Predominance of T lymphocytes in the dermal infiltrate of atopic dermatitis.

Tissue sections from diseased skin of sixteen patients with atopic dermatitis were investigated with haematoxylin-eosin and toluidine-blue staining, with direct immunofluorescence staining using FITC-conjugated antisera against IgG F(ab')2 and IgM, and with the indirect immunofluorescence method utilizing specific rabbit anti-human T lymphocyte antiserum with FITC-conjugated goat anti-rabbit Ig antiserum as the second layer. Furthermore, cryostat sections were investigated in a closed chamber immune adherence method using aminoethylisothiouronium bromide (AET) treated sheep red blood cells to detect E receptors on T lymphocytes, and with various types of coated sheep red blood cells to detect cells with IgG Fc receptors and complement factor C3b receptors. All sections presented dermal perivascular infiltrates of mononuclear cells as judged by haematoxylin-eosin staining. Staining with toluidine-blue demonstrated varying numbers of mast-cells, but in no case pathological increased number. The majority of the infiltrating cells presented rim-like membrane fluorescence with the anti-T antiserum, and the AET treated sheep red blood cells (SRBC) adhered to the infiltrates, thus indicating a predominance of T lymphocytes in the skin infiltrates of atopic dermatitis.