Immunohistochemical identification and crossreactions of amyloid-A fibril protein in man and eleven other species

Systemic Amyloid A Amyloidosis in Stejneger's Beaked Whales (Mesoplodon stejnegeri)

Stejneger's beaked whales (Mesoplodon stejnegeri) are one of the lesser known species of mammals, with little information available on their population status or incidence of diseases. Recent pathologic investigations on stranded and bycaught wild cetaceans around Hokkaido, Japan, revealed an unusually high incidence of systemic amyloidosis in this species, warranting further investigation. The objective of this study was to further characterize the systemic amyloidosis of Stejneger's beaked whales by retrospective histopathologic analyses of tissues from animals that stranded in Japan between 1994 and 2018. Various tissues from 35 individuals were examined histologically with hematoxylin and eosin, Congo red, and immunohistochemistry for amyloid A (AA), in which 12 (34%) were diagnosed with systemic amyloidosis. The organs with the highest severity of amyloid deposition were the stomach and intestine. The type of amyloid was confirmed as AA of approximately 9 kDa by 2-dimensional gel electrophoresis with extracted amyloid from the liver and subsequent Western blotting with an antiserum against AA peptide. There were no statistically significant associations between amyloidosis and sex, body condition of the whales, or the presence of chronic inflammation. The high prevalence of this disease might be of concern for overall population numbers, and continued pathologic monitoring of stranded animals is necessary throughout its distributional range.

Causes of mortality and morbidity in free-ranging mustelids in Switzerland: necropsy data from over 50 years of general health surveillance

BACKGROUND

Although mustelids occur worldwide and include a wide range of species, little is known about the diseases affecting them. Mustelids have regularly been submitted for post mortem investigation in the framework of the program for general wildlife health surveillance in Switzerland, which has been in place for nearly 60 years. We performed a retrospective analysis of the necropsy reports on mustelids submitted to the diagnostic service of the University of Bern. The aims of this study were to present an overview of the causes of mortality and morbidity observed in these carnivores, to assess differences among species, to assess changes in disease detection over the study period, and to describe the pathology of selected diseases.

RESULTS

Five hundred and sixty-six reports from 1958 to 2015 were analyzed. Most animals were stone martens (Martes foina, 46%) and badgers (Meles meles, 44%); the remaining species were polecats (Mustela putorius, 4.7%), pine martens (Martes martes, 2%), stoats (Mustela erminea, 1.4%), weasels (Mustela nivalis, 0.8%) and otters (Lutra lutra, 0.3%). Infectious diseases (n = 262) were frequent and were mostly bacterial or viral; non-infectious conditions (n = 169) were less common and were mostly traumatic or due to metabolic disorders. The most frequent diagnoses included distemper (75% were badgers), amyloidosis (96% were martens), bacterial respiratory infections (all mustelids), biting lice (badgers only) and pulmonary and gastro-intestinal helminths (all species). Less frequent diseases included histoplasmosis (badgers only), aspergillosis, toxoplasmosis, hepatozoonosis, and sarcoptic mange. Lesions due to infection with distemper virus were primarily appreciated in the respiratory tract and central nervous system; they presented species-specific characteristics such as necrosis in the ependyma in badgers and absence of syncytia in stone martens. Amyloidosis in martens was multisystemic in most cases and included both AA and AL amyloidosis; the main macroscopic change was severe splenomegaly.

CONCLUSION

Infectious diseases were the most frequent causes of morbidity and mortality of mustelids, with marked species-specific differences. Lung and skin were the most commonly affected organs. Contagious diseases such as canine distemper, sarcoptic mange and rabies in mustelids showed a similar temporal pattern as in red foxes (Vulpes vulpes), suggesting pathogen spillovers from foxes to mustelids.

Amyloidosis in association with spontaneous feline immunodeficiency virus infection

Tissues from 34 naturally feline immunodeficiency virus (FIV)-infected cats, 13 asymptomatic cats and 21 cats with signs of feline acquired immunodeficiency syndrome (F-AIDS), and 35 FIV-seronegative subjects were examined to determine the presence of amyloid deposits. Twenty experimentally FIV-infected cats and five specific pathogen-free (SPF) control cats were also included in the study. Paraffin-embedded sections from kidney and other organs were submitted to histological and histochemical analysis. Amyloid deposits were identified by a modified Congo red stain and confirmed by electron microscopy to demonstrate the presence of amyloid fibrils in amyloid positive glomeruli. In all positive cases, secondary amyloidosis was identified with potassium permanganate pretreatment and amyloid type was further characterised by immunohistochemistry using primary antibodies against human AA and feline AL amyloids. Amyloid deposits were present in different tissues of 12/34 (35%) naturally FIV-infected cats (seven presenting F-AIDS and five in asymptomatic phase) and in 1/30 FIV-seronegative cats. All the experimentally FIV-infected and SPF subjects showed no amyloid deposits. Amyloidosis has been reported in human lentiviral infections, and the data reported here demonstrate the need, in naturally FIV-infected cats, to consider the presence of amyloidosis in differential diagnosis of hepatic and renal disorders to better assess the prognosis of the disease.

Increasing fatal AA amyloidosis in hunting falcons and how to identify the risk: a report from the United Arab Emirates

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.

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.

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.

Systemic AA-amyloidosis in a European Wild Boar (Sus scrofa) Suffering from Generalized Tuberculosis

Summary An adult female wild boar (Sus scrofa) was found moribund in Cabaneros National Park (central Spain). The animal had a markedly emaciated carcass, with body weight of 25.9 kg. At necropsy, most of the parenchymatous organs had widespread variably sized granulomas. Generalized tuberculosis was confirmed by PCR detection of Mycobacterium bovis in the mandibular lymph node. Large amounts of a hyaline, pale eosinophilic material were observed in liver, kidney and intestine. Congo red staining and green birefringence identified amyloid, which was further classified as AA type based on immunohistochemical results. It is speculated that the abundant serum amyloid A derivatives deposited in the tissues as AA-amyloid may be associated with the generalized tuberculosis. This is the first report of amyloidosis in the European wild boar.

Serum amyloid A protein forms a complex with a fragment of apolipoprotein A-I in the domestic blue fox: a protective mechanism against AA amyloidosis?

The spontaneous occurrence of protein AA-type of amyloidosis varies among animal species. As reactive AA-type of amyloidosis has never been detected in the blue fox, we obtained acute phase sera to search for amyloid-protective elements. The purified SAA fraction was characterized by mass and sequence analyses to disclose any unique domains in the amino acid sequence. The data revealed an SAA protein with heterogeneities in several positions, and showed the typical insertion between positions 69 and 70. By comparing the amino acid sequence with that from other mammals, no unique sequence could be observed. However, a C-terminal fragment of apolipoprotein A-I (ApoA-I) was found attached to the SAA. The amino acid sequence of the ApoA-I fragment revealed a partially blocked and ragged N-terminus. A comparison of the amino acid sequence of ApoA-I with that from the dog showed that the ApoA-I fragment started about position 190, had an intact C-terminus, and showed an identical sequence in all positions, except one. Based on the data, we suggest an interaction of the C-terminal fragment of ApoA-I with the SAA protein that inhibits the AA fibrillogenesis in the blue fox.

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.

Generalized AA-amyloidosis in Siberian tigers (Panthera tigris altaica) with predominant renal medullary amyloid deposition

Generalized amyloidosis with predominant renal medullary amyloid deposition was found in four closely related Siberian tigers (Panthera tigris altaica) suffering from end stage kidney diseases. Only minimal to mild amounts of amyloid were deposited in various organs outside the kidneys with individually variable organ involvement. The Congo red staining affinity of amyloid deposits was sensitive to potassium permanganate oxidation. The deposits were further characterized as being of the amyloid-A (AA) type by immunohistochemistry using the mouse monoclonal antibody mc4 directed against a conserved region of the human AA-protein. A combination of immunohistochemistry and Congo red staining was much more sensitive for the diagnosis of amyloid deposits than Congo red staining alone. With this combination, even minimal amyloid deposits were detected that had been missed in the first reading using Congo-red-stained slides alone. Since no common primary cause was identified, the amyloidosis was classified as idiopathic generalized AA-amyloidosis with a potential familial predisposition.

Identification of lambda light chain amyloid in eight canine and two feline extramedullary plasmacytomas

Amyloid deposition in varying amounts and with variable patterns of distribution (focal or diffuse) was demonstrated in eight canine and two feline extramedullary plasmacytomas expressing lambda light chains. Frequently, the neoplastic plasma cells had been displaced by the amyloid deposits. Foreign-body giant cells were regularly detected in the vicinity of the amyloid. In all 10 cases, Congo-red staining of the amyloid was resistant to potassium permanganate oxidation. Immunohistochemically, the amyloid reacted positively with cross-reacting antibodies against human and equine A lambda amyloids. Extramedullary plasmacytomas accompanied by localized AL amyloidosis have so far been described in human beings, dogs, cats and horses.

Generalised AA-amyloidosis in a bat (Pipistrellus pipistrellus)

Generalized amyloidosis was found to be the cause of death in a female adult insectivorous pipistrelle bat (Pipistrellus pipistrellus) after chronic wound inflammation. Large amounts of amyloid were detected in liver, spleen, kidneys, stomach, intestine, lymphatic tissues, and endocrine and salivary glands. Congo red staining and green birefringence identified amyloid; the Congo red staining was sensitive to potassium permanganate oxidation. The amyloid was further classified immunohistochemically. The deposits reacted with two anti-human-AA-amyloid monoclonal antibodies in a peroxidase-antiperoxidase reaction, whereas no reaction was found with antibodies specific for other types of amyloid. Thus, the bat amyloid deposits were identified as generalized reactive AA-amyloidosis.

AA-like amyloid deposits confined to arthritic joints in two dogs with rheumatoid arthritis

Two dogs with clinical, serological, radiographic and pathological changes similar to those of rheumatoid arthritis of man and a previously undescribed pattern of amyloid deposits are described. As revealed by light and electron microscopical investigations, amyloid fibrils were found exclusively in articular tissue structures of arthritic joints and in one tonsil of one dog. Based on our immunohistochemical results, the amyloid protein is believed to be of a local AA type.

Equine cutaneous amyloidosis derived from an immunoglobulin lambda-light chain. Immunohistochemical, immunochemical and chemical results

Amyloid deposits from equine cutaneous nodular amyloidosis associated with extramedullary plasmacytoma were classified immunohistochemically as equine immunoglobulin lambda-light chain-derived and designated eA lambda (HIP). For chemical identification, the amyloid fibril proteins were separated on Sephadex G-100 in 6M guanidine.HCl. Polypeptides of predominantly 24 kDa and 50 kDa were found by polyacrylamide gel electrophoresis. They have preponderance of immunoglobulin lambda-antigenic determinants as detected by immunodiffusion and immunoblotting. Since the N-terminus of the major proteins was blocked, peptides were generated with trypsin and endoproteinase Asp-N and then isolated using reversed-phase high-performance liquid chromatography. Automatic amino-acid sequence determination of seven peptides showed novel sequences. Data bank comparison indicated that these peptides were derived from a monoclonal immunoglobulin lambda-light and a gamma-heavy chain. The light chain was considered to be the leading amyloidogenic polypeptide, since it was the predominant component in a virtually pure amyloid fibril preparation. Thus, immunoglobulin lambda-light chain-derived amyloidosis, so far established only in man and cat, has now also been identified in the horse.

Clinical chemical constituents in relation to liver amyloidosis in serum-producing horses

Serum activities of gamma-glutamyl transferase (GGT), alkaline phosphatase (AP), aspartate aminotransferase (AST), and concentrations of total bilirubin and total bile acids were screened during a 5 year period in 27 horses used for production of hyperimmune serum. The horses investigated were regularly immunized with live cultures of the endotoxin-releasing bacteria Escherichia coli or Pasteurella multocida, the individual animals having undergone such treatment for periods varying from 2 weeks to 10 years. In a majority of the horses, GGT-activity had increased within 6 to 7 years of first having undergone immunization. Constantly high values seemed to co-incide with the presence of advanced liver amyloidosis, as demonstrated by histopathological examination after slaughter. The AP activity was also increased but only moderately compared with GGT. Individual values more than 10-fold greater than the upper reference limit were recorded for GGT, while the highest AP values were less than double the upper reference limit. Activity of AST and bilirubin concentrations remained unaffected, whereas the concentration of total bile acids rose after 6 to 7 years of immunization compared to the baseline value. It is concluded that the determination of serum activities of GGT may serve as a practical routine test for the evaluation of liver amyloidosis status in serum horses.

Heterogeneity of human serum amyloid A protein. Five different variants from one individual demonstrated by cDNA sequence analysis

Serum amyloid A (SAA), a chemically polymorphic protein, is the most sensitive marker protein of the acute phase and the precursor of reactive amyloidosis, which is characterized by deposits of amyloid A protein (AA). We investigated the variability of the SAA gene family in one individual by sequencing 11 SAA-specific clones from an acute-phase-liver cDNA library. At least five different SAA variants were deduced from six different cDNAs. The 3' untranslated gene segments fall into two groups, based on nucleotide sequence and variability in length. Various nucleotide and amino acid substitutions were found predominantly in the 3' portion. Some of these substitutions are unique and increase the number of SAA variants in one individual to at least five. Moreover, genomic DNA of four individuals was examined by analysis of restriction-fragment length polymorphism. Besides two conserved strongly labelled bands, additional polymorphic bands were observed, indicating isotypic and/or allotypic SAA variations. Finally, three different mRNA species were detected by Northern-blot analysis, a finding that might be of relevance for the stability of SAA transcripts.

Amyloidosis and female protein in the Syrian hamster. Concurrent regulation by sex hormones

Previous results have shown that when compared to male Syrian hamsters, female Syrian hamsters have a distinct predisposition to acquire amyloidosis either normally with aging or experimentally with sodium caseinate or diethylstilbestrol (DES) treatments. In the present study, we tested the influence of testosterone on expression of amyloid to determine if this hormone was solely responsible for the sex-limited amyloidosis of the Syrian hamster. Males deprived of testosterone by castration acquired amyloid at an unusually young age, an age of onset similar to that in female hamsters. Also, the amyloidogenic effect of DES in male Syrian hamsters was inhibited by concomitant injections of testosterone, indicating that estrogens induce amyloid in male hamsters by inhibiting testosterone synthesis. When administered to female hamsters, testosterone inhibited expression of amyloid in aging female Syrian hamsters and extended the life span of this gender. Of the two components of amyloid, the major component Amyloid A-derived fibril or the minor constituent, Amyloid P component, only the P component is under sex hormone control in the Syrian hamster; testosterone inhibits the hepatic synthesis of the P component homologue (called female protein), which is normally expressed 100-200-fold greater in female vs. male Syrian hamster. In general, the serum level of female protein under various experimental conditions correlated with the presence of amyloid and indicated that in the Syrian hamster the P component homologue is of primary importance in the deposition of amyloid.

Immunoglobulin lambda-light-chain-derived amyloidosis (A lambda) in two horses

Tumorous amyloid deposits in the nasal mucosa of two horses differed from generalized AA-amyloidosis with respect to clinical features, organ distribution, and resistance to KMnO4 treatment. Using a panel of antibodies directed against different human amyloid fibril proteins and employing the peroxidase-anti-peroxidase (PAP) technique, we showed the described equine amyloid to be A lambda-type, as demonstrated by immunohistochemical cross-reactivity. Consequently, we identified a second amyloid class in horses and showed that immunoglobulin light-chain-derived amyloid may also be present in animals.

Immunohistochemical characterization of spontaneous amyloidosis in captive birds as AA-type, using monoclonal and polyclonal anti-AA antibodies against mammalian amyloid

Spontaneous amyloid diagnosed by means of Congo red and polarization microscopy in 3 flamingos, 1 crowned crane, 1 red-breasted goose, and 1 common golden-eye was studied using immunohistochemical techniques. The avian amyloid cross-reacted with a number of monoclonal and polyclonal anti-AA antibodies directed against mammalian amyloid fibril proteins. This confirmed that both "secondary" and "idiopathic" avian amyloid is of the AA-type. The results demonstrate the possibility to successfully using cross-reactive anti-AA antibodies for the diagnosis of non-mammalian amyloidosis.

Classification of naturally occurring arterial disease in the dog

Evaluation of induced arterial toxicity in safety assessment of drugs involves recognition of morphologic differences between groups of animals. In this organ system, as in all others, it is necessary to be familiar with the background pathology that can occur in control animals of the test species, since such lesion "noise" may complicate the evaluation of drug-related effects if naturally occurring diseases have morphologic features in common with those that can be produced by drugs. Background arterial lesions have been regarded as relatively unimportant in both the laboratory-maintained beagle and in the larger range of domesticated breeds of dog and few of these vascular lesions lead, per se, to functional organ compromise. At least this appears to be the case in young and middle-aged subjects, within the epidemiologic limits of data from veterinary medical centers where systematic and thorough necropsies are done and recorded. Arterial lesions are, however, not uncommon naturally occurring incidental necropsy findings in dogs; however, in most cases they are of uncertain functional significance. This presentation summarizes the main pathologic patterns of lesions that can affect arteries in dogs that are not used in safety evaluation studies. The main patterns can be classified as degenerative, proliferative, and inflammatory, although there is some overlap between these partly arbitrary designations. In some cases, etiopathogenesis of the arterial lesion is unclear; in others, there are clear associations with disease processes in other organ systems. Congenital vascular lesions and vascular components of congenital cardiac defects are excluded from consideration since such lesions are unlikely to occur in dog populations used in the safety assessment of drugs.

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.

Amyloid in the horse: a report of nine cases

Out of approximately 16,000 horses referred for clinical examination, nine had amyloidosis. Six of these horses had localised amyloid deposits in the wall of the nasal meatus and ventral turbinates associated with epistaxis. Horse 1 also developed malignant histiolymphocytic lymphosarcomas. The amyloid deposits were potassium permanganate-resistant and tryptophan-positive. Gel filtration of solubilised amyloid fibrils from Horse 1 revealed a major retarded fraction with an apparent molecular weight of 20 kD. This protein had an amino acid composition similar to human AL-amyloid proteins and horse immunoglobulin light chains. On Western blot a strong cross-reaction was observed between horse 1gG2a light chains and the Horse 1 amyloid. Horses 7 to 9 had suppurative verminous aneurysm, tuberculosis and an adrenal cortical adenoma, respectively, and had generalised amyloid deposits in liver and spleen. These amyloid deposits were found to be potassium permanganate-sensitive and positive for tryptophan. Gel filtration of solubilised amyloid fibrils from Horse 8 revealed a major retarded fraction (protein AA) with an apparent molecular weight of 10 kD. Immunoperoxidase-antiperoxidase staining showed the localised deposits to be negative or only weakly positive with antisera against bovine, hamster, dog and human protein AA and to be positive with anti-horse-one amyloid protein. The generalised deposits were found to be positive with the antisera against allogenic protein AA. The results of the potassium permanganate incubation, biochemistry, immunoblotting and immunochemistry, indicate that the localised amyloid of Horse 1 and most likely the amyloid of Horses 2 to 6, is of the AL-type. The generalised amyloid deposits were found to be of the AA type.

AA amyloid-associated gastroenteropathy in a horse

Systemic amyloidosis involving the digestive tract is described in an 11-year-old Morgan stallion. The disease was characterized clinically by weight loss, ptyalism, anaemia, persistent mature neutrophilia, hypoalbuminaemia and hypergammaglobulinaemia. The D-xylose absorption test indicated malabsorption. Necropsy revealed oral, oesophageal and gastric ulcers and reddened segments of small bowel mucosa with scant haemorrhages. Microscopically, amyloid deposits were found throughout all tissue layers of the digestive tract, except the serosa. Deposits of amyloid were most apparent in the small bowel mucosa and submucosal arteries. Amyloid was also present in the spleen and lymph nodes and to a lesser extent in the liver, kidneys, lungs, pancreas and bone marrow. All amyloid deposits gave the typical histochemical reaction for AA amyloid with the KMnO4-Congo red stain procedure and immunohistochemical cross-reactivity was demonstrated with antisera to both canine and bovine protein AA by the peroxidase-antiperoxidase technique. The cause of the amyloidosis was not identified, although the haematological and serological data were compatible with an underlying chronic inflammatory process.

Monoclonal antibodies against synthesized short peptides corresponding to human AA amyloid protein

Monoclonal antibodies (McAbs) were raised against the synthesized short peptides corresponding to 37-47 residues in amino acid sequence of human AA protein. The McAbs reacted immunohistochemically to amyloid tissues from cow, mouse, swan, and human AA amyloidosis. We concluded that the McAbs were useful for identification of AA type amyloidosis of various species, and that the 37-47 residues were effective antigenic sites in AA protein.

Characterization of amyloid protein AA and its serum precursor SAA in the horse

Amyloid was extracted from the liver of a horse that had developed amyloidosis after being used for several years for the production of antibodies to bacterial antigens. The amyloid fibrils were shown to be of the AA type. Two AA proteins with molecular weights of 9000 and 11,000 and with identical partial N-terminal amino acid sequences were identified. Marked structural homology with AA from other species including man was seen, although clear species-related antigenic specificity was observed. SAA isolated from an acute phase (septic abortion) horse serum was identical to AA with respect to antigenicity and the 10 first N-terminal amino acid residues that have been studied up to now. The bulk of SAA was present in the high-density lipoprotein complex in serum. Also SAA was heterogeneous with respect to size, most molecules having a molecular weight of 11,000, and a minority 9000.

Bovine amyloid protein AA: isolation and amino acid sequence analysis

Amyloid-laden renal glomeruli were selectively isolated from a cow with a history of multiple organ inflammatory diseases which terminated in amyloid-induced glomerulopathy and severe proteinuria. Lyophilized amyloid fibrils obtained by water extraction procedures were dissolved in 6M guanidine hydrochloride and gel filtered on Sepharose CL6B and Sephacryl S-300 Superfine columns for slab gel electrophoresis, analytic isoelectric focusing, and amino acid sequence analyses. Electrophoresis of material from the major retarded peak of the elution profile revealed that bovine protein AA moves as one band with an apparent molecular mass of about 14,000 Daltons. Several distinct bands between approximately pH 4.0 and 5.0 were observed when this material was evaluated by analytic isoelectric focusing, thus having a pattern resembling that of human and dog protein AA. A blocked N-terminus was demonstrated when protein from the major retarded peak was subjected to amino acid sequencing, but cyanogen bromide cleavage followed by gel filtration produced 3 peptide fragments for amino acid sequence analysis. These peptides had a high degree of homology with positions 4-14, 18-24 and 25-49 of human protein AA. An apparent complete homology between bovine protein AA and protein AA from other species was apparent at positions 35-45, providing further evidence that this is a functionally significant part of the serum protein AA (SAA) molecule.

Diagnosis of the type of amyloid in paraffin wax embedded tissue sections using antisera against human and animal amyloid proteins

Different histochemical techniques were compared on paraffin wax embedded tissue sections for routine classification of amyloid; the following methods were used: potassium permanganate, the indirect immunoperoxidase method using polyclonal anti-human amyloid antisera (anti-AA, anti-A lambda, anti-A kappa and anti-AF) and the peroxidase-antiperoxidase (PAP) method using antisera against human, bovine, hamster and canine AA amyloid. Anti-human AA antiserum appeared to be a useful tool in this respect. Polyclonal anti-AL antisera may be helpful in diagnosing AL amyloid, but were less of value than anti-AA serum. Strong cross reactivity between anti-bovine AA antiserum and human AA amyloid deposits was found. This indicates that animal amyloid AA antisera can also be used for the diagnosis of AA amyloid in human tissues.

Immunohistochemical identification of generalized AA-amyloidosis in a mountain gazelle (Gazella gazella)

Generalized amyloidosis was diagnosed post-mortem in a mountain gazelle (Gazella gazella). To test whether the amyloid deposits consisted of amyloid-A fibril protein a series of monoclonal and polyclonal antibodies directed against amyloid-A fibril protein of different species was applied to formalin-fixed paraffin sections using the indirect immunoperoxidase technique. The immunohistochemical results showed a moderate cross-reaction of gazelle amyloid with human, murine, hamster, and canine amyloid-A fibril protein. A strong cross-reaction, however, was found with one of two monoclonal anti-human amyloid-A antibodies and with an antiserum against bovine amyloid-A fibril protein, the amyloid fibril protein of another ungulate. These results demonstrate the presence of amyloid-A fibril protein in the gazelle amyloid and illustrate the diagnostic value of cross-reacting anti-amyloid-A antibodies for the identification of amyloid-A-amyloidosis in species and in individuals in which amyloid has not yet been examined.

Amyloid in canine mammary tumors

In canine mammary carcinomas, amyloid was present as amyloid-containing corpora amylacea and as local deposits between neoplastic epithelial cells or in stromal tissue. Histochemical staining methods revealed that this amyloid was not of the AA-type amyloid and contained tryptophan. The possible pathogenesis of this amyloid deposition is discussed.

AA-amyloidosis in dogs: partial amino acid sequence of protein AA and immunohistochemical cross-reactivity with human and cow AA-amyloid

Protein AA was purified from the kidneys of dogs with spontaneous reactive amyloidosis. The protein had a blocked N-terminal. Sequence analysis of a peptide obtained after cyanogen bromide cleavage revealed an amino acid sequence corresponding to positions 24-42 of human AA. This region showed a strong homology to protein AA of other species. Antiserum to both human and dog protein AA reacted immunohistochemically with AA amyloid of human, dog and cow origin.

Amyloidosis in a case of canine systemic lupus erythematosus

Concurrent systemic lupus erythematosus (SLE) and amyloidosis (renal and splenic) are reported in a 7-year-old female miniature Schnauzer. Treatment of tissue sections with potassium permanganate and dilute sulphuric acid prior to staining with Congo red indicated that the amyloid in this case is composed of AA protein (i.e. reactive systemic amyloid or so-called secondary amyloid). The rare association of amyloidosis and SLE, in both man and the dog, and the association with granulomatous pneumonia and leukopenia in this case are discussed.