed an advantage in reducing mortality over TPE. There was no difference in the development of ESRD between the two groups. Multivariate Cox regression analysis indicated that higher serum creatinine (SCr) and lower haemoglobin level were independent risks of ESRD. Age > 60, lower serum albumin (ALB), and failure to achieve remission at 6 months were independent risks of death.

CONCLUSIONS

PAIA treatment reduces MPO-ANCA and IgG as well as mortality in AAV patients, and may be beneficial for severe AAV in clinical practice. Higher SCr, lower serum ALB or haemoglobin levels, age > 60, and failure to achieve remission at 6 months independently predict the ESRD or death of AAV patients with severe renal involvement.KEY MESSAGESCompared with therapeutic plasma exchange, protein A immunoadsorption treatment eliminates myeloperoxidase anti-neutrophil cytoplasmic antibody (MPO-ANCA) and IgG better and reduces mortality in ANCA-associated vasculitis (AAV) patients with severe renal involvement.Higher serum creatinine, lower serum albumin or haemoglobin levels, age > 60, and failure to achieve remission at 6 months independently predict the end-stage renal disease (ESRD) or death of AAV patients with severe renal involvement.

Features of BAFF and APRIL receptors on circulating B cells in antineutrophil cytoplasmic antibody-associated vasculitis

To investigate the features of circulating B cells, their expressing receptors, serum levels of B-cell activation factor of the TNF family (BAFF), and a proliferation-inducing ligand (APRIL) in antineutrophil cytoplasmic antibody-associated vasculitis (AAV). Blood samples from 24 patients with active AAV (a-AAV), 13 with inactive AAV (i-AAV), and 19 healthy controls (HC) were included in this study. The proportion of B cells and their expressing BAFF receptor (BAFF-R), transmembrane activator and calcium modulator and cyclophilin ligand interactor (TACI), and B-cell maturation antigen were analyzed via flow cytometry. Serum levels of BAFF, APRIL, and interleukin (IL)-4, IL-6, IL-10, and IL-13 were also evaluated using an enzyme-linked immunosorbent assay. The proportion of plasmablasts (PB)/plasma cells (PC) and serum levels of BAFF, APRIL, IL-4, and IL-6 were significantly higher in a-AAV than in HC. Higher serum levels of BAFF, APRIL, and IL-4 were observed in i-AAV than in HC. Lower expression of BAFF-R on memory B cells and higher expression of TACI on CD19+ cells, immature B cells, and PB/PC were demonstrated in a-AAV and i-AAV than in HC. The population of memory B cells was positively associated with serum APRIL levels and BAFF-R expression in a-AAV. In conclusion, decreased expression of BAFF-R on memory B cells and increased expression of TACI on CD19+ cells, immature B cells, and PB/PC, as well as increased serum levels of BAFF and APRIL, were sustained even in the remission phase of AAV. Persistent aberrant signaling of BAFF/APRIL may contribute to disease relapse.

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.

Longitudinal monitoring of circulating immune cell phenotypes in anti-neutrophil cytoplasmic antibody-associated vasculitis

Anti-neutrophil cytoplasmic antibody-associated vasculitis (AAV) is a necrotizing multiorgan autoimmune disease that affects small- to medium-sized blood vessels. Despite the improvements in treatments, half of the patients with AAV still experience disease relapses. In this review, we focus on peripheral leukocyte properties and phenotypes in patients with AAV. In particular, we explore longitudinal changes in circulating immune cell phenotypes during the active phase of the disease and treatment. The numbers and phenotypes of leukocytes in peripheral blood were differs between AAV and healthy controls, AAV in active versus inactive phase, AAV in treatment responders versus non-responders, and AAV with and without severe infection. Therefore, biomarkers detected in peripheral blood immune cells may be useful for longitudinal monitoring of disease activity in AAV.

Anti-glomerular basement membrane vasculitis

Antiglomerular basement membrane disease (anti-GBM) is a rare life-threatening autoimmune vasculitis that involves small vessels and it is characterized by circulating autoantibodies directed against type IV collagen antigens expressed in glomerular and alveolar basement membrane. The typical clinical manifestations are the rapidly progressive glomerulonephritis and the alveolar hemorrhage. The diagnosis is usually confirmed by the detection of anti-GBM circulating antibodies. If not rapidly recognized, anti-GBM disease can lead to end stage kidney disease (ESKD). An early diagnosis and prompt treatment with immunosuppressive therapies and plasmapheresis are crucial to prevent a poor outcome. In this review, we discuss the primary form of anti-GBM (the so called Goodpasture syndrome) but also cases associated with other autoimmune diseases such as antineutrophil-cytoplasmic-antibody (ANCA) vasculitis, membranous nephropathy, IgA nephritis and systemic lupus erythematosus (SLE), as well as the few cases of anti-GBM vasculitis complicating kidney transplantation in the Alport syndrome.