CD34+ dermal dendritic cells and mucin deposition in dermatomyositis

Figure 1 Representative histological findings in active skin lesions of dermatomyositis. A: Alcian blue (pH 2.5); B: Vimentin; C: CD34; D: Tryptase for mast cell staining.

Figure 2 Number of positive cells in active skin lesions of patients with dermatomyositis. Vimentin+ fibroblasts, CD34+ DDCs and αSMA+ myofibroblasts are increased, but factor XIIIa+ DDCs are decreased in diseased skin compared to normal skin. A significant difference is evident for tryptase-positive mast cells between the diseased and control groups (P < 0.0003). DDCs: Dermal dendritic cells; α-SMA: α-smooth muscle actin.

Figure 3 Progress at monthly intervals and mast cell count after occurrence of exanthema.

Figure 4 Proposed pathogenic mechanism underlying dermal mucin deposition in dermatomyositis. α-SMA: α-smooth muscle actin; N: Nucleus; TSHR: Thyroid-stimulating hormone receptor; HAS: Hyaluronan synthase.