Diffuse panbronchiolitis—The response and recurrence after erythromycin therapy

Background/purpose Diffuse panbronchiolitis (DPB) is a rare clinicopathological entity. To date, no cohort study of DPB has been conducted in Taiwan. Erythromycin treatment improves the clinical outcome of DPB; however, whether relapse will occur or not is unclear. Herein, we report the first retrospective cohort of DPB patients in one medical center in Taiwan, including their clinical presentation and outcomes of erythromycin treatment. Methods The study comprised a retrospective cohort analysis of 27 patients with a confirmed diagnosis of DPB. Clinical, radiological, and laboratory parameters were analyzed, and the course and outcome of erythromycin treatment were examined. Results The mean age at symptom onset was 56.6 ± 18.5 years, and the time between symptom onset and a correct diagnosis was 4.3 ± 4.2 years. The percentages of patients with centrilobular micronodules on chest computed tomography, obstructive ventilator impairment with hypoxemia, and an elevated cold agglutinin titer were 72%, 37%, and 78%, respectively. After erythromycin treatment, 22 of the 27 (81.5%) patients showed clinical improvement, of whom six suffered a relapse. Four of these six patients clinically improved after a second course of erythromycin treatment. Conclusion Erythromycin therapy was suitable for DPB in our experience. In this study cohort, 27% experienced a relapse, of which two-thirds of the patients improved after a second course of erythromycin treatment.