Wound healing and growth factor expression in T lymphocyte deficiency

Background: There are many clinical situations in which immune suppression or deficiency occurs. This may lead to healing impairment. The aim of the present study was to characterize the effect of T lymphocyte deficiency on wound healing, and on -platelet-derived growth factor (PDGF), bFGF (basic fibroblast growth factor) and insulin-like growth factor-1 (IGF-1) expression, using an animal model. Methods: Nude and normal 10-12-week-old male BALB/c mice were given standard dermal incisions and killed at 1, 2, 4 or 6 weeks postinjury. The pelts were harvested and the wounds cut (perpendicularly) into strips for analysis. Strips from each animal were tested mechanically or processed for histological assessment and immunohistochemical detection of PDGF, bFGF and IGF-1 and colour video image analysis. The data were assessed by analysis of variance (anova). Results: The interaction between species and time resulted in statistically significant differences in mechanical properties. Wound peak load was higher in nude mice at weeks 1 and 2 postinjury, but lower in nude mice at week 6 postinjury. Colour video image analysis demonstrated that the expression of bFGF and IGF-1 was greater in nude mice at week 1 postinjury (P < 0.05). Conclusions: The mechanical data suggest that the overall effect of the T lymphocyte system on wound healing is initially inhibitory and later stimulatory. This may be associated with corresponding differences in wound growth factor expression.