α-Defensins in human diabetic retinas. Ocular tissue from 5 patients with diabetes mellitus and 5 cases of traumatic injury in persons without diabetes mellitus were stained for α-defensins. Sections were stained with a rabbit antiserum that recognizes HNP1-3 or serum from unimmunized rabbits at the same dilution as a control. Normal-appearing regions of the retina in samples from patients with diabetes mellitus stained for α-defensin (A-C). In contrast, α-defensins were not detected in diabetic retinas when the normal rabbit serum control was used as first antibody (D). Little or no expression of α-defensins was noted in proliferative retinal vessels (E) or in proliferative vessels at the rubeotic membrane (F). α-Defensins were not detected in retinal vessels from eyes removed because of trauma (G). Hematoxylin and eosin staining identified neutrophils (H).