Fig. 3.

Aflibercept + VEGF₁₆₅ + unfractionated heparin (UFC) complexes do not activate platelets in vivo. B6;SJL-Tg (FcγRIIa)11Mkz (FCGR2A) mice were injected with PBS (n = 5) or preformed immune complexes (n = 10 per group) via the tail vein. Ten minutes after reagent injection, mice were anesthetized, blood was collected by cardiac puncture, and platelet counts were measured using an automated cell counter. Following blood draws, animals were killed and lungs were dissected, rinsed, and embedded in paraffin. Paraffin blocks were sliced, and cut sections (2 µm thick) were deparaffinized, rehydrated, and stained. Shown are platelet counts per individual FcγRIIa animal by treatment group (a) along with representative H&E microscopy sections for PBS (b) bevacizumab (Bev) + VEGF₁₆₅ + heparin (c) and aflibercept + VEGF₁₆₅ + heparin (d). The horizontal line in (a) represents approximately 60 % of reduction from baseline mean platelet count. Microscopy images were captured at ×200 magnification. Insets represent ×700 magnification