Glycosylated human interleukin-1alpha, neoglyco IL-1alpha, coupled with N-acetylneuraminic acid exhibits selective activities in vivo and altered tissue distribution

In order to study the effect of glycosylation on its biological activities and to develop IL-1 with less deleterious effects, N-acetylneuraminic acid (NeuAc) with C9 spacer was chemically coupled to human recombinant IL-1alpha. NeuAc-coupled IL-1alpha (NeuAc-IL-1alpha) exhibited reduced activities in vitro and receptor-binding affinities by about ten times compared to IL-1alpha. In this study, we examined a variety of IL-1 activities in vivo. NeuAc-IL-1alpha exhibited a marked reduction in the activity to up-regulate serum IL-6, moderate reduction in the activities to up-regulate serum amyloid A and NOx. However, it exhibited comparable activities as IL-1alpha to down-regulate serum glucose and to improve the recovery of peripheral white blood cells from myelosuppression in 5-fluorouracil-treated mice. In addition, tissue level of NeuAc-IL-1alpha was high compared to IL-1alpha. These results indicate that coupling with NeuAc enabled us to develop neo-IL-1 with selective activities in vivo and enhanced tissue level.

[Multiple nodular pulmonary AA amyloidosis. A case report]

Amyloidosis is a uncommon disease which affect respiratory system with well defined patterns. We describe a case of multiple nodular pulmonary amyloidosis in a 81 year old man mimicking other entities: metastatic disease, tuberculosis and other granulomatose diseases. In our patient amyloide substance was type AA, being type AL the most frequent one in nodular pulmonary amyloidosis.

[AA amyloidosis complicating sarcoidosis]

INTRODUCTION

Amyloidosis combined with sarcoidosis has been very rarely described.

EXEGESIS

We report the case of a 72-year-old man presenting with sarcoidosis and amyloidosis AA. The association of peripheral and retroperitoneal adenopathies accompanied by loss of weight and histopathological results conducted to the diagnosis of sarcoidosis, excluding other causes. Corticosteroid therapy led to a decrease in clinical manifestations and after 2 years, clinical signs of amyloidosis have not progressed.

CONCLUSION

According to results previously described in the literature and the description of the present case, we conclude that sarcoidosis can be complicated by amyloidosis AA, the presence of which may justify corticosteroid therapy.

Clinical benefits of diagnosing incipient AA amyloidosis in pediatric rheumatic diseases as estimated from a retrospective study

OBJECTIVE

The diagnosis of AA amyloidosis could not be made in eight patients with pediatric rheumatic diseases as later verified employing the more sensitive combination of Congo red and additional immunocytochemistry (CRIC). The objective of this paper is to estimate the benefit of CRIC by reevaluating the historical charts with respect to the question as to which of the diagnostic and therapeutic measures would have been altered if the correct diagnosis had been known at the time of the primary biopsy.

METHODS

All subsequent biopsies of eight children with historically missed AA amyloidosis in their primary biopsies were retrieved, together with the historical data including the Congo red stains of the biopsies. The biopsies were reexamined blindly for the presence of amyloid and the results were compared with the historical data concerning diagnostic and therapeutic measures.

RESULTS

Using CRIC, AA amyloidosis could be identified an average of approximately three years earlier as compared to the historical data. This gain in time would certainly have altered the diagnostic as well as the therapeutic options, i.e. 10 out of 21 biopsies would have been spared and the earlier diagnosis would have initiated more significant antiinflammatory therapy.

CONCLUSION

Very early detection of amyloid reduces the diagnostic burden and unveils an option for a consequent antiinflammatory therapy very early in the course of AA amyloidosis.

The liver in systemic amyloidosis: insights from 123I serum amyloid P component scintigraphy in 484 patients

BACKGROUND AND AIMS

The liver is frequently involved in amyloidosis but the significance of hepatic amyloid has not been systematically studied. We have previously developed scintigraphy with 123I serum amyloid P component (123I-SAP) to identify and monitor amyloid deposits quantitatively in vivo and we report here our findings in hepatic amyloidosis.

METHODS

Between 1988 and 1995, 805 patients with clinically suspected or biopsy proven systemic amyloidosis were evaluated. One hundred and thirty eight patients had AA amyloidosis, 180 had AL amyloidosis, 99 had hereditary amyloid syndromes, and 67 had dialysis related (beta 2 microglobulin) amyloid. One hundred and ninety two patients with amyloidosis were followed for six months to eight years.

RESULTS

Hepatic amyloid was found in 98/180 (54%) AL and 25/138 (18%) AA patients but in only 1/53 patients with familial transthyretin amyloid polyneuropathy and in none with dialysis related amyloidosis. There was complete concordance between hepatic SAP scintigraphy and the presence or absence of parenchymal amyloid deposits on liver histology. Amyloidosis was never confined to the liver. Mortality was rarely due to hepatic failure, although hepatic involvement with AA amyloid carried a poor prognosis. Successful therapy to reduce the supply of amyloid fibril protein precursors was followed by substantial regression of all types of amyloid.

CONCLUSIONS

SAP scintigraphy is a specific and sensitive method for detecting and monitoring hepatic amyloid. Liver involvement is always associated with major amyloid in other organ systems and carries a poor prognosis in AA type. Appropriate therapy may substantially improve prognosis in many patients.

Amyloidosis: a review of recent diagnostic and therapeutic developments

Amyloid deposition is associated with a diverse range of disorders that includes Alzheimer's disease, type II diabetes mellitus and dialysis arthropathy. Although less common, systemic AA and AL amyloidosis remain important because effective treatments have increasingly become available. The pathology in all forms of amyloidosis involves the extracellular deposition of protein as characteristic fibrillar aggregates which interfere with tissue structure and function. Amyloid fibrils are derived from different unrelated proteins in the different forms of the disease but share many common properties, including the capacity to bind the normal plasma protein serum amyloid P component (SAP). This is the basis for our development of radiolabelled SAP as a nuclear medicine tracer for the diagnosis and quantitative monitoring of amyloid. Serial studies have shown that the deposits are far from inert but are actually turned over quite rapidly in many patients. The treatment of amyloidosis involves supportive measures whilst every effort is made to reduce the supply of the respective fibril precursor protein. Under favourable circumstances further amyloid deposition will be prevented. existing deposits will regress and improvement of organ function will occur. Since this strategy is not always possible or may fail, new approaches to inhibit fibril formation and promote regression of amyloid are being pursued.

Amyloidosis: a global problem common in Papua New Guinea

The increase in different precursor proteins that have been shown to form amyloid fibrils and the identification of common properties have not yet led to any unifying theory or mechanism for the pathogenesis of amyloidogenesis. Papua New Guinea holds a unique place in the story of amyloidosis and in this article we review the current status of amyloidosis research indicating how this relates to those forms relevant to Papua New Guinea. This review concentrates on secondary reactive amyloid (AA), which is found in the highest frequency in the world in parts of Papua New Guinea, and kuru, in which the amyloid protein itself is infectious. The history, pathogenesis and future prospects for these diseases are discussed in the light of what is known about other forms of amyloidosis.

Renal amyloidosis in childhood. An overview of the topic with 25 years experience

Amyloidosis is a heterogeneous group of diseases characterized by extracellular accumulation of an eosinophilic, hyalin and proteinaceous material containing mucopolysaccharide substance in various tissues and organs. Knowledge about the chemical structure of amyloid fibril proteins has led to the recognition of various forms of amyloidosis including Amyloid-A (AA), Amyloid-L (AL), hereditary, senile, dialysis-related, localized and cerebral amyloidosis. It is now recognized that all types of amyloid contain amyloid P (AP) component which is derived from the serum amyloid P component, a normal circulating glycoprotein and a member of the pentraxin family. A recent classification proposed by WHO-IUIS (Nomenciature Subcommittee) is based on the chemical nature of amyloid fibris rather than their clinical and pathologic features. The kidneys are frequently involved, and renal failure is the major cause of death. Childhood renal amyloidosis is almost always secondary (reactive, AA type) and usually associated with chronic inflammatory, infectious and heredofamilial diseases. In developed countries, rheumatoid arthritis is the most common cause of renal amyloidosis, while in developing countries patients with familial Mediterranean fever (FMF) (untreated) and chronic suppurative infections constitute a large proportion of renal amyloidosis cases. No specific therapy is currently available for amyloidosis. Once renal amyloidosis develops, progress to end-stage renal failure is almost inevitable within 2-13 years. The aim of treatment is to give effective supportive therapy and to control the underlying diseases by colchicine, alkylating agents and appropriate antibiotics. The prognosis of patients with end-stage renal failure can be improved by maintenance dialysis and renal transplantation. The growing knowledge about the pathogenesis and chemical nature of amyloid fibris may open up further avenues for the discovery of specific therapeutic modalities against amyloidosis.

Nomenclature of amyloid and amyloidosis. WHO-IUIS Nomenclature Sub-Committee

This classification of amyloid and amyloidosis is based on the amyloid fibril proteins, followed by a designation of the fibril protein precursor. Additional information includes the protein type or variant (where applicable) and the clinical diagnosis.

Therapy of amyloid diseases

Deposition of amyloid in the organism can lead to severe clinical symptoms and syndromes which are referred to as amyloidosis. However, amyloidosis is not a pathogenetically single disease entity. Various amyloid diseases are known which can clearly be distinguished by identifying the protein from which the amyloid is derived. Since the amyloid syndromes are pathogenetically diverse, each of the different amyloid diseases needs to be treated differently, and a type-specific amyloid therapy is mandatory. Unfortunately, an efficient therapy is not yet available for most amyloid syndromes. It is the purpose of this review to show how the different amyloid syndromes are distinguished definitively from each other and what has been successful in the effort to establish an efficient therapy of the various amyloid deposits and different amyloidoses.

Primary structures of dog and cat amyloid A proteins: comparison to human AA

1. The complete amino acid sequences of canine and feline amyloid A (AA) proteins were determined and compared with the sequence of human AA protein. 2. The dog and cat AA proteins were 84% homologous with human AA through residue 69. 3. Between the residues which correspond to 69 and 70 in the human sequence, the dog and cat proteins had an insertion of eight amino acids after which homology with human AA resumed. 4. While human AA commonly ends at position 76, the carboxyl termini of dog and cat AA proteins corresponded to position 86 in the sequence of the precursor protein-serum amyloid A. 5. These results are particularly interesting with respect to evolution of the serum amyloid A gene family.

Circular-dichroism studies on two murine serum amyloid A proteins

C.d. studies have shown that mouse SAA2 (serum amyloid A2) protein has about one-half of the alpha-helix content of the SAA1 (serum amyloid A1) analogue (15 as against 32%), although secondary-structure prediction analyses based on sequence data do not suggest such a large difference between the forms. The decreased helical content may be a reflection or indication of a stronger propensity to aggregation of the SAA2 form compared with SAA1. The main elements of secondary structure in both proteins are beta-sheets/turns. Interactions with Ca2+ are accompanied by small losses in alpha-helix content, whereas binding to chondroitin-6-sulphate in the presence of millimolar Ca2+ also decreases the amount of secondary structure. However, SAA2 binding to heparan sulphate increases its beta-sheet structure, whereas with SAA1 secondary structure is not apparently altered by its interaction with heparan sulphate. Computer-generated surface profiles show slight differences in accessibility, hydrophilicity and flexibility between the proteins. Understanding these differences may help to explain why SAA2 is found in amyloid fibrils whereas SAA1 is not. In particular, a stronger tendency to aggregation might be the reason why SAA2 is deposited exclusively in these fibrils.

A reproducible model for the study of factor X kinetics in AA amyloidosis

Factor X clearance was examined in a model of rapid AA amyloid deposition. Accelerated equilibration with extravascular compartments and accelerated removal postequilibration mimic features seen in patients with AL amyloidosis. The handling of Factor X was different from that of two other proteins, mouse albumin and IgG. Each protein had its own specific characteristic clearance properties, although in amyloidotic animals all proteins were cleared more rapidly in the postequilibration phase. The liver was by far the major site of Factor X clearance but this was true in all control groups as well. No significant difference was seen in tissue clearance site in any of the treatment groups, perhaps because the amount of AA amyloid in each tissue 3 days into the protocol was not yet large. Nevertheless, a reproducible model that possesses accelerated Factor X clearance is now available to study the mechanism of coagulation factor abnormalities in amyloidosis.

AA amyloidosis associated with systemic lupus erythematosus

A 54-year-old female with a 23-year history of systemic lupus erythematosus was admitted because of loss of renal function and nephrotic syndrome. Renal biopsy showed deposition of AA amyloid as demonstrated by Congo red staining and reactivity with protein AA-specific antibodies. Immune deposits were present in the mesangium and the glomerular basement membrane, but histopathological changes consistent with lupus nephritis were not detected. The rare association of systemic lupus erythematosus and amyloidosis is discussed in view of the characteristics of the acute phase reaction in systemic lupus erythematosus.

A new model of AA-amyloidosis induced by oral pristane in BALB/c mice

Fifteen male BALB/c mice were given six intermittent oral doses of O.I. ml pristane (2, 6, 10, 14 tetramethylpentadecane) within a period of 9 weeks. Fifteen mice receiving tap water using the same schedule formed the control group. Amyloidosis was first detected in the spleen of a mouse which had died 33 weeks after the first dose and 24 weeks after the last. All six mice which were subsequently autopsied 34-51 weeks after the first dose also showed amyloidosis involving liver and spleen. The most extensive tissue deposits were seen at 37-38 weeks whereas the older mice showed predominantly chronic renal lesions with papillary necrosis, scars and cystic change. Electron microscopy confirmed the identity of the amyloid fibrils and the presence of globular stellate amyloid 'bodies' in liver and spleen. The amyloid deposits were shown to be made up of AA (amyloid associated) protein using an indirect immunoperoxidase method and a monoclonal rat anti-murine AA protein antibody. We did not find any plasmacytomas or increased numbers of plasma cells in the bone marrow. None of the control mice developed amyloidosis. This new experimental model promises to provide a means of studying several aspects of secondary amyloidosis which may be relevant to the clinical situation.

Predicted secondary structure and membrane topology of the scrapie prion protein

The integral membrane sialoglycoprotein PrPSc is the only identifiable component of the scrapie prion. Scrapie in animals and Creutzfeldt-Jakob disease in humans are transmissible, degenerative neurological diseases caused by prions. Standard predictive strategies have been used to analyze the secondary structure of the prion protein in conjunction with Fourier analysis of the primary sequence hydrophobicities to detect potential amphipathic regions. Several hydrophobic segments, a proline- and glycine-rich repeat region and putative glycosylation sites are incorporated into a model for the integral membrane topology of PrP. The complete amino acid sequences of the hamster, human and mouse prion proteins are compared and the effects of residue substitutions upon the predicted conformation of the polypeptide chain are discussed. While PrP has a unique primary structure, its predicted secondary structure shares some interesting features with the serum amyloid A proteins. These proteins undergo a post-translational modification to yield amyloid A, molecules that share with PrP the ability to polymerize into birefringent filaments. Our analyses may explain some experimental observations on PrP, and suggest further studies on the properties of the scrapie and cellular PrP isoforms.

X-ray scattering and diffraction by wet gels of AA amyloid fibrils

Systemic amyloidosis is characterized by the extracellular accumulation of protein fibrils with typical ultrastructural morphology. The persistence in vivo of amyloid fibrils, which is responsible for their serious clinical effects, has been thought to reflect the particular, specific conformation of peptide chains constituting the fibrils. On the basis of earlier structural studies this conformation is generally considered to be almost exclusively anti-parallel beta-sheets. We have re-examined X-ray scattering by human amyloid A protein (AA) amyloid fibrils, with careful attention to the state of hydration of the preparations. We show that a stack of anti-parallel sheets is not consistent with the details of the X-ray pattern, which contains diffracted intensities that can be indexed on a 33A X 33A lattice. A structural model for the AA fibre consistent with the X-ray data is presented. The model takes account of the prediction of the secondary structure of the AA precursor SAA1(alpha) presented in our accompanying paper, and has the AA monomers arranged on a primitive lattice, with two unique molecules per unit cell.