Bronchiolitis Obliterans and Primary Ciliary Dyskinesia: What Is the Link?

Bronchiolitis obliterans (BO) is a rare form of chronic obstructive lung disease characterized by obliteration of the small airways caused by inflammation and fibrosis. In children, BO most commonly appears following a severe lower respiratory tract infection. This phenomenon has been described as post-infectious BO (PIBO). PIBO presents with dyspnea, tachypnea, and persistent hypoxemia, as well as characteristic radiographic findings on high-resolution CT (HRCT) of the lungs. A few DNAH1 genetic variants have been postulated to have a role in the development of BO in patients with primary ciliary dyskinesia (PCD), but there is limited evidence regarding this, and etiologies are uncertain. PCD is a genetically heterogeneous autosomal recessive disorder characterized by ciliary dysfunction that causes impaired mucociliary clearance, leading to bronchiectasis and recurrent lower respiratory tract infections due to several pathogenic organisms including Pseudomonas aeruginosa. The link between rare PCD genetic variants and BO remains undetermined. We report the first case in Puerto Rico with Pseudomonal PIBO as the initial presentation of PCD; the patient was a four-year-old male. We also engage in a comparison of our case with previously reported cases of PIBO in PCD patients.