Effective treatment with mepolizumab in a patient with severe eosinophilic granulomatosis with polyangiitis complicated with small intestine perforation

Abstract

Eosinophilic granulomatosis with polyangiitis (EGPA) is systemic vasculitis caused by eosinophilia affecting small to medium-sized blood vessels, which damages the organs. Antineutrophil cytoplasmic antibody-associated vasculitis EGPA treatment guidelines added anti-interleukin-5 antibody mepolizumab to the standard treatment protocol for active-non-severe EGPA based on the MIRRA study. Nevertheless, the role of mepolizumab in treating patients with active severe EGPA has not been established. We treated a patient with EGPA complicated with small intestine perforation using steroid pulse intravenous, high-dose glucocorticoids, intravenous high-dose immunoglobulin therapy, and mepolizumab without immunosuppression agents; the patient went into remission, suggesting that mepolizumab is an effective therapeutic agent that could lead to remission in severe EGPA.

Fig. 1

(A) No obvious abnormal shadows found in both lungs. (B) Mucus plugs and atelectasis found in the lower lobe of the right lung. (C) No abnormal findings were found.

Fig. 2

(A) Significant mucus retention observed in the paranasal sinuses, including the ethmoid sinus. (B) Nasal polyps and mild mucosal redness in the middle nasal meatus on both sides. (C1.2) Significant eosinophil infiltration observed in the nasal polyps. No necrotizing vasculitis or granulomas observed.

Fig. 3

(A) No ulcers, only non-specific inflammation in the large intestine. (B) Few eosinophils infiltrate the large intestine tissue after high-dose steroid administration.

Fig. 4

(A) Free air was observed in the abdominal cavity. (B) Free air, ileal perforation, and peritonitis were observed. (C) Free air was observed around the ileum. (D) A 2-cm perforation was observed opposite the ileal mesentery.

Fig. 5

Clinical course of drug treatment. After steroid administration, the eosinophil count decreased rapidly. The onset of bowel perforation occurred on Day 12 of hospitalization. Intravenous immunoglobulin (IVIG) therapy was performed on Day 32 to improve severe neurological symptoms. Mepolizumab was initiated on Day 43 which was continued regularly every 4–5 weeks. The eosinophil count remained around 100/μL even after discharge, and the steroid dose was gradually decreased to 3 mg/day. MPZ, mepolizumab; IVIG, intravenous high-dose immunoglobulin therapy; PSL, prednisolone; mPSL, methylprednisolone pulse therapy.