Sources/Clones
Amyloid-A (AA)
Dako (mc1), polyclonal anti-AA, Calbiochem/Novocastra (polyclonal), Axcel/Accurate (mc1), American Research Products (REU86.2), Biogenesis (polyclonal), Biosource (5G6), and Sanbio/Monosan/Accurate (REU86.2).
Transthyretin (ATTR/Prealbumin)
Axcel/Accurate (polyclonal), Biodesign (polyclonal), Biogenesis (polyclonal), Dako (polyclonal), and Fitzgerald (polyclonal).
B2-Microglobulin (BA2M)
Accurate (FMC16, polyclonal), Accurate/Sigma Chemical (BM63), Advanced Immunochemical (1F10, 2G3, 6G12), American Research Products (1672-18), Biodesign (GJ14, polyclonal), Biogenesis (B2M01), Biosource (MIG-85), Cymbus Bioscience (GJ14, polyclonal), Pharmingen (TU99), Sanbio/Monsan (B2M01), and Zymed (Z022).
Amyloid B-Precursor Protein (B-APP)
Boehringer Mannheim (polyclonal), Dako (6F/3D), and Zymed (LN27).
Fixation/Preparation
These antibodies are applicable to formalin-fixed paraffin-embedded tissue sections.
Background
The amyloidoses are characterized by local, organ-limited or generalized proteinaceous deposits of autologous origin (Glenner, 1980a, b). The pattern of distribution, progress of disease and complications are dependent on the fibril protein. Amyloid is characterized by the following:
• a typical green birefringence with polarized light after Congo red staining;
• non-branching linear fibrils with a diameter of 10 - 12 nm;
• an X-ray diffraction pattern which is consistent with Pauling's model of a cross- fibril (Lansbury, 1992).
The diagnosis and classification of amyloidosis requires both histological proof and detection of the amyloid fibril - histochemical confirmation of amyloid deposits using Congo red evaluation in polarized light followed by identification of the fibril protein by immunostaining, thereby revealing the probable underlying disease. Apart from the rare familial syndromes, localized forms of amyloid affect certain organs or lesions (AB in brain; calcitonin in medullary carcinoma; islet amyloid polypeptide in insulinomas or islets of Langerhans). The five major different fibril proteins are usually associated with the most common generalized amyloid syndromes: amyloid A (AA), amyloid of lambda- (Alamnda) and K- (AK) light chains, of transthyretin (ATTR) and B2-microglobulin origin. These fibril proteins may be deposited in a wide variety of tissues and organs (Glenner, 1980a, b). They therefore have to be considered in the investigation of any biopsy considered to be amyloidogenic.
Applications
In most instances good correlation is achieved between the immunohistochemical classification of amyloid and the underlying diseases (RÓken et al, 1996). AA-amyloidosis is commonly associated with chronic inflammatory disorders. AL-amyloidosis (either lambda- or K-light chain origin) is linked mainly to the plasma cell dyscrasias or interpreted as being idiopathic. ATTR-amyloidosis is found in cases with familial amyloidosis. ABM-amyloidosis is associated with long-term hemodialysis.
However, a critical issue in the clinicopathological typing of amyloidosis is the interpretation of the immunostaining (RÓken et al, 1996). Occasionally, more than one antibody may show immunostaining of amyloid deposits. Immunohistochemistry detects any associated contaminating component in the amyloid deposit (amyloid P component, apolipoprotein E and glycosaminoglycans) and not merely the currently known obligate fibril proteins. Further, the five syndromic fibril proteins originate from plasma proteins (Glenner, 1980a, b), which may themselves `contaminate' amyloid deposits. The most critical of these are the immunoglobulin light chains (RÓken et al, 1996). Based on these aberrant staining patterns, RÓken et al have proposed that the identification of a fibril protein with a single antibody demonstrates an even and homogeneous immunostaining for the entire amyloid deposit, whilst staining of the contaminant protein remains uneven. Instances also arise where two immunoreactive antibodies demonstrate similar uneven staining patterns, interpreted as being due to the irregular presentation of the epitope of the fibril protein, resulting in a similar staining pattern as contaminating proteins. These workers strongly recommend testing an additional specimen or biopsy to determine the causative fibril protein. In addition, the correlation of immunohistopathological observations and the clinical diagnosis is also mandatory to arrive at the correct classification of the amyloid fibril.
Another problem area is the false-negative detection of amyloid. This can be avoided by increasing the sensitivity of detection by using both immuno- and Congo redstaining methods (RÓken et al, 1996). The latter method of detection is also influenced by the sample quality. It has long been recognized that the diagnostic yield of gastrointestinal biopsies (especially rectal) is extremely high, but should contain submucosa. Other recommended sites include subcutaneous fat, sural nerve, heart, kidney and bone marrow. Whilst AA-amyloidosis is commonly detected in rectal biopsies, any involved organ or tissue is suitable for identification/classification of AL-amyloidosis. Interestingly, a recent study has shown that long-term hemodialysis-associated B2-microglobulin amyloid may also involve the gastrointestinal system in addition to the usual osteoarticular involvement (Shimizu et al, 1997).
The distinction and classification of amyloidosis has major therapeutic implications, as studies have recommended that AL-amyloidosis be treated with cytotoxic drugs (melphalan and prednisolone), whilst AA-amyloidosis responds better to colchicine and dimethylsulfoxide (Kyle et al, 1985; Ravid et al, 1982).
The role of antibodies against amyloid Bprecursor protein has assisted in the diagnosis of Alzheimer's disease (Iwamoto et al, 1997) and early detection of axonal injury (Sherriff et al, 1994) in the brain. Antibodies to transthyretin amyloid protein are useful in the diagnosis of cardiac amyloidosis (Jacobson et al, 1997).
References
•Glenner GG 1980a. Amyloid deposits and amyloidosis. The B-fibrilloses. New England Journal of Medicine 302: 1283-1292.
•Glenner GG 1980b. Amyloid deposits and amyloidosis. The B-fibrilloses. New England Journal of Medicine 302: 1333-1343.
•Iwamoto N, Nishiyama E, Ohwada J, Arai H 1997.
•Distribution of amyloid deposits in the cerebral white matter of the Alzheimer's disease brain: relationship to blood vessels. Acta Neuropathologica (Berlin) 93: 334-340.
•Jacobson DR, Pastore RD, Yaghoubian R et al 1997. Variant-sequence transthyretin (isoleucine 122) in late-onset cardiac amyloidosis in Black Americans. New England Journal of Medicine 336:466-473.
•Kyle RA, Greipp RP, Garton JP et al 1985. Primary systemic amyloidosis: comparison of melphalan/prednisolone versus colchicine. American Journal of Medicine 79: 708-716.
•Lansbury PT Jr 1992. In pursuit of the molecular structure of amyloid plaque: new technology provides unexpected and critical information. Biochemistry 31: 6865-6870.
•Ravid M, Shapiro J, Lang R et al 1982. Prolonged dimethylsulphoxide treatment in 13 patients with systemic amyloidosis. Annals of Rheumatic Diseases 41: 587-592.
•RÓken C, Schwotzer EB, Linke RP, Saeger W 1996. The classification of amyloid deposits in clinicopathological practice. Histopathology 29: 325-335.
•Sherriff FE, Bridges LR, Sivaloganathan S 1994. Early detection of axonal injury after human head trauma using immunocytochemistry for beta-amyloid precursor protein. Acta Neuropathologica (Berlin) 1994; 87: 55-62.
•Shimizu M, Manabe T, Matsumoto T et al 1997. B2 Microglobulin haemodialysis related amyloidosis: distinctive gross features of gastrointestinal involvement. Journal of Clinical Pathology 50: 873-875.
Bibliografia
Manual of diagnostic antibodies for immunohistology / Anthony S.-Y. Leong, Kumarasen Cooper, F. Joel W.-M. Leong.
Amyloid-A (AA)
Dako (mc1), polyclonal anti-AA, Calbiochem/Novocastra (polyclonal), Axcel/Accurate (mc1), American Research Products (REU86.2), Biogenesis (polyclonal), Biosource (5G6), and Sanbio/Monosan/Accurate (REU86.2).
Transthyretin (ATTR/Prealbumin)
Axcel/Accurate (polyclonal), Biodesign (polyclonal), Biogenesis (polyclonal), Dako (polyclonal), and Fitzgerald (polyclonal).
B2-Microglobulin (BA2M)
Accurate (FMC16, polyclonal), Accurate/Sigma Chemical (BM63), Advanced Immunochemical (1F10, 2G3, 6G12), American Research Products (1672-18), Biodesign (GJ14, polyclonal), Biogenesis (B2M01), Biosource (MIG-85), Cymbus Bioscience (GJ14, polyclonal), Pharmingen (TU99), Sanbio/Monsan (B2M01), and Zymed (Z022).
Amyloid B-Precursor Protein (B-APP)
Boehringer Mannheim (polyclonal), Dako (6F/3D), and Zymed (LN27).
Fixation/Preparation
These antibodies are applicable to formalin-fixed paraffin-embedded tissue sections.
Background
The amyloidoses are characterized by local, organ-limited or generalized proteinaceous deposits of autologous origin (Glenner, 1980a, b). The pattern of distribution, progress of disease and complications are dependent on the fibril protein. Amyloid is characterized by the following:
• a typical green birefringence with polarized light after Congo red staining;
• non-branching linear fibrils with a diameter of 10 - 12 nm;
• an X-ray diffraction pattern which is consistent with Pauling's model of a cross- fibril (Lansbury, 1992).
The diagnosis and classification of amyloidosis requires both histological proof and detection of the amyloid fibril - histochemical confirmation of amyloid deposits using Congo red evaluation in polarized light followed by identification of the fibril protein by immunostaining, thereby revealing the probable underlying disease. Apart from the rare familial syndromes, localized forms of amyloid affect certain organs or lesions (AB in brain; calcitonin in medullary carcinoma; islet amyloid polypeptide in insulinomas or islets of Langerhans). The five major different fibril proteins are usually associated with the most common generalized amyloid syndromes: amyloid A (AA), amyloid of lambda- (Alamnda) and K- (AK) light chains, of transthyretin (ATTR) and B2-microglobulin origin. These fibril proteins may be deposited in a wide variety of tissues and organs (Glenner, 1980a, b). They therefore have to be considered in the investigation of any biopsy considered to be amyloidogenic.
Applications
In most instances good correlation is achieved between the immunohistochemical classification of amyloid and the underlying diseases (RÓken et al, 1996). AA-amyloidosis is commonly associated with chronic inflammatory disorders. AL-amyloidosis (either lambda- or K-light chain origin) is linked mainly to the plasma cell dyscrasias or interpreted as being idiopathic. ATTR-amyloidosis is found in cases with familial amyloidosis. ABM-amyloidosis is associated with long-term hemodialysis.
However, a critical issue in the clinicopathological typing of amyloidosis is the interpretation of the immunostaining (RÓken et al, 1996). Occasionally, more than one antibody may show immunostaining of amyloid deposits. Immunohistochemistry detects any associated contaminating component in the amyloid deposit (amyloid P component, apolipoprotein E and glycosaminoglycans) and not merely the currently known obligate fibril proteins. Further, the five syndromic fibril proteins originate from plasma proteins (Glenner, 1980a, b), which may themselves `contaminate' amyloid deposits. The most critical of these are the immunoglobulin light chains (RÓken et al, 1996). Based on these aberrant staining patterns, RÓken et al have proposed that the identification of a fibril protein with a single antibody demonstrates an even and homogeneous immunostaining for the entire amyloid deposit, whilst staining of the contaminant protein remains uneven. Instances also arise where two immunoreactive antibodies demonstrate similar uneven staining patterns, interpreted as being due to the irregular presentation of the epitope of the fibril protein, resulting in a similar staining pattern as contaminating proteins. These workers strongly recommend testing an additional specimen or biopsy to determine the causative fibril protein. In addition, the correlation of immunohistopathological observations and the clinical diagnosis is also mandatory to arrive at the correct classification of the amyloid fibril.
Another problem area is the false-negative detection of amyloid. This can be avoided by increasing the sensitivity of detection by using both immuno- and Congo redstaining methods (RÓken et al, 1996). The latter method of detection is also influenced by the sample quality. It has long been recognized that the diagnostic yield of gastrointestinal biopsies (especially rectal) is extremely high, but should contain submucosa. Other recommended sites include subcutaneous fat, sural nerve, heart, kidney and bone marrow. Whilst AA-amyloidosis is commonly detected in rectal biopsies, any involved organ or tissue is suitable for identification/classification of AL-amyloidosis. Interestingly, a recent study has shown that long-term hemodialysis-associated B2-microglobulin amyloid may also involve the gastrointestinal system in addition to the usual osteoarticular involvement (Shimizu et al, 1997).
The distinction and classification of amyloidosis has major therapeutic implications, as studies have recommended that AL-amyloidosis be treated with cytotoxic drugs (melphalan and prednisolone), whilst AA-amyloidosis responds better to colchicine and dimethylsulfoxide (Kyle et al, 1985; Ravid et al, 1982).
The role of antibodies against amyloid Bprecursor protein has assisted in the diagnosis of Alzheimer's disease (Iwamoto et al, 1997) and early detection of axonal injury (Sherriff et al, 1994) in the brain. Antibodies to transthyretin amyloid protein are useful in the diagnosis of cardiac amyloidosis (Jacobson et al, 1997).
References
•Glenner GG 1980a. Amyloid deposits and amyloidosis. The B-fibrilloses. New England Journal of Medicine 302: 1283-1292.
•Glenner GG 1980b. Amyloid deposits and amyloidosis. The B-fibrilloses. New England Journal of Medicine 302: 1333-1343.
•Iwamoto N, Nishiyama E, Ohwada J, Arai H 1997.
•Distribution of amyloid deposits in the cerebral white matter of the Alzheimer's disease brain: relationship to blood vessels. Acta Neuropathologica (Berlin) 93: 334-340.
•Jacobson DR, Pastore RD, Yaghoubian R et al 1997. Variant-sequence transthyretin (isoleucine 122) in late-onset cardiac amyloidosis in Black Americans. New England Journal of Medicine 336:466-473.
•Kyle RA, Greipp RP, Garton JP et al 1985. Primary systemic amyloidosis: comparison of melphalan/prednisolone versus colchicine. American Journal of Medicine 79: 708-716.
•Lansbury PT Jr 1992. In pursuit of the molecular structure of amyloid plaque: new technology provides unexpected and critical information. Biochemistry 31: 6865-6870.
•Ravid M, Shapiro J, Lang R et al 1982. Prolonged dimethylsulphoxide treatment in 13 patients with systemic amyloidosis. Annals of Rheumatic Diseases 41: 587-592.
•RÓken C, Schwotzer EB, Linke RP, Saeger W 1996. The classification of amyloid deposits in clinicopathological practice. Histopathology 29: 325-335.
•Sherriff FE, Bridges LR, Sivaloganathan S 1994. Early detection of axonal injury after human head trauma using immunocytochemistry for beta-amyloid precursor protein. Acta Neuropathologica (Berlin) 1994; 87: 55-62.
•Shimizu M, Manabe T, Matsumoto T et al 1997. B2 Microglobulin haemodialysis related amyloidosis: distinctive gross features of gastrointestinal involvement. Journal of Clinical Pathology 50: 873-875.
Bibliografia
Manual of diagnostic antibodies for immunohistology / Anthony S.-Y. Leong, Kumarasen Cooper, F. Joel W.-M. Leong.
