Figure 4

Activation of p78 ^MX1 in lymphocytes and epithelial cells in a case of alopecia areata. A, low power field of a scalp biopsy with alopecia areata, showing an inflamed hair follicle (arrow) (H&E). B, low power field of staining with anti-p78^MX1 showing positive cells in and around the inflamed hair follicle (solid arrow), but not in an uninvolved region of another hair follicle (dashed arrow). Capillary endothelial cells stain throughout the dermis (asterisks). C, high power field of staining with anti-p78^MX1, showing that the p78-positive cells are a subset of lymphocytes (arrow) and outer root sheath epithelial cells (ORS, lines), as well as matrix cells (M) around the dermal papilla (DP). The inner root sheath (IRS) does not stain. A second case of sporadic alopecia areata revealed a similar pattern of staining (data not shown). CTS = connective tissue sheath.