Additional role of bronchial mucosal biopsy for ciliary structural abnormality in diagnosis of primary ciliary dyskinesia
Transmission electron microscopy (TEM) is one of diagnostic tests for primary ciliary dyskinesia (PCD). The mucosal samples obtained for cilia examination are generally procured from the nasal turbinate, but these specimens often yield inadequate results. The bronchial mucosa is recognized as an alternative sample, but no study has examined the additional utility of bronchial mucosa compared with nasal mucosa in the diagnosis of PCD. The medical records of 96 patients who underwent TEM for suspected PCD between April 1997 and June 2017 were reviewed. Patients were divided into three groups based on the site of mucosal biopsy: nasal biopsy (NB) group with nasal mucosal biopsy only; bronchial biopsy (BB) group with bronchial mucosal biopsy only; and nasal and bronchial biopsy (NBB) group with a combination of nasal and bronchial mucosal biopsies. The rate of PCD diagnosis was 28.8% (17/59) in the NB group, 41.2% (7/17) in the BB group, and 60.0% (12/20) in the NBB group. The yield of PCD diagnosis significantly increased in the NBB group compared with the NB group (P=0.012). In the NBB group, 25.0% (5/20) of patients were diagnosed with PCD by nasal mucosal biopsy, and 35.0% (7/20) of patients were additionally diagnosed by bronchial mucosal biopsy. The presence of sinusitis or bronchiectasis was not associated with prediction of PCD diagnosis from nasal or bronchial mucosal biopsy. The combination of nasal and bronchial mucosal biopsy for TEM showed higher yields of PCD diagnosis than nasal mucosal biopsy alone.