Sources/Clones
Accurate (CLBMPO.1), Axcel/Accurate (MPO-7, polyclonal), Biodesign (polyclonal) Caltag Laboratories (H43-5), Dako (MPO-7, polyclonal), and Research Diagnostics (CLB-MPO1-1).
Fixation/Preparation
May be applied to formalin-fixed, paraffin-embedded tissue sections. This antibody may also be used to label acetone-fixed, frozen sections and fixed-cell smears. The rabbit polyclonal antibody reacts with myeloperoxidase in a variety of fixatives including Zenker's acetic acid solution, B5 solution and formalin (Pinkus & Pinkus, 1991). Pretreatment with trypsin is essential before immunostaining. HIER does not appear to enhance immunoreactivity but is not deleterious. The monoclonal antibodies do not work on formalin-fixed tissues and should only be used on frozen sections.
Background
Myeloperoxidase is the major constituent of primary granules of myeloid cells. It therefore serves as a reliable marker for myeloid cells, including early (immature) and mature forms. The appearance of myeloperoxidase precedes neutrophil elastase during myeloid cell differentiation. Further, myeloperoxidase antibody does not react with lymphoid or epithelial cells (Pinkus & Pinkus, 1991). The myeloperoxidase immunogen was isolated from human granulocytes.
Other immunohistochemical markers for myeloid cells, e.g. lysozyme, CD15, Mac 387 and CD 68, despite being sensitive, lack specificity in that they also stain histiocytes and other cell types including epithelium (Mason & Taylor, 1975). CD 43 and CD 45RO also stain myeloid cells frequently, but demonstrate T cells and histiocytes as well (Traweek et al, 1993).
Applications
Immunostaining for myeloperoxidase on paraffin sections is helpful in confirming the myeloid nature of the primitive cells that infiltrate marrow tissue. Positive reaction excludes lymphoblastic leukemia and malignant lymphoma and is therefore crucial for patient management (Van Der Schoot et al, 1990). Skin infiltrated with acute myeloid leukemia, which may be subtle, benefits from the application of antimyeloperoxidase antibody to highlight the neoplastic population (Wong & Chan, 1995).
Granulocytic sarcoma presenting as a tumor mass may occur in isolation or in association with myeloid disorders (Nieman et al, 1981). In the absence of a history of a hematological malignancy, an erroneous diagnosis of lymphoma may lead to an inappropriate treatment being instituted. Hence a high index of suspicion and the use of antibodies (including myeloperoxidase) for the demonstration of the myeloid nature of the cellular proliferation avoids a misdiagnosis. A study of 22 cases of granulocytic sarcoma on archival material proved myeloperoxidase immunostaining to be the most sensitive for demonstrating neoplastic myeloid cells, being positive in all cases (Wong & Chan, 1995). Chloroacetate esterase and lysozyme were positive in only 68% and 86% of case respectively. Lysozyme may show a strong reaction in some cases of granulocytic sarcoma, complicating acute myelomonocytic leukemia. The advantage of myeloperoxidase is the reduced background staining. Various other studies (Pinkus & Pinkus, 1991; Traweek et al, 1993) have also demonstrated myeloperoxidase to be a highly sensitive tool for the confirmation of neoplastic myeloid cells in granulocytic sarcoma.
Comments
Antimyeloperoxidase should be included in the immunohistochemical panel for lymphoma investigation. Any "lymphoma" that cannot be classified with confidence should raise the suspicion of a granulocytic sarcoma. Furthermore, tumor cells marking with only T-cell markers CD 43 or CD 45RO, but not the specific T-cell marker CD 3 or, alternatively, which stain only for histiocytic markers such as CD 68 or CD 15, should raise the alarm for a possible granulocytic sarcoma (Wong & Chan, 1995).
References
•Mason DY, Taylor CR 1975 The distribution of muramidase (lysozyme) in human tissues. Journal of Clinical Pathology 28: 124-132.
•Nieman RS, Barcos M, Berard C et al 1981 Granulocytic sarcoma: a clinicopathologic study of 61 biopsied cases. Cancer 48: 1426-1437.
•Pinkus GS, Pinkus JL 1991 Myeloperoxidase: a specific marker for myeloid cells in paraffin sections. Modern Pathology 4: 733-741.
•Traweek ST, Arber DA, Rappaport H, Brynes RK 1993 Extramedullary myeloid cell tumors: an immunohistochemical and morphologic study of 28 cases. American Journal of Surgical Pathology 17: 1011-1019.
•Van Der Schoot CE, Daams GM, Pinkster J et al 1990 Monoclonal antibodies against myeloperoxidase are valuable immunological reagents for the diagnosis of acute myeloid leukaemia. British Journal of Haematology 74: 173-178.
•Wong KF, Chan JKC 1995 Antimyeloperoxidase: antibody of choice for labeling of myeloid cells including diagnosis of granulocytic sarcoma. Advances in Anatomic Pathology 2: 65-68.
Bibliografia
Manual of diagnostic antibodies for immunohistology / Anthony S.-Y. Leong, Kumarasen Cooper, F. Joel W.-M. Leong.
Accurate (CLBMPO.1), Axcel/Accurate (MPO-7, polyclonal), Biodesign (polyclonal) Caltag Laboratories (H43-5), Dako (MPO-7, polyclonal), and Research Diagnostics (CLB-MPO1-1).
Fixation/Preparation
May be applied to formalin-fixed, paraffin-embedded tissue sections. This antibody may also be used to label acetone-fixed, frozen sections and fixed-cell smears. The rabbit polyclonal antibody reacts with myeloperoxidase in a variety of fixatives including Zenker's acetic acid solution, B5 solution and formalin (Pinkus & Pinkus, 1991). Pretreatment with trypsin is essential before immunostaining. HIER does not appear to enhance immunoreactivity but is not deleterious. The monoclonal antibodies do not work on formalin-fixed tissues and should only be used on frozen sections.
Background
Myeloperoxidase is the major constituent of primary granules of myeloid cells. It therefore serves as a reliable marker for myeloid cells, including early (immature) and mature forms. The appearance of myeloperoxidase precedes neutrophil elastase during myeloid cell differentiation. Further, myeloperoxidase antibody does not react with lymphoid or epithelial cells (Pinkus & Pinkus, 1991). The myeloperoxidase immunogen was isolated from human granulocytes.
Other immunohistochemical markers for myeloid cells, e.g. lysozyme, CD15, Mac 387 and CD 68, despite being sensitive, lack specificity in that they also stain histiocytes and other cell types including epithelium (Mason & Taylor, 1975). CD 43 and CD 45RO also stain myeloid cells frequently, but demonstrate T cells and histiocytes as well (Traweek et al, 1993).
Applications
Immunostaining for myeloperoxidase on paraffin sections is helpful in confirming the myeloid nature of the primitive cells that infiltrate marrow tissue. Positive reaction excludes lymphoblastic leukemia and malignant lymphoma and is therefore crucial for patient management (Van Der Schoot et al, 1990). Skin infiltrated with acute myeloid leukemia, which may be subtle, benefits from the application of antimyeloperoxidase antibody to highlight the neoplastic population (Wong & Chan, 1995).
Granulocytic sarcoma presenting as a tumor mass may occur in isolation or in association with myeloid disorders (Nieman et al, 1981). In the absence of a history of a hematological malignancy, an erroneous diagnosis of lymphoma may lead to an inappropriate treatment being instituted. Hence a high index of suspicion and the use of antibodies (including myeloperoxidase) for the demonstration of the myeloid nature of the cellular proliferation avoids a misdiagnosis. A study of 22 cases of granulocytic sarcoma on archival material proved myeloperoxidase immunostaining to be the most sensitive for demonstrating neoplastic myeloid cells, being positive in all cases (Wong & Chan, 1995). Chloroacetate esterase and lysozyme were positive in only 68% and 86% of case respectively. Lysozyme may show a strong reaction in some cases of granulocytic sarcoma, complicating acute myelomonocytic leukemia. The advantage of myeloperoxidase is the reduced background staining. Various other studies (Pinkus & Pinkus, 1991; Traweek et al, 1993) have also demonstrated myeloperoxidase to be a highly sensitive tool for the confirmation of neoplastic myeloid cells in granulocytic sarcoma.
Comments
Antimyeloperoxidase should be included in the immunohistochemical panel for lymphoma investigation. Any "lymphoma" that cannot be classified with confidence should raise the suspicion of a granulocytic sarcoma. Furthermore, tumor cells marking with only T-cell markers CD 43 or CD 45RO, but not the specific T-cell marker CD 3 or, alternatively, which stain only for histiocytic markers such as CD 68 or CD 15, should raise the alarm for a possible granulocytic sarcoma (Wong & Chan, 1995).
References
•Mason DY, Taylor CR 1975 The distribution of muramidase (lysozyme) in human tissues. Journal of Clinical Pathology 28: 124-132.
•Nieman RS, Barcos M, Berard C et al 1981 Granulocytic sarcoma: a clinicopathologic study of 61 biopsied cases. Cancer 48: 1426-1437.
•Pinkus GS, Pinkus JL 1991 Myeloperoxidase: a specific marker for myeloid cells in paraffin sections. Modern Pathology 4: 733-741.
•Traweek ST, Arber DA, Rappaport H, Brynes RK 1993 Extramedullary myeloid cell tumors: an immunohistochemical and morphologic study of 28 cases. American Journal of Surgical Pathology 17: 1011-1019.
•Van Der Schoot CE, Daams GM, Pinkster J et al 1990 Monoclonal antibodies against myeloperoxidase are valuable immunological reagents for the diagnosis of acute myeloid leukaemia. British Journal of Haematology 74: 173-178.
•Wong KF, Chan JKC 1995 Antimyeloperoxidase: antibody of choice for labeling of myeloid cells including diagnosis of granulocytic sarcoma. Advances in Anatomic Pathology 2: 65-68.
Bibliografia
Manual of diagnostic antibodies for immunohistology / Anthony S.-Y. Leong, Kumarasen Cooper, F. Joel W.-M. Leong.
