Evaluating a method for diagnosing PCD in countries of limited resources; an ERS fellowship

Background: There is no gold standard to diagnose PCD so combination testing is used. High-speed video microscopy analysis (HSV) of ciliary function is highly sensitive but requires expensive equipment and specialists. Ability of non-specialists to diagnose PCD using simple equipment would improve diagnosis in resource-limited countries. Aim: To compare PCD diagnostic decisions of a non-specialist using clinical data and observational light microscopy (OLM), with a specialist multidisciplinary (MDT) service. Methods: 24 nasal brushings were analysed blind by OLM at room temperature (RT) by an ERS Fellow, and by HSV at 37 o C by specialists (normal, abnormal, equivocal, insufficient). Final diagnostic decisions (PCD negative, PCD positive, equivocal) by the Fellow based on OLM and clinical data were compared to MDT decisions using clinical data, nitric oxide, HSV and electron microscopy. Results: Comparing tests: OLM was 42.3% sensitive and 50% specific compared to specialist HSV. Most brushings were equivocal using either tests (13 by OLM at RT and 15 by HSV at 37 o C). When clinical data were added, there were significant differences between final diagnosis by Fellow and MDT (p Conclusion: PCD diagnosis cannot be reliably made using OLM and clinical data but requires state-of-the-art diagnostics and specialist multidisciplinary assessment.