Successful treatment of postinfectious bronchiolitis obliterans with gamma globulin in a tertiary center: 10 years of experience.

Introduction: Bronchiolitis obliterans is characterized by partial or total occlusion of the bronchioles due to inflammation and fibrosis, and the most common form is postinfectious bronchiolitis obliterans (PIBO). This study aimed to retrospectively present our intravenous immunoglobulin (IVIG) treatment experience in PIBO patients with a clinically severe course despite receiving commonly used treatment protocols.

Materials And Methods: The study included patients aged 0-18 with subtle immunological abnormalities who were followed up in our center for PIBO between 2010 and 2021. Clinical evaluation, body mass index (BMI), computerized tomography (CT) image scoring, and immunological parameters were recorded before and after IVIG treatment.

Results: Of the 11 patients included in the study, 90% were male, the mean age at diagnosis was 27.1 months (range: 5-68 months) and the mean current age was 81.4 months (range: 15-188 months). The number of hospital visits due to infection and the frequency of hospitalizations decreased markedly in the patients who underwent IVIG therapy. Oxygen therapy was discontinued in all patients, and improvements in radiological severity scores were observed. BMI z-scores improved over the baseline values after IVIG therapy.

Conclusion: Corticosteroids are considered the best first-line treatment to control inflammation in PIBO. In our study group, PIBO patients showed favorable clinical and radiological responses to regular IVIG treatment, possibly due to minor immune deficiency secondary to steroids or as a result of undetected adaptive and innate immune defects involved in the etiology of severe PIBO.