Accumulation of matrilysin (MMP-7) and macrophage metalloelastase (MMP-12) in actinic damage.

Photodamage is characterized by degradation of collagen and accumulation of abnormal elastin in the superficial dermis and several matrix metalloproteinases have previously been implicated in this process. Using immunohistochemistry and in situ hybridization, we have studied the localization of two elastolytic matrix metalloproteinases, matrilysin (matrix metalloproteinase-7) and human macrophage metalloelastase (matrix metalloproteinase-12) in solar damage. Human macrophage metalloelastase protein was detected in the superficial dermis in areas of elastotic material. Matrix metalloproteinase-7 was seen in the mid-dermis in regions with less damaged elastic fibers and morphologically better preserved collagen as well as in a band-like pattern below basal keratinocytes in eight of 18 solar elastosis. In samples taken from healthy volunteers 3 d after repeated ultraviolet A or ultraviolet B photoprovocation, occasional immunopositive cells for human macrophage metalloelastase (stromal) or matrix metalloproteinase-7 (sweat gland epithelium) were detected. In samples taken 1 d after ultraviolet B exposure, however, basal keratinocytes were matrix metalloproteinase-7 immunopositive, explaining the linear immunostaining below basal keratinocytes noted particularly in ultraviolet B treated 3 d specimens. Upregulation of metalloelastase was also demonstrated in the skin of hairless mice after repeated ultraviolet exposure. In normal skin, no staining for human macrophage metalloelastase or matrix metalloproteinase-7 was observed in association with elastin. The amount of immunoreactivity for the substrates of matrix metalloproteinase-7, versican, and tenascin, was clearly increased in solar elastosis and photoprovocated skin; versican but not tenascin was detected in the same areas as matrix metalloproteinase-7. Our results suggest that both matrix metalloproteinase-7 and -12 may contribute to remodeling of elastotic areas in sun-damaged skin.

Erythema elevatum diutinum in association with coeliac disease.

Erythema elevatum diutinum (EED) has been described in association with several immunological or infectious diseases. We describe a female patient who presented with clinically and histologically typical EED in whom previously undiagnosed coeliac disease was found. Appearance of EED lesions was preceded by widespread joint pains. In extensive laboratory tests, the only abnormal findings were an elevated erythrocyte sedimentation rate (ESR) and decreased haemoglobin and folic acid levels. Later, IgA and IgG type antireticulin and antigliadin antibodies were detected. Serum total IgA was elevated but no paraproteinaemia was found. In lesional skin, granular deposits of IgA and C3 were seen at the dermo-epidermal junction. A duodenal biopsy revealed total villous atrophy. Dapsone treatment was partly effective but complete healing of the EED lesions was achieved only after the introduction of a strict gluten-free diet. The patient has now remained symptom-free on the diet for 1.5 years.