CCR 4 and CCR 5 expression in conjunctival specimens as differential markers of T(H)1/ T(H)2 in ocular surface disorders.

BACKGROUND

Accurate inflammatory mechanisms in chronic ocular surface diseases (OSDs) cannot routinely be assessed. New techniques for investigating ocular surface inflammatory pathways are of major importance.

OBJECTIVE

To investigate the expressions of CCR 4 and CCR 5, known to be related to the T(H)2 and T(H)1 systems, respectively, and HLA-DR in conjunctival impression cytology specimens from patients with chronic OSDs.

METHODS

In this case-controlled study, impression cytology specimens were taken in a series of patients with vernal keratoconjunctivitis (n=21), giant papillary conjunctivitis (n=6), or keratoconjunctivitis sicca (KCS; n=17), or receiving topical antiglaucoma treatments (n=31), and from 20 normal subjects. Conjunctival cells were incubated with mAbs to CCR 4, CCR 5, CD45, and HLA-DR to quantify conjunctival inflammation in a masked manner using flow cytometry.

RESULTS

HLA-DR was higher in the glaucoma and KCS groups than in allergic and normal eyes. CCR 4 was overexpressed in allergy and glaucoma, whereas CCR 5 was higher in the KCS and glaucomatous groups. CD45 was expressed by only few cells in all groups, with almost no significant differences. CCR 4 expression was negatively correlated with CCR 5 and HLA-DR, whereas CCR 5 was positively correlated with HLA-DR.

CONCLUSION

This study confirms the overexpression of chemokine receptors by the conjunctival epithelium in OSDs. CCR 4 and CCR 5 expression may vary according to the immune pathway involved. Accurate mechanisms in ocular surface inflammatory reactions-that is, those related to the T(H)1 or T(H)2 systems-could be differentiated by CCR 4/CCR 5 profiles. Our results also suggest that long-term use of topical treatments may stimulate both systems.