Cytokines in tear fluid of patients with ocular graft-versus-host disease after allogeneic stem cell transplantation

Purpose: To investigate the profile of cytokines in tear fluid of patients after allogeneic stem cell transplantation (allo-SCT) and determine their relation to the presence and manifestations of ocular graft-versus-host disease (GvHD).
Methods: In this cross sectional study tear fluid was collected in 34 consecutive adult patients that previously underwent allo-SCT (16 with ocular GvHD and 18 without) and 16 age- and gender-matched healthy controls using the Schirmer test under local anesthesia. Tear fluid was analyzed by multiplex immunoassay for the presence of interleukin (IL)-2, IL-4, IL-6, IL-10, IL-17, tumor necrosis factor (TNF)-α and interferon (IFN)-γ. Levels of measured cytokines were correlated with the findings in slit lamp examination and the Ocular Surface Disease Index (OSDI).
Results: The levels of IL-6 and IFN-γ in tear fluid in ocular GvHD patients were significantly elevated in comparison to patients without ocular GvHD and healthy controls. The levels of IFN-γ correlated with the Schirmer score and tear break up time (TBUT). Tear IL-6 levels correlated with complaints of dry eyes, tear production, fluorescent staining of the cornea, and with the OSDI score.
Conclusions: IL-6 and IFN-γ were elevated in tear fluid of patients with ocular GvHD and correlated with different
symptoms of dry eye disease, suggesting that IFN-γ is elevated during the early stages and IL-6 is involved in later stages of ocular GVHD and exhibits moreover an association with its severity.