Purpose:
To determine the normal levels of secretory IgA (sIgA) in the tears and saliva, and to compare the levels in contact lens (CL) and non-contact lens (NCL) wearers.
Methods:
Reflex tears (using glass microcapillary tubes) and saliva samples were collected from 58 subjects (n=19 CL, n=39 NCL) and assayed for sIgA by immunoassay and for total protein by NanoOrange Protein Quantitation Kit. A natural log transformation was applied to produce data appropriate for parametric analysis.
Results:
The data are presented in Table 1.For all subjects (n=58), there was no significant correlation between levels of tear and salivary sIgA (r = 0.10, p = 0.44). There was also no correlation between tear protein and tear sIgA levels (r = 0.00, p = 0.99), which was contrary to the expected decrease in concentration of sIgA with decreasing total tear protein. There were no significant differences in mean tear sIgA (p = 0.47), tear protein (p = 0.33) or salivary sIgA (p = 0.99) between the CL and NCL wearers.
Conclusions:
Literature reports vary regarding the effect of CL wear on levels of tear sIgA and protein. In this study, there were no significant differences between CL and NCL wearers, suggesting other tear film markers may be more useful for monitoring changes due to CL wear. Overall, tear sIgA showed no correlation with either saliva sIgA or tear protein.
Keywords: contact lens • inflammation