Sources/Clones
Dako and Enzo Diagnostics.
Fixation/Preparation
34bE12 may be used on formalin-fixed, paraffin-embedded tissue sections. Although reactivity on formalin-fixed tissue is obtainable, better consistency is observed on Carnoy's or methacarn-fixed material. Proteolytic treatment with pronase (for prostatic basal cells) and microwave antigen retrieval (for papillary carcinoma of thyroid) is essential for formaldehyde-fixed material. This antibody may also be used on acetone-fixed cryostat sections and fixed-cell smears. Incubation of the primary antibody for 1 h at room temperature is sufficient for prostatic basal cells. However, incubation of primary antibody at 4 C overnight is necessary for papillary carcinoma of the thyroid gland.
Background
34bE12 identifies keratins of approximately 66 kD and 57 kD in extracts of stratum corneum. The antibody reacts with keratins 1, 5, 10 and 14 in Moll's catalog (molecular weight 68 kD, 58 kD, 56.5 kD, 50 kD) respectively (Moll et al, 1982). In normal tissue the antibody labels squamous, ductal and other complex epithelia.
Applications
Perhaps the most useful application for 34bE12 is in the detection of basal cells of the prostatic acini (O'Malley et al, 1990; Amin, 1995). Demonstration of this high molecular weight cytokeratin in the basal cells of prostatic acini is indicative of benignity. Further, 34bE12 is negative in adenocarcinoma of the prostate. In this context, it is also useful to demonstrate the basal cells in basal cell hyperplasia (partial or atypical) and atypical adenomatous hyperplasia of the prostate, the latter being difficult to distinguish morphologically from prostatic adenocarcinoma.
More recently the role of 34bE12 in diagnostic thyroid pathology was highlighted (Appendix 1.26). It was shown that 34bE12 positivity was confined to papillary carcinoma of the thyroid, whereas follicular neoplasms and hyperplastic nodules were either negative or showed focal staining (Raphael et al, 1995). 34bE12 is also consistently positive in squamous cell carcinomas, ductal carcinoma of breast, pancreas, bile duct and salivary gland. It has also been demonstrated in transitional cell carcinomas of the bladder, nasopharyngeal carcinoma, thymomas and epithelioid mesotheliomas (Gown & Vogel, 1985). Whilst this antibody has a variable positivity with adenocarcinomas, it is negative in hepatocellular carcinoma, renal cell carcinoma and endometrial carcinoma. Mesenchymal tumors, lymphomas, melanomas, neural tumors and neuroendocrine tumors are negative.
Comments
We have found 34bE12 to be extremely useful in both diagnostic prostatic and thyroid pathology. It should be noted that different incubation protocols need to be followed for these two applications of 34bE12.
References
•Amin MB 1995. Prostate mesonephric remnant hyperplasia. Advances in Anatomical Pathology 2:110-112. 2:110-112.
•Gown AM, Vogel AM 1985. Monoclonal antibodies to intermediate filament proteins. III. Analysis of tumors. American Journal of Clinical Pathology 84: 413-424.
•Moll R, Franke WW, Schiller DL, Geiger B, Krepler R 1982. The catalog of human cytokeratins: patterns of expression in normal epithelia, tumors and cultured cells. Cell 31:11-24.
•O'Malley FP, Grignon DJ, Shum DT 1990. Usefulness of immunoperoxidase staining with high-molecular-weight cytokeratin in the differential diagnosis of small-acinar lesions of the prostate gland. Virchows Archives A Pathologic Anatomy 417:191-196.
•Raphael SJ, Apel RL, Asa SL 1995. Detection of high-molecular-weight cytokeratins in neoplastic and non-neoplastic thyroid tumors using microwave antigen retrieval. Modern Pathology 8:870-872.
Bibliografía
Manual of diagnostic antibodies for immunohistology / Anthony S.-Y. Leong, Kumarasen Cooper, F. Joel W.-M. Leong.
Dako and Enzo Diagnostics.
Fixation/Preparation
34bE12 may be used on formalin-fixed, paraffin-embedded tissue sections. Although reactivity on formalin-fixed tissue is obtainable, better consistency is observed on Carnoy's or methacarn-fixed material. Proteolytic treatment with pronase (for prostatic basal cells) and microwave antigen retrieval (for papillary carcinoma of thyroid) is essential for formaldehyde-fixed material. This antibody may also be used on acetone-fixed cryostat sections and fixed-cell smears. Incubation of the primary antibody for 1 h at room temperature is sufficient for prostatic basal cells. However, incubation of primary antibody at 4 C overnight is necessary for papillary carcinoma of the thyroid gland.
Background
34bE12 identifies keratins of approximately 66 kD and 57 kD in extracts of stratum corneum. The antibody reacts with keratins 1, 5, 10 and 14 in Moll's catalog (molecular weight 68 kD, 58 kD, 56.5 kD, 50 kD) respectively (Moll et al, 1982). In normal tissue the antibody labels squamous, ductal and other complex epithelia.
Applications
Perhaps the most useful application for 34bE12 is in the detection of basal cells of the prostatic acini (O'Malley et al, 1990; Amin, 1995). Demonstration of this high molecular weight cytokeratin in the basal cells of prostatic acini is indicative of benignity. Further, 34bE12 is negative in adenocarcinoma of the prostate. In this context, it is also useful to demonstrate the basal cells in basal cell hyperplasia (partial or atypical) and atypical adenomatous hyperplasia of the prostate, the latter being difficult to distinguish morphologically from prostatic adenocarcinoma.
More recently the role of 34bE12 in diagnostic thyroid pathology was highlighted (Appendix 1.26). It was shown that 34bE12 positivity was confined to papillary carcinoma of the thyroid, whereas follicular neoplasms and hyperplastic nodules were either negative or showed focal staining (Raphael et al, 1995). 34bE12 is also consistently positive in squamous cell carcinomas, ductal carcinoma of breast, pancreas, bile duct and salivary gland. It has also been demonstrated in transitional cell carcinomas of the bladder, nasopharyngeal carcinoma, thymomas and epithelioid mesotheliomas (Gown & Vogel, 1985). Whilst this antibody has a variable positivity with adenocarcinomas, it is negative in hepatocellular carcinoma, renal cell carcinoma and endometrial carcinoma. Mesenchymal tumors, lymphomas, melanomas, neural tumors and neuroendocrine tumors are negative.
Comments
We have found 34bE12 to be extremely useful in both diagnostic prostatic and thyroid pathology. It should be noted that different incubation protocols need to be followed for these two applications of 34bE12.
References
•Amin MB 1995. Prostate mesonephric remnant hyperplasia. Advances in Anatomical Pathology 2:110-112. 2:110-112.
•Gown AM, Vogel AM 1985. Monoclonal antibodies to intermediate filament proteins. III. Analysis of tumors. American Journal of Clinical Pathology 84: 413-424.
•Moll R, Franke WW, Schiller DL, Geiger B, Krepler R 1982. The catalog of human cytokeratins: patterns of expression in normal epithelia, tumors and cultured cells. Cell 31:11-24.
•O'Malley FP, Grignon DJ, Shum DT 1990. Usefulness of immunoperoxidase staining with high-molecular-weight cytokeratin in the differential diagnosis of small-acinar lesions of the prostate gland. Virchows Archives A Pathologic Anatomy 417:191-196.
•Raphael SJ, Apel RL, Asa SL 1995. Detection of high-molecular-weight cytokeratins in neoplastic and non-neoplastic thyroid tumors using microwave antigen retrieval. Modern Pathology 8:870-872.
Bibliografía
Manual of diagnostic antibodies for immunohistology / Anthony S.-Y. Leong, Kumarasen Cooper, F. Joel W.-M. Leong.
