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Objective: Hereditary transthyretin-mediated amyloidosis is a treatable condition caused by amyloidogenic variants in the transthyretin-gene resulting in severe peripheral neuropathy or cardiomyopathy. Only about a third of over 130 known variants are clearly pathogenic, most are classified as variants of uncertain significance. A clear delineation of these into pathogenic or non-pathogenic is highly desirable but hampered by low frequency and penetrance. We thus sought to characterize their amylogenic potential by an unbiased in vitro approach., Methods: Thioflavin T and turbidity assays were used to compare the potential of mammalian cell expressed wt-transthyretin and 12 variant proteins (either variants of uncertain significance, benign, pathogenic) to aggregate and produce amyloid fibrils in vitro. As proof of principle, the assays were applied to transthyretin-Ala65Val, a variant that was newly detected in a family with peripheral neuropathy and amyloid deposits in biopsies. In silico analysis was performed to compare the position of the benign and pathogenic variants., Results: Transthyretin-Ala65Val showed a significantly higher amyloidogenic potential than wt-transthyretin, in both turbidity- and Thioflavin T-assays, comparable to known pathogenic variants. The other eight tested variants did not show an increased amyloidogenic potential. In silico structural analysis further confirmed differences between pathogenic and benign variants in position and interactions., Interpretation: We propose a biochemical approach to assess amyloidogenic potential of transthyretin variants. As exemplified by transthyretin-Ala65Val, data of three assays together with histopathology clearly demonstrates its amyloidogenicity., (© 2022 The Authors. Annals of Clinical and Translational Neurology published by Wiley Periodicals LLC on behalf of American Neurological Association.)

A high prevalence of AA-amyloidosis was identified in a breeding colony of northern tree shrews ( Tupaia belangeri ) in a retrospective analysis, with amyloid deposits in different organs being found in 26/36 individuals (72%). Amyloid deposits, confirmed by Congo red staining, were detected in kidneys, intestines, skin, and lymph nodes, characteristic of systemic amyloidosis. Immunohistochemically, the deposited amyloid was intensely positive with anti-AA-antibody (clone mc4), suggesting AA-amyloidosis. The kidneys were predominantly affected (80%), where amyloid deposits ranged from mild to severe and was predominantly located in the renal medulla. In addition, many kidneys contained numerous cysts with atrophy of the renal parenchyma. There was no significant association between concurrent neoplastic or inflammatory processes and amyloidosis. The lack of distinctive predisposing factors suggests a general susceptibility of captive T. belangeri to develop amyloidosis. Clinical and laboratory findings of a female individual with pronounced kidney alterations were indicative of renal failure. The observed tissue tropism with pronounced kidney alterations, corresponding renal dysfunction, and an overall high prevalence suggests amyloidosis as an important disease in captive tree shrews.

Nine cases of amyloidosis in caracals ( Caracal caracal ) from three different institutions in Europe were reviewed and evaluated histopathologically. The six males and three females died between 2008 and 2018 at an age of 6 yr ± 2.5 mo (median ± interquartile range). In two out of nine (2/9) animals, amyloidosis was an incidental postmortem finding; the animals died of bronchopneumonia and gastric ulceration due to Helicobacter spp., respectively. Seven (7/9) animals suffered from acute renal failure due to amyloidosis, one of them additionally of cardiac decompensation. The predominant clinical signs were weight loss, lethargy, dys- or anorexia, dehydration, increased BUN and creatinine, and azotemia. The main gross lesion was a pale renal cortex on cut surface; in two animals, the kidneys appeared enlarged. Histologically, glomerular amyloid was present in every animal (9/9), and was the predominant renal manifestation of amyloidosis. Additional findings included splenic amyloid (8/8), amyloid in the lamina propria of the intestine (5/5), and amyloid in the lingual submucosa (4/4). Gastric mineralization was present in four animals suffering from renal failure. In the animal dying from bronchopneumonia, severe pancreatic amyloid deposits mainly affecting the exocrine pancreas (1/5) were identified. Immunohistochemistry was employed to identify amyloid AA in eight cases; only in the caracal dying from bronchopneumonia AA was amyloid confirmed. In several organs, especially in those where only small amyloid deposits were detected, a Congo red stain was often necessary to confirm the deposition. The etiology of the amyloidosis remains unknown. Three caracals were related within two generations, another three within four generations, so one might hypothesize a familial trait. In conclusion, amyloidosis should be considered as a significant disease in the caracal. Particularly in cases with renal disease, it should be included as a major differential diagnosis.

Aims: To evaluate the influence of endomyocardial biopsy (EMB)-proven intramyocardial inflammation on mortality in patients with cardiac transthyretin amyloid (ATTR) or amyloid light-chain (AL) amyloidosis., Methods and Results: We included 54 consecutive patients (mean age 68.83 ± 9.59 years; 45 men) with EMB-proven cardiac amyloidosis. We followed up patients from first diagnostic biopsy to as long as 36 months (mean 11.5 ± 12 months) and compared their outcome with information on all-cause mortality with or without proof of inflammation on EMB. Intramyocardial inflammation was assessed by quantitative immunohistology. Patients suffering from amyloidosis revealed a significant poor prognosis with proof of intramyocardial inflammation in contrast to those without inflammation (log-rank P = 0.019). Re-grouping of patients indicated AL amyloidosis to have a significant impact on all-cause mortality (log-rank P = 0.012). The detailed subgroup analysis showed that patients suffering from AL amyloidosis with intramyocardial inflammation have a significantly worse prognosis compared with AL amyloidosis without inflammation and ATTR with or without inflammation, respectively (log-rank P = 0.014, contingency Fisher's exact test, P = 0.008)., Conclusion: Our study reports for the first time a high incidence (48.1%) of intramyocardial inflammation in a series of patients with EMB-proven cardiac amyloidosis and could show that in patients with AL amyloidosis, intramyocardial inflammation correlated significantly with increased mortality. Our data have a direct clinical impact because one can hypothesize that additional immunomodulating/anti-inflammatory treatment regimens in patients with biopsy-proven inflammation of heart muscle tissue could be beneficial for patients suffering from cardiac AL amyloidosis., (© 2017 The Authors. European Journal of Heart Failure © 2017 European Society of Cardiology.)

A 54-year-old man presented with protein-losing enteropathy. Biopsies from the stomach, duodenum, ileum and colon showed deposits of amyloid. The bone marrow showed plasmacytosis. After an initial misdiagnosis of AA amyloid, a revised diagnosis of ALκ amyloidosis was made at an expert referral laboratory. Care must be taken in the use of antibodies and proper controls in the performance and interpretation of immunohistochemistry for amyloidosis. A wide panel of amyloid-type-specific antibodies must be used and interpreted in comparative mode to avoid misdiagnosis., (Copyright 2015, NMJI.)

Background: Serum amyloid A (SAA) is an acute phase protein expressed primarily in the liver in response to various injuries and inflammatory stimuli and is recognized as a modulator of inflammation. Ovarian reproductive functions including folliculogenesis and ovulation use inflammatory processes; thus, studying SAA in this context is of interest., Objectives: We investigated the expression and localization of SAA in ovarian developing follicles and its levels in follicular fluids., Methods and Participants: Nonradioactive in situ hybridization and immunohistochemical staining were applied on ovarian paraffin tissue sections. ELISA and RT-PCR were applied on follicular aspirates and blood samples from women undergoing controlled ovarian stimulation for in vitro fertilization., Results: Expression of SAA mRNA and protein was found in follicular cells at all stages of follicular development, from primordial and primary follicles through antral follicles and corpora lutea. Expression was observed in granulosa, theca and luteal cells, and oocytes. Expression of SAA was also found in granulosa cells recovered from follicular aspirates. The SAA protein was detected in follicular fluids. Its levels were somewhat lower than in peripheral blood with strong correlation between the two compartments and with significant correlation with patient's body mass index. High follicular fluid SAA levels were associated with reduced pregnancy rate., Conclusions: SAA is locally produced in ovarian developing follicles and is a constituent of follicular fluids, suggesting its role within the follicular environment. Elevated follicular SAA levels are associated with decreased pregnancy rate and may signify lower reproductive performance.

Background: Treatment options in patients with amyloidotic transthyretin (ATTR) cardiomyopathy are limited. Epigallocatechin-3-gallate (EGCG), the most abundant catechin in green tea (GT), inhibits fibril formation from several amyloidogenic proteins in vitro. Thus, it might also halt progression of TTR amyloidosis. This is a single-center observational report on the effects of GT consumption in patients with ATTR cardiomopathy., Methods: 19 patients with ATTR cardiomyopathy were evaluated by standard blood tests, echocardiography, and cardiac MRI (n = 9) before and after consumption of GT and/or green tea extracts (GTE) for 12 months., Results: Five patients were not followed up for reasons of death (n = 2), discontinuation of GT/GTE consumption (n = 2), and heart transplantation (n = 1). After 12 months no increase of left ventricular (LV) wall thickness and LV myocardial mass was observed by echocardiography. In the subgroup of patients evaluated by cardiac MRI a mean decrease of LV myocardial mass (-12.5 %) was detected in all patients. This was accompanied by an increase of mean mitral annular systolic velocity of 9 % in all 14 patients. Total cholesterol (191.9 ± 8.9 vs. 172.7 ± 9.4 mg/dL; p < 0.01) and LDL cholesterol (105.8 ± 7.6 vs. 89.5 ± 8.0 mg/dL; p < 0.01) decreased significantly during the observational period. No serious adverse effects were reported by any of the participants., Conclusions: Our observation suggests an inhibitory effect of GT and/or GTE on the progression of cardiac amyloidosis. We propose a randomized placebo-controlled investigation to confirm our observation.

The molecular investigation of the amyloidoses began in the mid-19th century with the observation of areas in human tissues obtained at autopsy that were homogeneous and eosinophilic with conventional stains but became blue when exposed to mixtures of iodine and sulfuric acid. The foci corresponded to regions formerly identified as "waxy" or lardaceous. Subsequent identification of the characteristic staining of the same tissues with metachromatic dyes such as crystal violet or with the cotton dye Congo red (particularly under polarized light) and thioflavins allowed the pathological classification of those tissues as belonging to a set of disorders known as the amyloidoses. Not unexpectedly, progress has reflected evolving technology and parallel advances in all fields of biological science. Investigation using contemporary methods has expanded our notions of amyloid proteins from being simply agents or manifestations of systemic, largely extracellular diseases to include "protein-only infection," the concept that "normal" functional amyloids might exist in eukaryotes and prokaryotes and that aggregatability may be an intrinsic structural price to be paid for some functional protein domains. We now distinguish between the amyloidoses, that is, diseases caused by the deposition of amyloid fibrils and amyloid proteins (i.e., purified or recombinant proteins that form amyloid fibrils in vitro), which may or may not be associated with disease in vivo., (Copyright © 2012 Elsevier Ltd. All rights reserved.)

Every amyloid disease needs to be assessed for chemical composition of its amyloid because amyloid is pathogenetically diverse and each of the chemical amyloid types requires a different therapy. Basically four different approaches are being applied for typing of amyloid using immunohistochemistry, immunochemistry, mass spectrometry and chemistry. It is shown here how an easy immunohistochemical procedure has been developed over the years that can be used to classify specifically amyloid proteins for clinico-pathologic routine use. A larger number of tissues with chemically or immunochemically typed amyloids served as prototypes for developing a set of validated amyloid antibodies. These were examined for their performance to classify a larger number of tissues of patients submitted to us and other institutions allowing independent evaluation. The data reveal that out of 663 patients, including 15 different amyloid types, all 119 prototype Amyloids (100%) have been classified correctly and 97.9% of consecutive 581 unknown amyloid tissues submitted for typing to our laboratory of whom 37 became later prototypes. Twelve samples (2.1%) could not be classified. By using appropriate amyloid antibodies in a comparative manner, this procedure is accurate. It identifies the respective amyloid type and excludes simultaneously other amyloids. Its improved performance leads to an accurate amyloid diagnosis in most cases and provides a diagnostic marker which is independend of any other information for therapeutic considerations. These results can be obtained within a day in institutes competent in performing immunohistochemistry. This is the first report on immunhistochemical typing of amyloid providing detailed illustrations of the original results for training purposes. When the immunohistochemical method presented here was compared with mass spectrometry, a more recent method for amyloid typing, the advantages and failures of both methods became apparent in an international blinded comparison., (Copyright © 2012 Elsevier GmbH. All rights reserved.)

Fibrinogen A α-chain (AFib) and apolipoprotein AI (AApoAI) amyloidosis due to variants in the AFib and ApoAI genes are the most common types of hereditary amyloidosis in Europe and the United States. Liver is the exclusive source of the aberrant amyloidogenic protein in AFib and responsible for supplying approximately half of the circulating variant ApoAI. Nephrotic syndrome and renal impairment due to renal amyloidosis are common disease manifestations; however, recent research provides evidence to support a more diverse and systemic disease phenotype, which in turn has implications in the management of the hereditary amyloidoses with solid organ transplantation and, in particular, liver transplantation.

This report describes a case of systemic amyloidosis in a captive striped skunk. At necropsy, bilateral alopecia, as well as reno-, hepato-, and splenomegaly were present. Congo red staining and immunohistochemistry revealed depositions of AA-amyloid in different organs. The lack of a predisposing disease is suggestive of idiopathic systemic AA-amyloidosis.

An 11-year-old, neutered male domestic short-hair cat was presented with buphthalmos of the right eye and diagnosed with advanced glaucoma. Sonographic examination revealed an iridial thickening. Neoplasia was suspected and an enucleation was performed. Histopathology of the enucleated eye revealed abundant amyloid deposition predominantly in the anterior uveal tract accompanied by few to moderate numbers of well-differentiated plasma cells. The amyloid deposits were identified by staining with Congo red and showing green birefringence under polarized light. Immunohistochemically, amyloid and plasma cells stained intensely only with anti-ALλ antibody, supporting the amyloid tumor being an immunoglobulin-λ-light chain origin. Additional abnormalities included narrowing of the filtration angle and collapse of the ciliary cleft, and trabecular meshwork. One year post-enucleation, the cat was still healthy without signs of systemic amyloidosis or apparent metastatic disease. This is the first report of a cat with noncutaneous extramedullary plasmacytoma originating in the anterior uveal tract with resulting local amyloid., (© 2011 American College of Veterinary Ophthalmologists.)

Serum amyloid A (SAA) is an acute phase protein which is expressed primarily in the liver as a part of the systemic response to various injuries and inflammatory stimuli; its expression in ovarian tumors has not been described. Here, we investigated the expression of SAA in human benign and malignant ovarian epithelial tumors. Non-radioactive in situ hybridization applied on ovarian paraffin tissue sections revealed mostly negative SAA mRNA expression in normal surface epithelium. Expression was increased gradually as epithelial cells progressed through benign and borderline adenomas to primary and metastatic adenocarcinomas. Similar expression pattern of the SAA protein was observed by immunohistochemical staining. RT-PCR analysis confirmed the overexpression of the SAA1 and SAA4 genes in ovarian carcinomas compared with normal ovarian tissues. In addition, strong expression of SAA mRNA and protein was found in the ovarian carcinoma cell line OVCAR-3. Finally, patients with ovarian carcinoma had high SAA serum levels, which strongly correlated with high levels of CA-125 and C-reactive protein. Enhanced expression of SAA in ovarian carcinomas may play a role in ovarian tumorigenesis and may have therapeutic application.

Acute-phase proteins (APPs) are an evolutionarily conserved family of proteins produced mainly in the liver in response to infection and inflammation. Despite vast pro- and antiinflammatory properties ascribed to individual APPs, their collective function during infections remains poorly defined. Using a mouse model of polymicrobial sepsis, we show that abrogation of APP production by hepatocyte-specific gp130 deletion, the signaling receptor shared by IL-6 family cytokines, strongly increased mortality despite normal bacterial clearance. Hepatic gp130 signaling through STAT3 was required to control systemic inflammation. Notably, hepatic gp130-STAT3 activation was also essential for mobilization and tissue accumulation of myeloid-derived suppressor cells (MDSCs), a cell population mainly known for antiinflammatory properties in cancer. MDSCs were critical to regulate innate inflammation, and their adoptive transfer efficiently protected gp130-deficient mice from sepsis-associated mortality. The hepatic APPs serum amyloid A and Cxcl1/KC cooperatively promoted MDSC mobilization, accumulation, and survival, and reversed dysregulated inflammation and restored survival of gp130-deficient mice. Thus, gp130-dependent communication between the liver and MDSCs through APPs controls inflammatory responses during infection.

Introduction: The prevalence, pathophysiology, and clinical indicators of valvular amyloid deposition have not been clarified yet., Methods: One hundred fifty surgically resected heart valve specimens [67.4+/-1.0 years; aortic stenosis (AS), n=100; aortic regurgitation, n=19; mitral stenosis, n=7; mitral regurgitation, n=24] were qualitatively, semiquantitatively, and immunohistochemically analyzed and correlated with clinical data., Results: Amyloid was found in 83/150 specimens with highest prevalence in AS (74/100), intermediate prevalence in mitral stenosis (2/7) and regurgitation (7/24), and lowest prevalence in aortic regurgitation (2/19). Severe and polymorphic amyloid deposits were almost exclusively found in AS (35/100). Filamentous cloudy amyloid patterns occurred with the same frequency in AS (29/100). A combination of both was found only in AS (n=7/100). By immunohistochemistry, none of the most common amyloid proteins was identified except for a weak staining by the apolipoprotein AI antibody, but more intense adjacent to amyloid deposits. Amyloid correlated with valvular thickening (P<.05), hyperlipidemia (P=.07), coronary artery disease (P=.084), and obesity (P=.082)., Conclusions: Localized valvular amyloid is predominantly found in stenotic aortic valves. It appears to depend on atheroinflammatory conditions and high shear-stress hemodynamics. Further studies are needed to identify the underlying protein.

Liver transplantation (LT) is the only curative option for patients with familial amyloid polyneuropathy (FAP) at present. Twenty patients with FAP underwent LT between May 1998 and June 2007. Transthyretin mutations included predominantly the Val30Met mutation but also 10 other mutations. Seven patients received a pacemaker prior to LT, and because of impairment of mechanical cardiac function, 4 combined heart-liver transplants were performed, 1 simultaneously and 3 sequentially. The first patient, who underwent simultaneous transplantation, died. Seven patients died after LT, with 5 dying within the first year after transplantation. The causes of death were cardiac complications (4 patients), infections (2 patients), and malnutrition (1 patient). One-year survival was 75.0%, and 5-year survival was 64.2%. Gly47Glu and Leu12Pro mutations showed an aggressive clinical manifestation: 2 patients with the Gly47Glu mutation, the youngest patients of all the non-Val30Met patients, suffered from severe cardiac symptoms leading to death despite LT. Two siblings with the Leu12Pro mutation, who presented only with grand mal seizures, died after LT because of sepsis. In conclusion, the clinical course in patients with FAP is very variable. Cardiac symptoms occurred predominantly in patients with non-Val30Met mutations and prompted combined heart-liver transplantation in 4 patients. Although early LT in Val30Met is indicated in order to halt the typical symptoms of polyneuropathy, additional complications occurring predominantly with other mutations may prevail and lead to life-threatening complications or a fatal outcome. Combined heart-liver transplantation should be considered in patients with restrictive cardiomyopathy.

Slowly progressing subcutaneous nodules all over the body were detected in 1994 in an otherwise healthy, now 66-year-old woman (UNK). A first biopsy was taken 10 years ago and revealed amyloid. Immunohistochemistry was suggestive for ALkappa. From a nodular excisate, performed in the same year for cosmetic reasons, amyloid fibrils were extracted. Protein separation according to their size revealed multiple protein fragments below the MW of an intact kappa-light chain. They were identified as kappa-fragments by Western blotting. The kappa-fragments were cleaved into overlapping peptides using tryptic, N-Asp and chymotryptic digests. Peptides were sequenced by Edman-degradation and mass spectrometry. The complete amino acid sequence of the variable region and most of the constant region of ALkappa (UNK) was identified in various fragments comprising positions 1 to 207 of a monoclonal kappa(I)-light chain. Four novel and several rare amino acid exchanges have been identified as compared to 17 amyloidogenic and >100 non-amyloidogenic kappa(I)-sequences published, leading to increased hydrophobicity of ALkappa (UNK). Sequence analysis of C-region peptides allowed one to determine the kappa-allotype as being invb(+). A rabbit antibody was produced against ALkappa(I) (UNK). It strongly reacted with amyloid on formalin-fixed paraffin embedded tissue sections of the same patient and detected ALkappa-amyloid of many other patients. In contrast, antibodies produced against kappaBJP of subclasses kappa(I)-kappa(IV) failed to label ALkappa (UNK) amyloid deposits. The patient continues to be free of systemic disease, already for 14 years until today.

Amyloidosis occurs when certain soluble proteins are transformed into amyloid fibrils in the extracellular space. Most common are the light-chain amyloidoses; less common is the AA-amyloidosis, which follows chronic inflammatory diseases, and the amyloidoses of transthyretin (TTR) origin. We report on a women of Italian-German origin with the mutation TTR (Ser23Asn). Whole body scintigraphy using TC99m-DPD showed end stage hereditary amyloidosis caused by ATTR with predominant tracer retention in the myocardium. Myocardial biopsies revealed the presence of amyloid by Congo red staining. Further immunohistochemical analysis showed ATTR amyloidosis. DNA sequencing revealed a point mutation of the transthyretin gene leading to a single amino acid substitution. The only effective treatment in patients with manifest cardiac ATTR amyloidosis is combined heart and liver transplantation. Our patient was placed on a list for this procedure, but unfortunately she died during the standby procedure due to urosepsis.

We identified amyloid derived from a mutant fibrinogen A alpha chain associated with one of the hereditary amyloidoses by kidney biopsy. The recognition of molecular and etiologic diversity among amyloidoses has revolutionized the management of systemic amyloidosis and necessitates precision in amyloid typing. Pitfalls and recommendations for the differential diagnosis of renal amyloid and current standards of amyloid typing are briefly discussed. Diagnosis of the amyloidosis type must be based on identification of the chemical composition of the amyloid protein in deposits and not on clinical suspicion, laboratory tests, or genetic testing. A clinical correlation is required to support but not make a diagnosis of amyloid type. If a hereditary form is detected by amyloid protein typing, then molecular studies are indicated. Conversely, in cases in which DNA sequence indicates a mutant amyloid precursor protein, protein analysis of the deposits must provide the definitive evidence. Negative or inconclusive results must be investigated further by a reference laboratory with the capability of applying more sophisticated methods.

Neuropathologic and biochemical findings in a 34-year-old man whose disease began 2 years before death appearing as chronic progressive encephalitis and culminated in mutism are reported. Cerebrospinal fluid and serum of the patient showed a brain-restricted monoclonal lambda-light chain apparently produced by a small monoclonal immunoglobulin Glambda plasma cell population. In the preterminal stage, there was a systemic monoclonal gammopathy, the source of which could not be identified. At autopsy, there was extensive amyloid deposition in most vessels throughout the cerebral and cerebellar white matter, basal ganglia, and thalamus and diffuse leukoencephalopathy; cerebral and cerebellar cortices, other portions of the CNS, and non-CNS tissues were spared. Partial amino acid sequence analysis demonstrated that the amyloidogenic protein originated from immunoglobulin lambda-light chains which were produced by monoclonal plasma cells. There are 2 similar cases reported in the literature. The distribution of ALlambda deposits in these 3 cases indicates that widespread subcortical vascular amyloidosis with leukoencephalopathy is a novel clinicopathologic entity distinguished from other cerebral diseases with local amyloid light chain deposition, including amyloidoma, leptomeningeal vascular amyloidosis, solitary intracerebral plasmacytoma, primary intracerebral lymphoma with plasmacytic differentiation, and multiple sclerosis with demyelination-associated amyloid deposition.

In hunting falcons, a fatal syndrome of wasting, weight loss, green mutes and, finally, sudden death of emaciated birds has been observed in the United Arab Emirates (UAE). Histological examination using Congo red has revealed amyloid in most organs, in particular in the liver, spleen, kidney, and adrenal glands. Moreover, a retrospective study revealed amyloidosis in 100 cases among a total of 623 necropsied falcons between August 1995 and March 2004 in Dubai/UAE (16%; varying from 8 to 30% in different raptor bird species). The amyloid was immunohistochemically classified as amyloid A (AA), which was confirmed by Western blot analysis and N-terminal amino acid sequence analysis, suggesting it to be secondary to a chronic inflammatory process. Retrospective analysis has indicated a significantly increased prevalence of bumble foot and visceral gout among falcons with amyloidosis. In addition, a significant increase of amyloidosis from 5.6% of necropsied falcons with amyloidosis in 1995 to 40.0% in 2004 has been noticed. Finally, a semi-quantitative serum test for falcon serum amyloid A (f-SAA) has been developed. Among 38 falcons with fatal AA amyloidosis, f-SAA was increased pathologically in 36, whereas f-SAA was elevated in only one of 15 apparently disease-free falcons (p < 0.001). This significant result indicates that a normal f-SAA will indicate a minimal or even absent risk of succumbing to AA amyloidosis.

We have recently reported that the acute phase protein serum amyloid A (SAA), is locally and differentially expressed in neoplastic tissues of human colon. In the present study, we demonstrate that SAA enhances the plasminogen activation (PA)-activity of HT-29 colon cancer cell line. Cell-associated PA-activity was measured following the plasminogen-dependent ability of the cells to cleave the chromogenic substrate S-2251. The SAA-enhanced PA-activity was inhibited by anti-SAA antibodies. These antibodies also decreased the basal PA-activity of HT-29 cells and neutralized their cytokines (Interleukin-1beta+Interleukin-6)-enhanced PA-activity. Using specific chromogenic substrates and the fibrin clot-lysis assay, we found that SAA enhances also the PA-activity mediated by purified urokinase- and tissue-type plasminogen activators. Together, the data indicate that SAA enhances plasminogen activation and suggest its possible role in plasmin(ogen)-mediated colon cancer progression.

A 63-year-old Caucasian male, diagnosed with dilated cardiomyopathy in 1993, remained clinically stable for several years. In 2003, a marked increase of N-terminal pro-natriuretic peptide serum level (611 ng/ml to 4926 ng/ml) was observed; left ventricular (LV) septum thickness was 10 mm. In addition, sensorimotor polyneuropathy and autonomic dysfunction occurred. Further progression of heart failure occurred despite unchanged systolic LV function. Endomyocardial biopsy in 2006 revealed transthyretin amyloidosis by Congo red and immunohistochemical staining, as well as Val94Ala substitution by transthyretin gene analysis. Cardiac amyloid deposition was quantified by technetium-99m-3,3-diphosphono-1,2-propanodicarboxylic acid (99mTc-DPD) scintigraphy. Mutational search of the relatives (n = 1) was unremarkable. The transthyretin Val94Ala mutation is characterized by sensorimotor polyneuropathy, autonomic dysfunction, and gastrointestinal and cardiac involvement with amyloid. This mutation is an addition to the growing spectrum of transthyretin mutations with late onset of clinical symptoms, but noteworthy because of progressive, finally disabling disease course. Final clinical assessment of severity of cardiac involvement in the present patient is rendered complex by possible concomitant or preceding idiopathic dilated cardiomyopathy.

Mutations of the human transthyretin (TTR) gene have attracted medical interest as a cause of amyloidosis. Recently, we have described in detail an electrophoretic procedure with PAGE followed by IEF in urea gradients for the study of the microheterogeneity of TTR monomers (Altland, K., Winter, P., Sauerborn, M. K., Electrophoresis 1999, 20, 1349-1364). In this paper, we present a study on 49 different mutations of TTR including 33 that result in electrically neutral amino acid substitutions. The aims of the investigation were to test the sensitivity of the procedure to detect TTR variants in patients with TTR amyloidosis and their relatives and to identify some common characteristics that could explain the amyloidogenicity of these variants. We found that all tested amyloidogenic mutations could be detected by our method with the exception of those for which the corresponding variant was absent in plasma samples. Most of the electrically neutral amyloidogenic TTR variants had in common a reduced conformational stability of monomers by the activity of protons and urea. For three variants, e.g. TTR-F64L, TTR-I107V and TTR-V122I, the monomers had a conformational stability close to that of normal monomers but we found experimental and structural arguments for a weakening of the monomer-monomer contact. All types of amyloidogenic mutations affected the stability of TTR tetramers.

Over 100 mutations in the presenilin-1 gene (PSEN1) have been shown to result in familial early onset Alzheimer disease (EOAD), but only a relatively few give rise to plaques with an appearance like cotton wool (CWP) and/or spastic paraparesis (SP). A family with EOAD, seizures and CWP was investigated by neuropathological study and DNA sequencing of the PSEN1 gene. Abeta was identified in leptomeningeal vessels and in cerebral plaques. A single point mutation, p.L420R (g.1508T > G) that gives rise to a missense mutation in the eighth transmembrane (TM8) domain of PS1 was identified in two affected members of the family. p.L420R (g.1508T > G) is the mutation responsible for EOAD, seizures and CWP without SP in this family.

Serum amyloid A (SAA) is an acute phase reactant, whose level in the blood is elevated in response to trauma, infection, inflammation, and neoplasia. Elevated levels of SAA in the serum of cancer patients were suggested to be of liver origin rather than a tumor cell product. The role of SAA in human malignancies has not been elucidated. We investigated the expression of SAA at various stages of human colon carcinoma progression. Nonradioactive in situ hybridization applied on paraffin tissue sections from 26 colon cancer patients revealed barely detected SAA mRNA expression in normal looking colonic epithelium. Expression was increased gradually as epithelial cells progressed through dysplasia to neoplasia. Deeply invading colon carcinoma cells showed the highest levels of SAA. Expression was also found in colon carcinoma metastases. Cells of lymphoid follicles of the intestinal wall, inflammatory cells, ganglion cells, and endothelial cells, also expressed SAA mRNA. Immunohistochemical staining revealed SAA protein expression that colocalized with SAA mRNA expression. RT-PCR analysis confirmed the expression of the SAA1 and SAA4 genes in colon carcinomas, expression that was barely detectable in normal colon tissues. These findings indicate local and differential expression of SAA in human colon cancer tissues and suggest its role in colonic tumorigenesis.