Current concepts of amyloid

Amyloid neuropathy: immunocytochemical localization of intra- and extracellular immunoglobulin light chains

Sural nerve specimens from ten patients with amyloidosis (hereditary, associated with lymphoproliferative disorders, or of unknown origin) and peripheral neuropathy were investigated by immunohistochemistry at the light and electron microscopic level. Peroxidase-antiperoxidase and immunogold techniques were applied to glutaraldehyde-fixed, osmicated and epoxy-embedded tissue. In five cases, four of which associated with lymphoproliferative disorders, amyloid deposits strongly and exclusively reacted with antibodies to kappa or lambda light chains, respectively. By electron microscopy, bundles of immunogold-labelled amyloid fibrils could be identified in coated and uncoated single membrane-bound vesicles of endoneurial macrophages. Schwann cells did not contain intracellular amyloid but their processes were entangled in amyloid fibrils and their basement membranes were sometimes fused with the fibrillar masses. It is concluded that immunoglobulin light chains in AL (amyloid of immunoglobulin light chain origin) amyloidosis precipitate, forming amyloid fibrils, in the presence of, and presumably with the assistance of, endoneurial cells. Inefficiency of phagocytosis appears to be one of the major causes for the deleterious effects of amyloid.

Proteoglycans in the pathogenesis of Alzheimer's disease and other amyloidoses

Proteoglycans and the amyloid P component are two constituents of amyloid that appear to be present regardless of the type of amyloid protein deposited, the extent of amyloid deposition and the tissue or organ involved. This article reviews the literature concerning proteoglycans and/or glycosaminoglycans in amyloidosis and describes recent studies which demonstrate their localization to the characteristic lesions of Alzheimer's disease and the amyloid plaques containing PrP protein in the prion diseases. Additionally, the possible interaction of proteoglycans with various amyloidogenic proteins, including the beta-amyloid protein in Alzheimer's disease is discussed. It is postulated that proteoglycans localized to a number of different amyloids play a common role in the pathogenesis of amyloidosis. Some of these hypothesized roles include 1) inducing amyloidogenic precursor proteins to form amyloid fibrils containing a predominant beta-pleated sheet structure, 2) influencing amyloid deposition to occur at specific anatomical sites within tissues and/or 3) aiding in prevention of amyloid degradation once amyloid has formed.

Impaired Kupffer cell function precedes development of secondary amyloidosis

It has been demonstrated previously that the acute phase reactant, serum amyloid A (SAA), is subject to degradation by surface membrane-associated proteinases of peripheral blood monocytes. However, monocytes obtained from the blood of patients with amyloidosis degraded SAA incompletely, leaving a cleavage product that, biochemically and immunologically, resembled the amyloid protein A (AA) deposited in their tissues. To investigate the role of fixed macrophages in amyloidogenesis and to establish more definitively that amyloid deposition is attributable to faulty processing of the precursor protein rather than aberrant synthesis, secondary amyloidosis was induced in C57BL/6J mice by serial injections of casein. Kupffer cells (KC) were isolated from livers of mice that had received 0, 8, 13, 18, and greater than 30 injections of the stimulant. The cells were cultured with SAA for 4, 8, and 18 h and then subjected to electron microscopy and enzyme analyses. The medium was analyzed by SDS-PAGE to determine the amount of residual SAA and/or the appearance of AA. KC of healthy animals degraded SAA completely whereas KC of stimulated mice showed increasing amounts of residual SAA and the appearance of the AA cleavage product. The AA peptide appeared in KC cultures early during the course of casein injections and before any amyloid could be demonstrated in the organs of the stimulated mice. The addition of KC isolated from healthy mice to cultures that had produced AA eliminated the abnormal peptide. The results, indicate that defective KC function precedes amyloidosis. The abnormal AA cleavage product formed by such cells is still susceptible to hydrolysis by normal cells. In addition, ultrastructural evidence is presented that suggests that KC may also play a role in fibrillogenesis of the AA protein.

Immunopathology of the amyloid diseases

The relentless accumulation of nonimmunogenic fibrils that resist phagocytosis, proteolysis, and other normal host defense mechanisms leads to death when amyloidosis involves vital organs. Effective treatment for most of the amyloidoses lies in the future, but recent findings have enabled a classification of these diseases and are beginning to shed some light on possible pathogenetic mechanisms.

Amyloidosis in Malaysian aborigines (Orang Asli)

Material from 334 consecutive autopsies on Orang Asli subjects performed in the University Hospital, Kuala Lumpur between May 1967 and June 1978 was examined for amyloidosis. Nine positive cases were found, all in patients above 40 years of age, giving an age-corrected incidence of about 9%. In 6 cases, amyloidosis was probably secondary to tuberculosis. The remaining 3 cases exhibited a pericollagenous distribution characteristic of primary amyloidosis. Involvement of the heart and lungs was prominent. However, there were considerable similarities in the distribution and staining properties of the amyloid in the 2 groups. Though both the heart and kidney were frequently affected, the kidney was the most common organ to give rise to clinical symptoms. Infection probably plays a major contributory role in amyloidosis in the Orang Asli.

Amyloidosis presenting as a mass in the neck

A 54-year-old white male presented with a large suprahyoid midline mass. On thorough history and physical examination, he had features which characterize amyloidosis, including congestive heart failure and carpal tunnel syndrome. The classification, clinical findings, and associated syndromes are reviewed. A striking feature of the amyloid deposit is its rapid growth. Amyloidosis should now be considered in a differential diagnosis of a neck mass.

Experimental paracoccidioidomycosis in the Syrian hamster: morphology, ultrastructure and correlation of lesions with presence of specific antigens and serum levels of antibodies

Male hamsters (134) received intratesticular injection of a live cerebriform culture of Paracoccidioides brasiliensis and were sacrificed from 6 hours up to 123 days onwards. Tissues from testis, lymph nodes, lungs, liver, spleen, kidneys and intestines were examined microscopically; presence of specific antigens was saught in lesions of testis, regional lymph nodes and liver by indirect immunofluorescence (IF); inoculation site lesions were studied electron microscopically and circulating specific antibodies measured by complement fixation and IF tests. Up to 24 hours inoculation site lesions showed fungi surrounded by PMNs; 48 hours latter macrophages accumulated forming loose nodules; epithelioid granulomata appeared after 5 days. Fungi, scarce in early lesions, increased in numbers up to the time when epithelioid granulomata dominated the picture; in young granulomata fungi were abundant and small; older granulomata contained rare, vacuolated fungi. Ultrastructurally the space between fungi and host-cells was larger around reproducing forms decreasing in size as the parasites grew larger and being a virtual slit around old degenerated fungi. Immunofluorescence studies revealed that fungal walls were brightly fluorescent; in early lesions macrophages surrounding fungi or free in the intersticium contained fluorescent antigenic material in the cytoplasm; similar macrophages were observed in draining lymph nodes as early as 18 hours after inoculation, and latter, in macrophage nodules and Kupffer cells in the liver; epithelioid and giant cells appear to block diffusion of antigens, since in epithelioid granulomata fluorescence was limited to fungal walls. Disseminated paracoccidioidomycosis occurred in 100% of animals after day 5 of infection. Besides specific lesions (containing fungi), antigens were identified by immunofluorescence in 'non specific' lesions in the liver (diffuse or nodular Kupffer cell hyperplasia) and in the lymph nodes (histiocytic hyperplasia). Serum antibodies appeared in low titers, up to day 20, increasing onwards. From day 70 on, titers decreased and lesions changed from confluent epithelioid to loose granulomata infiltrated by PMNs; fungi that before were large and quiescent now were small and in active reproduction. Secondary amyloidosis was present in 85% of the amimals. In the hamster, Paracoccidioidomycosis develops as a chronic progressive disease and the lesions are related both to fungi and its antigens.

The amyloid P-component (protein AP): an integral part of the amyloid substance?

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

Amyloidosis of the larynx

Amyloidosis of the larynx is a rare disease, accounting for less than 1% of all benign laryngeal 'tumours'. Three cases of this type of lesion are reported--one of the vocal cord, one of the false vocal cord and one of the subglottis and trachea. In 2 of the patients the amyloidosis was localized, while the third was later found also to have an epipharyngeal solitary plasmacytoma with amyloid deposits and in addition amyloidosis of the nasal cavity. However, the amyloidosis in this patient may still be regarded as being localized, as the clinical examination and laboratory tests afforded no evidence of generalized disease. Amyloidosis of the larynx may be manifested as a localized tumour or as a diffuse infiltration. The symptoms and signs will, of course, depend on the site of the amyloid deposit. When the vocal cords are involved hoarseness may result, and this was the most prominent sign in the present cases. The treatment of laryngeal amyloidosis is primarily by endoscopic excision. Amyloid substance has specific staining properties. The Congo red reaction with a green birefringence in polarized light and Phorwhite BBU using fluorescence microscopy are regarded as the most reliable staining reactions. Electron microscopy has revealed a typical fibrillar structure of amyloid.

Renal amyloidosis and schistosomiasis

A retrospective study of 60 renal biopsies obtained from nephrotic subjects with schistosomiasis showed amyloid deposits in 10 cases. Distribution was usually segmental, mainly mesangial and overlapped with the conventional mesangio-proliferative lesions of schistosomiasis. The invariable clinical presentation was proteinuria with generalized oedema of insidious onset and a slowly progressive or intermittent course. Differences from conventional schistosomal nephropathy are described. Response to anti-schistosomal treatment was very poor. Repeat renal biopsies showed no regression of the lesions. The possible links between schistosomiasis and amyloidosis are discussed and causes of amyloid deposition suggested.

Amyloid in the corpora amylacea of the rat mammary gland

Histochemical and electron microscope studies indicated there was amyloid in corpora amylacea in tumors, duct ectasias and lobular hyperplasias of rat mammary glands. Electron microscopy showed fibrils that closely resembled amyloid fibrils in human and bovine amyloid and in bovine corpora amylacea. Amyloid deposition may be more common in rats than is generally thought.

Laryngeal amyloidosis: clinicopathologic study of seven cases

The larynx is usually involved with amyloid as an isolated phenomenon and infrequently in generalized amyloidosis. This study includes six females and one male with an average age of 54 years who complained chiefly of prolonged hoarseness. At direct laryngoscopy, the amyloid usually presented as firm, nonulcerated yellow, red, or white lesions most often involving the ventricle, true and false cords. Surgical biopsy and/or excision was the only form of treatment. One patient experienced recurrence of her amyloid seven years after her first operation while another patient developed extralaryngeal amyloid. Amyloid is deposited extracellularly as amorphous eosinophilic material in vascular walls and basement membranes of minor salivary glands, as random tissue masses, or as "rings" in adipose tissue. Under the electron microscope, all types of amyloid have the same basic structure. However, chemical analysis has revealed three different classes of amyloid: amyloid of immunoglobulin origin, amyloid of unknown origin, and apudamyloid. Evidence suggests an immunoglobulin origin of at least some cases of amyloid localized to the larynx. It is theorized that the secretions of a monoclonal plasmacytic infiltrate of the larynx are metabolized into immunoglobulin light chain fragments by adjacent histiocytes and deposited extracellularly as amyloid.

Parallel intraylysosomal amyloid fibrils, a possible result of phagocytosis

Vacuoles of mesenchymal cells in the papillae of bovine kidneys with amyloidosis were studied by histochemical electron microscopy for acid phosphatase as a marker for lysosomes. The vacuoles contained parallel amyloid fibrils. The vacuoles of reticular interstitial cells were found to be lysosomes. Vacuoles of macrophage-like cells of the same papillae were positive, partially positive, or negative for the enzyme activity. A suspension of papillary material was injected subcutaneously in rats in a 21-day light and electron microscopy and enzyme histochemistry study. Amyloid was demonstrated in vacuoles of macrophages throughout this period and initially also in neutrophils. In most vacuoles amyloid fibrils were randomly arranged but in others parallel arrangement was demonstrated. Amyloid was only at the inoculation sites. Intralysosomal bovine amyloid may occur in parallel fibrillar arrangement without a definite indication for amyloid production.

Crystalloids of prostatic carcinoma: relationship to Bence-Jones crystals

Previously undemonstrated protein crystalloid structures were found to occur in the malignant acini of prostatic carcinomas in 23% of cases systematically reviewed. Histochemically and immunohistochemically, they appear closely related, if not identical, to Bence-Jones crystals. Thus, the prostatic carcinoma cell is the first neoplastic cell besides those of the lymphocytic-plasmacytic series shown to produce such crystalline structures. Like the proteolytic splitting of amyloid from Bence-Jones proteins, it is postulated that prostatic epithelium may enzymatically split corpora amylacea from a Bence-Jones-like protein which it synthesizes. It is further postulated that malignant prostatic cells may lack the necessary enzymatic machinery to accomplish this with resultant accumulation of crystalloids within their acini. Prostatic crystalloids were never found in benign glands with rare exceptions and then were limited to benign appearing glands adjacent to carcinoma. The presence of such crystalloids in microscopic sections of prostate may be of diagnostic aid in determining the presence of malignancy or of a premalignant state.

Occurrence of amyloidosis secondary to the induction of experimental hypertension in mice

Following the induction of three different forms of experimental hypertension, deposits of amyloid were found in the spleens of 5-20 per cent of the mice late in the course of the hypertension, Amyloidosis was found in nude (with genetical aplasia of the thymus) as well as in haired (normal) mice. The highest frequency of amyloidosis was observed in mice with hypertension due to partial infarction of one kidney and contralateral nephrectomy. The hypertensive vascular disease, involving lesion of the vessels and of the organs supplied by the affected vessels, is believed, to represent a stimulus for the reticulo endothelial system (RES) with development of amyloidosis as a secondary event.

Amyloidosis associated with multiple myeloma

Amyloidosis is a rare, fatal disease caused by deposition of a sulfated mucopolysaccharide in various tissues and organs. Seven to ten per cent of patients with multiple myeloma, a disease of abnormal myeloid cells, have associated amyloidosis. A case of amyloidosis associated with multiple myeloma is described and a differential diagnosis for oral amyloidosis is presented to familiarize the practitioner with this entity.

The pathogenesis of amyloid deposition: a new hypothesis

Amyloid proteins are probably derived from a variety of precursor glycoproteins. It is postulated that there may be at least two key events in the pathogenesisi of amyloidosis. The first is an increase in the load of glycoprotein being brought to a site of degradation. In the case of myeloma this might be in the form of excess immunoglobulin light chains. In the case of secondary amyloidosis the form taken could be enzyme-alpha-globulin complexes. The second is an inability of the degrading site to handle the arriving substrate at a sufficiently rapid rate, the rate limiting step being at some point along the degradation pathway. We postulate that an acquired enzyme deficiency prevents removal of the carbohydrate moiety of the presented glycoprotein. This results in the accumulation of a normal intermediate (amyloid protein) during the breakdown of the glycoprotein substrate. Evidence for the operation of these mechanisms is discussed and their detailed nature and implications considered.

A historical note on the iodine-sulphuric acid reaction of amyloid

The historical development of the iodine-sulphuric acid reaction for amyloid is described. The reaction dates back to 1814 when Colin and Gaultier de Claubry, and independently Stromeyer, introduced the iodine reaction for starch. A variant of the acidified iodine reaction appears to have been used for printing paper by Gmelin in 1829, and in 1838 Schleiden used the iodine-sulphuric acid test on plants to demonstrate what he considered to be a transformation of the plant material into starch. Shortly afterwards Payen (1839) defined "cellulose", and the iodine-sulphuric acid reaction became a standard procedure used by botanists to demonstrate this plant component. In 1853 Virchow used Harting's (1847) procedure to demonstrate the reaction of Purkynĕ's corpora amylacea to this test, on the assumption that they might be cellulose derivatives, and applied it to what appeared to be similar corpuscles in a "waxy" spleen. The first histochemical reaction for amyloidosis had thus been introduced into pathology, and continued to exert from that time on an important influence on amyloid research, whose impact is felt to the present day.

Significance of urinary C3 excretion in glomerulonephritis

The third component of complement (C3) was measured in the urine of 98 patients with a variety of renal diseases. Renal biopsy was performed on 83 of the patients and examined by light, electron, and immunofluorescence microscopy. Urinary C3 was detected in cases of membranous glomerulonephritis, mesangiocapillary glomerulonephritis, rapidly progressive glomerulonephritis, and renal amuloidosis. It was not detected in minimal lesion glomerulonephritis; in cases of proliferative glomerulonephritis it was detected only in those showing histological evidence of a progressive lesion. Concentrations were low or undetectable in cases of non-immunological renal diseases. There was a good correlation between urinary C3 concentrations and the deposition of C3 in glomerular capillary walls, as seen by immunofluorescence microscopy, and there was no correlation with the degree or selectivity of proteinuria. Urinary C3 excretion appears to be an accurate indicator of continuing activity of disease. It is suggested that the presence of C3 in urine is due to complement fixation by immune complexes in glomerular capillary walls, and that urinary C3 estimations have potential applications in the study of glomerulonephritis.

Free radical theory of aging: inhibition of amyloidosis in mice by antioxidants; possible mechanism

The antioxidants, alpha-tocopherol acetate and a quinolone derivative (Santoquin), inhibited the development of amyloidosis when added to the diet of casein-injected C3HeB/FeJ male mice. Santoquin, and to a lesser extent butylated hydroxytoluene (BHT), also depressed the appearance of a plasma protein fraction in these mice; the effect of alpha-tocopherol was not determined. Consideration of the current knowledge of amyloid, in the light of these antioxidant studies, prompted the following hypothesis. Amyloidosis is largely the result of an enhanced rate of oxidative degradation of a connective-tissue glycoprotein(s) coupled with oxidative/enzymatic changes in the plasma, both of the tissue-derived substances and of immunoglobulins, to form the amyloid fibril protein subunits (AL and AA) which subsequently aggreagate to form the amyloid fibrils.

Increased life span and decreased weight in hamsters exposed to cigarette smoke

Five groups of fifty-one 2-month-old male Syrian golden hamsters received three 10-minute exposures to cigarette smoke per day, 5 days per week, for the duration of their lives. Three of the groups were also chronically exposed to aerosols of chrysotile asbestos, cobalt oxide, and nickel oxides, respectively. The fourth group received twelve weekly injections of 0.25 mg of diethylnitrosamine. The smoke-exposed groups lived significantly (P less than .01) longer than their sham-exposed cohorts and untreated controls. Their mean body weights were significantly (P less than .01) lower than in the sham-exposed groups. The hypothesis is proposed that delayed onset of amyloidosis and lower body weight in the smoke-exposed hamsters may have been responsible for their increased life spans. It is hypothesized that cigarette smoke affected the immune system of the animals, resulting in retardation of amyloidosis, a frequent cause of death in hamsters.

Amyloidosis and Light Chain Plasmocytoma

Nine cases of light chain plasmocytomas, 6 type λ and 3 type k, have been studied in reference to amyloid presence and localisation. Bone marrow plasmocytosis, light chains in serum and/or in the urine, and osteolytic lesions were demonstrated in all the patients. Initial symptoms, i.e., macroglossia and lymphadenopathy, were secondary to amyloid deposits in two patients; the absence of overt evidence of plasmocytoma had previously led to the diagnosis of « primary » amyloidosis in one case. Amyloidosis may therefore be associated with concealed plasmocytomas, evident only after a certain period of time. Amyloidosis was not detected in the sites where it was clinically suspected in two cases. However, on bone marrow aspirates, amyloid was present in seven patients where thioflavine T appeared as homogeneous, amorphous, intercellular substance localised in small areas.

Diagnosis of cardiac amyloidosis by myocardial biopsy

A case of cardiac amyloidosis with severe heart failure is presented. The diagnosis was confirmed by myocardial biopsy. The microscopical and ultrastructural changes in this biopsy are described in detail.

Experimental amyloidosis: the inducer is a polyclonal B-cell activator to which susceptibility is under genetic control

Experimental amyloidosis in mice can be induced by repeated injections of casein. It has now been demonstrated that casein induces strong polyclonal antibody synthesis in mouse B spleen lymphocytes. This effect is much more pronounced in spleen cells from anyloid-susceptible mice (CBA/J) than amyloid-resistant mice (A/J). It is suggested that amyloidosis can be due in some instances to a constant exposure for molecules which induce polyclonal B-cell activation.

Immunopathological lymph node findings in Hodgkin's disease: correlation to survival

217 diagnostic lymph nodes biopsies from cases of Hodgkin's disease were classified according to the criteria established by the Rye Conference. These were later subdivided into survival groups using immunopathological parameters solely. In the light of findings based upon 63 cases whose progress has been followed, it appears that the classification of Hodgkin's disease according to immunopathological parameters may serve to eliminate many of the inconsistencies encountered with the utilization of classical procedures, especially in the correlation between histopathological analysis and prognosis. The new classification consists of three groups: I. Long survivals (greater than 5 years): extensive lymph node preservation of antibody mediated (average approximately 65%) and cell mediated (average approximately 37%) immunity, and/or a nodular birefringent fibrosis-hyalinosis. - - - (15,9%). II. Medium survivals (less than or equal to 5 greater than 2 years): partial lymph nodes preservation of antibody mediated (average approximately 42%) and/or cell mediated (average approximately 17%) immunity, and/or numerous epithelioid cal to 2 years): minimal lymph node antibody mediated (average approximately 7%) and cell mediated (average approximately 1%) immunological activity, no epithelioid cell infiltrates and no birefringent fibrosis-hyalinosis. - - - (41,2%).

Amyloidosis: a rational approach to diagnosis by intraoral biopsy

Amyloidosis and its oral manifestations are briefly described. The techniques for antemortem tissue diagnosis of amyloidosis are reviewed and evaluated. In screening for amyloidosis, biopsy of specific oral lesions (when present) is recommended instead of the traditional biopsy of normal-appearing gingiva. This approach is illustrated with four cases. Although rectal biopsy is generally accepted as the screening technique of choice, it is suggested that intraoral biopsy be considered as an easier, safer, more comfortable, and possibly more fruitful technique. It is advocated that in cases of both documented and suspected amyloidosis both intraoral and rectal biopsies should be performed in order to help provide documentation of the most useful technique for routine screening.

The clinical spectrum of light chain myeloma. A study of 35 patients with special reference to the occurrence of amyloidosis

During a 40 month interval, 35 patients were seen with a plasma cell dyscrasia in which the only detectable monoclonal immunoglobulin abnormality consisted of excess production of either type kappa or type lambda light chains (Bence Jones protein). This group constituted 17.3 per cent of the total number of patients with plasma cell dyscrasias and 25.7 per cent of the patients with myeloma identified during the same period. Variable initial clinical presentation, the absence of a typical monoclonal serum spike and the unreliability of commonly used urine protein tests made recognition of the disorder difficult in many patients. Sulfosalicylic acid and p-toluene sulfonic acid proved valuable in screening for ueine protein. Definition of "proteinuria" by quantitative, electrophoretic and immunochemical studies was essential for diagnosis. Bence Jones proteinemia was present in 80 per cent of the patients; panhypogammaglobulinemia and lytic bone lesions were demonstrable in more than 60 per cent. Although no specific morphologic abnormality of marrow plasma cells was evident by light microscopy, the absence of rouleau on peripheral blood smear was a helpful diagnostic clue. Although patients with lambda light chains presented with more Bence Jones proteinuria, this did not correlate with the severity of initial renal functional impairment or with survival when compared to patients with kappa light chains. No other clinical or laboratory observation differentiated the groups with kappa light chains from those with lambda light chains. Amyloid was identified in seven patients. Their course was dominated by the features of primary systemic amyloidosis instead of the usual findings of classic myeloma. Patients with amyloidosis had lower initial serum albumin levels, fewer lytic bone lesions and reduced survival compared to patients without amyloidosis.

Ultrastructural and enzyme histochemical aspects of amyloidosis in the bovine renal medulla

Electron micrsocopic studies of bovine kidneys with amyloidosis showed macrophage-like cells in the interstitial amyloid that were either disseminated or in small groups. They had rather uniform protracted vacuoles filled with parallel fibrils. Similar vacuoles were also found in some reticular interstitial cells. In some samples electron-dense vacuoles and vacuoles containing fibrils were seen. Protracted lysosomal enzyme activity was seen in macrophage-like cells and reticular interstitial cells; these areas of activity showed green birefringence with Congo red. The vacuoles were thought to be lysosomes, and the parallel amyloid fibrils could be a consequence of intracellular formation or of phagocytosis.

Immunological responses to Candida albicans II. Amyloidosis in mice induced by candidiasis

Candida albicans infection in the mouse thigh rapidly induces amyloidosis in mice of the C57BL/Ks strain; amyloid is induced more slowly and to a lesser extent by viable candida in C3H and AKR mice, and by both viable Saccharomyces cerevisiae and heat-killed C. albicans in C57BL/Ks mice.

Blockage of amyloid induction by colchicine in an animal model

Colchicine was found to have a strong inhibitory effect on amyloid induction in an animal model. When CBA/J mice were treated with colchicine concurrently with the amyloid induction regimen, the incidence of amyloidosis was, depending upon the dosage of colchicine, significantly decreased (0.005-0.010 mg colchicine per day) or completely blocked (more than 0.015 mg colchicine per day). The colchicine treatment was effective not only when colchicine was given for the entire course of the amyloid induction regimen but also when it was given only in the late pre-amyloid or the amyloid phase of the regimen or to the recipients after the transfer of amyloid. The data suggest the colchicine is effective in blocking amyloidogenesis at its final stage(s), while it may not affect significantly amyloid already deposited in the tissue.