Secretory IgA epitopes in basal tears of extended-wear soft contact lens wearers and in non-lens wearers.

Purpose: To determine secretory IgA epitopes in tears of extended-wear soft contact lens wearers and non-wearing controls. Methods: We developed enzyme-linked immunosorbent assays (ELISA) to determine the tear concentrations of two epitopes of secretory IgA, the IgA alpha-chain and the secretory component. These epitopes were measured in basal tears of 20 individuals in 6 nights of extended wear of etafilcon A soft contact lenses and in 19 non-lens-wearing individuals. Results: Levels of IgA alpha-chain immunoreactivity were significantly decreased in the lens-wearing group compared to non-lens wearers. However, the level of secretory component immunoreactivity was not significantly different between groups. IgA alpha-chain and secretory component immunoreactvity were highly correlated; however, some samples showed a marked variation between these two values. Conclusion: Tear concentrations of sIgA epitopes are significantly reduced in extended-wear contact lens wearers, and may contribute to the increased susceptibility to ocular infection seen in this group. [ABSTRACT FROM AUTHOR]