Elevated Neutrophil Elastase in Tears of Ocular Graft-Versus-Host Disease Patients

Purpose To investigate the levels of neutrophil elastase (NE), matrix metalloproteinases (MMPs), and myeloperoxidase (MPO) in tear washes of patients with ocular graft-vs-host disease (oGVHD). Design Case-control study. Methods Based on established criteria, oGVHD patients (n = 14; 28 eyes) and age-/sex-matched healthy controls (n = 14; 28 eyes) were enrolled. Tear washes were collected and analyzed for NE using a single-analyte enzyme-linked immunosorbent assay (ELISA). MMPs (1, 2, 3, 7, 8, 9, 12), MPO, and tissue inhibitor of matrix metalloproteinase (TIMP)-1 were analyzed using multianalyte bead-based ELISA assays. Total MMP activity was measured using a fluorimetric assay. Correlation studies were performed between NE, MMP-8, MMP-9, and MPO within study groups. Results NE, MMP-8, MMP-9, and MPO levels were elevated in oGVHD tears when compared with controls ( P P P P P  = .001). MMP-9 correlated with MPO (r = 0.55, P  = .002). In controls, NE, MMP-9, and MPO significantly correlated with each other ( P Conclusions The marked increase in NE in oGVHD tears that correlated strongly with elevated MMP-8, MMP-9, and MPO suggests a common neutrophilic source and provides evidence of neutrophil activity on the ocular surface of oGVHD patients.