Comparison of ciliary beat frequencies at different temperatures in young adults

Abstract

Rationale: Direct visualisation of ciliary beat pattern (CBP) and ciliary beat frequency (CBF) has been recommended as the first-line diagnostic test in patients suspected of having primary ciliary dyskinesia (PCD). However, the test procedure is not yet completely standardised, and centres measure the CBF at different temperatures.

Objectives: It was the aim of the study to compare CBF at different temperatures, to establish normative values, to check for age dependency and to measure the temperature on the nasal mucosa of the participants.

Methods: High-speed video-microscopy analysis with a Sisson-Ammons Video Analysis (SAVA) system was used to determine CBP and CBF in the participants.

Measurements: Nasal brushings were taken and CBF was measured in randomised order at three temperatures: 25°C, 32°C and 37°C.

Main results: In total, 100 healthy young adults (74 female, 26 male), aged 20.2-31.9 years, were included in the study. We found a highly significant difference among the groups: the median CBF was 7.0 Hz at 25°C, 7.6 Hz at 32°C and 8.0 Hz at 37°C. The maximum time period ex vivo was 65 min and did not differ significantly. However, CBF was significantly higher when the cilia were kept at a higher temperature before the measurements were made. We found no correlation between CBF and the age of the participants. The median nasal mucosal temperature in our study participants was 30.2°C (range 24.7-35.8°C) comparable to the 30.2-34.4°C described in the literature.

Conclusions: The most appropriate temperature at which to measure CBF is 32°C. In our study, with 95% confidence for this temperature the CBF was between 6.3 and 9.0 Hz.

FIGURE 1

Median and individual results for ciliary beat frequency (CBF) shown at the three temperatures. CBF was significantly higher when measured at higher temperatures (Wilcoxon matched pairs test for 25°C versus 32°C: p<0.0001; 25°C versus 37°C: p<0.0001; 32°C versus 37°C: p<0.0001).

FIGURE 2

Ciliary beat frequency (CBF) measured at different temperatures in ascending (↑) or descending order (↓). Data are shown as median and individual results. CBF was always significantly higher in corresponding subgroup in which the measurement was made in descending order (25°C: p=0.002; 32°C: p<0.050; 37°C: p=0.0001).

FIGURE 3

Time periods ex vivo to measure the ciliary beat frequency at the different temperatures in ascending (↑) or descending order (↓). Data are shown as median and individual results. The time periods ex vivo for the corresponding subgroups were significantly shorter for 25°C in ascending order (Mann–Whitney test p<0.0001), but for 32°C and for 37°C they were significantly shorter in descending order (Mann–Whitney test for 32°C: p<0.0001; for 37°C: p<0.0001).

FIGURE 4

Association between the time periods ex vivo and the ciliary beat frequency (CBF) measured at a) 25°C, b) 32°C and c) 37°C. Data are shown as individual results and linear regression lines. There was a significant correlation for 25°C (p=0.0002, Spearman r=0.368, slope of the regression line +0.008) and for 37°C (p<0.0001, Spearman's rank r=−0.391, slope of the regression line −0.012), but not for 32°C (p=0.162, Spearman's rank r=−0.141, slope of the regression line −0.024).

FIGURE 5

No significant correlation between age of the participants and ciliary beat frequency (CBF) measured at a) 25°C, b) 32°C and c) 37°C: 25°C, p=0.051, Spearman's rank r=0.196, slope of the regression line +0.022; 32°C, p=0.521, Spearman's rank r=0.065, slope of the regression line 0.000; 37°C, p=0.336, Spearman's rank r=−0.097, slope of the regression line −0.019.

FIGURE 6

Nasal mucosal temperatures are shown as median and individual results. The temperature was significantly higher on the right mucosa compared to the left mucosa (Wilcoxon test, p=0.046).