Comparison of salivary IgA secretion rate collected by the aspiration method and swab method

Abstract

Salivary immunoglobulin A (IgA) is used as an immunity marker, as saliva can be easily collected, noninvasively with little stress. However, several saliva collection methods can be used. Our comparison between samples collected using different methods demonstrated that the salivary IgA secretion rate in samples collected using an aspiration method was significantly correlated with that in samples collected using a swab method. Moreover, the significant circadian variation in salivary IgA secretion rate in the aspirated saliva suggested that the aspiration method does not suppress salivary IgA secretion rate variability compared with the swab method. Therefore, the aspiration method should be considered as the preferable saliva collection method.

Keywords: IgA; Saliva collection; aspiration; swab.

Fig. 1.

Correlation of salivary IgA secretion rate in samples collected by swab and aspiration methods. Correlation was analyzed using Pearson’s correlation coefficient.

Fig. 2.

Box-whisker plot of salivary IgA secretion rate Distribution of salivary IgA secretion rate (µg/5 min) among the young and elderly participants, in samples collected by the swab and aspiration methods. The box-whisker plot displays the mean, quartiles, and the minimum and maximum values observed for each group. The plot elements and the statistics they represent are as follows: the length of the box represents the interquartile range (the distance between the 25th and 75th percentiles); the horizontal line in the box interior represents the mean; and the vertical lines issuing from the box extend to the minimum and maximum values of the analysis variable.