Gelatinase B in vernal keratoconjunctivitis

Objectives: To investigate the expression of gelatinase B in the conjunctiv a of patients with vernal keratoconjunctivitis (VKC) and the cellular sourc e of this enzyme. Methods: Conjunctival biopsy specimens from 12 patients with active VKC and 12 control subjects were studied using immunohistochemical techniques and a monoclonal antibody against gelatinase B. The phenotype of gelatinase Binflammatory cells was examined using double immunohistochemical analysis a nd monoclonal antibodies against eosinophil peroxidase or macrophage CD68. Quantitative zymography was used to compare the activity of gelatinase B in conjunctival biopsy specimens from 10 patients with active VKC and 7 contr ol subjects. Results: Gelatinase B was detected in a few polymorphonuclear cells in 8 co ntrol specimens. All VKC specimens showed gelatinase B immunoreactivity in the epithelial and stromal inflammatory infiltrate. Compared with control s pecimens, VKC specimens showed significantly more gelatinase B-positive cel ls (mean SD, 40.8 +/- 29.9 vs 10.3 +/- 2.4; P < .02). Most gelatinase B-pos itive cells were eosinophils (90.2% +/- 3.6%). Zymography revealed that gel atinase B levels in VKC specimens were significantly higher than the levels found in normal conjunctiva (3780.3 +/- 3541.0 vs 610.1 +/- 397.1 scanning units; P < .03). Conclusions: These findings suggest overexpression of gelatinase B by eosin ophils in VKC specimens and participation of gelatinase B in the pathologic changes in VKC. Clinical Relevance: Control of the release and/or activation of gelatinase B in eosinophils may provide a new therapeutic strategy for treating VKC.