Proteins found in the tear film show promise as potential diagnostic markers for chronic graft-vs.-host disease (GVHD) and could be used as a noninvasive and simple test for screening, diagnosis and grading severity, a study in The Ocular Surface suggests.

A team of Chinese researchers enrolled 23 ocular chronic GVHD patients and 16 others with dry eye disease as the control group. The study considered several ocular surface parameters including tear break-up time (TBUT), corneal fluorescein staining, ocular surface disease index scores and Shirmer’s test results. The investigators measured 23 cytokines and considered their consistency with the different ocular surface parameters.

The study found ICAM-1, IL-1β, IL-6 and IL-8 showed elevated levels in the eyes of GVHD patients compared with the dry eye group—possibly indicating new diagnostic markers, the researchers said. Additionally, IL-7 and EGF had lower levels in the GVHD patients than the dry eye subjects. Also of note: IL-6 and IL-8 showed a stronger correlation with corneal fluorescein staining, and the levels of IL-6 and ICAM-1 were most consistent with fluorescein TBUT.

“Because tear sampling is noninvasive and simple, this method is expected to be overwhelmingly applicable for the screening and diagnosis of chronic GVHD,” the study concluded.