Inflammatory cell subpopulations in keloid scars

The aim of this study was to investigate the contribution of lymphocytes an d macrophages to keloid scarring by morphologically characterising inflamma tory cell subpopulations in keloid scars in comparison with normal skin. We took 3 min punch biopsies from the anterior forearms of eight normal healt hy volunteers. Eight keloid scars were excised using an intralesional techn ique. All tissue was snap frozen in liquid nitrogen and serial sections wer e stained with a panel of anti-inflammatory cell monoclonal antibodies. The numbers of macrophages and lymphocytes and the proportions of the subpopul ations were compared. Higher numbers of both macrophages and lymphocytes we re found in keloid dermis (P = 0.01 and P = 0.02, respectively (Mann-Whitne y U-test)). There was no significant increase in the expression of the lymp hocyte activation markers, CD25 and CD27. However, there was a significantl y higher CD4(+): CD8(+) (Th: Ts) ratio (P = 0.046) in keloid tissue. This s uggests that an imbalance in these inflammatory cell subpopulations may con tribute to keloid scarring in man. (C) 2001 The British Association of Plas tic Surgeons.