Nasal nitric oxide and pulmonary radioaerosol mucociliary clearance as supplementary tools in diagnosis of primary ciliary dyskinesia
Primary ciliary dyskinesia (PCD) is a rare, usually autosomal recessive inherited disorder, characterized by abnormalities in ciliary structure and/or function. Frequent, intermittent or chronic airway infections precipitated by impaired airway mucociliary clearance may cause permanent lung damage and reduced lung function. Early diagnosis is considered important for the prevention of lung damage, but diagnosis is probably often delayed or even missed since diagnosis of PCD is both complex and time consuming, and yet not always exact. The aims of this PhD thesis were to evaluate the discriminative capacity and "real-life" clinical application of two candidates for supplemental diagnostic testing for PCD: Nasal nitric oxide (nNO) measurement placed as a first line test to point out probable PCD patients for further investigation or exclude patients, regardless of age, Pulmonary radioaerosol mucociliary clearance (PRMC) as a second line test for PCD investigation in children from 5 years of age. And additionally, Proposing an algorithm for the pathway of diagnosing PCD based on these two studies and recommendations from the literature. Nasal NO and PRMC demonstrated to be two highly valid supplementary diagnostic tools to be placed in each end of the diagnostic pathway when investigating selected patients referred for PCD work up. Nasal NO measurement demonstrated to have an obvious place as a first line test in the pathway of PCD investigation and PRMC as second line test as a supplement to ciliary function test and EM-test in cases of difficult diagnoses. Neither of these tests can stand alone in diagnosis or excluding of PCD. PCD remains to be a diagnosis that should be made at a tertiary PCD centre, as clinical evaluation of referred patients is crucial before excluding the disease.