Identification of an epidermal basement membrane defect in recessive forms of dystrophic epidermolysis bullosa by LH 7:2 monoclonal antibody: use in diagnosis

LH 7:2 is a monoclonal antibody that was raised against an extract of human epidermal cells and identifies an epitope within the lamina densa of the basement membrane of stratified squamous epithelia. Using indirect immunofluorescence we found intense labelling with LH 7:2 at the epidermal basement membrane (EBM) of normal skin, and in skin samples from patients with simplex, junctional, dominantly inherited dystrophic and acquired forms of epidermolysis bullosa (EB), as well as bullous pemphigoid. Staining was absent or only very faint in generalized recessive dystrophic EB (RDEB), and patchily reduced in the localized form of RDEB. We conclude that LH 7:2 recognizes an EBM antigen which may be important in the pathogenesis of RDEB. Moreover, the antibody provides a useful probe for the rapid diagnosis of RDEB and is of special value in helping to discriminate between localized RDEB and typical dominant dystrophic EB--conditions which closely resemble each other clinically and which cannot be distinguished by means of transmission electron microscopy.

Psoriasis: maintenance of an intact monolayer basal cell differentiation compartment in spite of hyperproliferation

Frozen sections of punch biopsies from normal epidermis and psoriatic involved and uninvolved epidermis have been examined immunocytochemically using a panel of anti-keratin monoclonal antibodies with various specificities in the skin. Since psoriasis is thought to involve hyperproliferative expansion of the basal compartment from one to about three cell layers in thickness, the samples were screened with antibodies to intermediate filament determinants associated with basal cells, suprabasal cells and hyperproliferating keratinocyte-derived cell lines, respectively. The basal-suprabasal division was observed to be intact, with only one layer of basal cells demarcated by the specific antibodies used under all circumstances. This suggests that (a) psoriatic "basal cell hyperproliferation' may not specifically involve the basal cell compartment containing the stem cells, but rather a population of amplifying transit cells which are predominantly suprabasal, and that (b) while keratinocyte differentiation begins as the cells lose contact with the basal lamina, the first stages at least of differentiation are not dependent on the loss of the capacity to divide.

Mycosis fungoides of the tonsil: a T-cell lymphoma involving the skin and tonsil

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Malignant histiocytosis

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Epidermolysis bullosa: preliminary observations of blister formation in keratinocyte cultures

Keratinocytes from patients with different types of epidermolysis bullosa (EB) demonstrated an abnormal tendency to blister or bleb formation after 14-22 days in culture. The changes were most marked in samples from cases of junctional EB and were not observed in control cultures of normal skin. These findings suggest the possibility of a primary abnormality of keratinocyte adhesion in different varieties of EB and that keratinocyte culture should provide a useful model for further studies on disorders of adhesion in EB.

Treatment of chronic actinic dermatitis with azathioprine

Fourteen patients with severe unremitting chronic actinic dermatitis were treated with oral azathioprine in a dosage of 100-200 mg daily for a mean 11.5 months. Clinical improvement, apparently permanent, occurred after a few weeks to several months and continued for up to 2 years. Nine patients cleared or improved markedly, one patient cleared and then relapsed again on treatment, two patients showed no response and two patients needed to discontinue therapy because of gastrointestinal side-effects. We feel that in many patients azathioprine can be a very effective therapy for this extremely incapacitating disease.

Mepacrine pigmentation in systemic lupus erythematosus. New data from an ultrastructural, biochemical and analytical electron microscopic investigation

A case of mepacrine pigmentation occurring in a patient with systemic lupus erythematosus has been investigated by fluorescent light microscopy, gas--liquid chromatography and analytical electron microscopy. There is strong evidence for the presence of mepacrine itself within the typical granules, which have been shown by electron microscopy to be membrane bound and intracellular. Analytical electron microscopy also showed that the granules contain large quantities of iron and smaller quantities of sulphur.

Systemic sclerosis with subcutaneous nodules

A case of systemic sclerosis with subcutaneous nodules is described. The nodules consisted of fibrinoid degeneration with surrounding fibrosis, but lacked the typical histiocytic palisade of the rheumatoid nodule. The patient had neither coexistent rheumatoid arthritis nor circulating rheumatoid factor.

Localized heat urticaria treated by inducing tolerance to heat

A patient with localised heat urticaria is described. Tolerance of the skin to hear was produced by repeated exposure to hot water and complete symptomatic remission was accomplished.