Blood coagulation factor XIII contributes to the development of traction retinal detachment

The blood coagulation factor XIII catalyzes the crosslinking of fibrin monomers at the end of the coagulation cascade. Additional functions are the enzymatic coupling of fibrinectin to itself, fibrin, and collagen. We located the two subunits of factor XIII in 20 surgically obtained periretinal membranes, using double label immunofluorescence microscopy. Both subunits of factor XIII could be detected in all specimens. The positive staining in all specimens examined prompted us to determine the source of factor XIII. The abundant fibroblastic cells did not contain factor XIII. Macrophages, half of which stained for the alpha-subunit of factor XIII could not account for the presence of factor XIII because these cells were not present in all specimens, and did not stain for the beta-subunit. Factor XIII is probably derived from the exudation of plasma and platelets through disrupted blood-ocular barriers. This is confirmed by the detection of both subunits in vitreous aspirates from patients with proliferative intraocular disorders (n = 15) by Western blotting.