Factors Contributing to Occasional Failures in Demonstration of Pemphigus Antibodies by the Immunofluorescence Test**From the Department of Microbiology, State University of New York at Buffalo, Buffalo, New York 14214.

ABSTRACTThe failure to demonstrate pemphigus antibodies in sera of some patients with active lesions may be due to their species or organ specificity, to prozones, to interference by other antibodies or to errors in technique. In vivo binding of IgG to the intercellular areas can, however, be demonstrated in sections of biopsies of lesions even when the indirect staining fails to reveal the presence of pemphigus antibodies. The available evidence indicates that all active cases of true pemphigus have pemphigus antibodies

Organ Culture Studies of Pehmphigus Antibodies

The ultrastructural and light microscopic features of acantholysis produced in organ culture were compared with those of human pemphigus lesions. In both, an intraepidermal split was seen and typical suprabasal acantholytic cells were present. These cells contained small bundles of tonofilaments, usually located away from the cell periphery. Desmosomal plaques with inserted tonofilaments frequently remained along the periphery of acantholytic cells and along the upper portion of the periphery of basal cells. The ultrastructural similarity between in vitro and in vivo lesions provides additional evidence to suggest that organ cultures may provide a valid model for studying the dynamics of pemphigus lesion formation

Detection of DNA-Psoralen Photoadducts in Mammalian Skin

An immunofluorescence (IF) method for the detection of 8-methoxypsoralen (8-MOP) photoadducts to DNA has been developed to assess nuclear damage in keratinocytes and melanocytes after psoralen plus UVA (PUVA) treatment, both under in vitro and in vivo conditions. Cryostat sections of the albino and pigmented guinea pig and human skin were used for in vitro studies to establish minimal and maximal drug concentration and UVA dosimetry for the detection of DNA-8-MOP photoadducts. Limits of detection were as low as 10 ng/cm2 8-MOP and 1 J/cm2 UVA for skin sections and sodium bromide-split epidermal sheets. Guinea pigs treated with topical PUVA revealed positive IF stain in epidermal cell nuclei at a threshold dose of 100 μg/cm2: 8-MOP and 13 J/cm2 UVA. Pretreatments of cryostat cuts with ethanol and alkali before IF test enhanced the sensitivity of detection in vivo about 10-fold and enabled us to follow the repair of DNA damage after treating normal guinea pig skin with a dose of 50 μg/cm2 8-MOP plus 6 J/cm2 UVA. The most interesting findings were as follows: (1) A sensitive method to detect PUVA-induced nuclear damage in epidermal and dermal cells was developed. (2) PUVA treatment induced nuclear DNA damage to melanocytes as well as to adjacent keratinocytes, and melanocytes appeared to be 10 times less vulnerable to photo-damage than keratinocytes. (3) There was a greater propensity for the proliferative cells to be damaged by PUVA. (4) PUVA induced nuclear damage up to 700 μm depth in the dermis. (5) The usefulness of the IF test in detecting DNA damage in μg and ng amounts in vivo and in following the repair of damaged DNA induced by PUVA

The Ultrastructural Localization of IgA Deposits in Chronic Bullous Disease of Childhood (CBDC)

A case of bullous disease in a child with linear IgA immune deposits at the basement membrane zone and with some clinical, histological, and electron microscopic characteristics both of dermatitis herpetiformis and bullous pemphigoid, is described.The bulla formed between the basal lamina and basal cell membranes as in bullous pemphigoid, but at the same time there were numerous inflammatory cells in the dermis just below the partly destroyed basal lamina and also abundant fibrin deposits in very recent bulla and in the skin, all of which is rather characteristic of dermatitis herpetiformis.Ultrastructurally, the IgA deposits were located chiefly below the lamina basalis (the dermal type) but also, though less abundantly, in the lamina lucida, very much as we have seen them to be in adult cases with linear IgA immune deposits at the basement membrane zone. The investigations have supplied further evidence showing the chronic bulbous disease of childhood to be actually a counterpart of the form in adults with the same linear localization of IgA deposits

Immunogold Localization of the 97-kD Antigen of Linear IgA Bullous Dermatosis (LABD) Detected with Patients' Sera

The classification of linear IgA bullous dermatosis in the group of subepidermal blistering diseases is still a matter of controversy. This situation is due partly to the considerable clinical heterogeneity of the disease but also results from the difficulties in characterization and localization of the specific basement membrane zone antigen(s) recognized by immunoglobulin (Ig)A antibodies. In the present study, we have combined the Western blot detection of circulating autoantibodies with an ultrastructural immunogold labeling of human skin antigens using the same patients' sera. Our results, obtained with a short series of sera showing exclusive IgA class reactivity with the epidermal portion of salt-split skin, indicate that the antibodies recognizing the 97-kD antigen on immunoblot bind to the hemidesmosomal plaques of basal keratinocytes and the adjacent lamina lucida. These homogeneous laboratory results remain in striking contrast to the heterogeneity of clinical pictures in the patients studied, suggesting a participation of complementary, possibly not humoral, phenomena in the pathogenesis of linear IgA bullous dermatosis