Heterogeneity and individualized therapy for eosinophilic granulomatosis with polyangiitis.

Eosinophilic granulomatosis with polyangiitis (EGPA), as a heterogeneous component of antineutrophil cytoplasmic antibody-associated vasculitis, may be induced by a series of environmental and genetic factors, involved with a variety of immune cells and immune components, and presented with various clinical manifestations, with multiple organs and systems (respiratory, skin, heart, kidney, nerve, etc.) involved. The choice of glucocorticoid (GC) dosage and immunosuppressant in traditional treatment strategies varies greatly from individual to individual and is not universally applicable in all the EGPA phenotype spectrum, especially in relapsing or refractory diseases. With the understanding of the heterogeneity of EGPA, a variety of therapeutic approaches are emerging and improving the traditional treatment model. In this review, we summarized the heterogeneity of EGPA etiology and pathogenesis. Clinical and pathological manifestations of the same organ involved also show significant differences and there are even gender differences. Biological treatments that mainly target type 2 inflammatory pathways are widely used in clinical practice for remission induction and maintenance of EGPA. Targeted biological therapy has shown excellent performance in reducing GC dosage and controlling symptoms and recurrence. However, a large number of high-quality randomized controlled studies are still under research for relapsing or refractory EGPA with special organ involvement. We believe that EGPA has a highly heterogeneous phenotype spectrum, and the treatment patterns targeting key molecules in the pathogenesis are of great value for individual treatment of EGPA.