Quantitative analysis of interleukin-6 in vitreous from patients with proliferative vitreoretinal diseases.

PURPOSE To explore immunological mechanisms in the pathogenesis of proliferative vitreoretinal diseases, we measured the concentration of interleukin-6 in the vitreous body and serum from patients with proliferative diabetic retinopathy (PDR), proliferative vitreoretinopathy (PVR), and premacular fibrosis. To evaluate immunological etiology, interleukin-6 levels in each disease were compared with disease severity. METHODS Clinical samples were obtained at the beginning of pars plana vitrectomy from 30 eyes of 26 patients with PDR, 12 eyes of 12 patients with PVR, and 10 eyes of 10 patients with premacular fibrosis. Interleukin-6 was quantitated with an enzyme-linked immunosorbent assay. RESULTS The levels of detectable interleukin-6 in the vitreous specimens ranged from 22.8 to 666.4 pg/mL in the PDR patients and from 28.2 to 416.3 pg/mL in the PVR patients. No interleukin-6 was detected in the vitreous specimens from patients with premacular fibrosis or in any serum samples from patients. Interleukin-6 levels of vitreous specimens from PDR patients were higher than those from PVR patients (P <.02, Mann-Whitney U-test). There was no correlation between clinical severity and interleukin-6 levels in vitreous specimens from either PDR or PVR patients. CONCLUSION Our results indicated that cell-mediated immunity is involved in the pathogenesis of proliferative vitreoretinal diseases.