Changes in vitreous concentrations of human hepatocyte growth factor (hHGF) in proliferative diabetic retinopathy:...

We measured human hepatocyte growth factor (hHGF) concentrations in the original vitreous and in the artificial vitreous after vitrectomy in 13 patients with proliferative diabetic retinopathy (PDR) undergoing repeated pars plana vitrectomy, in order to investigate whether the vitreous hHGF concentration is related to the recurrence of PDR after vitrectomy as well as to the original occurrence of PDR. We also examined the relationship between vitreous concentrations of hHGF and transforming growth factor-beta(2) (TGF-beta(2)), the predominant TGF-beta isoform in the vitreous, in 14 patients with PDR. For the original vitreous, mean hHGF concentrations were higher (P<0.05) in that from patients with severe PDR (vitreous haemorrhage, fibrovascular proliferation and tractional retinal detachment) than in that from patients with vitreous haemorrhage alone. In the artificial vitreous, mean vitreous hHGF concentrations were higher (P<0.05) in that from patients with severe PDR than in that from patients with vitreous haemorrhage alone or with vitreous haemorrhage plus fibrovascular proliferation. No correlation was found between the hHGF concentration in the artificial vitreous and time between vitrectomies. Vitreous hHGF concentrations were directly proportional to vitreous concentrations of latent TGF-beta(2) (r=0. 831; P=0.0002), but inversely proportional to vitreous concentrations of active TGF-beta(2) (r=0.495; P=0.072), which inhibits hHGF production. A decreased conversion of latent into active TGF-beta(2) in ocular disorders such as PDR is likely to result in an increased concentration of hHGF in the vitreous. Thus intraocular hHGF may be involved in pathological mechanisms causing not only the occurrence, but also the recurrence, of PDR.