Relation between total tear IgE and specific serum IgE in seasonal allergic conjunctivitis

Recently, a new commercial test for total tear immunoglobulin E (IgE), based on immunochromatography (Allerwatch), was developed. We examined the relation between the total IgE level in tears and specific serum IgE.

A prospective, nonrandomized, cross-sectional study was conducted in 35 patients with allergic conjunctivitis (allergic group), 30 age- and sex-matched healthy control subjects (control group), and 8 patients with epidemic keratoconjunctivitis. In all subjects, the total tear IgE score was determined with the Allerwatch test (0, 1, and 2), and serum levels of total IgE and specific IgE for 12 inhaled allergens were measured with the Phadezym PRIST and CAP-RAST systems, respectively.

The total tear IgE-positive rate was significantly higher in the allergic group than in the control and epidemic keratoconjunctivitis groups (100.0% vs. 0.0% vs. 0.0%; P < 0.00001). In the allergic group, the total tear IgE score was significantly correlated with the log-transformed total serum IgE level (r = 0.61) and with the serum levels of IgE for cedar pollen (r = 0.35), house dust (r = 0.46), Dermatophagoides pteronyssinus (r = 0.49), and acarus (r = 0.36). Multivariate logistic regression analysis showed that the log-transformed total serum IgE level was the only significant predictor of the total tear IgE score (odds ratio = 1.85, P = 0.00008).

The total tear IgE score, determined with the Allerwatch test, was correlated with the total and specific serum IgE levels. This rapid test is easy to perform, sensitive, and highly specific for the detection of ocular allergy on an outpatient basis.