Abstract
Purpose::
Vernal keratoconjunctivitis (VKC), nasal polyps and asthma are inflammatory diseases that exhibit dramatic morphological changes of the mucosa. We hypothesized that inflammatory cells typical of VKC, eosinophils and CD4+ cells, express matrix metalloproteases (MMP) that may contribute to specific tissue remodeling aspects in different organs.
Methods::
Mucosal biopsies were obtained from 1) conjunctiva of healthy donors; 2) tarsal conjunctiva of VKC patients; 3) bronchi of non-asthmatic subjects; 4) bronchi of mild stable asthmatic patients; 5) nasal mucosa of healthy donors and 6) nasal polyps of allergic patients. Immunostaining for collagens I and III, metalloprotease (MMP)-9, eosinophils (EG2+) and CD4+ cells was evaluated. Double immunostaining for MMP/EG2 and MMP/CD4 was also performed in pathological tissues.
Results::
Collagens were highly diffuse in the giant papillae of vernal keratoconjunctivitis and in nasal polyps, while they were increased to a lesser extent in the subepithelium of asthmatic patients compared to normal respective tissues. MMP-9 staining was increased in all pathological tissues, yet was the most intense in VKC tissues. In all pathological tissues, MMP-9 positive staining was in association with eosinophils and CD4+ cells. Double staining showed that 48±11%, 37±4%, 33±4% of EG2+ cells were also MMP-9+ in VKC, polyps and asthma, respectively, and that 37±2%, 48±2%, and 47±7% of CD4+ were MMP-9+ in the same tissues.
Conclusions::
Expression of MMP by eosinophils and CD4+ cells may play an important role in inducing the structural changes seen in VKC, nasal polyps and asthma. Eosinophils seem to be more relevant in MMP-9 production in VKC, while CD4+ cells seem to be more involved in MMP-9 expression in airways.
Keywords: conjunctivitis • immunohistochemistry • extracellular matrix