Summary of Arafat, S. et al; Elevated neutrophil elastase in tears of ocular graft-versus-host disease patients. American Journal of Ophthamology Apr 2017. Click here for the full article.

Graft-versus-host disease is a systemic complication and major cause of morbidity and mortality in patients that have undergone a transplantation procedure. It is a complex disease that involves an interplay between the donor and recipient adaptive and innate immune systems and potentially affects a variety of tissues depending on the type of transplant. Ocular graft-versus-host disease (oGvHD) occurs in 40-60% of all recipients and can be seen in up to 90% of patients with chronic GvHD. Neutrophil elastase (NE) is an important multi-functional enzyme predominantly released by neutrophils. Besides its antimicrobial role, NE also activates cellular receptors (TLRs) and is considered to be one of the most destructive enzymes owing its ability to degrade almost all components of the extracellular matrix.

The purpose of this study was to compare neutrophil elastase levels in tears of oGvHD patients with normal subjects. 14 oGvHD patients and 14 matched normal controls were enrolled in the study. Neutrophil elastase (cat. # HK319) was measured from tear washes of both eyes. The results demonstrated that NE-levels of oGvHD patients were 250-fold higher in comparison to the matched controls. Secondary markers such as MPO, MMP-8 and MMP-9 were also significantly elevated in the oGvHD group. This study shows that NE can be a potential marker of ocular inflammation. However, the effectiveness of NE as an inflammatory biomarker remain unkown. Large, well-designed prospective studies are needed to test the effectiveness of an NE assay.