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New publication by Bestcilia partner: challenges in nNO testing for PCD diagnosis

Researchers from Bestcilia partner team, University of Southampton (United Kingdom), have recently released a publication focusing on the risks surrounding a wider usage of nasal nitric oxide (nNO) measurement in PCD diagnosis. The routine use of nNO measurements has recently been proposed in asthmatic diseases by the UK National Institute for Health and Care Excellence. Although more widespread usage of nNO tests can be useful in PCD diagnostics, scientists from Southampton emphasize that careful interpretation of nNO readings and proper training of the analysts are crucial to reduce the risk of falsely positive PCD diagnoses.

Although clinically similar to other respiratory diseases, PCD is characterized by exceptionally low levels of nNO. At present, nNO measurement is used as a screening test in patients showing clinical symptoms similar to PCD, before conducting other more specialized PCD diagnostic tests: ciliary beat analysis (HSVA), ciliary ultrastructure analysis (TEM) and genetic tests. As the more specialized tests are costly and require specialist personnel, they are frequently performed in reference centers, thus patients’ access to such tests is often limited. With the extension of NO screening to regular asthma diagnosis, the nNO testing method seems to be an attractive alternative to the localized.

However, by analyzing almost 300 patients referred for PCD diagnostics, researchers from Southampton discovered that while almost 94% of PCD-positive patients using nNO testing were diagnosed correctly, the nNO measurement also yielded a considerable amount of false positives.

It should be noted that accuracy of tests of this kind rests largely on the prevalence of PCD in the tested population; the authors of the article emphasize the need for careful interpretation of nNO readings and proper training of the analyst.

It can thus be concluded that nNO tests show promise for excluding a PCD diagnosis, although they do not make a reliable diagnostic tool when used in isolation. A more widespread usage of nNO tests would rely on screening only patients with classical PCD symptoms to avoid generating large numbers of false positive cases. However, with NO analysers becoming more available recently, nNO tests could potentially prove useful in PCD diagnostics as they reduce the costs associated with the traditional diagnostic methods.

Full article is available here.