Assessment of serum levels of angiogenic factors in dizygotic twin infants with and without retinopathy of prematurity

The aim of the study was to evaluate the plasma concentrations of vascular endothelial growth factor (vegf-a), its soluble receptors vegfr-1 and vegfr-2, insulin like growth factor (igf-1) and soluble tie-2 in twin infants with and without retinopathy of prematurity (rop). eleven pairs of twin infants (total 22 infants) were included in the study: there were 11 infants with advanced stage rop in the study group and 11 infants with no rop in the control group. before time-point measurements, the peripheral venous blood samples were first centrifuged, and the plasma was then stored at -70°c. the plasma concentrations of the angiogenic factors were measured by using highsensitivity enzyme-linked immunosorbent assay (elisa) kits. the average gestational age of the infants at the time of birth and the time at which the serum samples were collected were 30.5±2.3 and 37.5±2.5 weeks, respectively. the average serum levels of all the angiogenic factors were higher in infants with rop, but the differences were not statistically significant (p>0.05). in this study, serum samples of twins with and without rop were evaluated simultaneously. the time of serum sampling in the study group corresponded to the period of phase 2 rop. therefore, there appeared to be no difference between the rop group and the control group.