Serum thrombospondin-1, growth differentiation factor-15, and resolvin D1 and E1 levels in the pathogenesis of keratoconus.

PURPOSE: This study aimed to evaluate the serum levels of thrombospondin-1, growth differentiation factor-15, resolvin D1, and resolvin E1 in patients with keratoconus. METHODS: Thirty-five patients with keratoconus and 35 control subjects of similar age and sex were evaluated. The keratoconus group was divided into four stages according to the modified Krumeich classification. Commercial kits were used to determine thrombospondin-1, growth differentiation factor-15, resolvin D1, and resolvin E1 levels in serum samples using enzyme-linked immunosorbent assay (ELISA). Serum thrombospondin-1, growth differentiation factor-15, resolvin D1, and resolvin E1 levels were compared between the patient and control groups. RESULTS: The keratoconus group consisted of 14 females and 21 males, and the control group consisted of 14 females and 21 males, with mean ages of 29.4±8.8 and 30.0±7.8 yr, respectively. There were significant differences in serum thrombospondin-1, growth differentiation factor-15, resolvin D1, and resolvin E1 levels between the serum of the keratoconus and control groups (p=0.006, p<0.001, p<0.001, and p=0.001, respectively). No significant correlations were found between keratoconus stage and serum thrombospondin-1, growth differentiation factor-15, resolvin D1 and resolvin E1 levels (r=-0.025, p=0.892; r=-0.019, p=0.913; r=-0.036, p=0.838; and r=-0.108, p=0.538, respectively). CONCLUSION: Serum levels of thrombospondin-1, growth differentiation factor-15, resolvin D1, and resolvin E1 were significantly lower in patients with keratoconus. These results suggest that these parameters may be associated with the pathogenesis of keratoconus.