Novel Tear Biomarkers in Ocular Graft Versus Host Disease Associated with Th1/Th2 Immune Responses: A Case Series and Literature Review.

Ocular graft versus host disease (oGVHD) is a common complication of allogeneic hematopoietic stem cell transplantation and may be associated with dry eye disease and chronic inflammation and fibrosis. Immune dysregulation, particularly the Th1/Th2 imbalance, plays a key role in the progression of oGVHD. This case study presents two oGVHD patients (a 20-year-old with acute oGVHD and a 59-year-old with chronic oGVHD), analyzing clinical dry eye parameters (Schirmer test I, tear film break-up time, Ocular Surface Disease Index (OSDI), and kerato-conjunctival staining) alongside tear biomarkers. A 27-plex tear cytokine analysis was performed using the Luminex200 platform, assessing various biomarkers against a control group-defined normal range. Key biomarkers included beta2-microglobulin (β2-MG), complement components, chemokines, growth factors, and both pro-inflammatory and anti-inflammatory cytokines, as well a series of soluble ligand and receptors. The study identified distinct biomarker progression patterns during topical corticosteroid treatment in the acute oGHVD patient, suggesting potential shifts in Th1/Th2 responses as the disease progressed. Notably, the soluble CD27, TNF-related apoptosis-inducing ligand (TRAIL) receptor 2 (TRAIL-R2), chemokine ligand 2 (CCL2), and IL-1β, initially elevated, normalized during treatment, while tear-soluble Fas remained highly elevated (>400-fold). Conversely, soluble TRAIL, which was initially at very low levels (100-fold lower), increased during treatment and reached normal tear levels, coinciding with improvements in the clinical ocular inflammation symptoms and OSDI score. This case study also highlights potential differences between acute and chronic oGVHD, particularly in the distinct patterns of novel tear biomarkers such as CD27, TRAIL/TRAIL-R2, and CCL2. Enhancing our understanding of biomarker dynamics may improve disease monitoring and pave the way for personalized management strategies to improve patient outcomes.