How a New Treatment Affects Nose and Throat Inflammation in a Rare Disease

This trial is studying how a medication called mepolizumab works in people with a rare condition called eosinophilic granulomatosis with polyangiitis (eGPA). Researchers want to understand how this medication affects the balance of bacteria and immune activity in the nose and throat. The study includes people with eGPA receiving the medication, plus comparison groups with asthma, nasal polyps, or no illness at all.

eGPA is a rare disease where the immune system causes inflammation in blood vessels and organs, often affecting the nose, throat, and lungs. This medication has shown promise in treating eGPA, but scientists want to learn exactly how it works in these areas and whether it changes the natural bacteria living in your nose—information that could help doctors treat the disease better.