Stem cell factor in the tear fluid of vernal keratoconjunctivitis patients

To evaluate the contribution of stem cell factor (SCF) to the pathogenesis of vernal keratoconjunctivitis (VKC), we determined levels of soluble SCF in the tear fluid of VKC patients.

Samples of tear fluid were obtained from 38 VKC patients and 13 normal controls after we received informed consent from each participant. In the 38 VKC patients, disease severity was mild in 13, moderate in 17, and severe in 8. The levels of soluble SCF in tear fluid were determined by enzyme immunoassay.

Mean +/- SD SCF levels in tears were 90.3 +/- 23.4 pg/ml in patients with mild VKC, 225.3 +/- 101.2 pg/ml in those with moderate VKC, and 872.0 +/- 313.2 pg/ml in those with severe VKC, and 68.3 +/- 15.3 pg/ml in healthy controls. The increase in SCF levels in patients with moderate or severe VKC was statistically significant compared with the level in healthy controls.

Soluble SCF may make a crucial contribution to the pathogenesis of VKC.