Abstract
SUMMARY: Skin lesions from six patients with systemic lupus erythematosus, five patients with discoid lupus erythematosus, twelve patients with systemic sclerosis, five patients with localized morphoea and twenty controls were examined by immunohistological techniques using fluorescein-labelled antihuman IgG, anti-human C3 and anti-human renal glomerulus antisera.The major immunohistological changes in systemic sclerosis and in localized morphoea consisted of foci of intercollagenous staining for connective tissue antigens in the reticular layer of the dermis. It is suggested that these findings indicate collagen neogenesis.In lupus erythematosus the major changes occur in the dermo-epidermal junction and consist of deposits of IgG and C3 and thickening and disruption of the membrane as demonstrated by the use of heterologous sera containing antibasement membrane antibodies.Immunohistological techniques are useful in the diagnostic differentiation between scleroderma and lupus erythematosus.