Hypovitaminosis D: a novel finding in primary ciliary dyskinesia.

BACKGROUND: A relationship between low levels of serum vitamin D and respiratory infections has been established. No study has examined the frequency and clinical relevance of vitamin D deficiency in patients with primary ciliary dyskinesia (PCD). METHODS: Vitamin D levels were measured in 22 PCD patients (7 females, 10.5 years, range, 2-34 years). In PCD, pulmonary function tests (PFTs), sputum microbiology, self-reported physical activity (PA) level, and quality of life (QoL) by means of the Saint George's Respiratory Questionnaire (SGRQ), were also assessed. RESULTS: Seventy-two percent of PCD patients were vitamin-D deficient-to-insufficient and 28% were sufficient. No differences in PFTs parameters were found between vitamin D deficiency-to-insufficiency and sufficiency groups. Patients with vitamin D deficiency-to-insufficiency had significantly higher SGRQ total scores, and thus poorer QoL (p = 0.03). Seventy-nine percent of PCD subjects had limitations in performing vigorous activities, and 53% performed less than 3 hours of PA per week. Vitamin D deficiency-to-insufficiency and sufficiency groups did not show any differences in age at PCD diagnosis or at onset of respiratory symptoms, BMI, atopy, current asthma or bronchiectasis. However, 79% of patients with bronchiectasis had vitamin D deficiency-to-insufficiency. No differences were found in the rate of positive sputum cultures and in the number of antibiotic courses between the two groups. CONCLUSIONS: Hypovitaminosis D is common in PCD patients, and is associated with poorer QoL. We recommend the assessment and treatment of hypovitaminosis D to be included in the routine management of PCD.

Defective neutrophil motility in patients with primary ciliary dyskinesia.

Microtubules are important in the regulation of the motile functions of a variety of cells, including leukocytes, ciliated cells and spermatozoa. Polymorphonuclear leukocyte function was studied in ten patients with primary ciliary dyskinesia, an inherited disorder of microtubules in sperm tails and cilia. Neutrophil chemotaxis in Boyden chambers was slightly reduced, but only one patient showed a migration below normal values. In vivo mobilization of polymorphonuclear leukocytes into skin windows was also slightly decreased. In contrast, neutrophil polarization and orientation was normal. The bactericidal activity of neutrophils from patients with primary ciliary dyskinesia was normal, while the ingestion of bacteria was decreased. The abnormalities of neutrophil function in patients with primary ciliary dyskinesia are related to motility. It is suggested that the microtubule defect responsible for the abnormal pattern of ciliary beating is a general abnormality also responsible for the depression of polymorphonuclear leukocyte motility.

Chemotaxis of blood neutrophils from patients with primary ciliary dyskinesia.

Primary ciliary dyskinesia is characterized by chronic upper and lower respiratory infections which are caused by the grossly impaired ciliary transport. Since the cilia and neutrophils both utilize microtubular system for their movement, it has been speculated that neutrophil motility such as chemotaxis might be impaired in patients with primary ciliary dyskinesia. Neutrophils were purified from whole blood from 16 patients with primary ciliary dyskinesia and from 15 healthy controls. Chemotactic responses of neutrophils to leukotriene B(4) (LTB(4)), complement 5a (C5a), and formylmethionylleucylphenylalanine (fMLP) were examined using the under agarose method. The chemotactic differentials in response to LTB4, C5a, and fMLP in neutrophils from the patient group were significantly lower than the corresponding values in neutrophils from the control group (p<0.05 for all comparisons). The difference in chemotactic index between the two groups was statistically significant for LTB4 and fMLP (p<0.05 for both comparisons), but not for C5a (p=0.20). Neutrophils from patients with primary ciliary dyskinesia showed a decreased chemotactic response as compared with those from normal subjects. It is concluded that the increased frequency of respiratory tract infection in patients with primary ciliary dyskinesia is possibly due to the defective directional migration of neutrophils, as well as to the defective mucociliary clearance of the airways.