Distribution of fibronectin in diabetic skin.

Distribution of the fibronectin (FN) present in the forearm skin was studied in 23 controls and 34 insulin dependent diabetics. All the subjects were lean males under 50 years. After biopsy FN was studied by an indirect immunofluorescence technic. A semi-quantitative evaluation was attempted by giving a score to the fluorescent intensity read at the three following sites: vascular basement membranes, papillary dermis, and the dermo-epidermal basement membranes. We found an increased amount of FN-immunofluorescence in diabetic skins. This increase was seen not only in vascular basement membranes but also at the two other sites. No correlation was found between apparent FN levels and the duration or equilibration of diabetes. These results are consistent with other findings of the literature concerning the involvement of the intercellular matrix in diabetes.