Human immunoglobulin isotype profiles produced in response to antigens recognized by monoclonal antibodies specific to Anisakis simplex

BACKGROUND: Anisakis simplex is a medically important pathogen which not only causes anisakiasis but may provoke allergy reactions, ranging from mild urticaria to anaphylactic shock. OBJECTIVE: To investigate anti-Anisakis isotype profiles in anisakiasis and Anisakis allergy patients. METHODS: Capture ELISA techniques were used to investigate the isotype profiles of antibodies specific for two defined Anisakis simplex antigens, in serum from Japanese patients with confirmed anisakiasis and from Spanish patients with allergy to Anisakis. The antigens were 'UA2R antigens' (two proteins with MW of 48 and 67 kDa, recognized by our monoclonal antibody UA2) and 'UA3R antigens' (two proteins with MW of 139 and 154 kDa, recognized by our monoclonal antibody UA3). RESULTS: Considering IgG, the two most frequent isotypes in the response to the UA2R antigens were IgG1 and IgG2, with IgG4 detected in only one case; in response to the UA3R antigens, by contrast, the two most frequent isotypes were IgG1 and IgG4 (though IgG2 remained reasonably frequent). As regards potential utility for serodiagnosis, 95% of the Japanese anisakiasis patients and 84% of the allergy patients showed detectable IgG1 antibodies to the UA3R antigens. Furthermore, all allergy patients showed IgE antibodies to these antigens. CONCLUSION: Anisakis simplex contains antigens that induce responses which are differentially regulated. Because of their immunogenicity, immunodominance and allergenic nature, we consider that the 139/154-kDa antigens recognized by our MoAb UA3 are good candidates for use in tests for the diagnosis of anisakiasis and of the allergy caused by this parasite.     

Prevalence of and risk factors for IgE sensitization to Anisakis simplex in a Spanish population

BACKGROUND: The number of allergic reactions to A. simplex reported in Spain has increased dramatically in the last decade. Nevertheless, there have been no studies of the prevalence of and possible risk factors for IgE sensitization to this parasite, possibly because suitably specific diagnostic methods have only recently become available. The objective was to investigate the prevalence of and risk factors for IgE sensitization to A. simplex in Galicia, a region of northwestern Spain with a population of about 3 million and high average fish consumption (78.5 g/person per day). METHODS: The study was performed with a random sample of 2801 healthy blood donors distributed in 53 geographic areas, proportional to the density of donors. IgE sensitization to A. simplex was tested by a capture ELISA method that has proved to be the most specific method currently available. RESULTS: The results showed a total of only 12 positive subjects, of whom five also showed IgG1 sensitization. All positive subjects and 101 randomly selected seronegative subjects were then included in a case-control study of risk factors for sensitization to A. simplex, based on a telephone interview about fish consumption (especially raw and undercooked fish). All seropositive subjects (but only 25% of seronegative subjects) reported consumption of undercooked fish or homemade raw-fish products. CONCLUSIONS: Our results strongly suggest that sensitization to A. simplex is caused only by live larvae, and not by allergens contained in fish tissues, and that ingestion of homemade boquerones (anchovies [Engraulis encrasicholus] in vinegar), and to a much lesser extent of undercooked fish, are the main risk factors for IgE sensitization to Anisakis in this region.     

Factors influencing the sensitivity of herpes simplex virus detection in clinical specimens in a simultaneous enzyme-linked immunosorbent assay using monoclonal antibodies

A rapid simultaneous enzyme-linked immunosorbent assay (ELISA) using monoclonal antibodies was investigated for herpes simplex virus (HSV) detection. All HSV isolated (n = 127) were detected, whereas no response was obtained with HSV negative preparations. Equivalent results were obtained from 275 of 277 clinical specimens in the monoclonal ELISA and in an ELISA using polyclonal antibodies, confirming that appropriately selected monoclonal antibodies may be as efficacious as polyclonal antibodies in antibody-based assays. In clinical specimens, the rate of HSV detection (sensitivity) relative to tissue culture isolation was low for both assays, and the major factor responsible for this was the low concentration of virus present in some specimens. The sensitivity of ELISA obtained in routine use varied with different panels of unselected specimens and was related to the speed of development of the cytopathic effect. These results emphasise the need for caution in assigning a definitive sensitivity level to ELISA tests evaluated on different panels of specimens.     

Measurement of serum IgG4 levels by a competitive immunoenzymatic assay with monoclonal antibodies

A competitive indirect ELISA is described for the measurement of IgG4 levels. It uses a monoclonal anti-subclass antibody and purified monoclonal IgG4 as standards. This method is sensitive and reproducible and more accurate than hemagglutination inhibition and radial immunodiffusion. Serum IgG4 levels in 173 normal adults were < 0.01–2.1 mg/ml (mean 0.30 mg/ml) in women and < 0.01–1.87 mg/ml (mean 0.465 mg/ml) in men.     

The use of monoclonal antibodies in (reverse) passive haemagglutination tests for herpes simplex virus antigens and antibodies

Three monoclonal antibodies against herpes simplex virus type 2 have been tested for their suitability as reagents in reverse passive haemagglutination. Two of these antibodies with specificity for virus glycoprotein D, when linked to red blood cells, were able to capture antigens without being agglutinated, but addition of immune serum subsequently led to agglutination. Haemagglutination using these monoclonal antibody-linked, antigen-captured red cells was readily applicable to testing human sera for antibodies to herpes simplex virus and the titres obtained correlated with those from virus plaque neutralisation tests. The procedure has been termed "Specific Antigen Capture Passive Haemagglutination." A further monoclonal antibody with specificity for the major DNA-binding protein of type 2 herpes virus-infected cells (a nonstructural protein) showed conventional reverse passive haemagglutination when linked to red blood cells and was specific for type 2 herpes simplex virus. The nature and potential uses of these simple reverse passive haemagglutination procedures using monoclonal antibody reagents are discussed.     

Monoclonal antibodies directed against human Rh antigens in tests with red cells of non-human primates

Human anti-D (Rh_o) monoclonal antibodies (Mabs) of the IgG (70) and IgM (27) classes were tested with red blood cells (RBCs) of various non-human primates, from anthropoid apes to New World monkeys. Significant differences in reactivity were observed among antibodies of two classes depending on taxonomic position of primate animals. Only IgM Mabs gave positive reactions (9 out of 18 Mabs) with blood of Old World monkeys. Allotypic reactions with RBCs of African apes were produced by a majority of IgG Mabs but by very few IgM reagents, most of the latter reacting with RBCs of all chimpanzees and all gorillas tested. Eight out of 70 IgG anti-D defined chimpanzee polymorphisms related to chimpanzee R^c antigen which is the chimpanzee counterpart of human D antigen. Most of IgG anti-D Mabs (61/70) were found specific of D^gor antigen (gorilla counterpart of human antigen D). Most of anti-D which were found negative with all chimpanzee RBCs were also negative with human D^IVb RBCs and most of anti-D which agglutinated human D^IVb RBCs were positive with some or all chimpanzee blood samples. Differences among Mabs evidenced in tests with non-human primate RBCs reflect the complexity of the immune reactions to the human D antigen. The results obtained with anti-Rh Mabs of specificities other than D confirmed that chimpanzee, gorilla and gibbon express c-like epitopes and that antigens C, E, e are absent in non-human primates.     

Immunochemical characterization of human antibodies to lymphoblastoid interferon.

Antibodies produced in recurrent respiratory papillomatosis (RRP) patients treated with lymphoblastoid interferon (lyIFN) may neutralize antiviral activity or may only bind to lyIFN. These antibodies were characterized for immunoglobulin class, IgG subclass, and light chain type by an indirect immunoassay. Serum dilutions were incubated on lyIFN-coated plates and the presence of antibody detected using peroxidase-conjugated goat antibodies to each human immunoglobulin class and light chain isotype, or using MoAbs to each human IgG subclass. Neutralizing activity was measured as the inhibition of lyIFN antiviral activity for Vervet monkey cells challenged with Semliki Forest Virus. Among antibody-positive patients, 12% produced IgM coincident with IgG, and 25% produced IgA coincident with IgG. Thus, antibody responses in patients treated with lyIFN are not exclusively of IgG class. The predominant lyIFN-specific subclasses were IgG1 and IgG3, which occurred in 70% and 83% of patients, respectively. An IgG4 response was detected in two patients who also had antibody of other isotypes; no IgG2 antibody was detected in any patient. Antibodies were not IgG subclass-restricted, a trend which was more pronounced in patients having neutralizing antibody than non-neutralizing antibody. Light chain molecules of lyIFN-specific antibody were of both kappa and lambda isotypes, with kappa chains occurring most frequently. Among patients having non-neutralizing antibodies, monotypic light chains occurred in 65% of the patients, whereas no patient with neutralizing antibody had monotypic light chain antibody. Sera from 599 normal human volunteers were assayed for antibody, and seven were found to be immunoreactive to lyIFN. Only one serum of the seven was positive for neutralizing activity.     

Seropositivity to a major allergen of Anisakis simplex, Ani s 1, in dyspeptic patients with Helicobacter pylori infection: histological and laboratory findings and clinical significance

Previous studies have demonstrated a high prevalence of seropositivity to the Ani s 1 protein in dyspeptic patients with Helicobacter pylori infection, but it is not known whether this represents episodes of anisakiasis misdiagnosis or previous exposure to the parasite without clinical relevance. To investigate the clinical significance of seropositivity to the Ani s 1 protein, a cohort study was performed with 87 consecutive dyspeptic patients who were treated for H. pylori infection. Fourteen (16.5%) patients were seropositive for the Ani s 1 protein, which was associated with the consumption of uncooked fish (p 0.0002). There were no differences in histological findings between subjects seropositive or seronegative for Ani s 1, but seropositive patients had increased eosinophil and basophil leukocyte counts (p < 0.05). Anti-Ani s 1 IgE was associated with a lack of improvement in the group of patients with non-ulcer dyspepsia after successful eradication of H. pylori (p 0.016). Thus, in at least a subset of patients with H. pylori infection, seropositivity to Ani s 1 could have clinical relevance. In addition, these data highlight that only anisakiasis associated with severe allergic or gastric symptoms is currently being diagnosed.     

Analysis of a major target of the human immune response to cytomegalovirus using monoclonal antibodies

Two murine monoclonal antibodies (C6D1 and D2B1) were found to react with a set of cytomegalovirus (CMV)-infected cell polypeptides, which comprise a major target of the human immune response to CMV. C6D1 reacted with proteins of 50 kilodaltons (KD) and 40KD molecular weight; D2B1 reacted with these two proteins plus a third of 35KD. Western blot analysis demonstrated that these protein targets also react with serum antibody from patients with acute or latent CMV infection. Immunofluorescence staining of CMV-infected diploid fibroblast cells by C6D1 and D2B1 showed that the protein targets are found in the nucleus throughout the course of viral infection. The proteins were shown to be late proteins dependent on viral DNA synthesis for their expression. Not all wild-type CMV strains tested expressed proteins that react with C6D1 and D2B1. Using an immunofluorescence stain of diploid fibroblasts infected with CMV strains from infected patients, we found that 70 of 76 (92%) wild-type strains reacted with C6D1 and 23 of 24 (96%) with D2B1. One strain was not reactive with either C6D1 or D2B1. Western blot analysis of 11 wild-type strains revealed that two isolates either lack the C6D1 and D2B1 protein targets or have forms of these proteins that migrate at different molecular weights.     

Use of a monoclonal antibody in a double-sandwich ELISA for detection of IgM antibodies to Toxoplasma gondii major surface protein (P30)

A double-sandwich ELISA, developed for detection of IgM antibodies to the major surface protein of Toxoplasma gondii (P30), is proposed for the diagnosis of acute acquired toxoplasmosis. The method is based on the capture of serum IgM antibodies, which are revealed indirectly by the sequential addition of a Toxoplasma extract and a beta-galactosidase-conjugated anti-P30 monoclonal antibody. All 57 patients tested with serological characteristics of recently acquired toxoplasmosis showed high levels of IgM anti-P30 antibodies. In addition, 5 out of the 24 patients with chronic toxoplasmosis and all 7 patients with a clinical acute infection in which the classical IgM serology was negative, also presented significant anti-P30 IgM antibodies. Patients with either rheumatoid factor or antinuclear antibodies were all negative. In view of its simplicity, specificity and sensitivity, this method is recommended for the current diagnosis of T. gondii infection.     

Elisa test system with monoclonal antibodies to human IgG4 for the detection of allergen-specific antibodies in pollinosis

G. N. Gabrichevskii Moscow Research Institute of Epidemiology and Microbiology. Institute. of Experimental Cardiology, All-Union Cardiologic Scientific Center, Academy of Medical Sciences of the USSR, Moscow. (Presented by Academician of the Academy of Medical Sciences of the USSR A. I. Vorob'ev.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 108, No. 11, pp. 574–577, November, 1989.     

The preservation and loss of various non-haematopoietic antigens in human post-mortem tissues as demonstrated by monoclonal antibody immunohistological staining

Immunohistological methods using monoclonal antibodies have proved to be valuable in the differentiation between cells of various origins. We have previously shown most leucocyte differentiation antigens to be very resistant to post-mortem disintegration (Pallesen & Knudsen 1985). In the present study we have examined the preservation of several non-haematopoietic antigens in tissue samples of human skin, kidney, liver, pancreas, lung, thyroid gland, uterine tissue, female breast and brain from 30 autopsies performed at specific intervals after death. Frozen tissue sections were stained using monoclonal antibodies and an immunoperoxidase method. A total of 17 monoclonal antibodies against various intermediate filament proteins, epithelial antigens, various hormones and factor VIII related antigen were tested. We found surprisingly good preservation and staining of tissue antigens--even 3 d after death--in all organs except pancreas. It is concluded that many tissue antigens are fairly resistant to post-mortem disintegration and that immunohistology may be applied to diagnostic problems in human autopsy material.     

Murine hybridoma monoclonal antibodies against insulin: cross-reactivity with insulins of three species and blocking of insulin binding to its receptor

Six hybridoma cell lines secreting monoclonal antibodies against pig insulin and cross-reacting with human and bovine insulins were obtained. Five of these monoclonal antibodies were IgG1, kappa, one IgG2b, kappa; their pI values were in the range of pH 6.3-7.4 and dissociation constants of the insulin-antibody complexes were 0.3-2 X 10(-8) mol/l, as determined by an immunoradiometric inhibition assay. All of these antibodies reacted with sterically closely related determinants and blocked the binding of 125I-pig insulin to the receptor on human MOLT-4 cell line.     

Cord blood levels of immunoglobulin G subclass antibodies to food and inhalant allergens in relation to maternal atopy and the development of atopic disease during the first 8 years of life

BACKGROUND: Factors that either protect from or enhance the development of atopic disease appear to be acting early in life. The gestational environment, including maternal immune responses, such as transplacentally transferred immunoglobulin (Ig) G antibodies to allergens, may be of importance in this respect, since allergen-specific immunity has been demonstrated to develop in utero. OBJECTIVE: To evaluate the relation between cord blood IgG subclass antibodies to allergens, maternal atopy and development of atopic disease in the children. MATERIAL AND METHODS: The study group comprised a cohort of 96 children participating in a prospective study up to 8 years of age. Cord blood IgG subclass antibodies to ovalbumin, beta-lactoglobulin, Bet v 1 and cat dander were analysed by ELISA. RESULTS: The levels of all IgG subclass antibodies to ovalbumin and rBet v 1 were higher in newborn infants with an atopic mother, as compared with babies with nonatopic mothers. IgG1 antibody levels to cat and IgG4 antibody levels to beta-lactoglobulin and cat were also higher in atopic than in nonatopic mothers, whereas the other subclass antibody levels to those allergens were similar. High levels of cord blood IgG antibodies to cat and birch, but not to the food allergens, were associated with less atopic symptoms in the children during the first 8 years of life. Moreover, children who developed IgE antibodies to cat had lower levels of IgG antibodies to that allergen at birth. CONCLUSIONS: High levels of cord blood IgG subclass, especially IgG4, antibodies to food and inhalant allergens are associated with maternal atopy. High levels of IgG antibodies to inhalant, but not food, allergens are associated with less development of atopy in the children.     

Detection of antibodies to human nerve antigens in sera from leprosy patients by ELISA.

Anti-neural antibodies have been implicated to play a role in the pathogenesis of nerve damage in leprosy patients. To find the relationship between anti-neural antibodies and clinical findings, we attempted to detect antibodies against neurofilament-enriched proteins by ELISA in sera from leprosy patients. Of 289 sera from leprosy patients, 74 (25.6%) had significant anti-neural antibodies; in contrast, 1 (5.0%) of 20 tuberculosis patients and 11 (7.1%) of 154 controls were seroreactive to nerve antigen. When clinical types were considered, a significant level of anti-neural IgG antibodies was detectable in 53 (30.1%) of 176 sera from lepromatous patients compared with 21 (18.6%) of 113 sera from tuberculoid patients, indicating that lepromatous patients were more likely to be seropositive to nerve antigens in ELISA. Some of the ELISA-reactive sera showed antibody reactivity with 38-kD, 40-kD and 43-kD nerve antigens in Western blotting analysis. There was no apparent correlation between seroreactivity to nerve antigens and bacterial load in leprosy patients. Although there was no statistical significance, anti-neural antibodies were detectable more often among the patients on chemotherapy than the untreated and among the patients with erythema nodosum leprosum than without. The results, therefore, suggest that anti-neural antibodies are elicited during the course of leprosy and may be associated with the extensiveness of nerve involvement in the patients.     

Role of immunoglobulin E sensitization in eczema,previously referred to as atopic dermatitis

This review aims to clarify existing knowledge on the relationship between eczema and immunoglobulin (Ig)E sensitization. Over the years this debate has been complicated by unclear definitions of what constitutes an atopic individual. The new, uniform allergy nomenclature introduced by the European Academy of Allergology and Clinical Immunology and the World Allergy Organization uses the term eczema to denote what was previously known as ‘atopic dermatitis’ or ‘atopic eczema’. Despite detailed knowledge of localized IgE–allergen interactions at the level of the skin, the exact role of IgE and IgE antibody sensitization in the disease process remains widely debated. The association between IgE sensitization and eczema has been clearly demonstrated in population-based studies. There is, however, variation in the strength of the association between IgE sensitization and eczema in hospital versus community studies. While IgE sensitization is not a useful disease discriminator, once other factors have been taken into account, knowledge of atopic status appears to have prognostic value in children with eczema, since IgE sensitization is associated with an increased risk of developing allergic respiratory disease later in life. These children may also experience a more persistent and severe disease.     

Binding of platelets to human monocytes: A source of artifacts in the study of the specificity of antileukocyte antibodies

A serious and often ignored source of artifacts when testing the specificity of antibodies is the contamination of leukocyte preparations with platelets which subsequently adhere to monocytes. The presence of Ca²⁺ chelating agents or acetylsalicylic acid in the washing buffers inhibits adhesion of platelets to monocytes, thus permitting an accurate distinction among antibodies that are specific for monocytes, platelets or both. The analysis of the specificity of various new or recently described monoclonal antibodies reactive with these cell types is reported here.     

Radioimmunoassay for the detection of IgG antibodies to herpes simplex virus and its use as a prognostic indicator of HSV excretion in transplant recipients

We report the development of a solid-phase radioimmunoassay for the detection of IgG antibodies to herpes simplex virus (HSV), using a mouse monoclonal antibody specific for the Fc portion of human IgG as the radiolabelled detecting antibody. The binding ratio to test antigen at a single serum dilution, 1:100, correlated significantly with the endpoint titre by radioimmunoassay and with neutralising antibody titre. When compared to neutralisation the radioimmunoassay had a sensitivity of 100% and a specificity of 93%. We believe that the anomalous results are not false positives but represent an increased sensitivity of the radioimmunoassay. We found, by either radioimmunoassay or neutralisation, that high levels of antibody prior to transplantation were associated with a significantly increased risk of HSV excretion post-transplantation in both renal and bone marrow transplant recipients. Thus the radioimmunoassay is a sensitive, specific, and rapid test that can be used as a prognostic indicator of HSV excretion in transplant recipients.