High Antibody Activity Research Articles

Complete heart block and seizures in an adult with systemic lupus erythematosus: A possible pathophysiologic role for anti‐SS‐A/Ro and anti‐SS‐B/La autoantibodies

To determine the serum autoantibody profile in an adult patient with systemic lupus erythematosus manifested by complete heart block (CHB) and seizures, and to investigate the source of autoantibodies found in the patient's cerebrospinal fluid (CSF). The serum and CSF autoantibody profiles were determined by serologic testing and Western blot studies. An antibody activity index was devised to determine the source of the autoantibodies found in the CSF. The patient's serum contained anti-SS-A (52 kd and 60 kd), anti-SS-B, anti-U1 RNP, and anti-Sm autoantibodies. Studies of her CSF, however, revealed only anti-SS-A and anti-SS-B autoantibodies, with a high antibody activity index. The finding of anti-SS-A (52 kd and 60 kd) and anti-SS-B autoantibodies was similar to reported findings in congenital CHB. Intrathecal synthesis of anti-SS-A and anti-SS-B was the source of autoantibodies found in the CSF. This patient's symptoms may be pathophysiologically linked to an immune reaction between the anti-SS-A and anti-SS-B autoantibodies and neural tissue in the brain and heart.

Crevicular IgG antibodies and recovery of Streptococcus mutans implanted by mouthrinsing.

After challenge with a streptomycin-resistant strain of Streptococcus mutans (S. mutans), a tendency to higher recovery of S. mutans was found in gingival crevicular fluid (GCF) from surfaces with a low IgG antibody activity against S. mutans than in GCF from surfaces with a high antibody activity. This suggests that antibodies in GCF may interfere with the establishment of S. mutans on gingival tooth surfaces. In GCF collected from some sites, considerably higher IgG antibody activity was observed than in homologous serum, indicating that part of the IgG response to S. mutans was locally derived.

INHIBITORY ACTIVITY OF MITE IgG4 ANTIBODY ON ANTIGEN-INDUCED HISTAMINE RELEASE FROM HUMAN PERIPHERAL BLOOD LEUKOCYTES

Several reports have yielded conflicting results on the role of IgG4 antibody on the surfaces of target cells in immediate type allergy. This study was performed to elucidate whether IgG4 antibody inhibits IgE-mediated histamine release from target cells after antigenic stimulation, and whether it has reaginic activity. Serum was obtained from patients with nasal allergy receiving specific immunotherapy for housedust and mites. IgE and IgG4 were enriched affinity chromatographically using monoclonal antibodies to IgE and IgG4, respectively, from the pooled sera. Both fraction revealed high antibody activity to Dermatophagoides Farinae antigen. Peripheral blood leukocytes from three non-allergic donors were passively sensitized with 100 or 300 micrograms of IgG4 according to the method of Levy and Osler with a slight modification. Minimal or no histamine release was observed from leukocytes after challenge with both mite antigen and anti-IgG4 monoclonal antibodies. Furthermore, to investigate the reaginic activity of IgG4, leukocytes from patients with nasal allergy were stimulated with anti-IgG4 antibodies. The leukocytes of only three out of twenty patients released up to 10% histamine regardless of the IgG4 concentration, while the other patients' leukocytes released minimal amounts of histamine. Two of the three above-mentioned non-allergic donors were passively sensitized with 100 or 300 micrograms of IgG4 either one hour after sensitization with 100 ngs of IgE or simultaneously with the same amount of IgE. After sensitization with 100 ngs of IgE, one showed high-grade histamine release after challenge with 0.5 micrograms/ml mite antigen and the other showed middle-grade release with 0.1 micrograms/ml mite. With the presence of 300 micrograms of IgG4, histamine release was significantly inhibited in both donors regardless of the manner of sensitization.(ABSTRACT TRUNCATED AT 250 WORDS)

Crevicular IgG antibodies and recovery of locally implanted Streptococcus mutansR in humans

This study was undertaken with the aim of examining the effect of highly different IgG antibody activities in gingival crevicular fluid (GCF) on the elimination of a streptomycin-resistant strain of Streptococcus mutans (S. mutans) topically implanted on the tooth. Two groups of people were selected for the study, one with high and one with low specific IgG antibody activity (IgG antibody activity against S. mutans) in GCF. During an experimental period of 15 d the specific IgG antibody activity in GCF in the same individual stayed on a relatively constant level. Between individuals, however, the specific IgG antibody activity varied considerably. The number of indigenous mutans streptococci and the number of implanted bacteria on the same tooth surface were strongly correlated. The implanted S. mutans strain was rapidly eliminated in all subjects. No difference in the elimination of the implanted strain of S. mutans could be demonstrated between the groups of high and low specific IgG antibody activity.

Detection of Thyroid Microsomal and Thyroglobulin Antibodies by New Sensitive Radioimmunoassay in Hashimoto's Disease; Comparison with Conventional Hemagglutination Assay.

We evaluated clinical usefulness of thyroid microsomal antibody (MCAb) and thyroglobulin antibody (TGAb) measured by new sensitive radioimmunoassays (RIA). These assays are simple and reproducible; the intra- and inter-assay coefficients of variation were 3.6-6.8% and 6.6-13.2% in the MCAb assay, and 3.2-7.7% and 7.6-12.3% in the TGAb assay, respectively. In 126 patients with Hashimoto's disease, the antibody activity determined by this RIA correlated with that determined by the hemagglutination assay (HA) (r = 0.848 for MCAb, r = 0.686 for TGAb, p less than 0.001). MCAb was detected by RIA in all of 115 HA-positive and 4 of 11 HA-negative patients, and TGAb by RIA in all of 84 HA-positive and 29 of 42 HA-negative patients: the prevalence of MCAb was 94% and that of TGAb was 90% in the disease. Moreover, some showed high antibody activity only in RIA. In another group of 14 patients with biopsy-proved Hashimoto's disease with no antibody activity by routine HA tests, serum MCAb was detected in 3 (21%), TGAb in 11 (79%), and both activities in 2 (14%). Our results indicate that (1) the RIA tests are more sensitive than the conventional HA test, and that (2) the present RIA test for TGAb is more sensitive than that for MCAb in detecting autoimmune abnormalities, especially in patients with biopsy-proved Hashimoto's disease who give negative results in the HA test.

Serum IgG Antibody Response to Antigens of Presumed Periodontal Pathogens: A Case-control Study using ELISA and Western Blot Analysis

The present study examined the IgG antibody activity in sera from a case:control population against whole cell proteins of Porphyromonas gingivalis and four other presumed periodontal pathogens: Bacteroides intermedius ; Capnocytophaga ochracea ; Wolinella recta ; Fusobacterium nucleatum . Whole cell enzyme-linked immunosorbent assays (ELISA) were performed to provide quantitative data on levels of IgG antibody and immunoblotting of whole cell lysates was carried out on 10 case:control pairs to identify the major individual antigens of each organism. For all organisms the mean level of IgG antibody activity against whole cells was higher in the cases compared to controls. For P. gingivalis the difference was highly significant ( p <0.0005). For C. ochracea the difference approached statistical significance ( p =0.058). Case sera with high antibody activity against P. gingivalis reacted with a large number of components on immunoblots in the molecular weight range 20 000-90 000, whereas control sera reacted weakly with only a small number of components of 80 000-90 000. Cases and controls showed high reactivity with B. intermedius whole cell lysates on immunoblots. Although numerous proteins of the other organisms were recognised by case and control sera, no discriminatory antigens were detected. The demonstration of discriminatory antigens of P. gingivalis justifies further work on their characterisation and possible role as virulence factors. Keywords: Porphyromonas gingivalis ; Antibody; Immunoblots; ELISA; Periodontitis-related pathogens.

Evidence for Human Antibodies That Recognize an Aflatoxin Epitope in Groups with High and Low Exposure to Aflatoxins

Antibody activity against an aflatoxin epitope has been detected in serum from individuals who live in Kenya and who experience high exposure to aflatoxin B1. The activity was higher than in Danish people. The highest antibody activity was found in individuals who were recently exposed to aflatoxin B1. The ratio between IgG and IgM activities was higher in individuals with a high antibody titer. The specificity of the antibody activity differed in the serums obtained from Danish and Kenyan persons ("Danish" and "Kenyan" serum, respectively). The activity in Danish serum was inhibited by an aflatoxin-like substance isolated from human urine, whereas aflatoxin B1 did not inhibit the activity. In contrast, the activity in Kenyan serum was not inhibited by the aflatoxin-like substances. Therefore, the presence of antibodies against aflatoxin in humans indicates exposure to aflatoxin or aflatoxin-antigenic material. However, the biological consequences of these antibodies remain unknown.

Significance of the recognition of certain antigenic regions on the human thyroglobulin molecule by natural autoantibodies from healthy subjects.

We have evaluated the epitope specificity of natural antihuman thyroglobulin (hTg) autoantibodies (aAb) in the plasma of healthy individuals. By an indirect ELISA technique, we selected 56 plasma samples with high anti-hTg antibody activity and used the IgG fraction isolated from these plasma to study the antigenic domains on the hTg molecule recognized by the natural anti-hTg aAb. A panel of 15 mAb, coupled to alkaline phosphatase and recognizing six regions (I to VI) on the hTg molecule, served to identify the domains recognized by the natural anti-hTg aAb using a competitive ELISA procedure. A total of 26 of the IgG fractions was found to interact with at least one of the regions defined by our battery of mAb. Region V was recognized by the majority of the IgG fractions. Interestingly, region II was rarely recognized by the same IgG fraction that reacted with region V. Inasmuch as we have previously shown that region II is mainly recognized by aAb in the serum of subjects with various thyroid disorders, we propose that recognition of region V reflects the normal physiologic state of the immune system with respect to the hTg molecule.

Purification of IgG from serum with caprylic acid and ammonium sulphate precipitation is not superior to ammonium sulphate precipitation alone

Immunoglobulin G (IgG) from bovine serum raised against Aeromonas Salmonicida was purified by ammonium sulphate precipitation (ASP) or caprylic acid treatment followed by ammonium sulphate precipitation (CAAS). Purity of IgG samples prepared by both methods were examined by High Performance Gel Permeation Chromatography, electrophoresis and antibody activity assay. Results suggest that IgG prepared by ASP is better than that obtained by CAAS method in terms of the yield of the IgG monomers and the recovery of the antibody activity.

Cold agglutinin disease

Cold agglutinin disease is a normo- or macrocytic anemia due to antibodies, active under body temperature, mostly belonging to the immunoglobulin class M. Initially the agglutination of erythrocytes with acrocyanosis is reversible at body temperature. High antibody activity or long lasting period of coldness lead to intravascular or intrahepatic hemolysis, but high risk anemia is rare. Beside the idiopathic form, infection induced (especially infectious mononucleosis, cytomegalovirus, Mycoplasma pneumoniae, Klebsiella), and drug induced (especially quinidine, alpha methyldopa, penicillin, para-aminosalicylic acid, various analgetics, sulfonylurea), tumor associated (especially malignant lymphomas), and autoimmune disease associated (especially systemic lupus erythematosus) cold agglutinin anemias are discribed. "Cross reacting antigenity" to the hemolysing agent and the membrane of erythrocyte, exogenous induced changing of erythrocytic antigenity, and diversification concerning the production of antibodies are discussed as pathophysiological explanations.

A highly specific two-site ELISA for pneumococcal C-polysaccharide using monoclonal and affinity-purified polyclonal antibodies

A two-site ELISA for the detection of pneumococcal C-polysaccharide (PnC) has been developed. A monoclonal antibody directed against the phosphorylcholine residue of the PnC was used as catcher and an affinity-purified polyclonal anti-PnC rabbit antiserum for detection. Polyclonal antibodies against the PnC as well as capsular antigens were obtained by immunizing rabbits with type 1 pneumococci. Antibodies against the phosphorylcholine determinant of PnC could be removed by affinity purification. Remaining antibodies reacted in an ELISA with type 1 capsular polysaccharide as well as with PnC. Only in the fraction with the highest antibody activity against PnC, phosphorylcholine exhibited a slight inhibitory action. It is concluded that the purified antibody preparation reacted with an antigenic determinant shared by the two polysaccharides, in all probability a determinant associated with 2-acetamido-4-amino-2,4,6-trideoxygalactose which is the only monosaccharide component in common between PnC and the type 1 capsular polysaccharide. By the use of this affinity-purified antibody preparation, reactions with alpha-streptococci, occurring with non-purified serum, were abolished. The sensitivity and specificity of the test was determined using capsulated and non-capsulated pneumococci and alpha-streptococci known to cross-react with unpurified serum against the pneumococcal C-polysaccharide.

Quantitative and qualitative changes in the humoral response of dogs through the course of infection with Dirofilaria immitis.

The present study compared the humoral response of dogs which developed microfilaremic or occult forms of dirofilariasis following experimental infection with Dirofilaria immitis L3 larvae. Quantitative analysis by ELISA revealed that antibody levels to adult somatic (AS), excretory-secretory (ES), and microfilarial (MF) antigens were highest during the patent phase of infection in dogs with either form of dirofilariasis. Patent sera from dogs destined for occult infections contained anti-AS and anti-MF antibody concentrations of 1,572 and 1,004 micrograms/ml, respectively, while microfilaremic-bound dogs contained 1,044 and 906 micrograms/ml, respectively. Chronic sera (430 days post infection) from occult dogs contained anti-AS and anti-MF antibody levels of 982 and 600 micrograms/ml, respectively, which were higher than in microfilaremic dogs. The antibody response to ES antigen was generally 10-fold less in absolute antibody concentrations at all time points tested. Immunoperoxidase staining of antigens transferred to nitrocellulose revealed the presence of several antigenic proteins which were recognized by occult, and to a lesser extent or not at all, by microfilaremic dogs. Sera drawn from occult-bound dogs 280 days post-infection, a time corresponding to microfilarial clearance (transition phase), contained higher antibody activity to microfilarial proteins weighing 47.5, 42.0, 34.2, and 22.4 kilodaltons compared to the microfilaremic dogs. This difference in antigen recognition became more apparent during the chronic phase of infection.

Serum antibodies toAspergillus fumigatusin Danish farmers

182 Danish farmers and 105 city-dwelling control subjects were investigated for serum IgG antibodies to three purified Aspergillus fumigatus antigen fractions and unfractionated culture filtrate by enzyme-linked immunosorbent assay (ELISA). Farmers had higher levels of antibodies to all four ELISA antigens than non-farming controls. In farmers and controls high antibody activity was recorded with an antigen fraction of approximate molecular weight 470 000 daltons. Antibody levels to this fraction were higher in non-smokers than smokers in both study groups. Cattle farmers had higher antibody levels to the 470 000 daltons fraction than farmers with no animals on the farm. Farmers with higher antibody activity to any of the three fractionated ELISA antigens tended to have fewer respiratory symptoms than farmers with lower antibody activity. It was concluded that occupational exposure and smoking habits are the main determinants of the immune response to A. fumigatus in man.

Available immunoglobulin A antibodies in mouth rinses and implantation of Streptococcus mutans.

Immunoglobulin A (IgA) antibodies reacting with Streptococcus mutans were analyzed in mouth rinses from 38 adults. Antibody activity was determined by an enzyme-linked immunosorbent assay. The IgA antibody activity varied considerably in samples from different individuals. Of the 38 subjects, 12 volunteered in an implantation experiment and were challenged with streptomycin-resistant S. mutans. The results indicated that individuals with relatively high IgA antibody activity in mouth rinses more rapidly eliminated the challenge strain than subjects with low IgA antibody activity.

SEARCH FOR CANINE-DISTEMPER-VIRUS ANTIBODIES IN MULTIPLE SCLEROSIS: A Detailed Virological Evaluation

Sera and cerebrospinal fluid samples from multiple-sclerosis (MS) patients, matched controls, and subacute sclerosing panencephalitis (SSPE) patients were analysed for the presence of antibodies specific for measles and canine distemper virus (CDV). Virus-specific antibodies were identified by hæmagglutination inhibition, neutralisation, and immune precipitation in combination with polyacrylamide-gel electrophoresis. SSPE and MS patients had a higher antibody activity towards measles virus than controls. Moreover, human sera partly neutralised CDV; this was attributed to antibody activity against CDV proteins, antigenically related to those of measles virus. However, CDV-specific antibodies were not found in the samples tested. These findings indicate that MS can develop without a preceding CDV infection.

The effect of 2-mercaptoethanol on IgM and IgG antibody activity

The effect of reduction by 2-mercaptoethanol (2-ME) on antibody activity was studied in antisera with high anf low IgG concentrations. Sera obtained from B10.LP nu/nu mice during a primary response against a rat PVG/c skin graft contained only 2-ME sensitive antibodies. However, when analyzed on sucrose gradients, IgG as well as IgM antibody activity was present. After raising the low serum IgG concentration (0.3–0.7 mg/ml) of these sera by additional of normal mouse serum (5.1 mg IgG/ml), 2-ME resistant antibodies became detactable. Hyperimmune C57BL6 anti PVG/c lymphocyte serum with a high IgG concentration (20.2 mg/ml) and antibody activity predominatly located in the IgG class was not affected by 2-ME treatment. These data show that IgG antibodies, although less susceptible to reduction than IgM antibodies, are not resistant to this treatment. At high IgG concentrations the proportion of inactivated IgG with specific antibody will be negligible but a low IgG concentrations the use of this method leads to serious underestimation of IgG antibody activity.

Studies of nuclear ADP-ribosylation

Recent studies on poly(ADP-ribose) are reviewed. Poly(ADP-ribose) was shown to have α(1″ → 2′) ribose-ribose bonds. High molecular weight poly(ADP-ribose) with a branched structure was demonstrated. The structure of the branch linkage was determined as 2″-[1′-ribosyl-2″ (1‴-ribosyl)]-adenosine 5′,5″,5‴-tris(phosphate). The known sites of ADP-ribosylation of proteins were summarized. The enzymatic synthesis of poly(ADP-ribose) was classified into three steps, initiation, elongation and branching. Degradation of poly(ADP-ribose) may be mainly performed by α(1″ → 2′)-poly(ADP-ribose) ribohydrolase. Specific antibodies against poly(ADP-ribose) and its monomer, 2′-ribosyl adenosine 5′,5″-bis(phosphate), were obtained and used for quantitative measurement of naturally occurring poly(ADP-ribose). High antibody activity was found in the serum of the patients with systemic lupus erythematosus. Poly(A)·poly(U) could also raise specific antibody against poly(ADP-ribose) in rabbits. Nicotinamide, an inhibitor of poly(ADP-ribose) polymerase, increased sister chromatid exchanges. Among the nicotinamide analogues tested, N′-methylnicotinamide was the best inducer of differentiation of Friend erythroleukemia cells. Purified poly(ADP-ribose) induced differentiation of mouse myelogenous leukemia cells.

Highly cytotoxic antisera obtained in [formula omitted] rats against a syngeneic gross virus induced lymphoma

Antisera raised in W Fu rats against the syngeneic ( C58NT)D lymphoma induced by the Gross agent may provide specific antibodies for passive immunotherapy of Gross virus-induced murine leukaemia. Searching for high antibody activity towards tumour cells, which is highly desirable for passive immunotherapy, eight immunization schedules were assayed in 68 W Fu rats: groups of five to thirteen adult rats received subcutaneously an injection of 100–700 × 10 6 viable ( C58NT)D cells, followed after an interval of three to eight weeks, by weekly subcutaneous injections of 50–250 × 10 6 viable cells. The injection of 400 × 10 6 tumour cells followed four weeks later by five weekly injections of 200 × 10 6 cells gives highly cytotoxic antisera. However, kinetic studies of the antibody response show that if near maximal titers may be reached twenty days after a single inoculation, highly cytotoxic antisera were only reliably obtained after three booster injections. In repeatedly inoculated rats, blood could be drawn several times from the same animal, between the fourth and the twentieth day after the last injection without loss in cytotoxic activity.

Development of an intravenous gamma-globulin with Fc activities. I. Preparation and characterization of S-sulfonated human gamma-globulin.

S-sulfonated gamma-globulin (S-GG) was prepared by treating gamma-globulin with sulfite and tetrathionate ions. About four interchain disulfide bonds were selectively cleaved to give S-sulfonate groups. Although the above treatment strongly suppresses anticomplementary activity and nonspecific skin reactivity, the resulting S-GG retains high antibody activity. Furthermore, S-GG was found to maintain satisfactory levels for prolonged periods in vivo. The physicochemical and antigenic analyses of S-GG suggest that the S-sulfonation induces structural modification only at restricted sites.

Human B-lymphocyte antigens expressed by lymphocytic and myelocytic leukemia cells: Lymphocyte-dependent antibody studies with rabbit antisera

Rabbit antisera raised to papain-solubilized antigens from malignant spleen cell membranes had high lymphocyte-dependent antibody activity against normal B lymphocytes but no significant activity against T lymphocytes from the same donor. Leukemia blast cells from acute lymphoblastic and acute myelogenous leukemia and cultured B lymphoblastoid cell lines were also positive but the T line, Molt 4, and PHA blast cells were negative. Twelve rabbits were immunized with spleen cell extracts from 4 different patients with advanced malignant lymphomas. All produced antisera showing high lymphocyte-dependent activity with titers ranging from 10 4 to 10 8. Studies indicated that the sera were reacting against a common antigen present on B cells and certain leukemia cells. These conclusions are supported by earlier complement-dependent antibody studies which, in addition, strongly suggested that the antigen being detected was part of the Ia-like alloantigen found on B lymphocytes. Lymphocyte-dependent antibody effector function was blocked by the original antiserum but not by F(ab′) 2 fragments made from the same serum.