Temperature modifies ciliary beating in healthy subjects, but also in PCD and non-PCD patients

<bold>Introduction:</bold> Primary ciliary dyskinesia(PCD) is an inherited ciliopathy in which respiratory ciliary beating is abnormal. Digital high-speed videomicroscopy(DHSV) is a diagnostic test for PCD, but lacks standardization. Particularly, DHSV is performed at different temperatures, which may influence ciliary beating. The relationship between ciliary beating and temperature has been studied in healthy subjects, but not in patients referred for a PCD diagnostic. <bold>Aim:</bold> To evaluate the effect of the temperature used during DHSV on ciliary beat frequency(CBF) and beat pattern(CBP) <bold>Methods:</bold> Beating cilia were recorded using DHSV at 37°C and at room temperature(RT), using nasal brushings from 48 subjects divided in 3 groups: 14 healthy subjects, 15 PCD positive patients, and 19 referred patients with a negative PCD diagnosis. Ciliary beating was assessed by CBF and the percentage of abnormal CBP. <bold>Results:</bold> CBF was higher when measured at 37°C than at RT in the 3 groups. The percentage of abnormal CBP was also higher when measured at 37°C than at RT in non-PCD patients and in healthy subjects, but similar at both temperatures in PCD patients. <table-wrap><object-id>erj;64/suppl_68/PA3312/TB1</object-id><object-id>T1</object-id><object-id>TB1</object-id><table><colgroup><col></col><col></col><col></col><col></col><col></col></colgroup><tbody><tr><td></td><td></td><td>CBF(Hz)</td><td>p-value</td><td>Abnormal CBP(%)</td><td>p-value</td></tr><tr><td>PCD</td><td>RT</td><td>5.8(2.8–7.6)</td><td>0.019</td><td>100(72–100)</td><td>0.054</td></tr><tr><td>37°C</td><td>7.4 (1.2–13.6)</td><td>98(52–100)</td></tr><tr><td>Non-PCD</td><td>RT</td><td>9.0(7.8–10.1)</td><td><0.001</td><td>46(26–77)</td><td>0.020</td></tr><tr><td>37°C</td><td>15.6(14.1–16.9)</td><td>38(24–61)</td></tr><tr><td>Healthy subjects</td><td>RT</td><td>5.3(4.9–6.5)</td><td><0.001</td><td>27(17–41)</td><td>0.029</td></tr><tr><td>37°C</td><td>13.8(12.6–15.1)</td><td>35(26–50)</td></tr></tbody></table></table-wrap> Data expressed as median(interquartile range) <bold>Conclusion:</bold> Our results show that the temperature used during DHSV may influence ciliary beating in healthy subjects, but also in PCD and non-PCD patients. This should be considered when using normal data or cut-off for DHSV in PCD diagnosis.