Eosinophils in vasculitis: characteristics and roles in pathogenesis

Abstract

Eosinophils are multifunctional granular leukocytes that are implicated in the pathogenesis of a wide variety of disorders, including asthma, helminth infection, and rare hypereosinophilic syndromes. Although peripheral and tissue eosinophilia can be a feature of many types of small-vessel and medium-vessel vasculitis, the role of eosinophils has been best studied in eosinophilic granulomatosis with polyangiitis (EGPA), where eosinophils are a characteristic finding in all three clinical stages of the disorder. Whereas numerous studies have demonstrated an association between the presence of eosinophils and markers of eosinophil activation in the blood and tissues of patients with EGPA, the precise role of eosinophils in disease pathogenesis has been difficult to ascertain owing to the complexity of the disease process. In this regard, results of clinical trials using novel agents that specifically target eosinophils are providing the first direct evidence of a central role of eosinophils in EGPA. This Review focuses on the aspects of eosinophil biology most relevant to the pathogenesis of vasculitis and provides an update of current knowledge regarding the role of eosinophils in EGPA and other vasculitides.

Rheumatoid arthritis presenting as rheumatoid meningitis: A case report

“…[2][3][4] As seen in our patient, rheumatoid meningitis can develop irrespective of systemic inflammation and arthritis. [2,5] The rarity of diagnosis limits available information about the disease, with the largest case series using less than two dozen patients. [2,6] Classically this disease presents as a late manifestation of RA; however, there are multiple case reports of the disease presenting in the first year of diagnosis.…”

“…[11,12] However, MTX and TNF blockers can be used as a steroid sparing agents for patients who wish to avoid other immunosuppressants such as cyclophosphamide or azathioprine, all of which have previously been used for treatment. [5,12] Additionally, rituximab and tocilizumab have shown promise as a well-tolerated steroid sparing agent. [13,14] Regardless of treatment, rheumatoid meningitis remains a serious and deadly complication of RA with a mortality rate of up to 70%.…”

“…Rarely, rheumatoid meningitis can be the initial presenting symptom of rheumatologic disease and should be kept in the differential in patients with or without a history of RA. [5,7] Once the diagnosis is suspected, prompt treatment is essential given the poor overall morbidity and mortality rate.…”

“…[7] Typically, histopathological examination of meningeal tissue is required which can reveal rheumatoid nodules, nonspecific meningeal inflammation, or vasculitis. [5] Differential diagnosis for epithelioid granulomas, besides RA, includes meningeal carcinomatosis, neurofibromatosis, lymphoma, Sturge-Weber angiomatosis, syphilis, tuberculosis, sarcoidosis, and other inflammatory disorders. [9] Rheumatoid nodules are not required for diagnosis, and necrotizing granulomas without giant cells or epithelioid cells have previously been seen in rheumatoid meningitis, similar to our own patient.…”

Recalcitrant steroid-resistant EGPA with multisystem involvement

“…[1,2] Specifically, organ damage secondary to eosinophil infiltration underlies airway and lung parenchymal, cardiac and gut involvement, while mononeuritis multiplex, glomerulonephritis and purpura characterize the vasculitic phase. [3][4][5] We report the clinical disease course of a gentleman with steroid-resistant EGPA characterized by recalcitrant peripheral eosinophilia, central and peripheral nervous system involvement, myocarditis, diffuse alveolar hemorrhage (DAH), necrotizing myopathy, and extensive eosinophilic degranulation in gastrointestinal tissues; the latter only apparent after staining with targeted monoclonal antibodies to eosinophil peroxidase (EPX). This case highlights the synchronous presentation of multiple rare manifestations of EGPA, highlighting the multisystem complexity and clinical heterogeneity of this disease entity.…”