Histologic distribution of staining by a monoclonal antibody (psi-3) in psoriasis and occurrence of psi-3 antigen in other cutaneous diseases

Towards a molecular definition of keratinocyte activation after acute injury to stratified epithelia

While in recent years we have come to increasingly appreciate the multifaceted role of skin, probably none of these novel contributions is as vital as its barrier function, inferred centuries ago. In human skin this function is fulfilled nearly entirely by the epidermis, a thin stratified squamous epithelium made up primarily of keratinocytes and located at the skin surface. Disruption of the integrity of epidermis triggers a homeostatic response involving blood-derived elements and resident skin cell types that is designed to rapidly restore a functional epithelial lining over the wound site. This article is focused on the process of recruitment of keratinocytes from intact skin tissue at the proximal wound edges to participate in re-epithelialization.

Epithelial distribution of a myelomonocytic antigen LI in relation to cutaneous malignancies and melanocytic naevi

The distribution of LI antigen in four common skin tumours was examined immunohistochemically in 40 samples of formalin-fixed routine biopsy material. Presence of LI in the dermis depended on the extent and composition of the inflammatory infiltrate; LI was found mainly in reactive histiocytes and neutrophils. Intense epidermal staining was seen adjacent to squamous cell carcinoma, basal cell carcinoma and malignant melanoma, but not adjacent to melanocytic naevi. In specimens of melanocytic naevi, LI staining around pilosebaceous units was weak or absent. Around the three malignant types of lesion, epidermal LI positivity faded distally--thereby indicating the extent of the tumour. LI was, in addition, expressed by the most highly differentiated cells in squamous cell carcinomas, whereas the other neoplasms were negative. Antibody to LI may, thus, be a useful adjunct for distinction between various types of skin tumours.

Use of a monoclonal antibody (VM-2) plus the immunogold-silver technique to stain basal cell carcinoma cells

A newly described murine monoclonal antibody, VM-2, stains both basal cell carcinoma cells and squamous cell carcinoma cells of the skin. We have combined this monoclonal antibody with a newly described technique, the immunogold-silver stain, to produce a method for rapid characterization of basal cell carcinoma cells. This method does not require the use of a fluorescence microscope and gives a very intense stain of the tumor cells. Tumor-containing tissue from 12 patients was stained and included 2 cases of morphealike basal cell carcinoma. All the tumors stained with VM-2 gold. Thus, staining with this technique may be helpful in diagnosing tumors of epithelial origin and may also find application in delineating residual tumor cells in microscopically controlled excision.

Characterization of two monoclonal antibodies to human epidermal keratohyalin: reactivity with filaggrin and related proteins

Two monoclonal antibodies (AKH1 and AKH2) were elicited with partially purified human filaggrin and characterized by immunohistochemistry on normal and abnormal skin biopsies, immunoblotting techniques, and antigen purification. Both antibodies react strongly with the granular cell layer consistent with the distribution of keratohyalin and show a more diffuse reaction with the stratum corneum in normal skin biopsies. Reaction in cultured human keratinocytes is limited to immunofluorescent granules in flattened, well-differentiated cells in confluent cultures, in which we have previously demonstrated keratohyalin. On immunoblots AKH1 reacts with filaggrin (37 kD) and profilaggrin (400 kD), while AKH2 primarily stains bands of 150 and 300 kD. The AKH2 antigens were identified in the cationic protein fraction used for immunization and were purified by gel permeation and high-performance liquid chromatography. Amino acid composition of these proteins differs only slightly from filaggrin. Immunohistochemical staining patterns of the two antibodies are very similar in the genetic disorders of keratinization tested, except for ichthyosis vulgaris, and reflect the presence and distribution of keratohyalin. In ichthyosis vulgaris, AKH1 staining is weak, consistent with the morphology and with biochemical absence of profilaggrin/filaggrin; however, AKH2 staining is positive, although weaker than normal, suggesting the presence of the AKH2 antigens even when keratohyalin is absent or abnormal. Antibodies AKH1 and AKH2 may be useful as differentiation markers for keratinization in tissues and for cells in culture. Antibody AKH1 can be used specifically for detection of profilaggrin/filaggrin in tissues, cultured keratinocytes, and extracts.

Monoclonal antibodies and the skin biopsy: current and potential clinical applications

Monoclonal antibodies are becoming increasingly useful in the clinical diagnosis and/or treatment of a number of unrelated diseases. Discussion will be directed to those monoclonal antibodies recognizing antigens within the skin which appear to have either proven or potential application in the diagnostic evaluation of the skin biopsy.