Prenatal diagnosis of epidermolysis bullosa (EB) using fetal skin biopsy specimens has been successfully performed in Europe and America, but this technique has not previously been attempted in Asia. For the first time in Asia, we attempted to make a prenatal diagnosis of EB in a high-risk fetus by fetal skin biopsy. A skin biopsy was obtained from the fetus at risk of gravis type junctional epidermolysis bullosa of Herlitz. The biopsy specimen was studied by electron microscopy and immunohistochemistry using various monoclonal antibodies against the epidermal basement membrane zone (BMZ). There were no ultrastructural abnormalities in the BMZ, including the hemidesmosomes. Indirect immunofluorescence showed normal expression of GB3 antigen. The pregnancy was continued, and a normal, healthy infant was born. The prenatal diagnosis of epidermolysis bullosa is now available in Tokyo. This clinical diagnostic service is available to families from various parts of Asia.
Conventional chemical fixation and paraffin-embedding procedures give good preservation of morphology, although the antigenicity of many proteins in the tissue sample is destroyed. On the other hand, fresh frozen sections can preserve the antigenicity, but provide poor morphological preservation. To overcome this dilemma, cryofixation and freeze drying were used on human skin tissue, applying methodology which has only been used to study lymphoid tissue. First, fresh human skin was cryofixed in liquid isopentane (-160 degrees C) cooled by liquid nitrogen. The skin was then freeze-dried at -40 degrees C and 10(-2) atmospheric pressure for 72 h, followed by embedding in paraffin. Sections 4 microns thick taken from this cryofixed, freeze-dried, and paraffin-embedded skin were stained with hematoxylin-eosin or used for immunolabeling with antibodies against basement membrane antigen, including type IV and type VII collagen, bullous pemphigoid antigen, epidermolysis bullosa acquisita antigen, and GB3 antigen. The morphological preservation of these sections was as good as that of routine formalin-fixed and paraffin-embedded skin sections. The basement membrane was clearly immunostained with all antibodies used, and the intensity of the reaction was as strong as that seen in frozen sections. Evaluation of antigen distribution in conjunction with the detailed skin structure was therefore possible in the same sections.
A 2-year-old girl developed small tense bullae on the diaper area, face and extremities. Immunofluorescent studies revealed linear deposits of IgA, IgM and C3 at the basement membrane zone (BMZ). In addition, IgA2 deposits, as well as IgA1, were clearly demonstrated in the lesional skin. However, in circulation, only IgA1 anti-BMZ antibodies were found. Immunoelectron microscopic study showed IgA deposits just underneath the basilar surface of the basal cells, which seemed to be associated with hemidesmosomes. The survey of the literature suggests that the involvement of IgA2 is extremely rare in this disease.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.