Antigens keratin

An abbreviated panel of antibodies directed against three antigens—keratin, S-100 protein, and CD45 (leukocyte common antigen—EC A)—can separate... 

An abbreviated panel of antibodies directed against three antigens— keratin, S-100 protein, and CD45 (Leukocyte Common Antigen-LCA)— can separate poorly differentiated tumors into four diagnostic categories carcinoma, neural tissue tumor/melanoma, hematopoietic tumor, and sarcoma as shown in Table 2. 

Basaloid squamous cell carcinoma (BSCC) also may be either a primary thymic tumor > ° or a mediastinal metastasis from a primary neoplasm of the oropharynx, hypopharynx, larynx, esophagus, lungs, or anorectal region. Keratin is universally present in BSCC with a diffuse cytoplasmic pattern of labeling, and reactivity for epithelial membrane antigen, keratin 5/6, and p63 may also be observed. h78,80,8i author s experi-... 

This antihypertensive drug was withdrawn from use after a number of cases of occulomucocutaneous syndrome (skin rashes, keratinization of the eye, and other tissues). Mechanism is unknown, but there is evidence for metabolism (microsomal enzyme mediated) to a reactive intermediate capable of reacting with protein and forming antigenic conjugates. Antipractolol antibodies are detected in patients. Syndrome is not reproducible in animals, but in hamsters, practolol accumulates in the eye. 

Hazelbag, H. M., V. D. Broek, L. J. C. M., Van Dorst, E. B. L., Offerhaus, G. J. A., Fleuren, G. J., and Hogendoom, P. C. W. 1995. Immunostaining of chain-specific keratins in formalin-fixed, paraffin-embedded tissues a comparison of various antigen retrieval systems using microwave heating and proteolytic pretreatments. J. Histochem. Cytochem. 43 429-437. 

A direct detection method was recently developed for these adducts in stratum comeum of human skin based on immunofluorescence microscopy (30). Three partial sequences of keratins containing glutamine or asparagine, adducted with a 2-hydroxyethyl-thioethyl group at the omega-amide function, were synthesized and used as antigens for raising antibodies. After immunization, monoclonal antibodies were obtained with affinity for keratin isolated from human callus exposed to 50 xM sulfur mustard (see Plate 1). In contrast to the immunochemical... 

Dillman et al. (2003) have recently shown that sulphur mustard causes keratin 14 and keratin 5 to clump into stable aggregates. These appear within 15 min of exposure to sulphur mustard. It was noted that a number of blistering disorders (epidermolysis bullosa simplex and epidermolytic hyperkeratosis) are associated with abnormalities of these keratin molecules (Fuchs et al, 1994). The role of keratin 14 in linking to plectin (another component of the hemidesmosomes) and to the bullous pemphigoid antigen le was also noted. Werrlein and Madren-Whalley (2000) demonstrated that sulphur mustard reduced expression of keratin 14... 

KER, keratin, detected by a mixture of GAMS.2, MAK-6, and AEl /AE3 EMA, epithelial membrane antigen VIM, vimentin DES, desmin MSA, muscle-specific actin SMA, smooth muscle (alpha isoform) actin GALD, h-caldesmon S-IOOP, S-100 protein OCN, osteocalcin LM, laminin UL, Ulex europaeus I lectin binding FS, fibrosarcoma SGRMS, spindle cell rhabdomyosarcoma LMS, leiomyosarcoma MPNST, malignant peripheral nerve sheath tumor MSS, monophasic spindle cell synovial sarcoma SCAS, spindle cell angiosarcoma KS, Kaposi s sarcoma FOS, fibroblastic osteosarcoma. 

FIGURE 4.18 Synovial sarcoma showing immunoreactivity for keratin (A) and epithelial membrane antigen (B). 

The majority of keratin immunostaining is performed on FFPE tissues. The duration of formalin fixation is a key factor when trying to optimize the technical performance of keratin immunoperoxidase stains. The fixation time is closely related to the time required for enzymatic predigestion.212 Generally, tissue fixed in 10% formalin for more than 2 days requires greater antigen retrieval, with less time required for tissues fixed briefly (hours) in 10% formalin. Most, if not all, keratin antibodies require epitope retrieval (depending on antibody and fixation duration) for optimal keratin antibody performance. 

When antibodies to CK7, CK20, CK5, or other keratins are combined in panels with various antibodies to other intermediate filaments (e.g., vimentin), antibodies to supplemental epithelial antigens (e.g., CEA, EMA), or antibodies to specific cell products or transcription factors (e.g., neuroendocrine granules, TTFl, WTl), a more specific identification of cell type may be rendered. An algorithmic approach as shown in Fig. 8.20 may be used in arriving at the correct diagnosis. 

Pinkus GS, Etheridge CL, O Connor EM. Are keratin proteins a better tumor marker than epithelial membrane antigen A comparative immunohistochemical study of various paraffin-embedded neoplasms using monoclonal and polyclonal antibodies. Am J Clin Pathol. 1986 85 269-277. 

Thomas P, Battifora H. Keratins versus epithelial membrane antigen in tumor diagnosis an immunohistochemical comparison of five monoclonal antibodies. Hum Pathol. 1987 18 728-734. 

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