Insular Amyloid in a Case of Type HI Glycogenosis with a Special Reference to the Origin of Amyloid Fibrils

Amyloid depositions of pancreatic islets were investigated with electron microscopy in a case of type III glycogenosis.

Beta cells adjoining small amyloid depositions were shown to have cytoplasmic invaginations where closely packed amyloid fibrils were disclosed regularly orientated amyloid bundles. In the cytoplasm of the beta cells, some membrane-bounded vesicles contained amyloid fibrils and a few beta granules directly transformed into the fibrils within the vesicles.

These findings indicate that, at least in this case, the beta cells play a crucial role in the formation of insular amyloid.     

Amyloid formation in insulinoma.

Local amyloid depositions were investigated with electron microscopy in a functioning beta cell adenoma of the pancreas. Beta granule-containing neoplastic cells adjoining small amyloid depositions were shown to have cellular invaginations containing radiating amyloid bundles, indicating the neoplastic cells were involved in the formation of amyloid. Seen in the larger mayloid depositions were attenuated, thin, cellular processes of the neoplastic cells, separating the amyloid stroma into globules. The globular separations of the amyloid correlated well with the light-microscopic globular appearance of amyloid stroma. Possible mechanisms are discussed for the amyloid deposition of insulinoma with relation to amyloidogenesis of other types of amyloidosis.     

Heterogenität des Samenblasenamyloids Immunhistochemischer Nachweis von Lactoferrin und Amyloid vom Präalbumin-Transthyretin-Typ

Zusammenfassung Organlimitierte Amyloidablagerungen in den Samenblasen k?nnen im h?heren Lebensalter auftreten. Die Samenblasenamyloidose konnte bislang keinem bekannten Amyloidtyp zugeordnet werden. In der vorliegenden Studie wurden bei 50 konsekutiven Autopsief?llen von M?nnern über 50 Jahren die Samenblasen histologisch untersucht, um die Inzidenz und den Ph?notyp der Samenblasenamyloidose besser zu charakterisieren. Bei 7 Patienten (14%) wurde eine Samenblasenamyloidose gefunden. Das Amyloid wurde bei diesen Patienten sowie von einem zus?tzlichen Fall histochemisch, immunhistologisch und elektronenmikroskopisch charakterisiert. Die Samenblasenamyloidosen waren bei 6 Patienten (75%) mit geringen Amyloidablagerungen im Herzen kombiniert. Die Samenblasenamyloidosen von 6 Patienten (75%) zeigten eine positive Reaktion mit einem Antik?rper gegen Lactoferrin, einem in den Samenblasen produzierten Glykoprotein. Bei 4 dieser Patienten bestanden gleichzeitig Amyloidablagerungen im Herzen. Bei diesen Ablagerungen handelte es sich jedoch um einen anderen Amyloidtyp (Immunglobulin Leichtkettenamyloid AL-lambda-Typ). In 2 F?llen (25%) wurde in Herz und Samenblasen der gleiche Amyloidtyp (Pr?albumin-Transthyretin-Typ) identifiziert, so da? bei diesen Patienten die Samenblasenamyloidose im Rahmen einer generalisierten Amyloidose aufgetreten ist. Unsere Untersuchungen zeigen, da? die meisten Amyloidablagerungen der Samenblasen organlimitierte Formen sind, die durch Ablagerung von Lactoferrin verursacht werden. Diese Samenblasenamyloidosen sind von einem Begleitbefall im Rahmen einer systemischen senilen Amyloidose abzugrenzen.

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Summary Localized depositions of amyloid in the seminal vesicles may occur in elderly men. Ear-lier immunohistochemical studies have failed to identify immunoreactivity of known amyloid material. In this autopsy study, all seminal vesicles of males older than 50 years were histologically examined to determine incidence and phenotype of seminal vesicle amyloidosis. Seven out of 50 patients (14%) showed depositions of amyloid in the seminal vesicles. These amyloid depositions as well as one additional case were characterized histochemically, immunohistochemically and electronmicroscopically. All but two of these patients (75%) showed simultaneously amyloid depositions in the heart. Lactoferrin immunoreactivity was found in 6 patients (75%). Lactoferrin is an ironbinding, bacteriostatic glycoprotein, which is produced in the seminal vesicles. Four patients with lactoferrin positive amyloid in seminal vesicle showed different amyloid depositions in the heart (immunoglobulin light chain amyloid AL-lambda). Two cases (25%) showed the same amyloid type in heart and seminal vesicles (prealbumin-transthyretin type amyloid). Our study shows that most amyloidoses of the seminal vesicles are organ-limited depositions of lactoferrin. These forms of localized amyloidosis have to be separated from senile systemic amyloidosis with seminal vesicle involvement.

     

Amyloid formation in prolactinoma

Amyloid deposits within a prolactin-secreting pituitary adenoma were investigated with light and electron microscopy. The appearance of amyloid with Congo red revealed amorphous and round green-yellow birefringence under polarized light. Spheroidal concretions disclosed prolactin-positive areas by immunohistochemistry. The amyloid commonly exhibited a structure of fine fibrils of 10 to 13 nm in width, with a hollow core. The fibrils were usually grouped in compact, stout bundles. Some bundles were present in extracellular space, others were obviously within the adenoma cells. Extracellular amyloid fibrils frequently gathered in a stellate arrangement to make a round body. The presence of intracellular amyloid fibrils in adenoma cells may represent that the source of the amyloid is neoplastic cells rather than mesenchymal cells. In addition, prolactin-positive parts in round bodies presumably exemplify that the amyloid fibrils are formed by hormone-relating proteins.     

Amyloid Neuropathy: Relationship between Amyloid Fibrils and Macrophages

A case of amyloid neuropathy associated with a multiple myeloma IgG light chain is reported. Under light microscopy the peripheral nerve exhibited several amyloid deposits. Electron microscopy revealed numerous amyloid deposits; at their periphery, macropha-gic histiocytes were observed, containing a few tufts of parallel fibrils in their cytoplasm. A few plasma cells were scattered in the endoneurium and did not exhibit such a relationship. These findings resemble those recently observed in stem-cell cultures of IgG lambda chain human myeloma.     

An Analysis of the Close Relationship of Lysosomes to Early Deposits of Amyloid: Ultrastructural Evidence in Experimental Mouse Amyloidosis

On the basis of recent morpholgic and biochemical studies which suggested the possible involvement of reticuloendothelial (RE) cells and proteolytic enzymes in amyloidogenesis, the present study was undertaken to examine the ultrastructural interrelationship between lysosomes and amyloid fibrils at the sites of very early amyloid deposition. In the spleen, liver and kidney of the experimental mouse model, foci of amyloid deposits were closely associated with the RE cells. The lysosomal enzyme activity, as marked by cytochemical demonstration of acid glycerophosphatase activity, was localized in the primary type lysosomes (as defined by their electron microscopic appearance), in the Golgi complexes, in the small cytoplasmic vesicles and occasionally widespread in the cytoplasm. They showed an intimate relationship to the amyloid fibrils. The findings were interpreted as favoring the hypothesis that the hydrolases play a role in amyloid fibril formation. The enzyme activity was also demonstrated in the secondary type lysosomes which occasionally contained amyloid fibrils that appeared to be phagocytized.     

Amyloid in surgical pathology

Amyloid is defined as a proteinaceous tissue deposit that shows a typical green birefringence in polarized light after staining with Congo red, the presence of non-branching linear fibrils of indefinite length with a mean diameter of 10 nm, and a distinct X-ray diffraction pattern consistent with Pauling's model of a cross -fibril. Amyloid may deposit locally or may present as a systemic disease. The origin of amyloid is diverse: 25 different fibril proteins have been described so far. The precursor proteins differ from each other in their primary structures and functions. The only common denominator is the propensity to form anti-parallel cross -fibrils under certain circumstances. Early diagnosis of amyloid is still a major challenge in surgical pathology. Histological proof can be obtained using Congo-red staining and polarization microscopy. However, small deposits may be difficult to discern, and sensitivity can be improved using fluorescence microscopy. Classification of amyloid is mandatory, since amyloid is treatable and different treatment regimens are applied to different amyloid diseases. This review focuses on the epidemiology, clinical features, pathology and diagnosis of amyloid in surgical pathology.     

Localized Primary Amyloid Tumor of the Thyroid Developing in the Course of Hashimoto's Thyroiditis

A case of localized primary amyloid tumor of the thyroid gland developing in the course of Hashimoto's thyroiditis was studied using histochemistry, immunohistochemistry and electron microscopy. The patient was diagnosed as having Hashimoto's thyroiditis by histological examination of the thyroid and by the presence of a high titer of serum thyroglobulin and thyroid microsomal antibodies. In addition, the thyroid gland exhibited multiple nodular deposits of amyloid which were resistant to prior incubation with potassium permanganate. The amyloid deposits were surrounded by numerous histiocytes and multinucleated giant cells which contained small amyloid droplets in their cytoplasm. However, no amyloid deposits were observed in the walls of blood vessels. lmmunohistochemistry showed that the amyloid was strongly positive for amyloid P component, IgG and kappa light chains. Ultrastructurally, the amyloid was composed of straight fibrils with a diameter of 7 to 10 nm. Histiocytes extended slender cytoplasmic processes in a radial fashion into amyloid fibrils, which exhibited a highly organized star-like pattern. This was considered to be an extremely rare case of localized primary amyloidosis of the thyroid, in which IgG, especially kappa light chains (AL), was present as a precursor protein. Acta Pathol Jpn 42: 210–216. 1992.     

Glycosaminoglycans in Extracts of Cardiac Amyloid Fibrils from Familial Amyloid Cardiomyopathy of Danish Origin Related to Variant Transthyretin Met 111

We have previously demonstrated an association between secondary AA type amyloid fibrils and glycosaminoglycans (GAGs) in human liver. The present study was aimed at investigating whether a similar association could be demonstrated in isolated cardiac amyloid fibrils from a unique Danish family with amyloid cardiomyopathy related to variant transthyretin (TTR) with a single amino acid substitution of a methionin for leucine at position 111 (TTR Met 111). Using gel filtration and ion exchange chromatography, significant amounts of GAGs were detected in close association with purified myocardial amyloid fibrils, whereas only trace amounts of polysaccharides were present in the corresponding normal preparation. The GAGs were identified as 50% chondroitin sulfate, 33% heparin/heparan sulfate, and 17% hyaluronan. With the methods used the amyloid associated GAGs appeared as high molecular weight free polysaccharide chains, and not as part of intact proteoglycans (PGs) in the fibril extracts. We conclude that the association between purified amyloid fibrils and GAGs may be a general feature of amyloid deposits. Also, we suggest that the proportion of different GAGs in the amyloid deposits may depend both on the organ or tissues affected and the type of proteins making up the fibrils.     

Seminal vesicle amyloid: the first example of exocrine cell origin of an amyloid fibril precursor.

Amyloid fibrils have been extracted from seminal vesicles, and a dominant 14 kD amyloid fibril protein has been identified. An antiserum to this protein reacted both with amyloid and with epithelial cells in some normal seminal vesicles. These reactions were blocked with seminal vesicle secretion and seminal vesicle amyloid fibril protein, but not by degraded amyloid fibrils or fibril protein from other types of amyloid. It is concluded that seminal vesicle amyloid is derived from secretory proteins of the seminal vesicles. As such, it is the first amyloid described which appears to be the product of an exocrine secretory cell.     

Immunohistochemical, Electron Microscopic, and Immunoelectron Microscopic Features of Plasmacytoma of the Thyroid with Amyloid Deposition

A rare case of primary plasmacytoma of the thyroid with amyloid deposition is reported. The tumor consisted of diffuse proliferation of atypical plasma cells showing IgG lambda-type monoclonal growth. Amyloid deposition with focal giant cell reaction was also observed. Bone marrow aspiration and systemic skeletal radiographic surveys revealed no evidence of multiple myeloma and myelomatosis. Radial arrangement of amyloid bundles was observed ultrastructurally. By immunoelectron microscopic examination, δ chain was detected in the amyloid fibrils and rough endoplasmic reticulum of the tumor cells. Our findings suggest the following: amyloid fibrils originate from monoclonal light chains produced by tumor cells, and histiocytes contribute to amyloid deposition as well as to giant cell reaction in extramedullary plasmacytoma.     

Central Nervous System Pathology of Tuberous Sclerosis in Children

Ten cases of tuberous sclerosis involving the central nervous system (CNS) in children aged 2 days to 15 years were studied. The abnormal cells found in subependymal, cortical, and white matter lesions were examined by light and electron microscopy. Histochemistry and immunohistochemistry were also employed. The results were similar in all lesions. Approximately one-third of the abnormal cells were positive by glial fibrillary acidic protein (GFAP), one-half by Nissl, and one-quarter by Holzer's stains. The intensity and pattern of GFAP staining varied from cell to cell and could not be predicted before staining.

Ultrastructurally the cytoplasm of abnormal cells contained moderate to large numbers of 9-to 12-nm diameter fibrils and frequent dense bodies with crystalline appearance. Stacked rough endoplasmic reticulum was variable. Cell junctions and glycogen were rare. Nuclei were usually vesicular with a prominent nucleolus.

Individual cells of tuberous sclerosis have features of both neurons and astrocytes. The disease may affect cells before differentiation. The predominant abnormal features of the cells in tuberous sclerosis are a great increase in fibrils and the presence of dense bodies, which may be a nonspecific reaction or result from a metabolic defect affecting the cells.     

Amyloid fibril proteins

Amyloidosis refers to a group of protein folding diseases. Various innocuous and soluble proteins in physiological conditions polymerize to insoluble amyloid fibrils in several serious diseases, including Alzheimer's disease (AD) and prion diseases. In addition, senile amyloidosis is a form of amyloidosis in which the incidence and severity of amyloid deposition increases with age without any apparent predisposing conditions and it was thought that the amyloidosis was related to some physiological changes which accompany ageing. Although the etiology and pathogenesis of amyloid disease are not fully understood, drastic structural changes of the amyloid proteins from the normal forms to the unique beta-sheet fibrils is the most important event in amyloid diseases. The present article introduces the three amyloid diseases, AD, prion diseases and mouse senile amyloidosis in which Abeta, PrP(Sc) and AApoAII amyloid fibrils deposit respectively. We discuss the nucleation dependent polymerization model as a model that explains the kinetics of fibrillization of these amyloid proteins. Exogenous amyloid fibrils may act as templates (nuclei) and change the conformation of endogenous amyloid protein to polymerize into amyloid fibrils. This hypothesis makes the boundary between transmissible and non-transmissible amyloidosis ambiguous and proposes the common pathogenesis for them.     

Human Osteogenic Sarcoma: Fine Structural Localization of Adenosine Triphosphatase

The localization of ATPases in 7 osteogenic sarcomas of osteoblastic, chondroblastic and fibroblastic type was investigated at the fine structural level using two types of substrates: one with lead as capturing ion and one with strontium (the latter presumed to reveal sites of Na⁺-K⁺-dependent transport ATPase).

Reaction product with the lead-ATP medium was located on the plasma membrane and the membranes bordering subjacent vesicles and vacuoles in all the various types of osteoblastlike and fibroblastlike cells and also in types 1 and 3 chon-droblastlike cells, and multinucleated giant cells believed to be neoplastic. Furthermore, deposits of reaction product were demonstrated in lysosome-like organelles in all the aforementioned cells. Except in the case of chondroblastlike cells, precipitates marking the localization of enzyme were confined to areas of the plasma membrane where adjacent cells were closely applied (the free surface lacked precipitates). In chondroblastlike cells the reaction product was usually deposited along the whole plasma membrane. Presence of L-Homoarginine or L-Tetramisole in the incubation medium in concentrations that have been shown to completely abolish alkaline phosphatase activity did not affect the occurrence of the reaction product with ATP as substrate indicating that the enzyme hydrolysing ATP was substrate-specific.

Reaction product marking sites of Na⁺-K⁺-dependent ATPase was confined to plasma membranes and lysosomes of cells in vessel walls.

The observations strengthen the notion obtained in studies on the localization of alkaline phosphatase, namely that osteoblastlike, chondroblastlike, and fibroblastlike cells in osteogenic sarcomas are histogenetically related to one another and to those multinucleated giant cells that presumably are of a neoplastic nature.     

Amyloid fibril formation in the rough endoplasmic reticulum of plasma cells from a patient with localized A lambda amyloidosis

Evidence for amyloid fibril formation in rough endoplasmic reticulum (RER) of plasma cells from the duodenum of a 62-year-old man with localized A lambda amyloidosis is described. The inclusions in RER of plasma cells were composed of tightly packed, regular arrays of fibrils cut in both longitudinal and cross-sections. The fibrils within the inclusions, measuring 10 nm in width, were oriented parallel to the long axis of the inclusions. By immunoelectron microscopy with an antihuman A lambda antiserum, gold particles labeled the fibrils located both in the RER of plasma cells and in the extracellular space. In addition, electron-dense material in the dilated RER was occasionally labeled. These findings suggest that at least some amyloid fibrils are unequivocally created in the RER of plasma cells.     

Multinodular Deposition of AA-type Amyloid Localized in the Adrenal Glands of an Old Man

Multinodular amyloid deposits localized in non neoplastic adrenal glands were found incidentally at autopsy in an 83-year-old Japanese man. Clinically, the patient lacked evident deficiency of adrenal hormones. The nodules of the stromal amyloid deposits were scattered in the adrenal cortex, where the parenchymal cells were compressed and atrophic. The deposits were confirmed to be amyloid by Congo red staining and polarization microscopy. Amyloid fibrils were also demonstrated in the deposits by electron microscopy. The amyloid deposits were permanganate-sensitive and showed immunohistochemical staining for serum amyloid P component and serum amyloid A protein (SAA), implying that they were AA amyloid. There have been no reports describing localized amyloid deposits of the AA type in non neoplastic adrenal glands. The patho-genesis and clinical significance of the amyloid deposition in the present case remain only speculative. Acta Pathol Jpn 42: 893–896, 1992.     

Beta amyloid is focally deposited within the outer basement membrane in the amyloid angiopathy of Alzheimer''s disease. An immunoelectron microscopic study.

The fine structure of cerebral amyloid angiopathy, especially in small and presumably early deposits, was examined by immunolabeling of the beta/A4 protein in semithin and ultrathin sections from brains with Alzheimer's disease. The following findings emerged: 1) in large leptomeningeal arteries, small, focal amyloid deposits appear to consist of clusters of delicate (approximately 8 nm diameter) amyloid fibrils, not previously described, in the outermost part of the basement membrane (BM) at the media-adventitia junction; 2) in small leptomeningeal arteries and perforating cortical arterioles, small foci of delicate amyloid fibrils were observed within the BM. They appeared mostly in the outer portion of the BM, around intact smooth muscle cells, rather than in the subendothelial region. In larger and presumably more advanced deposits, coarse amyloid fibrils (approximately 10 nm) occupied the abluminal BM, and adjacent smooth muscle cells showed degeneration; and 3) in capillaries, small amounts of delicate (approximately 8 nm) amyloid fibrils, not previously described, were seen within the BM in the smallest discernible deposits. The BM at these sites was abnormally folded and layered. In larger deposits, amyloid fibrils appeared to extravasate from the outer BM of the capillary into the neuropil and were surrounded by astrocytic foot processes and/or microglia. Our results suggest that vascular amyloid fibrils may first be formed within the abluminal vascular BM, that is, outside of cells. The BM may trap degradative intermediates of the amyloid precursor protein that contain the beta/A4 region, and local proteases may then cleave them further to yield amyloidogenic fragments.     

Association of Microglia with Amyloid Plaques in Brains of APP23 Transgenic Mice

Microglia are a key component of the inflammatory response in the brain and are associated with senile plaques in Alzheimer's disease (AD). Although there is evidence that microglial activation is important for the pathogenesis of AD, the role of microglia in cerebral amyloidosis remains obscure. The present study was undertaken to investigate the relationship between beta-amyloid deposition and microglia activation in APP23 transgenic mice which express human mutated amyloid-beta precursor protein (betaPP) under the control of a neuron-specific promoter element. Light microscopic analysis revealed that the majority of the amyloid plaques in neocortex and hippocampus of 14- to 18- month-old APP23 mice are congophilic and associated with clusters of hypertrophic microglia with intensely stained Mac-1- and phosphotyrosine-positive processes. No association of such activated microglia was observed with diffuse plaques. In young APP23 mice, early amyloid deposits were already of dense core nature and were associated with a strong microglial response. Ultrastructurally, bundles of amyloid fibrils, sometimes surrounded by an incomplete membrane, were observed within the microglial cytoplasm. However, microglia with the typical characteristics of phagocytosis were associated more frequently with dystrophic neurites than with amyloid fibrils. Although the present observations cannot unequivocally determine whether microglia are causal, contributory, or consequential to cerebral amyloidosis, our results suggest that microglia are involved in cerebral amyloidosis either by participating in the processing of neuron-derived betaPP into amyloid fibrils and/or by ingesting amyloid fibrils via an uncommon phagocytotic mechanism. In any case, our observations demonstrate that neuron-derived betaPP is sufficient to induce not only amyloid plaque formation but also amyloid-associated microglial activation similar to that reported in AD. Moreover, our results are consistent with the idea that microglia activation may be important for the amyloid-associated neuron loss previously reported in these mice.     

The Amyloid P-Component (Protein AP): an Integral Part of the Amyloid Substance?

The P-component of amyloid (protein AP) appears to be present in all types of amyloid substance regardless of the clinical category of amyloidosis or the chemical class of the amyloid fibril. The role of protein AP in the formation of amyloid substance has not been established. In a patient with primary amyloidosis, significant amounts of protein AP were found closely associated with the amyloid fibril proteins and was released from the latter only after dissociation and reduction of the amyloid fibril preparation. EDTA seemed to be very effective in releasing protein AP, and it is thought that the close association between the amyloid fibrils and protein AP is calcium-dependent. The very close association between the amyloid fibrils and protein AP suggests that the latter is an integral part of the amyloid substance.     

Amyloid of human islets of Langerhans

Summary Isolated amyloid from the islets of Langerhans of patients with maturity onset diabetes mellitus was compared with amyloid fibrils from patients with different types of systemic amyloidosis. It was found that systemic amyloids had in common rigid and non-branching filaments with a width of about 75 å and that these filaments sometimes were attached laterally, forming thicker fibrils. Similar filaments could also be extracted from islet amyloid but the main part of this amyloid was built up by large aggregates of very thin and often very wavy units. This structure, which has not been previously described in human amyloid, probably explains some properties of isolated islet amyloid.Supported by the Swedish Medical Research Council (Project No. 102) and Nordisk Insulinfond. Thanks are due to Anni Bedy and Cristina Bittkowski for skilled technical assistance