Mucociliary transport using 99mTc-albumin colloid:: a reliable screening test for primary ciliary dyskinesia

Background: A study was undertaken to assess the reliability of the nasal mucociliary transport test using Tc-99m-albumin colloid as a screening test for primary ciliary dyskinesia (PCD) and to compare it with the gold standard nasal biopsy for study of ciliary motility and ultrastructure. Methods : During a 4 year period both tests were performed in 55 children referred with persistent or recurrent respiratory tract infections. Their median age was 4 years ( range 1 month to 15 years). Results : The nasal biopsy results were as follows: PCD, n = 8; secondary ciliary dyskinesia (SCD), n = 19; normal, n = 28. The mucociliary transport test was abnormal in 29 patients ( all 8 with PCD, 7/19 with SCD, and 14/28 with a normal biopsy). The sensitivity of the mucociliary transport test to diagnose PCD was therefore 100% (8/8) (95% exact confidence limits 63.06 to 100.00); the specificity was only 55% (26/47) (40.95 to 69.89). The negative predictive value was 100% (26/26) (86.77 to 100.00) and the positive predictive value was 28% (8/29) (12.37 to 47.24). Conclusion : Mucociliary transport is a non-invasive screening test that can be performed even in infants. The sensitivity of the test is high but its specificity is low. A normal test result excludes PCD.