This study was performed to evaluate the level of I-TAC in tears of patients with dry eye syndrome and its correlation with the tear surface parameters.

I-TAC levels were measured by enzyme-linked immunosorbent assay (ELISA) in tear samples collected from 33 dry eye patients (16 patients with Sjögren syndrome and 17 patients with non-Sjögren syndrome) and 15 control subjects. The correlations between I-TAC levels and tear surface parameters including tear film break-up time (BUT), basal tear secretion, tear clearance rate (TCR), corneal sensation, keratoepitheliopathy and conjunctival goblet cell density were analyzed.

The mean levels of I-TAC were 717±377 pg/ml in patients with dry eye and 444±119 pg/ml in control subjects ( P =0.003). The mean levels in Sjögren syndrome patients (1261±324 pg/ml) were significantly higher than those of non-Sjögren syndrome patients (614±131 pg/ml, P =0.003). I-TAC levels correlated significantly with basal tear secretion ( P =0.006), TCR ( P =0.007), keratoepitheliopathy ( P =0.022) and goblet cell density ( P <0.001), but did not correlate with BUT ( P =0.110) and corneal sensation ( P =0.090).

The level of I-TAC is elevated in tears of patients with dry eye syndrome including Sjögren syndrome. The level correlates with disease severity and tear surface parameters.