Antineutrophil Cytoplasm Antibody-Associated Vasculitis
EGPA is a form of AAV characterized by asthma and eosinophilia. EGPA has been excluded from most AAV trials because of difficulty in evaluating the disease activity including asthmatic symptoms and likely differences in pathogenesis. There are fewer data supporting current EGPA treatments than for GPA/MPA. The French Vasculitis Study Group examined the response to glucocorticoids in nonsevere EGPA and to glucocorticoids and cyclophosphamide in severe EGPA. Relapse rates in nonsevere EGPA are high if treated with glucocorticoids alone and studies of combinations with other immunosuppressants are needed. Similarly, only anecdotal data exist for the role of rituximab in EGPA. Case reports and case series have demonstrated good responses to rituximab in certain manifestations of EGPA, though it lacked a clear pathophysiological rationale except the presence of ANCA.
A Th2 response with elevated IL-4, IL-5 and IL-13 is predominant in the disease development of EGPA. Two small open label studies of an anti-interleukin-5 antibody, mepolizumab, have reported good effects with safety in EGPA, and a larger trial is being prepared. Pitakinra is a human recombinant protein and inhibits IL-4 and IL-13 pathway by acting as an IL-4 receptor α antagonist. Pitakinra might be effective for EGPA. Both drugs have shown efficacy for bronchial asthma.
IFN-α is known to counteract Th2 response, and small studies suggested its efficacy in both remission induction and maintenance in EGPA. However, its unfavorable safety profile has restricted its use.
Treatments for Eosinophilic Granulomatosis With Polyangiitis
EGPA is a form of AAV characterized by asthma and eosinophilia. EGPA has been excluded from most AAV trials because of difficulty in evaluating the disease activity including asthmatic symptoms and likely differences in pathogenesis. There are fewer data supporting current EGPA treatments than for GPA/MPA. The French Vasculitis Study Group examined the response to glucocorticoids in nonsevere EGPA and to glucocorticoids and cyclophosphamide in severe EGPA. Relapse rates in nonsevere EGPA are high if treated with glucocorticoids alone and studies of combinations with other immunosuppressants are needed. Similarly, only anecdotal data exist for the role of rituximab in EGPA. Case reports and case series have demonstrated good responses to rituximab in certain manifestations of EGPA, though it lacked a clear pathophysiological rationale except the presence of ANCA.
A Th2 response with elevated IL-4, IL-5 and IL-13 is predominant in the disease development of EGPA. Two small open label studies of an anti-interleukin-5 antibody, mepolizumab, have reported good effects with safety in EGPA, and a larger trial is being prepared. Pitakinra is a human recombinant protein and inhibits IL-4 and IL-13 pathway by acting as an IL-4 receptor α antagonist. Pitakinra might be effective for EGPA. Both drugs have shown efficacy for bronchial asthma.
IFN-α is known to counteract Th2 response, and small studies suggested its efficacy in both remission induction and maintenance in EGPA. However, its unfavorable safety profile has restricted its use.