[Value of lacrymal IgE determination and conjunctival cytology in the diagnosis of chronic conjunctivitis].

PURPOSE: Chronic conjunctival inflammatory diseases may depend upon various strongly intricated mechanisms. Discriminating allergy from nonspecific inflammation has become of striking importance for diagnosis and treatment. We investigated conjunctival inflammatory response by comparing two objective biological tools, tear IgE detection and HLA DR expression by conjunctival epithelium, as indirect indicators of activation of the Th1 and Th2 subsets, respectively.

METHODS

Sixty-eight patients (135 eyes) with chronic conjunctivitis underwent tear IgE dosage by an ELISA technique and quantification of HLA DR expression in impression cytology specimens. 34 had direct or indirect clinical indications of allergic mechanisms, 22 had chronic conjunctivitis without any sign of allergy, and 12 suffered from isolated nonallergic dry eyes.

RESULTS

Patients clinically considered as allergic only showed positive IgE in 31 out pf 68 eyes (46 per cent), whereas 11/44 (25%) and 7/24 (29%) eyes with nonspecific conjunctivitis and dry eyes respectively were also positive. HLA DR positivity in epithelial cells was found in 18/61 (29.5%), 15/40 (37.5%) and 9/22 (41%) eyes, respectively. HLA DR expression by epithelial cells was negatively correlated with tear IgE, as most specimens positive to one criterion were negative to the other one (37 eyes DR+ IgE-, 35 eyes DR- IgE+, and 5 eyes DR+ IgE+; chi-square: p = 0.0001).

CONCLUSION

As IgE synthesis and HLA DR induction may represent indirect indicators of the activation of the Th1 and Th2 subsets, association of these two simple tests could be interesting for the routine assessment of the mechanisms of inflammatory ocular surface diseases.