Tumor necrosis factor as effector molecule in monocyte mediated cytotoxicity.

A newly developed assay system which uses actinomycin D (Act D) pretreated Wehi 164 target cells allows for the measurement of human monocyte cytotoxicity in a 7-h 51Cr release assay. Using the monocyte specific monoclonal antibody M42 in a direct rosetting procedure we confirm herein that among human peripheral blood mononuclear cells cytotoxicity is restricted to monocytes. When applying stringent conditions that exclude exogenous lipopolysaccharide (LPS) we could demonstrate that as little as 0.1 ng of LPS per ml triggers this cytotoxicity. Further, a factor can be detected in supernatants of mononuclear cells which is also cytotoxic against Act D treated Wehi 164 cells. This cytotoxic factor can be triggered by LPS within 4 h, but at as low a LPS concentration as 0.001 ng/ml. Since one of the LPS triggered monocyte products is tumor necrosis factor (TNF), we tested the effect of recombinant TNF cloned from the U937 cell line and we could show potent lytic activity against Act D pretreated but not, or only minimally, against untreated Wehi 164 target cells. Recombinant TNF rapidly lysed the target with significant specific release occurring as early as after 3 h in the assay. By contrast, recombinant interleukin 1 gave no lysis while lymphotoxin derived from the RPMI 1788 cell line was effective. An affinity purified antiserum directed against TNF neutralized the lytic activity of recombinant TNF and also the cytotoxic factor produced by LPS triggered mononuclear cells, while the antiserum was ineffective against lymphotoxin. Further, the antiserum when added to the assay of effector cells and Act D treated Wehi 164 cells also completely ablated cytotoxic activity. Size fractionation of cytotoxic factor and recombinant TNF by high pressure liquid chromatography led to a superimposable peak of cytotoxicity in the molecular weight range of 9,500-17,000. Further, immunoblotting with the anti-TNF antibody revealed the same Mr 15,500-16,500 band for the recombinant TNF and LPS triggered cytotoxic factor. Taken together, our data demonstrate that the cytotoxic activity of human monocytes against Act D treated Wehi 164 is mediated entirely by a LPS triggered molecule that is very similar or identical to the human tumor necrosis factor. The assay system thus provides a powerful tool to analyze the biology of TNF in humans.

Amphiphilic properties of the low molecular weight component of serum amyloid-A protein shown by charge-shift electrophoresis.

To test whether the low molecular weight component of serum amyloid-A protein (SAAL) is amphiphilic in character, serum amyloid-A protein (SAA)-containing sera and isolated SAAL were subjected to charge-shift electrophoresis by the technique of Helenius and Simons (Helenius, a. and Simons, K. (1977) Proc. Natl. Acad. Aci. U.S.A. 74, 529-532). When compared to six hydrophilic and two amphiphilic serum proteins, SAAL was shown to behave like the latter in this test. Therefore, SAAL displays properties of apolipoproteins and integral membrane proteins. In the same test, amyloid-A protein (AA) also was found to be amphiphilic, confirming a previous report. The fact that protein AA displays a larger charge shift than that of protein SAAL suggests that the main hydrophobic site of SAAL resides in its N-terminal AA-portion rather than in its C-terminal (SL) part.

Serological identification and separation of canine lymphocyte subpopulations.

In vitro treatment of bone marrow grafts with absorbed rabbit-antidog thymocyte globulin (ATG) prevented graft-versus-host disease in a substantial number of the dogs differing by one DLA haplotype. Absorbed ATG has now been used for serological identification of canine lymphocyte populations. Specific labeling of canine T-lymphocytes by absorbed ATG could be demonstrated by (a) a distribution of ATG-positive cells in suspensions of canine lymphoid organs similar to that of T cells observed in other species and by specific staining of paracortical thymus-dependent lymph node areas in immunohistochemistry, (b) complementary labeling of nylon-wool-separated cells by ATG and antiimmunoglobulin sera, and (c) correlation of ATG surface labeling with responder activities in mixed lymphocyte cultures.

Amyloid typing using antisera to prototype fibril proteins. A brief note.

Amyloid fibril proteins from three patients with generalized amyloidosis were isolated and chemically characterized by N-terminal amino-acid sequence studies in two of them. As they belonged to three different amyloid classes they served as prototypes for the preparation of antisera specific for each class. Using these antisera in immunodiffusion, amyloid fibril proteins of 15 additional cases with generalized amyloidosis have been investigated. These could be grouped into four categories: seven belonging to the amyloid A type, three to the amyloid L, lambda type, and three to the amyloid L, kappa type; the amyloid fibril proteins of two patients could not be classified by these agents and may represent still unidentified amyloid types.

Transthyretin-associated neuropathic amyloidosis. Pathogenesis and treatment.

Hereditary amyloidoses form a clinically and genetically heterogeneous group of autosomal dominantly inherited diseases characterized by the deposit of insoluble protein fibrils in the extracellular matrix. They typically present with polyneuropathy, carpal tunnel syndrome, autonomic insufficiency, and cardiomyopathy and gastrointestinal features, occasionally accompanied by vitreous opacities and renal insufficiency. Other phenotypes are characterized by nephropathy, gastric ulcers, cranial nerve dysfunction, and corneal lattice dystrophy. Rarely, involvement of the leptomeningeal or cerebral structures dominates the clinical picture. The age at onset is as early as 17 and as late as 78 years. The basic constituents of amyloid fibers are physiologic proteins that have become amyloidogenic through genetically determined conformation changes. Mutated transthyretin (TTR), formerly termed prealbumin, is the most frequent offender in hereditary amyloidosis. Orthotopic liver transplantation (OLT) stops the progression of the disease, which is otherwise invariably fatal, by removing the main production site of amyloidogenic protein. The indications for OLT and its success depend on the grade of cardiovascular and autonomic dysfunction at the time of surgery, age, comorbidity, and type of mutation. Alternative treatment modalities with drugs stabilizing the native tetrameric conformation of TTR and inhibiting fibril formation are currently being studied.

Direct determination of molecular ratios of peptides coupled via N-succinimidyl 3-(2-pyridyldithio)propionate to carrier proteins using high performance liquid chromatography.

A simple, rapid and reproducible method is presented for direct determination of the substitution ratio of a carrier protein with a synthetic nonradioactively labeled peptide. The peptide was covalently linked by a thiol group of a cysteine residue to the immunogenic carrier protein using the heterobifunctional reagent N-succinimidyl 3-(2-pyridyldithio)propionate. The substitution ratio was determined after reductive cleavage of the intermolecular disulfide bond between peptide and carrier and the amount of carrier and peptide quantitated directly by calibrated HPLC analysis within 15 min.

Monoclonal antibodies against amyloid fibril protein AA. Production, specificity, and use for immunohistochemical localization and classification of AA-type amyloidosis.

Monoclonal antibodies against amyloid fibril protein AA were produced by cell fusion of murine P3 X 63-Ag8.653 myeloma cells with spleen cells of immunized Balb/c mice. To increase immunogenicity, protein AA was coupled to horseradish peroxidase (HRP) or human high molecular weight kininogen (HMWK). Using micro-ELISA (enzyme-linked immunosorbent essay) seven hybridoma cell lines secreting antibodies that specifically bind to protein AA have been selected and cloned. When applied to formalin-fixed paraffin sections of a variety of different amyloid types using immunoperoxidase methods, five monoclonal antibodies bound specifically and strongly to amyloid only of the AA type. Since a series of different AA-amyloids could be stained, these reagents may be used to routinely diagnose AA-amyloidosis in tissue sections. A monoclonal antibody against HRP has also been produced that has been utilized to develop a monoclonal peroxidase-antiperoxidases (PAP) complex. When three immunoperoxidase methods were compared, the sensitivity of a conventional rat PAP was comparable to the monoclonal PAP complex, but the latter was easier to handle. Both methods were more sensitive than the indirect immunoperoxidase technique.

High-sensitivity diagnosis of AA amyloidosis using Congo red and immunohistochemistry detects missed amyloid deposits.

Biopsy diagnosis of early amyloid-A (AA) amyloidosis has often been difficult. Examination of 57 consecutive biopsy specimens from 42 patients with inflammatory pediatric diseases permitted comparison of the precision of biopsy amyloid diagnosis in six different laboratories (labs), which applied the following methods: Congo red alone (four unspecialized labs combined as Lab 1), Congo red and electron microscopy (Lab 2), or Congo red and immunohistochemistry using monoclonal antibodies (Lab 3). Lab 3 reexamined the diagnoses made by Lab 1 and Lab 2. Of the 42 patients, 17 patients with 32 biopsies were selected for this study based on the presence of amyloid in at least one biopsy. Whereas massive or no amyloid was concordantly recognized by all labs in 18 biopsies from nine patients, discordance was demonstrated in 14 biopsies from eight patients. Comparison of Labs 1-3 revealed amyloid in 12 rectal and 18 renal biopsies evaluated by Lab 3, whereas Lab 2 missed amyloid in two of 18 renal biopsies and Lab 1 missed amyloid in 11 of 12 rectal biopsies. Most amyloid was missed when only minute amounts of amyloid were present. Had our technique (Lab 3) been available at the time of biopsy, amyloid could have been diagnosed years earlier, thereby sparing the patient further biopsies and allowing initiation of earlier treatment before organ damage could occur.

Immunoelectron microscopic classification of amyloid in renal biopsies.

Recent classification of amyloidosis is based on the chemical type of amyloid protein involved. In this study, routinely embedded kidney biopsies from nine patients with generalized amyloidosis and renal involvement were tested by immunoelectron microscopy, using the protein A-gold technique, with a panel of antibodies against the following amyloid proteins: AA, A lambda, A kappa and AF. Among the antibodies, the anti-AA was monoclonal (mc1) and the others polyclonal. In all nine cases, only one type of antibody reacted with each amyloid type. Six cases were classified as AA and three cases as A lambda type. These classifications were in agreement with the clinical data and the results of serum and urine immunoelectrophoresis. The gold particles were always associated with amyloid fibrils. No reaction was evident when an amyloid type was stained by a non-corresponding antibody, or in the four control cases without amyloid. The results show that antigenic classification of amyloid is feasible on routinely processed ultra-thin epoxy sections by immunoelectron microscopy, and thus affords the possibility of retrospective studies.

Amyloid deposits in lymph nodes: a morphologic and immunohistochemical study.

In a series of approximately 80,000 lymph nodes, amyloid deposition was found in 18; 12 of those nodes were selected, on the basis of availability of specimens, for investigation by immunohistochemical typing to identify the protein of origin and by correlation with morphologic criteria and clinical information. Four patterns of amyloid deposition were identified: lymph node vessel involvement, follicular deposition, diffuse deposition, and a combination of follicular and diffuse deposition. All cases were classified immunohistochemically with the amyloid type-specific antisera anti-AA, anti-A lambda, anti-A kappa, anti-ASc1, and anti-AF. Immunoglobulin-derived protein (AL) in lymph nodes was found in every case of isolated amyloidosis, lymphoplasmacytic/lymphoplasmacytoid immunocytoma, plasmacytoma, and idiopathic amyloidosis. Among the cases of AL amyloidosis were nine of A lambda and one of the A kappa type. AA protein was present in two cases of reactive systemic amyloidosis. There was no useful morphologic correlation with the immunohistochemically identified amyloid types.

Amyloid localized to tenosynovium at carpal tunnel release. Immunohistochemical identification of amyloid type.

Thirty-five patients seen at the Mayo Clinic from 1968 to 1977 who had carpal tunnel syndrome and local deposition of amyloid without evidence of systemic amyloidosis were identified. The unlabeled immunoperoxidase method was used with antisera against purified amyloid proteins of the AA, A kappa, A lambda, AF/ASC1 (prealbumin) (transthyretin), and AB (beta 2-microglobulin) types. In 33 of the 35 patients, amyloid stained with antisera to transthyretin; in the remaining 2 patients, the amyloid did not stain with any antisera. Nine of the 35 patients had a monoclonal protein in the serum, and 2 had a monoclonal light chain in the urine. Systemic amyloidosis or multiple myeloma did not develop in any of these 11 patients. During follow-up, systemic amyloidosis developed in only 2 of the 35 patients: 1 had senile systemic amyloidosis and 1 had tissue that was inadequate for immunohistochemical staining. Amyloid localized to the tenosynovium consists of transthyretin, and systemic amyloidosis rarely develops.

Amyloid goiter and arthritides after kidney transplantation in a patient with systemic amyloidosis and Muckle-Wells syndrome.

A case of hereditary AA amyloidosis with Muckle-Wells syndrome is described. After a successful kidney transplantation for chronic renal failure due to renal amyloid deposits at age 21, the patient, a white female now 26 years of age, developed a large amyloid goiter as a manifestation of the systemic amyloidosis and recurrent monarthritides. Both observations are novel for this disease. Subtotal thyroidectomy and oral colchicine administration, known to be effective in preventing complications of familial Mediterranean fever, another hereditary type of AA amyloidosis, proved highly effective in the management of this unusual case.

Immunohistochemical distinction between amyloidosis and fibrillar glomerulopathy.

Six patients with glomerulonephritis and glomerular proteinaceous deposits constituted by fibrillar ultrastructures similar to those of amyloid but lacking the Congo red tinctorial affinity characterizing amyloid were studied. Clinically, these patients had proteinuria and hematuria; in addition, three patients had hypertension and one renal failure. Protein deposits in their kidney biopsy sections were evaluated by immunofluorescence, immunoperoxidase, and immunoelectron microscopic (protein A-gold) techniques, using antibodies against IgG, IgA, IgM, C3, C1q, fibrinogen, immunoglobulin kappa and lambda light chains, and against amyloid fibril proteins of different types, including AA, A lambda, A kappa, and AF. By immunofluorescence and immunoperoxidase, in all cases the deposits stained intensely with antibodies against IgG, C3, and kappa and lambda light chains; one case also showed C1q immunoreactivity. By contrast, none stained with antibodies against various amyloid fibril proteins. Immunoelectron microscopic findings corroborated this data, indicating that the nonamyloid fibrillar deposits studied are antigenically distinct from known amyloid deposits and that they contain IgG-derived material.

Cardiac amyloid deposits in endomyocardial biopsies. Light microscopic, ultrastructural, and immunohistochemical studies.

In four patients with unexplained, abnormal thickening of the interventricular septum as demonstrated by echocardiography, right ventricular endomyocardial biopsy revealed unexpected cardiac amyloid deposits that resulted in increased myocardial thickness and rapidly progressive heart failure. Light microscopically, amyloid was observed in the subendocardial layer, interstitium, and walls of the intramural arterioles. Electron-microscopically, the amyloid fibrils were adjacent to the basement membranes of the heart muscle cells and the vascular smooth muscle cells. Immunohistochemical typing with specific antibodies against different amyloid fibril proteins on glutaraldehyde-fixed paraffin sections revealed different amyloid types. In two patients with generalized idiopathic amyloidosis and in two others with amyloidosis in multiple myeloma, the A-lambda form was diagnosed. In a fifth patient, AA-amyloidosis was found in familial Mediterranean fever with cardiac manifestation without thickening of the interventricular septum. The amyloid deposits were located almost exclusively within the walls of the myocardial arterioles. The amount of amyloid as observed in the myocardial biopsies correlates with the rapidly progressive cardiac failure. It is suggested that in patients with abnormal thickening of the interventricular septum of unknown origin the diagnosis should be clarified by endomyocardial biopsy.

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.

Atypical familial motor neuropathy in patients with mutant TTR Ile68Leu.

Two sisters from an Italian family shared progressive motor symptoms, preceding the onset of sensory and autonomic disturbances. The familial occurrence of axonal and slowly progressive polyneuropathy led us to consider these patients as candidates for TTR molecular analysis. We found a missense mutation causing Ile68Leu TTR substitution in both. The aims of this work are to report the possibility of a motor onset of amyloid polyneuropathy and to suggest the search for TTR mutations in familial cases of axonal polyneuropathy. Second, to stress the possible occurrence of amyloid within the spinal canal as the potential pathogenesis and responsible for motor presentation.

Highly sensitive diagnosis of amyloid and various amyloid syndromes using Congo red fluorescence.

In order to find how best to diagnose amyloid deposits as early as possible, the sensitivity of three different methods that can be applied to the diagnosis of amyloid in tissue sections have been compared: the Congo red staining method (CR), the combination of CR and immunocytochemistry (CRIC) and Congo red fluorescence (CRF). Tissue blocks were available from 25 patients, including 11 with immunohistochemically distinct and 3 with chemically undefined amyloid diseases. The results revealed (a) that CRF is more sensitive than either CR or CRIC, as shown qualitatively and quantitatively, (b) that CRF can therefore be utilized to track down even minute amyloid deposits, which can be missed by the other two methods; (c) that the specificity of CRF and CRIC is secured on double-stained sections by the demonstration of green birefringence (GB) of the CRF-marked and IC-marked areas; (d) that CRF can be performed on the spot by just changing the light source; and (e) that CRF is not hampered by the congruent IC chromogen overlay, which ensures the specific classification of the amyloid deposits as applied to different amyloid classes. In conclusion, CRF was demonstrated to be the most sensitive method for direct diagnosis of amyloid in tissue sections. This method can, therefore, allow the earliest diagnosis and classification of amyloid, which is a good basis for an amyloid class-specific therapy while organ damage is still minimal.

Cerebrovascular involvement in systemic AA and AL amyloidosis: a clear haematogenic pattern.

Amyloid deposits in cerebral vessels are common in beta-amyloid diseases (Alzheimer's disease, congophilic amyloid angiopathy, Down's syndrome and hereditary cerebral amyloidosis with haemorrhage of the Dutch type). We report of 20 autopsies on patients who had died with systemic amyloidosis of the AA, Alambda and Akappa types: the brains were examined for the occurrence of amyloid. Vascular amyloid was detected in choroid plexus (in 17 of 20 cases), infundibulum (5 of 8), area postrema (6 of 11), pineal body (3 of 7) and subfornical organ (2 of 3), but not in cortical and leptomeningeal vessels. Immunohistochemical classification of the cerebral amyloid and the systemic amyloid syndrome showed identity proving the same origin of both. The distribution is indicative of a haematogenic pattern of amyloid deposition in systemic amyloidosis and is different from that in Alzheimer's, prion, ATTR and cystatin C diseases. It corresponds to areas of the brain with a "leaky" blood-brain barrier. Additionally, all the cases with AA amyloidosis exhibited an Abeta coreactivity in choroid plexus vessels. In one exceptional case, Abeta reactivity of AA amyloid also occurred outside of the brain.

Diagnosis and immunohistochemical classification of systemic amyloidoses. Report of 43 cases in an unselected autopsy series.

Fourty-three cases of systemic amyloidosis were identified in an unselected autopsy series from our institute (6305 autopsies between 1979 and 1993) and classified immunohistochemically by means of a panel of antisera directed against five major amyloid fibril proteins. Amyloid A (AA) amyloidosis was the most common type, being found in 21 cases (48.8%). Transthyretin-derived (ATTR) amyloidosis was present in 11 cases (25.6%), and immunoglobulin light chain-derived (AL) amyloidosis in 10 cases (23.3%). A single case (2.3%) contained deposits of more than one type of systemic amyloid. AA amyloidosis was associated with chronic inflammatory or infectious diseases (81%), malignant tumours (19%) or both (9.5%). Immunoglobulin light chain-derived amyloidoses were associated with myeloma (50%) or primary (idiopathic; 50%). In AA and AL amyloidosis the kidney was the organ most frequently involved. ATTR amyloid affecting mostly the heart and lungs presented as senile systemic amyloidosis. Systemic amyloidosis was the cause of death in 5 cases (12%) and caused symptoms in 17 cases (39%). Our results suggest that most cases can be classified by using a panel of sensitive and specific antibodies against five major amyloid fibril proteins. This technique may make amyloid type-specific therapy possible for AL amyloid patients who do not have evidence of an underlying plasma cell dyscrasia.