Use of the enzyme-linked immunosorbent assay for measurement of allergen-specific antibodies

A sensitive and specific enzyme-linked immunosorbent assay (ELISA) for allergen-specific IgG antibodies is described. Various solid-phase supports (microtiter plates), coating procedures, binding kinetics, and presentation of allergen in the assay were investigated. Using optimal conditions the indirect ELISA, in which the allergen is coated onto the well, was capable of detecting 2.4 ng/ml specific IgG antibodies to bee venom phospholipase A2(PLA2). The sandwich ELISA, in which the allergen was immobilized via specific antibody precoated onto the well, detected 0.24 ng/ml IgG antibodies to PLA2.     

High dose gammaglobulin therapy in adults with idiopathic thrombocytopenic purpura (ITP) clinical effects

Summary This study of the effect of high-dose intravenous gammaglobulins with one or two courses of therapy in 18 adults with idiopathic thrombocytopenia purpura showed a platelet rise in thirteen patients. The highest response rates were seen in splenectomized adults. In chronic patients the response was transient only. If therapy was effective, increased values of platelet-associated IgG were reduced, while shortened platelet survival times were prolonged. There was no influence of high-dose gammaglobulins on platelet function. Different 7S-preparations such as -propiolactone modified Ig, pH 4 treated Ig and reduced and alkylated Ig have comparable effects.Supported by the Deutsche Forschungsgemeinschaft (Mu 277/9-4)     

检测LAM-IgG指标诊断与鉴别诊断结核性腹水

目的：了解检测腹水标本阿拉伯糖甘露糖脂IgG抗体（LAM－IgG)指标诊断与鉴别诊断结核性腹水的应用价值。方法：研究对象包括恶性腹水组（恶性组）38人,结核性腹水组（结核组）32人,其他良性腹水组（对照组）32人,采集腹水为检测标本,应用斑点免疫金渗滤试验（dot-IGFA)技术检测LAM－IgG。结果：LAM－IgG的阳性结果为：恶性组5．3％（2／39）,结核组65．6％（21／32）,对照组0。结论：在诊断与鉴别诊断结核性腹水方面,LAM－IgG指标的特异性,敏感性均较高,具有应用价值。     

RTS,S/AS01E malaria vaccine induces IgA responses against CSP and vaccine-unrelated antigens in African children in the phase 3 trial

BackgroundThe evaluation of immune responses to RTS,S/AS01 has traditionally focused on immunoglobulin (Ig) G antibodies that are only moderately associated with protection. The role of other antibody isotypes that could also contribute to vaccine efficacy remains unclear. Here we investigated whether RTS,S/AS01_E elicits antigen-specific serum IgA antibodies to the vaccine and other malaria antigens, and we explored their association with protection.MethodsNinety-five children (age 5–17 months old at first vaccination) from the RTS,S/AS01_E phase 3 clinical trial who received 3 doses of RTS,S/AS01_E or a comparator vaccine were selected for IgA quantification 1 month post primary immunization. Two sites with different malaria transmission intensities (MTI) and clinical malaria cases and controls, were included. Measurements of IgA against different constructs of the circumsporozoite protein (CSP) vaccine antigen and 16 vaccine-unrelated Plasmodium falciparum antigens were performed using a quantitative suspension array assay.ResultsRTS,S vaccination induced a 1.2 to 2-fold increase in levels of serum/plasma IgA antibodies to all CSP constructs, which was not observed upon immunization with a comparator vaccine. The IgA response against 13 out of 16 vaccine-unrelated P. falciparum antigens also increased after vaccination, and levels were higher in recipients of RTS,S than in comparators. IgA levels to malaria antigens before vaccination were more elevated in the high MTI than the low MTI site. No statistically significant association of IgA with protection was found in exploratory analyses.ConclusionsRTS,S/AS01_E induces IgA responses in peripheral blood against CSP vaccine antigens and other P. falciparum vaccine-unrelated antigens, similar to what we previously showed for IgG responses. Collectively, data warrant further investigation of the potential contribution of vaccine-induced IgA responses to efficacy and any possible interplay, either synergistic or antagonistic, with protective IgG, as identifying mediators of protection by RTS,S/AS01_E immunization is necessary for the design of improved second-generation vaccines.Clinical trial registration: ClinicalTrials.gov: NCT008666191.     

Vaccination with chimeric protein induces protection in murine model against ascariasis

An estimated 400 million people are infected by parasites of the genus Ascaris and the existing control measures are inefficient. Vaccine development using B cell antigens is a promising strategy for increased protection against this parasite. The present study aimed at developing a chimeric protein capable of conferring protection against infection by Ascaris sp. For this purpose, we performed B-cell epitope predictions on previously described vaccine candidate proteins from Ascaris suum and the corresponding peptides were used to construct a chimeric protein. Female BALB / c mice were immunized subcutaneously in three doses at 10 day intervals with a vaccine formulation comprised of the chimeric protein together with monophosphoryl lipid A (MPLA). Control groups included protein alone, MPLA, or PBS. After challenge infection, animals vaccinated with chimeric protein plus MPLA showed a reduction of 73.54% of larval load in the lung compared to control group animals. Animals immunized with chimeric protein plus MPLA also display higher IgG response and a reduction in lung inflammation. Our study highlights how chimeric proteins containing more than one B cell epitope can enhance immune protection against helminthic infection and offer new approaches to the development of Ascaris vaccines.     

The Subclass Nature and Clinical Significance of the IgG Antibody Response in Patients Undergoing Allergen-Specific Immunotherapy

The purpose of this paper is to discuss the methodological difficulties in quantitation of human IgG subclass antibodies to allergens, to describe the subclass nature of the IgG antibody response in patients undergoing allergen-specific immunotherapy, and to discuss the possible immunological functions and clinical significance of allergen-specific IgG antibodies of different subclasses. Based on results obtained by use of assays with documented specificity it is concluded that the IgG antibody response during allergen-specific immunotherapy is IgG1 and IgG4 restricted, although low levels of IgG2 and IgG3 antibodies to some allergens may occur. In most patients the early IgG antibody response is IgG1 dominated and the late IgG4 dominated. A too early or too pronounced IgG4 dominated antibody response seems to indicate a poor clinical outcome of immunotherapy with inhalant allergens, whereas a pronounced early IgG1 antibody production has been found to be associated with a decrease in synthesis of IgE antibodies to an insect venom. It is therefore proposed that an early IgG1 dominated response is necessary to induce suppression of the ongoing IgE antibody production, which in its turn may be a prerequisite for long-lasting clinical effect. The possibility of induction of an early IgG1 dominated response in every patient by use of alternative immunotherapy procedures is discussed.     

Human Peripheral Eosinophils with Receptors for IgM: Demonstration and Ultrastructural Morphology

Receptors for IgM were detected on peripheral blood human eosinophils by a rosette technique with ox red blood cells coated with the IgM fraction of the specific immunserum. Between 14 % and 43 % (mean 27 %) FcµR positive cells were found after an overnight incubation period at 37°C by using this technique. The specificity of the receptors for IgM was assessed by studying the inhibitory capacity of purified human IgM in the rosette assay. From an ultrastructural point of view, the EA^M rosette-forming cells are mature eosinophlic granulocytes characterized by a nucleus with a variable number of lobes and a certain number of «first type» granules partially or totally devoid of their content.     

Exposure to formaldehyde and phenol during an anatomy dissecting course: sensitizing potency of formaldehyde in medical students

BACKGROUND: The sensitizing potency of formaldehyde and phenol during anatomy dissecting was investigated. The objective was to determine whether exposure induces specific IgE or IgG against formaldehyde-albumin or phenol-albumin. METHODS: In 27 medical students, specific IgE against formaldehyde-albumin by RAST plus ELISA and specific IgE against phenol-albumin by ELISA were assessed. In addition, specific IgG against formaldehyde-albumin was assessed in 23 students. Symptoms before and during dissecting were assessed, and indoor formaldehyde and phenol were measured. RESULTS: Mean indoor formaldehyde was 0.265 +/- 0.07 mg/m3, and mean indoor phenol was 4.65 +/- 2.96 mg/m3. Specific IgE/IgG against formaldehyde-albumin was not found at the beginning. Four students developed specific IgE against formaldehyde-albumin (RAST classes of > or =2.0), and all four also had specific IgE in the ELISA, but IgG against formaldehyde-albumin was not found. Specific IgE against phenol-albumin was not seen. Itch and paresthesia of the hands (P<0.00001), dizziness (P<0.008), burning eyes (P<0.01), headache, sneezing, epistaxis, gingival bleeding, oral or pharyngeal itch, and shortness of breath were experienced. CONCLUSIONS: Formaldehyde exposure during dissecting may induce specific IgE, but not IgG, against formaldehyde-albumin. Sensitization did not correlate with symptoms.     

Clonally restricted insulin autoantibodies in a cohort of 2200 healthy blood donors

Summary Serum samples of 2200 blood donors were screened for anti-insulin IgG by enzyme-linked immunosorbent assay. Specificity of detected antibodies was verified by competition with an excess of insulin and observation that saturated anti-insulin IgG were no longer measurable. The upper limit of measured signal in the population was defined as the mean plus three SD. In the direct assay, 32 sera were positive. Among these, 22 (1%) contained saturable insulin antibodies (true positive) and 10 were non-saturable and considered as non-insulin-specific. The positive blood donors were requested to answer a questionnaire and according to their answers, none had ever received insulin, was a first degree relative of a Type 1 (insulin-dependent) diabetic patient or had experienced a hypoglycaemic episode. None of the 22 true positive sera detected by enzyme-immunosorbent assay bound ¹²⁵-I-insulin to any significant extent. The nine sera yielding the highest signal were further characterized with regard to heavy and light chains as well as species specificity of ligand. Anti-insulin IgG from healthy blood donors contained only one heavy (1 2/9; 3 7/9) and one light ( 8/9; 1/9) chain. Three sera were human insulin specific; two were non-species-specific; the other four bound insulin in the order human = porcine > bovine. These results indicate that low affinity clonally restricted antibodies against insulin are present in unselected blood donors with a prevalence of 1%.     

91例免疫相关性皮肤病患者血清花粉IgG抗体检测结果分析

目的：检测免疫相关性皮肤病患者血清花粉IgG阳性情况。方法：采用Dot-ELISA法检测受检患者血清花粉IgG抗体。结果：56％受检患者血 清花粉IgG抗体阳性,其中荨麻疹、湿疹、接触性皮炎和过敏性紫癜等过敏性皮肤病患者血清花粉IgG抗体阳性率为83．0％,其它免疫相关性皮肤病为18．4％（P＜0．005）。血清花粉IgG抗体阳性的34例荨麻疹患者中,早春花粉抗体阳性高达91．2％,晚春花粉52．9％,夏秋花粉29．4％（P＜0．005）。结论：致敏性花粉与过敏性皮肤病有较大关系。春季花粉,特别是早春花粉,是本地区花粉相关性荨麻疹的主要致敏花粉。