Abnormal keratocytes and stromal inflammation in chronic phase of severe ocular surface diseases with stem cell deficiency

Background/Aims: Stevens-Johnson syndrome (SJS), ocular cicatricial pemphigoid (OCP) and alkali burns are associated with chronic, severe inflammation of the ocular surface that occasionally lead to corneal stem cell deficiencies. The corneal stroma in these diseases has not been studied comprehensively. The purpose of this study was to determine whether the keratocytes in the stroma were normal and whether the stroma remained inflamed in the chronic phase of these diseases. Methods: Five pathological corneas, two with SJS, two with OCP and one with an alkali burn were examined. Corneal specimens were obtained during lamellar keratoplasty and the histological sections were immunostained with antibodies against CD34 and several cell surface antigens. The level of expression of proteoglycans (lumican, keratocan, biglycan) and chemokines (monocyte chemoattractant protein 1, macrophage inflammatory protein (MIP) 1 alpha, MIP1 beta) were examined by quantitative real-time RT-PCR. Results: The number of CD34-positive cells in the stroma was decreased and the expression level of biglycan increased in all of the pathological corneas. The numbers of CD45-positive and CD14-positive cells were increased in four of the five pathological corneas. The expression level of MIP1 alpha and MIP1 beta were markedly increased in all of the pathological corneas. Conclusions: These findings indicate that the keratocytes are abnormal and inflammation is still present in the corneal stroma in the chronic phase of SJS, OCP and alkali burns.