Immunohistochemical localization of fibronectin as a tool for the age determination of human skin wounds

We analyzed the distribution of fibronectin in routinely embedded
tissue specimens from 53 skin wounds and 6 postmortem wounds. In
postmortem wounds a faint but focal positive staining was
exclusively found at the margin of the specimens which dit not
extend into the adjacent stroma. Vital wounds were classified into
3 groups. The first comprising lesions with wound ages ranging from
a few seconds to 30 min, the second comprising those with wound
ages upt to 3 weeks, and the third group with lesions more than 3
weeks old. Ten out of 17 lesions with a wound age up to 30 min
showed a clear positive reaction within the wound area. Three
specimens in this group were completely negative, while in 4
additional cases the result was not significantly different from
postmortem lesions. These 7 cases were characterized by acute death
with extremely short survival times (only seconds). In wounds up to
3 weeks old fibronectin formed a distinct network containing an
increasing number of inflammatory cells corresponding to the wound
age. In 2 cases with a survival time of 17 days and in all wounds
older than 3 weeks fibronectin was restricted to the surface of
fibroblasts and to parallel arranged fibers in the granulation
tissue without any network structures. We present evidence that
fibronectin is a useful marker for vital wounds with a survival
time of more than a few minutes. Fibronectin appears before
neutrophilic granulocytes migrate into the wound area. Since a
faint positive fibronectin staining is seen in postmortem lesions
and bleedings, we propose that only those wounds which show strong
positive fibronectin staining also extending into the adjacent
stroma should be regarded as vital.