Group II PLA(2) content of tears in normal subjects.

PURPOSE To determine the concentration of group II phospholipase (PL) A(2), an antimicrobial molecule, in tears of normal subjects in different age and sex groups. METHODS PLA(2) content of tears was measured in 122 healthy volunteers with ages ranging from 20 to 89 years (mean, 49.5 years) by a time-resolved fluoroimmunoassay using a polyclonal rabbit antibody to recombinant human PLA(2). RESULTS The mean concentration of PLA(2) in tears was 54.5 +/- 33.9 microg/ml. It was highest in the age group 20 to 29 years (81.6 +/- 32.0 microg/ml), and a decrease of concentration occurred with an increase of age. PLA(2) values were statistically significantly lower in the age group 60 to 69 years (P = 0.0013) and 70 years or more (P = 0.0001) than in the age group 20 to 29 years. There were no statistically significant differences in PLA(2) content of tears between the genders in any age group (P = 0.798). CONCLUSIONS The results indicate that tears contain a high concentration of PLA(2) and that PLA(2) levels decrease with an increase of age and/or reflex tear component of the sample analyzed.