Dividing the Janus vasculitis? Pathophysiology of eosinophilic granulomatosis with polyangitis.
Eosinophilic granulomatosis with polyangitis (EGPA) is a rare small- and medium-sized vessel vasculitis belonging to the group of anti-neutrophil cytoplasm antibody (ANCA)-associated vasculitides (AAV). It is commonly divided into two phenotypes depending on the presence of ANCAs targeting myeloperoxidase (MPO). MPO-ANCAs are present in 31% to 38% of patients and are associated with a vasculitis phenotype of the disease, whereas patients without MPO-ANCA are at risk of cardiac involvement. Despite significant advances in understanding the overall pathogenesis of the disease, the explanation for this dichotomy is still unclear. In this review, we synthesize our knowledge of the pathogenesis of EGPA and attempt to i) distinguish EGPA from other diseases including other AAVs, asthma, allergy and hypereosinophilic-associated conditions and ii) speculate about the preponderant mechanisms, which could explain the two disease phenotypes.
INSERM, U1016, Institut Cochin, Paris, France; CNRS, UMR8104, Paris, France; Université Paris Descartes, Sorbonne Paris Cité, Paris, France; Université Paris Descartes, Faculté de Médecine, Pôle de Médecine Interne, Centre de référence pour les vascularites nécrosantes et la sclérodermie systémique, hôpital Cochin, Assistance Publique-Hôpitaux de Paris, Paris, France.
Benjamin
B
Chaigne
INSERM, U1016, Institut Cochin, Paris, France; CNRS, UMR8104, Paris, France; Université Paris Descartes, Sorbonne Paris Cité, Paris, France; Université Paris Descartes, Faculté de Médecine, Pôle de Médecine Interne, Centre de référence pour les vascularites nécrosantes et la sclérodermie systémique, hôpital Cochin, Assistance Publique-Hôpitaux de Paris, Paris, France.
Benjamin
B
Terrier
INSERM, U1016, Institut Cochin, Paris, France; CNRS, UMR8104, Paris, France; Université Paris Descartes, Sorbonne Paris Cité, Paris, France.
Nathalie
N
Thieblemont
INSERM, U1016, Institut Cochin, Paris, France; CNRS, UMR8104, Paris, France; Université Paris Descartes, Sorbonne Paris Cité, Paris, France.
Véronique
V
Witko-Sarsat
INSERM, U1016, Institut Cochin, Paris, France; CNRS, UMR8104, Paris, France; Université Paris Descartes, Sorbonne Paris Cité, Paris, France; Université Paris Descartes, Faculté de Médecine, Pôle de Médecine Interne, Centre de référence pour les vascularites nécrosantes et la sclérodermie systémique, hôpital Cochin, Assistance Publique-Hôpitaux de Paris, Paris, France. Electronic address: luc.mouthon@cch.aphp.fr.
Luc
L
Mouthon
D000818:Animals; D019268:Antibodies, Antineutrophil Cytoplasmic / Q000276:immunology; D001249:Asthma / Q000150:complications; D001402:B-Lymphocytes / Q000276:immunology; D004804:Eosinophils / Q000276:immunology*; D014890:Granulomatosis with Polyangiitis / Q000150:complications / Q000276:immunology*; D006801:Humans; D009195:Peroxidase / Q000276:immunology
D019268:Antibodies, Antineutrophil Cytoplasmic; D009195:Peroxidase
ANCA-MPO; Eosinophilia; Eosinophilic granulomatosis with polyangitis; Th2 response; Vasculitis