T-LYMPHOCYTES AND THE LACK OF ACTIVATED MACROPHAGES IN WOUND MARGIN BIOPSIES FROM CHRONIC LEG ULCERS

The objective of this study was to characterize the leucocyte infiltra te which accumulates at the margin of chronic wounds, These leucocytes are a rich source of cytokines and growth factors, and an inappropria te function of these cells may contribute to the maintenance of wound chronicity. The leucocyte populations were Stained immunohistochemical ly with monoclonal antibodies specific for surface receptors which giv e an indication of cellular function, Wound margin biopsies taken from chronic leg ulcers exhibited a localized infiltrate of CD45+ leucocyt es associated with vascularized tissue in the dermis adjacent to the w ound margin, Lymphocytes were identified in highest numbers in this ar ea and CD45RO+ T lymphocytes predominated over B lymphocytes, which we re either absent or present in very low numbers, In the majority of ch ronic wounds examined, CD4+ T lymphocytes were present in greater numb ers than CD8+ T lymphocytes with a mean (+/- SD) ratio of CD4+:CD8+ of 1.5 +/- 0.6. CD68+ macrophages were identified in all layers of the d ermis at the chronic wound margin, In 60% of wounds examined, macropha ges were negative for the activation associated markers CD16 (Fc gamma III receptor) and CD35 (C3b receptor). In those biopsies where CD16 a nd CD35 positive macrophages were observed these were preferentially l ocated in the perivascular regions. These data indicate that as monocy tes extravasate into chronic wound tissue they may be subjected to mic roenvironmental influences which either suppress or do not induce macr ophage activation. Suppression of macrophage activation may lead to an inappropriate cytokine/growth factor secretion and contribute to the maintenance of wound chronicity.