[Clinical characteristics of primary ciliary dyskinesia in children]

Although primary ciliary dyskinesia (PCD) is a group of inherited diseases, accurate diagnosis and appropriate clinical care to prevent and treat the complications could maintain patients' quality of life and normal life span. The diagnosis of PCD may often be delayed because it is frequently misdiagnosed as bronchitis, sinusitis and otitis. This study aimed to analyze and summarize the clinical features of PCD and explore diagnostic and differential diagnostic procedures in children.

Patients were all chosen from the inpatient department of Beijing Children's Hospital, Capital Medical University between 1990 - 2006. The tunica mucosa bronchiorum and/or nasal mucous membrane were gained through bronchoscope in children suspected to have PCD. The ciliary ultrastructures were analyzed through the electron microscope. The clinical features and procedures of the diagnosis and differential diagnosis in children with PCD were analyzed.

There were totally 26 children diagnosed as PCD with 10 (38.5%) Kartagener syndrome. All Kartagener syndrome children had mirror image dextrocardia with normal cardiac structure and situs inversus viscerum. The bronchoscopy performed in eight of 10 Kartagener syndrome children showed bronchus transposition. Twenty-six children came from twenty-five families. Although the siblings of four probands also had the symptoms of chronic cough with sputum, running nose and recurrent respiratory infections, only a boy and his sister were diagnosed as Kartagener syndrome simultaneously. Their parents and the other family members were healthy. Of the 26 patients, 11 were boys and 15 were girls. The median age at diagnosis was 8.7 years. The age of onset was between the second day after delivery and fifteen years old, median age was 3 years. The course of disease before diagnosis was eleven days to twelve years (median 3.5 years). All the children had the symptom of cough, 24 of which had productive cough. Seven cases were found to have clubbing fingers. Dynein arm defect was found in 10 children, 6 of them had total absence of dynein arms and 4 had decreased dynein arm numbers. Microtube derangements were found in 8 children. One Kartagener syndrome child had a normal cilia structure. Bronchiectasis, consolidation and increased lung markings were found in 8, 6 and 7 patients separately on the radiographic study. Twenty patients had sinusitis. Nine of sixteen children had decreased PEF, FEV1 and/or FEF 25 - 75 on the pulmonary function test. Fifteen culture samples obtained from 6 children's sputum and/or bronchoalveolar lavage fluid were positive for 8 strains of Pseudomonas aeruginosa, 5 strains of Streptococcus pneumoniae and 2 strains of Candida albicans. In 1 subject more than one organism were found in the same sample. Hearing lost and gastroesophageal reflux were detected in 3 of 4 and 3 of 5 examined children respectively.

The onset of PCD can occur from neonate to adolescence and usually has a chronic course. The common symptom of pediatric PCD was productive cough and significant growth retardation. The most common ultrastructural abnormalities associated with PCD were the total absence of dynein arms, decreased dynein arm numbers and microtube derangement. Some patients have normal ciliary structures. Bronchiectasis, consolidation and sinusitis were usually seen on the radiography. Pseudomonas aeruginosa and Streptococcus pneumoniae were the two common bacterial organisms obtained from sputum and/or bronchoalveolar lavage fluid of PCD children. Some patients have mixed infections. PCD children have high percentages of hearing lost and gastroesophageal reflux.