Intraoperative Video assessment provides a quick and inexpensive tool evaluating Primary Ciliary Dyskinesia in Comparison with Ultrastructure Examination

Summary: Background: Primary ciliary dyskinesia (PCD) is a genetically heterogeneous disease of ciliary defects inducing chronic sinus and pulmonary infections by insufficient mucociliary clearance. PCD shares a clinical phenotype with a broad range of chronic respiratory ailments and in the absence of a gold-standard test, the American Thoracic Society (ATS) created a diagnostic pathway which includes a combination of confirmation tests for patients with suspected ciliary dyskinesia consisting of nasal nitric oxide (nNO) measurement, transmission electron microscopy (TEM), and genetic testing. Though nNO measurement is relatively simple and inexpensive, it is only a viable testing methodology for patients ≥ 5 years old and the remaining confirmatory tests are expensive and require technical expertise. The aim of this study is to describe simple videomicroscopy findings recorded during intraoperative (IO) evaluation and investigate its predictive value in the PCD diagnostic pathway in comparison to the ultrastructural and genetic findings. Design: Simple videomicroscopy assessment took place intraoperatively with fresh specimens in RPMI. Specimen adequacy was assessed based on semi-quantity estimation of the amount of cilia, ciliary beating pattern and frequency. Ultrastructural analysis was performed. Cases were collected from 2010 to 2024 and patient presentation, TEM, IO evaluation, nNO, and clinical history were reviewed when available. Available genetic testing was reviewed for relevant variants in PCD causing genes, candidate genes, and ciliome genes. Results: 100 cases were collected from 98 patients with nasal or carinal ciliary biopsies taken for assessment of ciliary dyskinesia. 19 of the 100 cases were clinically diagnosed with PCD.  Testing for nNO was reported for only one of a hundred cases. Sensitivity for TEM and IO evaluation were similar (67% and 68%) and varied for specificity (76% and 65%). Genetic testing was available for 33% of cases, 30% of which reported variants in PCD causing genes.   Conclusion: Our results support the notion that intraoperative simple videomicroscopy evaluation of cilia is highly consistent with final results obtained by EM assessment.  However, in children with PCD, TEM and IO evaluation remain unable to independently confirm a diagnosis of PCD.   In summary, although IO evaluation lacks the specificity power of TEM, its sensitivity and accessibility nominate intraoperative simple videomicroscopy as part of the diagnostic pathway for PCD. Katherine N Killian, Qian Wang, Catherine K. Gestrich, Claudia Salgado, and Miguel Reyes-Múgica