Detection of fibrocytes in human skin wounds and its application for wound age determination

Abstract

Fibrocytes, a newly identified cell type, are bone marrow-derived mesenchymal progenitors that coexpress hematopoietic cell antigens and fibroblast products. In this study, a double-color immunofluorescence analysis was carried out using anti-CD45 and anti-collagen type I antibodies to examine the time-dependent appearance of fibrocytes, using 53 human skin wounds with different wound ages (group I, 0-3 days; group II, 4-7 days; group III, 9-14 days; and group IV, 17-21 days). In wound specimens with an age of less than 3 days, CD45+/collagen type I+ fibrocytes were not detected. The fibrocytes were initially observed in wounds aged 4 days, and their number increased in lesions with advances in wound age. In a semiquantitative morphometrical analysis, the average number of fibrocytes was highest in the wounds of group III. These findings imply that human skin wounds containing fibrocytes are at least 4 days old. Moreover, a fibrocyte number of over 10 indicates a wound age between 9 and 14 days (i.e., group III). Based on the average number of fibrocytes in each group, a fibrocyte number of over 15 more strongly suggests a wound age of 9-14 days. Together, our observations indicate the participation of fibrocytes in wound healing of human skin inducing the accumulation of extracellular matrix components, and therefore, detection of fibrocytes could be a useful marker for wound age determination.

Estimating wound age: looking into the future

“…For example, fibrocytes, bone marrow-derived mesenchymal progenitors that coexpress hematopoietic cell antigens and fibroblast products, were recently studied by double-colour immunofluorescence analysis using anti-CD45 and anti-collagen type I antibodies. Results revealed the absence of fibrocytes in human skin wounds until day 4, with a peak at days 9-14 [67].…”

Forensic application of intrarenal aquaporin-2 expression for differential diagnosis between freshwater and saltwater drowning

“…Hematoxylin and eosin staining was carried out for routine histological analysis. For immunohistochemical analyses [23][24][25], deparaffinized sections were immersed in 0.3% H 2 O 2 in methanol for 30 min to eliminate endogenous peroxidase activity, followed by incubation with PBS containing 1% normal serum corresponding to the secondary IgG and 1% bovine serum albumin to reduce nonspecific reactions. The sections were incubated with rabbit anti-human AQP1 pAbs (1:2,000), goat anti-human AQP2 pAbs (1:1,000), or rabbit anti-human AQP4 pAbs (1:1,000) at 4°C overnight.…”

Immunohistochemical detection of MMP-2 and MMP-9 in a stasis-induced deep vein thrombosis model and its application to thrombus age estimation

“…When forensic pathologists encounter cases of DVT-related PTE, they are always required to estimate how old the venous thrombi are, as well as skin wound age determination. Immunohistochemical techniques are widely used in the forensic research fields to estimate the age of skin wounds or brain contusions [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18]; however, there are only a few forensic studies on thrombus age estimation [19][20][21].…”