Risk factors for respiratory relapses in patients with EGPA

<bold>Background:</bold> Respiratory manifestations significantly burden patients with EGPA; thus, determining the risk factors for respiratory relapse is essential. <bold>Aim:</bold> Evaluation of risk factors for respiratory relapses in patients with EGPA. <bold>Methods:</bold> This retrospective study included 86 patients. Respiratory relapse was defined as isolated worsening of asthma and/or ENT manifestations requiring therapeutic adjustment. <bold>Results:</bold> During the median 5-year follow-up, 33/86 patients experienced respiratory relapse (38.4%); among these, the relapse preceded EGPA recurrence in 17/33 (51.5%) with a median time of 4.5 weeks. Airflow obstruction and lower baseline FEV1, chest symptoms, prolonged treatment with low-dose oral CS, and EGPA flares were significantly associated with higher risk of respiratory relapses (p=0.0067,p=0.0025,p=0.0328,p=0.0009,p=0.0194). In patients with more severe airflow obstruction at baseline, respiratory relapses occurred with a significantly higher dose of oral CS (median, 12.2 vs. 7.44 mg/d;p=0.0211) and were accompanied by significantly lower peripheral eosinophil count (median,360/mm3 vs. 1300/mm3;p=0.0146) compared to patients with less severe airflow obstruction. There was no significant relationship between the risk of respiratory relapse and EGPA features at baseline. Respiratory relapses did not affect deaths (p=0.324); however, the presence of chest symptoms was associated with better survival (p=0.0338). <bold>Conclusions:</bold> Respiratory relapses in EGPA are common and significantly associated with airflow obstruction, lower baseline FEV1, chest symptoms, and prolonged treatment with low-dose oral CS. They have no impact on survival and their risk of occurrence does not depend on the baseline EGPA features.