Elevated levels of human α-defensin in tears of patients with allergic conjunctival disease complicated by corneal lesions: Detection by SELDI ProteinChip system and quantification

Purpose: To analyze levels of α-defensin in the tears of allergic patients (with/without corneal lesions) comparing the results with those of normal control subjects. Methods: Screening of the protein profiles of the tears of allergic patients with corneal epithelial lesions and normal controls was performed by surface enhanced laser desorption/ionization (SELDI) ProteinChip array initially. ELISA was then performed to quantify the levels of α-defensin in the tears of allergic patients (with/without corneal epithelial lesions) and normal control patients. Results: Proteins expressing significant differences between patients and controls by SELDI analysis were examined. Several peptides with molecular weights similar to α-defensins were found to be expressed to a greater extent in allergic patients. ELISA was performed in tears of allergic patients and control subjects to ascertain the presence and increased expression of α-defensins in allergic patients. Concentrations of α-defensins in allergic patients with corneal epithelial lesions were significantly higher than those of allergic patients without epithelial lesions or normal controls. Conclusions: Alpha-defensins were found in greater concentrations in tears of allergic patients with corneal lesions. The antimicrobial effects of α-defensins may play a role in the prevention of secondary infection of corneal lesions in allergic patients. SELDI ProteinChip technology is a useful and effective tool in profiling the differential expression of proteins in tears.