The Diagnosis of Primary Ciliary Dyskinesia: Putting The European Respiratory/American Thoracic Guideline Into Practice

Primary ciliary dyskinesia (PCD) is a rare inherited disease which is characterised by progressive lung disease, chronic rhinosinusitis, repeated middle ear infections, laterality defects, and reduced fertility. An early diagnosis is critical to reduce morbidity, however diagnosis is often delayed due to the heterogeneity in clinical presentation. Diagnosis relies on multiple tests, and the American Thoracic (ATS) and European Respiratory (ERS) societies have previously developed separate diagnostic guidelines. Both differed in recommendations and approach. The recently published joint ERS/ATS guidelines for the diagnosis of PCD is the first evidence-based guidelines that unifies the approach recommendations between both societies. These guidelines were formulated by a task force (TF) comprised of experts in the field, and were guided by a systematic reviews and GRADE (Grading of Recommendations, Assessment, Development and Evaluation) approach. The TF formulated three 'Patients, Intervention, Comparison, Outcomes' (PICO) questions to determine the accuracies of (1) nasal nitric oxide (nNO) (2) high-speed video microscopy (HSVM) and 3) immunofluorescence (IF) when compared to a reference test of either transmission electron microscopy (TEM) and/or genetics. There were also three narrative questions which sought to determine (1) what clinical presentation would support a clinician to refer a patient for PCD diagnostic testing (2) what additional diagnostic tests could be useful and (3) how to overcome PCD diagnostic challenges in resource limited settings. This review presents example cases that highlight the recommendations of the clinical practice guidelines.