Amyloidosis in black-footed cats (Felis nigripes)

A high prevalence of systemic amyloidosis was documented in the black-footed cat (Felis nigripes) based on a retrospective review of necropsy tissues (n = 38) submitted as part of ongoing disease surveillance. Some degree of amyloid deposition was present in 33 of 38 (87%) of the examined cats, and amyloidosis was the most common cause of death (26/38, 68%). Amyloid deposition was most severe in the renal medullary interstitium (30/33, 91%) and glomeruli (21/33, 63%). Other common sites included the splenic follicular germinal centers (26/31, 84%), gastric lamina propria (9/23, 39%), and intestinal lamina propria (3/23, 13%). Amyloid in all sites stained with Congo red, and in 13 of 15 (87%) cats, deposits had strong immunoreactivity for canine AA protein by immunohistochemistry. There was no association with concurrent chronic inflammatory conditions (P = .51), suggesting that amyloidosis was not secondary to inflammation. Adrenal cortical hyperplasia, a morphologic indicator of stress that can predispose to amyloid deposition, was similarly not associated (P = .09) with amyloidosis. However, adrenals were not available from the majority of cats without amyloidosis; therefore, further analysis of this risk factor is warranted. Heritability estimation suggested that amyloidosis might be familial in this species. Additionally, tissues from a single free-ranging black-footed cat had small amounts of amyloid deposition, suggesting that there could be a predilection for amyloidosis in this species. Research to identify the protein sequence of serum amyloid A (SAA) in the black-footed cat is needed to further investigate the possibility of an amyloidogenic SAA in this species.     

Immunohistochemical distribution of amyloid deposits in 25 cows diagnosed with systemic AA amyloidosis

The distribution of amyloid deposits was histopathologically and immunohistochemically examined in 25 cows aged 5 to 10 years that had been diagnosed with systemic AA amyloidosis. This examination revealed that amyloid deposits were also present in the hypophysis, ovary, uterus, mammary gland and skeletal muscle, in addition to the liver, kidney, spleen, pancreas, thyroid gland, adrenal gland, gastrointestinal mucosa, heart, lung and lymph nodes. The examined cows tended to have chronic inflammations, including chronic mastitis (six cases) or chronic pneumonia (four cases), which is thought of as a causative agent of AA amyloidosis. In contrast, five cases did not exhibit any chronic inflammation.     

Oxazolone-induced gastrointestinal disorders enhance the oral transmission of AA amyloidosis in mice

Amyloid A (AA) amyloidosis is a lethal disease characterized by systemic AA amyloid deposition, and is reported in many animal species. Despite experiments have shown that AA amyloidosis can be transmitted orally, horizontal transmission and cross-species transmission are concerns, the transmission mechanism has been unknown. In this study, we examined the oral transmission efficiency of AA amyloidosis using oxazolone-induced gastrointestinal disorder mice. As a result, the upper or lower gastrointestinal disorder groups developed more severe amyloid deposition in systemic tissues than the group without gastrointestinal disorders. The results of this study suggest that gastrointestinal damage promotes the oral transmission of AA amyloidosis.     

Renal medullary amyloidosis in Dorcas gazelles

Between January 1976 and September 1987 renal medullary amyloidosis (RMA) was diagnosed in 17 Dorcas gazelles; the necropsy prevalence rate was 17/32 (53%). The most severe amyloid deposits were in the renal medulla; glomeruli were spared. Renal cortical lesions of interstitial fibrosis and tubular atrophy and dilatation significantly correlated with RMA (P less than 0.01) and were considered to be secondary changes. There were varying degrees of lymphoplasmacytic inflammation and tubular cast formation which did not significantly correlate with RMA. Amyloid was confirmed histochemically and by electron microscopy and was identified as AA type by the permanganate method. Progressive renal failure was the cause of death or necessitated euthanasia in 7/17 (41%) gazelles. RMA in Dorcas gazelles does not appear to be familial. A high prevalence of chronic or recurring Actinomyces (Corynebacterium) pyogenes infections may be an important factor.     

Amyloid A amyloidosis secondary to avian tuberculosis in naturally infected domestic pekin ducks (Anas platyrhynchos domestica)

To investigate the correlation between avian tuberculosis and duck amyloidosis, the liver, lung, spleen, kidney, duodenum and pectoralis muscle of ducks naturally infected with Mycobacterium avium subsp. avium were used to detect amyloidosis by Congo red staining and potassium permanganate-Congo red staining. The expression level of IL-1β, IL-6, IL-10, TNF-α and SAA2 were detected by quantitative real-time RT-PCR (qRT-PCR). The results showed that the liver, lung, spleen, kidney, duodenum and pectoralis muscle of the infected ducks exhibited amyloid proteins under ordinary light microscopy and the polarization light under polarized light microscopy. However, no amyloid deposition in potassium permanganate-Congo red staining sections indicated that the amyloidosis was AA amyloidosis. In addition, the expression level of IL-1β, IL-6, IL-10, TNF-α and SAA2 increased from 4 to 43. This study showed that avian tuberculosis could induce secondary amyloidosis in naturally infected ducks.     

Amyloidosis in six dairy cows

Amyloidosis was diagnosed in 6 Holstein cows that were examined because of chronic intractable diarrhea. Besides diarrhea, the chief finding was a nephrotic-like syndrome, in that there was edema, hypoproteinemia, and proteinuria. Other consistent clinicopathologic abnormalities were hyperfibrinogenemia, low-normal serum calcium content or hypocalcemia, hypomagnesemia, prolonged bromosulphalein half time, high serum urea nitrogen concentration, high serum creatinine concentration, and low urine specific gravity. Foci of inflammation including traumatic reticuloperitonitis, traumatic pericarditis, salpingitis, mastitis, and metritis were found. There was histologic evidence of amyloid in the kidneys, liver, adrenal glands, and spleen. The iodine-sulfuric acid test for amyloid was positive in 2 cows. The Congo red dye test for amyloid was positive in 2 other cows. In spite of supportive care, all the cows either died naturally or were euthanatized. Because foci of inflammation were found in each cow, it was concluded that the most likely classification of amyloidosis in these cases would be reactive systemic amyloidosis and that the major amyloid fibril protein would be type AA.     

Amyloidosis in two Stejneger's beaked whales (Mesoplodon stejnegeri) stranded at the Sea of Japan.

Amyloidosis is a disease characterized by the tissue deposition of autologous extracellular fibrillar proteins that can result in compression of adjacent tissues. Amyloidosis is well-recognized in a wide variety of animals, including mammals, birds, and reptiles. However, to date, there is only one report of amyloidosis in cetaceans. During 1999 and 2000, among 12 Stejneger's beaked whales (Mesoplodon stejnegeri) that were stranded along the Sea of Japan's coast, amyloidosis was found in two whales (case 1, 498 cm, male; case 2, 520 cm, female). For this study population, the prevalence rate of amyloidosis was approximately 17%. These two animals were considered physically and sexually mature based on body length, external features, gonad characteristics, and skeletal features. Livers were notably swollen, fragile, and pale (brownish yellow) on gross examination. A large deposit of amyloid was found in Disse's spaces along with marked atrophy of the hepatocytes. Numerous granulomas, including many nematodes (Crassicauda sp.), were found along with amyloid deposition in the kidneys. Amyloid was also detected in the heart, spleen, adrenal gland, and pancreas. Amyloid in both cases was identified by typical morphology on H&E and Congo red staining. Electron microscopy displayed a typical network of fine fibrils measuring about 11 nm in diameter. This is the first report of amyloidosis in two Stejneger's beaked whales stranded on the coast of the Sea of Japan.     

The role of chicken IL-1β, IL-6 and TNF-α in the occurrence of amyloid arthropathy

In this study, the roles of IL-1β, IL-6 and TNF-α in amyloid arthropathic chickens with variable amounts (severe, moderate and mild) of amyloid accumulation were investigated. The presence and the levels of cytokines were evaluated in serum and in joint tissues by using ELISA and immunohistochemistry, respectively. One hundred brown layer chicks were allocated into four groups and intra-articular injections of Freund’s adjuvant were used to induce amyloid arthropathy in Groups II, III and IV. Vitamin A in group II, and methylprednisolone in Group IV were added to enhance and to reduce the severity of amyloidosis, respectively. At the end of the study, a positive correlation was observed among the incidence and severity of amyloidosis, the serum amyloid A levels and the IL-1β values both in the serum and tissues. Elevation in the tissue TNF-α levels in parallel with the severity of amyloidosis has also been noted. As a conclusion, IL-1β appears to play an important role in avian AA amyloidosis either alone or in combination with TNF-α. Further investigation is needed for understanding the role of the pro-inflammatory cytokines in avian AA amyloidosis.     

Species-barrier on the cross-species oral transmission of bovine AA amyloidosis in mice

In AA amyloidosis, cross-species oral transmission has been demonstrated in several animal models. While it is known that the transmission efficiency of AA amyloidosis between different species is lower than that among the same species, the mechanism of this species-barrier is unclear. In this study, we found at first that mice orally given a large amount of bovine AA simultaneously with inflammatory stimulation did not develop AA amyloidosis. Therefore, we hypothesized that the low efficiency of the cross-species oral transmission of AA amyloidosis might be due to the low absorption rate in Peyer’s patches. To evaluate the hypothesis, we next investigated whether bovine AA was taken up by Peyer’s patches and translocated to other organs in vivo and ex vivo models. The direct absorption of bovine AA by Peyer’s patches was not observed. Besides, translocation of bovine AA to the mesenteric lymph nodes, spleen, liver, or kidney was not observed except the mesenteric lymph node of a single mouse. Thus, absorption of bovine AA by Peyer’s patches occurred much less efficiently in mouse models of cross-species oral transmission of AA amyloidosis. The present study suggests that the less efficient amyloid uptake by Peyer’s patches may be involved in the species-barrier of oral transmission of AA amyloidosis.     

The Pathogenesis of Reactive Systemic Amyloidosis

The diagnosis of amyloidosis is based on the presence of extracellular tissue deposits of proteinaceous material that demonstrate a characteristic green color when stained with Congo red and viewed under polarized light. Several different proteins are amyloidogenic but, in domestic animals, spontaneously occurring systemic amyloidosis is reactive in nature and characterized by the presence of amyloid protein AA. This type of systemic amyloidosis may occur secondary to chronic inflammatory or neoplastic disease, but in many instances no predisposing disease is found. A sustained increase in the serum concentration of serum amyloid A protein (SAA) is necessary but not sufficient for the development of reactive amyloidosis. Other inherited and acquired host-related factors are likely to be important in the development of reactive amyloidosis because this condition develops in few patients with chronic inflammatory disease. The tissue tropism of amyloid deposits varies with the amyloid protein itself and species affected. The consequences of amyloidosis for the host depend upon the tissues involved and the response of these tissues to the presence of the amyloid deposits. In domestic animals, reactive systemic amyloidosis is nephropathic, leading to end-stage renal disease, and the clinical presentation is that of uremia.     

Serum amyloid A and haptoglobin levels in bovine amyloidosis

Serum amyloid A (SAA) and haptoglobin (Hp) levels were determined in 25 cows suffering from amyloidosis. SAA levels in cows with amyloidosis ranged between < 0.3 and 225.8 microg/ml, with a median level of 105.1 microg/ml, and Hp levels ranged between < 20 and 1860 microg/ml, with a median level of 950 microg/ml. These levels were significantly higher than the levels observed in healthy cows (SAA levels ranged from < 0.3 to 13.5 microg/ml, with median of 1.4 microg/ml, and Hp levels were undetectable in all cases), but were not significantly different from the levels observed in control cows with chronic inflammation. There was a significant correlation between SAA and Hp levels in cows with chronic inflammation , but not in cows with amyloidosis. It was concluded that the serum SAA levels in cows with amyloidosis might be changed by some factor other than inflammation.     

Renal amyloidosis in cattle with inflammatory diseases

BACKGROUND: The association of inflammatory diseases such as traumatic reticuloperitonitis (TRP), mastitis, metritis, and pododermatitis with renal amyloidosis in cattle is poorly described. HYPOTHESIS: Serum amyloid A (SAA) levels are elevated during inflammatory diseases, and renal amyloidosis is formed as a complication. ANIMALS: This study was conducted with 82 crossbred cattle with mastitis (n = 18 cows), metritis (n = 11 cows), TRP (n = 30 cows), and pododermatitis (n = 23 : 15 cows and 8 beef cattle). Ten clinically healthy cows served as controls. Methods: Hematological, urinary, and blood parameters, including SAA, were measured by an automated procedure provided with trade kits. Determination of amyloidal structures was made by histopathological examination of renal biopsy specimens. RESULTS: At the end of this trial, amyloidosis was detected in 5 cows displaying typical nephrotic syndrome, with hypoproteinemia and proteinuria in combination with polyuria and weight loss. Furthermore, it was observed that cows with renal amyloidosis had significantly higher (P < .01) total leukocyte counts, serum and urine enzyme activities, and urea and creatinine concentrations, with lower serum total protein concentrations, when compared with animals without renal amyloidosis. CONCLUSIONS AND CLINICAL IMPORTANCE: The incidence of AA amyloidosis in cattle in this study suggests that cattle with mastitis, metritis, and pododermatitis have a high prevalence of systemic amyloidosis in response to inflammation.     

Systemic amyloidosis in a mare

A mare with chronic cachexia had multiple skin nodules, abdominal masses (attached and free floating), and large lymph nodes. Fine-needle aspiration cytologic evaluation of a skin mass revealed multinucleated giant cells surrounding eosinophilic material. Histologic evaluation revealed extensive amyloid deposits within the masses, lymph nodes, and the interstitium of many organs. The presence of systemic (visceral) and organ-limited (cutaneous) forms of amyloid is rare in horses. Amyloid congophilia was retained after potassium permanganate oxidation. The fibrils were thus distinct from the AA (secondary) fibrils that are found in most cases of equine amyloidosis, suggesting that this mare may have had primary amyloidosis. Regardless of fibril type, the presence of multinucleated giant cells in association with eosinophilic material in cytologic preparations of skin nodules may suggest a differential diagnosis of amyloidosis in horses.     

An ancillary tool for the diagnosis of amyloid A amyloidosis in a variety of domestic and wild animals

Immunohistochemistry, the standard method for diagnosing amyloid A (AA) amyloidosis, is limited in animals because it requires a large array of animal-specific anti-AA antibodies, not commercially available. The Shtrasburg method (SH method) is a highly specific and sensitive technique, helping in the diagnosis and determination of AA amyloidosis in humans. The aim of this study is to determine whether the SH method is applicable in the diagnosis of AA amyloidosis in a variety of animals. Tissue samples were obtained from animals suffering from spontaneous or experimentally induced AA amyloidosis (mice, hamsters, guinea pigs, cheetahs, cats, cows, ducks, a dog, a goose, a chicken, and a turaco). Detection of the amyloid and quantitative evaluation were performed using Congo red staining, and specific AA typing was performed by the potassium permanganate technique. The studied tissues were subjected to the SH method, which confirmed the AA nature of the amyloid deposit, by displaying in polyacrylamide gel electrophoresis protein bands consistent with the molecular weight of the species-specific AA, in all the animals examined, except mice, hamsters, and guinea pigs. N-terminal analysis of these bands corroborated their AA origin. We conclude that the SH method may be used as an ancillary simple tool for the diagnosis of AA amyloidosis in a large number of domestic and wild animals. Moreover, our findings further increase the feasibility of applying this method in humans.     

Pathology of AA amyloidosis in domestic sheep and goats

We describe the main pathologic changes in small ruminants affected by AA amyloidosis, together with the partial sequence of the protein involved. Twenty-one sheep and one goat were selected for presenting macroscopic kidney lesions compatible with systemic amyloidosis. Available tissue samples were studied by histologic, immunopathologic, and ultrastructural means. Renal lesions were characterized grossly by pale cortical surfaces with scattered, miliary, whitish-yellow foci and on cut cortical surfaces by straight, whitish-yellow striations. Gangrenous pneumonia was observed in 16 out of 21 affected sheep (76.2%), although other chronic inflammations were also observed. Amyloid was detected in all grossly affected kidneys using Congo red staining, lesions being most remarkable in glomeruli, affecting 95.5% of animals studied. Congophilic deposits were also observed in intertubular interstitium (68.2%) and medulla (57.1%). All amyloid-affected animals presented proximal convoluted tubule lesions, mostly characterized by an increase in diameter and by hyaline granular degeneration that were responsible for the macroscopic appearance of the kidney. Histologically, amyloid was also seen in blood vessels, spleen, liver, lymph nodes, gastrointestinal tract, and adrenal glands. All amyloid deposits demonstrated greenish-yellow birefringence with polarized light, and the antisera prepared against goat amyloid extracts specifically reacted with birefringent congophilic deposits of both sheep and goats. Ultrastructurally, these deposits were formed by masses of straight, nonbranching fibrils located predominantly in the basement membranes of glomerular capillaries and in the mesangium. Partial sequence of the protein in sheep and goats indicated a high degree of homology with the previously reported sequence of sheep Serum Amyloid A.     

Localized amyloidosis in canine mammary tumors

Histopathologic and immunohistochemical examinations were performed on localized amyloidosis associated with mammary tumors in two dogs. These tumors were identified as adenoma and adenocarcinoma. An acellular, amorphous pale eosinophilic material (amyloid) was observed in the lumina of acini lined by neoplastic cells and in the stroma of the tumors. Concentrically laminated pale eosinophilic bodies (corpora amylacea) were also found in the lumina of the acini. Amyloid and corpora amylacea stained positively with Congo red with and without 5% potassium permanganate pretreatment and revealed a green birefringence under polarized light. Corpora amylacea showed an occasional Maltese-cross pattern. Immunohistochemically, amyloid and corpora amylacea usually stained positively with anti-bovine alpha-casein antibody but negatively with anti-human amyloid AA, anti-bovine kappa-light and lambda-light chains, anti-human lactoferrin, anti-human transferrin, anti-human secretory component, and anti-human polyglucosan antibodies. These findings suggested that the amyloid deposition in these canine mammary tumors was related to lactating casein.     

Amyloidosis in the black-footed ferret (Mustela nigripes).

This study describes clinical, histologic, immunohistochemical and electron microscopic features of amyloid A amyloidosis occurring in black-footed ferrets (Mustela nigripes) from eight U.S. zoological institutions. Ferrets had nonregenerative anemia, serum chemistries consistent with chronic renal disease, and proteinuria. Amyloid was present in a variety of tissues, but it was most severe in renal glomeruli and associated with tubular protein loss and emaciation. Congo red/potassium permanganate (KMnO4) and immunohistochemical stains revealed that the amyloid was of the AA type. Concurrent diseases and genetic predisposition were considered the most important contributing factors to development of amyloidosis. Analysis of the genetic tree did not reveal convincing evidence of a common ancestor in the affected ferrets, but a genetic predisposition is likely because all the captive black-footed ferrets are related.     

Immunohistochemical identification of amyloid, using an anti-human serum amyloid P component (SAP) antibody, is possible in ruminants but not in dogs and cats

Amyloidosis represents a heterogenous group of diseases that have in common the deposition of fibrils composed of proteins of beta-pleated sheet structure, a structure which can be specifically identified by histochemistry using the Congo red or similar stains. Amyloid consists primarily of the amyloid fibrils but also of the amyloid P component (AP). This component, which is identical with the serum counterpart (SAP), is found in all types of human amyloid, and immunohistochemical identification of AP has been proposed as an adjunct to the universal, type-independent diagnosis of human amyloidosis. In the present study of animal amyloidosis, we compared the amyloid-specific Congo red stain with an immunohistochemical protocol using an anti-human SAP antibody for the identification of amyloid in formalin fixed tissue samples. The species and types of amyloidoses investigated were: (i) seven cows, one yak (Bos grunniens), and one sheep affected with amyloidosis of presumed AA type, (ii) one dog with a pancreatic endocrine tumour producing amyloid of presumed AIAPP type, (iii) two cats with presumed AIAPP-amyloidosis of the islets of Langerhans, one cat with presumed AA-amyloidosis, and one cat with an amyloid-producing odontogenic tumour. Intense immunostaining co-localized with amyloid, identified by its congophilia and green birefringence, using a protocol without any antigen retrieval in each of the seven cows, the yak and the sheep. The method seemed more sensitive in the ruminants than the Congo red stain, but was unable to detect amyloid in the dog and the cats regardless of the application of various antigen retrieval protocols. However, specific identification of amyloid still rests on the Congo red method or similar histochemical techniques.