IgG Subclass Antibody Response in Grass Pollen-Allergic Patients Undergoing Specific Immunotherapy

All four subclasses of IgG antibodies to timothy grass pollen extract were measured by a three-layer immunoradiometric assay in sera from 20 grass pollen-allergic patients who underwent specific immunotherapy in a 3-year prospective study. Both IgG1 and IgG4 antibody levels rose significantly during the first 8 weeks of immunotherapy. IgG1 antibody level passed its peak (median 5.4 U/ml) after 12 weeks. At this time, the ratio between the medians of IgG1 and IgG4 antibodies was 2.25. IgG4 antibody level reached its peak (median 11.6 U/ml) just before termination of immunotherapy. At this time IgG1/IgG4 ratio was 0.43. Two years after the end of immunotherapy, IgG1 and IgG4 antibody levels were 0.0 and 1.8 U/ml in median, respectively. The amounts of IgG2 and IgG3 antibodies detected in the sera were less than 1.6 U/ml and were considered insignificant. Preseasonal serum IgG1 and IgG4 antibody levels did not correlate significantly with symptom scores in the subsequent season. Serum IgG4 level obtained after 12 weeks of immunotherapy was significantly correlated to symptom score in the third season, i.e. the season just after termination of therapy (rs = 0.529, t = 2.567, P = 0.02). In this work, a serum IgG4 antibody level higher than 8.0 U/ml after 12 weeks of therapy predicted poor clinical result at the end of immunotherapy with 100% sensitivity and 87% specificity. An IgG4/IgG1 ratio greater than 1.0 after 12 weeks' therapy had the same predictive value.     

Isotype and IgG Subclass Distribution of Autoantibody Response to Alpha-enolase Protein in Adult Patients with Severe Asthma

Purpose

A possible involvement of autoimmune mechanism in the pathogenesis of bronchial asthma has been proposed. Recently, alpha-enolase protein was identified as a major autoantigen recognized by circulating IgG autoantibodies in patients with severe asthma. To evaluate a possible pathogenetic significance of these autoantibodies in severe asthma, isotype (IgG, IgA, IgM, and IgE) and IgG subclass (IgG1, IgG2, IgG3, and IgG4) distributions of autoantibodies to recombinant human alpha-enolase protein were analyzed.

Patients and Methods

We examined serum samples from 10 patients with severe asthma and 7 patients with mild-to-moderate asthma, and 5 healthy controls by immunoblot analysis. Severe asthma was defined as patients having at least 1 severe asthmatic exacerbation requiring an emergency department visit or admission in the last year despite continuous typical therapies.

Results

IgG1 was the predominant IgG subclass antibody response to alpha-enolase protein in patients with severe asthma. IgG1 autoantibody to alpha-enolase protein was detected in 7 of 10 patients with severe asthma (70%), 1 of 7 patients with mild-to-moderate asthma (14.3%), and none of 5 healthy controls (0%) (chi-square test; p < 0.05). IgA, IgM, and IgE autoantibodies to alpha-enolase protein could not be detected in patients with severe asthma.

Conclusion

IgG1 subclass was the predominant type of autoantibody response to alpha-enolase protein in patients with severe asthma, suggests a possibility of IgG1 autoantibody-mediated complement activation in the pathogenesis of severe asthma.     

A Three-Layer Immunoradiometric Assay for Determination of IgG Subclass Antibodies in Human Sera ("IgG Subclass RAST")

We report the development of a three-layer immunoradiometric assay (TIRA) for measurement of IgG antibodies of all four subclasses in human sera. The first layer consists of diluted human serum, the second layer is monoclonal mouse antibodies to human IgG subclasses., and the third layer is ¹²⁵I-labelled rabbit anti-mouse IgG. Monoclonal anti-IgG1. anti-IgC3 and anti-IgG4 reacted only with their complementary IgG subclass, whereas the anti-lgG2 showed slight cross-reactivity to immunoglobins of other subclasses and classes and to light chain proteins. The observed cross-reactivity was found to be without importance, when the TIRA was applied to measurement of IgG subclass antibodies. Equipotency was established by use of appropriate dilutions of the monoclonal antibodies, and the assay was calibrated by use of human reference serum. The TIRA therefore permits reliable inter-individual and intra-individual comparisons of the IgG antibody response in all four subclasses. Von-sped fie binding obtained with pooled normal human serum was below 0.33'#. Inter-assay coefficient of variation was between 18 and 27%, The TIRA was applied to measurement of IgG subclass antibodies to timothy grass pollen in sera from grass pollen allergies undergoing immunotherapy.     

Specific Antibody Deficiency in Adult Patients With IgG or IgG Subclass Deficiency

PurposeSpecific antibody deficiency (SAD) involves a deficient response to a polysaccharide vaccine despite having normal immunoglobulin levels. The failure of the polysaccharide response can be observed as a component of various primary antibody deficiencies. However, only a few studies have described the clinical and immunological profiles in SAD and/or other primary immunodeficiencies (PIDs) in adults.MethodsA total of 47 patients who had a clinical history suggestive of antibody deficiency or had already been diagnosed with various antibody deficiencies were enrolled. Polysaccharide responses to 7 pneumococcal serotypes (4, 6B, 9V, 14, 18C, 19F and 23F) were measured using the World Health Organization enzyme-linked immunosorbent assay (WHO-ELISA), and postvaccination immunoglobulin G (IgG) titers were compared to clinical and laboratory parameters.ResultsBased on the American Academy of Allergy, Asthma, and Immunology (AAAAI) criteria for the WHO-ELISA, 11 (23.4%) patients were diagnosed as having SAD. Sixteen-three percent of them had combined with other types of PID, such as IgG subclass deficiency and hypogammaglobulinemia. Postvaccination IgG titers for the serotypes 4/9V/18C correlated with IgG2 (P = 0.012, P = 0.001, and P = 0.004) and for 6B/9V/14 with IgG3 (P = 0.003, P = 0.041, and P = 0.036, respectively). The IgG3 subclass levels negatively correlated with forced expiratory volume in 1 second (FEV1, %) and FEV1/forced vital capacity (P < 0.001 and P = 0.001, respectively).ConclusionSAD can be diagnosed in patients with normal IgG levels as well as in those deficient in IgG or the IgG3 subclass, implicating that restricted responses to Streptococcus pneumoniae polysaccharide antigens commonly exist in patients with predominantly antibody deficiency.     

Diagnosis and immunotherapy of mould allergy

The IgG subclass response was evaluated by a sensitive allergen- and subclass-specific solid phase immunoradiometric assay during a 1-year placebo-controlled, double-blind study of immunotherapy with Cladosporium herbarum in 22 adult asthmatics. The IgG response was mainly restricted to subclasses 1 and 4 but a few patients were IgG2 and IgG3 responders. An intense and early IgG1 response was observed during the first clusters of injection followed by a levelling down of the titer. The IgG4 response had a later onset and showed slowly increasing levels during the 12 months of immunotherapy. The graded clinical efficacy estimated by symptom-medication score was significantly correlated to the preseasonal IgG1 value, with high values indicating a deleterious response of immunotherapy (deterioration of disease activity). Likewise, the fold increase of IgG1 and IgG4 after two clusters of immunotherapy (i.e. after 4 weeks) was significantly related to the clinical outcome. Little or no increase of IgG1 and IgG4 was associated with improvement, i.e. decrease in symptom-medication score. The magnitude of the IgG1 response during the dose-increase phase was directly correlated to the number of systemic side effects. No relation of IgG1, IgG4 or IgG4/IgG1 ratio to changes in the IgE-mediated parameters (skin prick test, bronchial challenge and circulating specific IgE) was observed. Our data, which are based on few patients and only one allergen system, do not support the hypothesis of IgG acting as blocking antibody being the immunologic mechanism of immunotherapy. The association between high IgG4 values and a deleterious efficacy of immunotherapy might be caused by IgG4 acting as sensitizing antibodies. This explanation, however, is opposed by the lack of relation to systemic side effects.     

Ovalbumin-specific immunoglobulin G and subclass responses through the first 5 years of life in relation to duration of egg sensitization and the development of asthma

BACKGROUND: Egg sensitization, particularly persistent sensitization, is a risk factor for later asthma. However, little is known about accompanying IgG and subclass responses and how they might relate to asthmatic outcome. OBJECTIVE: To characterize hen's egg ovalbumin (OVA) IgG and subclass responses through the first 5 years of life in relation to duration of egg sensitization and later asthma. SUBJECTS and METHODS: The subjects (n=46) formed part of a larger cohort, born to atopic parents, who had been evaluated prospectively for the development of asthma. Egg sensitization was classified as transient (positive egg skin prick test at 1 year only) or persistent (positive skin test for at least 2 years). Plasma OVA IgG, IgG1 and IgG4 concentrations at birth (cord), 6 months, 1 and 5 years of age were measured by ELISA. RESULTS: The kinetics of OVA IgG and IgG1 responses, but not IgG4, differed between egg sensitized and non-egg sensitized (NES) children. Only persistently sensitized children had a rise in OVA IgG1 concentration through the first year of life, and at 1 year of age they had significantly higher OVA IgG and IgG1 than either transiently sensitized or NES children. High OVA IgG1 was associated with later asthma: at 1 year of age, OVA IgG1 greater than 14,500 U predicted asthma with a sensitivity 64% and specificity 74%. CONCLUSION: OVA IgG and subclass responses relate to the duration of egg sensitization. Measurement of OVA IgG1 concentration in infancy might offer a useful adjunct to identify those at an increased risk of asthma.     

食物不耐受IgG抗体在肠易激综合征中的检测意义

探讨食物不耐受IgG抗体检测在肠易激综合征中的临床价值.采用ELISA法半定量检测57例肠易激综合征患者血清中14种食物不耐受IgG抗体.结果显示,57例肠易激综合征患者中有43例食物不耐受IgG抗体呈阳性反应,以鸡蛋、牛奶、蟹的致敏性最高;14种IgG抗体阳性率分别为:牛奶(40.4%)、小麦(3.5%)、牛肉(7....     

Immunoglobulin class and IgG subclass distribution of anticardiolipin antibodies in patients with systemic lupus erythematosus and associated disorders.

The class and subclass distribution of an antibody response may give insight into the stimulating mechanism and likely effector functions. IgA, IgG and IgM anticardiolipin antibodies (aCL) were quantified in a consecutive series of 200 samples sent to an autoimmune serology laboratory to determine the relationships between aCL responses of each of these antibody classes and, in particular, whether there was any utility in the measurement of IgA aCL. Positive results for one of the three aCL isotypes were found in 105 samples (53%), and in 41 samples IgA aCL was detected (21%). However, amongst these unselected samples, little additional information was obtained by measurement of IgA aCL, which was found in conjunction with IgM or IgG aCL in all but five samples, and in these the isolated elevation of IgA aCL was only slight, and showed no disease specificity. The levels of each of the four IgG subclasses of aCL were measured in a subgroup of serum samples from 28 patients with autoimmune disease and from 29 patients with syphilis. Amongst the SLE patients IgG1 and IgG3 aCL were the predominant IgG subclasses, consistent with an antigen-driven, T cell-dependent antibody response. However, a subgroup of eight of the autoimmune subjects had predominant elevation of IgG2 aCL, possibly implying a role for T cell-independent antibody production to cardiolipin. Amongst the syphilis patients IgG1 and IgG3 aCL were also the predominant subclasses of aCL but IgG4 aCL were also detected in the majority of subjects, consistent with prolonged antigenic stimulation.     

非特异性免疫疗法在支气管哮喘治疗中的应用进展

支气管哮喘是呼吸系统的常见病及多发病之一,其是由嗜酸性粒细胞、肥大细胞、T淋巴细胞、中性粒细胞等多种细胞及细胞组分参与的气道慢性过敏反应炎症性疾病,在全球范围内的发病率及死亡率不断上升,严重影响公众健康和患者生活质量。研究发现,支气管哮喘的发病涉及机体免疫紊乱,Th1/Th2细胞比例失衡是哮喘发病的重要机制,在此基础上,支气管哮喘的免疫疗法取得一定进展,本文基于支气管哮喘的免疫学机制,对非特异性免疫疗法在支气管哮喘治疗中的研究及应用进展进行综述,以期为支气管哮喘的治疗提供新的方向和思路。     

Immunotherapy in the age of anti-IgE

Recent results of allergen immunotherapy research have continued to validate efficacy and have also demonstrated a truly preventive aspect for this treatment. This review summarizes the basic principles of effective allergen immunotherapy and highlights some of the advances that have been published in the past year. These studies show that allergen immunotherapy, when done appropriately and properly, not only causes a decrease in symptoms and use of medication as well as an improved quality of life, but that the progression of disease from allergic rhinitis to asthma is substantially decreased and the development of new allergies is diminished. In addition, laboratory studies continue to demonstrate significant changes in the immune system with a shift in the immune pathway from TH₂ toward a TH₁ response. The impact of anti-IgE as a therapeutic agent with allergen immunotherapy is also be reviewed.     

Prospective estimation of IgG, IgG subclass and IgE antibodies to dietary proteins in infants with cow milk allergy

Prospectively, serum levels of IgE, specific IgE antibodies (AB) to whole cow milk protein (CMP), bovine se-albumin, bovine immunoglobulin, bovine lactoferrin, bovine lactalbumin and beta-lactoglobulin (BLG), IgG and IgG subclass antibodies to ovalbumin (OA) and BLG, and IgG4 RAST to CMP (bovine whey) were measured in 39 infants with cow milk protein allergy (CMPA) at birth (cord blood), at time of diagnosis and before and after milk challenge at the age of 12 months. Immunological measurements were also undertaken in 33 control infants without CMPA at birth, at 6 months and at 18 months. At no time, were differences found between the levels of IgG and IgG subclass AB to OA and BLG in control versus infants with CMPA. In the 39 infants with CMPA no correlation was found between the levels of IgE, IgG and IgG subclass AB in cord blood and subsequent levels of these values, irrespective of the type of CMPA (IgE-mediated (CMA) or non-IgE-mediated (CMI)), and irrespective of whether remission had occurred. In cord blood 25/33 (76%) of the infants with CMPA had specific IgE-AB to one or more of the bovine milk proteins indicating a prenatal intrauterine sensitization to cow milk protein. At 6 months the frequency of specific IgE-AB to bovine milk proteins was significantly (p less than 0.05) higher in infants with CMA versus CMI, and at 12 months total serum-IgE and the increase of these specific IGE-AB and RAST to CMP were significantly higher (p less than 0.05) in infants with persistent CMA. From 6 to 12 months withholding milk resulted in a significant fall in specific IgE-AB to CMP, and IgG, IgG1 and IgG4 anti-BLG followed by an increase after milk challenge. Decreasing levels of IgG anti-OA from birth to 6 months reflect passive maternal transfer of IgG through the placenta, and increasing levels of IgG anti-BLG, already from birth to 6 months, may represent an early exposure to CMP in all infants. Significantly higher levels (p less than 0.05) of IgG anti-OA AB, IgG1 and IgG4 anti-BLG AB were found in infants with persistent CMA, indicating a close relation between the synthesis of IgE and IgG and between IgE and IgG subclasses (IgG1 and IgG4) in symptomatic cow milk-allergic individuals.(ABSTRACT TRUNCATED AT 400 WORDS)     

The inductive effect of interleukin-4 on IgG4 and IgE synthesis in human peripheral blood lymphocytes

Using murine monoclonal antibodies against human IgG subclasses, specific and sensitive ELISAs assay to quantify the four human IgG subclasses in cell culture supernatants were established. The effect of human recombinant interleukin-4 (IL-4) on the regulation of IgG subclasses by normal peripheral blood lymphocytes was investigated. In addition to the enhancement of IgE synthesis, IL-4 preferentially induced IgG4 synthesis in vitro, whereas IL-4 had no effect on IgG1, IgG2, and IgG3 synthesis. IL-4-induced IgG4 production was blocked in a dose-dependent manner by recombinant interferon-gamma and anti-human IL-4 monoclonal antibody. Collectively, this data indicates that IL-4 plays an important regulatory role in both IgG subclass and IgE synthesis.     

Characterization of IgE and IgG Antibody Responses to Dermatophagoides farinae in Rats

Rats (Brown Norway/Wistar Fu) that were pretreated or not pretreated with cyclophosphamide were immunized with varying amounts of Dermatophagoides farinae allergen extract with alum as adjuvant. Sera were analysed by RAST and by crossed radioimmunoelectrophoresis (CRIE). The highest IgE antibody responses were recorded in animals pretreated with cyclophosphamide that had received low immunizing doses of antigen. The IgE antibody pattern in CRIE was, however, not influenced by the dose of antigen or by cyclophosphamide pretreatment. The IgG pattern in CRIE closely resembled the IgE pattern, demonstrating a similar specificity of the antibody responses of the two isotypes. This indicates non-class specific control of the specificity of antibody responses.     

急性肾小球肾炎尿IgG测定的临床研究

目的：探讨小儿急性肾小球肾炎（AGN）尿IgG测定的临床意义。方法：用免疫比浊法测定32例AGN患儿急性期和恢复期的尿IgG，比较两者尿IgG的阳性率。同时应用LOGISTIC多元回归分析急性期尿IgG与血尿、浮肿、高血压、BUN和年龄的相关关系。结果：急性期尿IgG阳性率为78％，比恢复期31％明显增高，χ^2=14.19,p＜0．005，急性期尿IgG与血尿、浮肿、高血压、BUN和年龄无相关关系。结论：AGN患儿尿IgG阳性反映肾小球滤过膜通透性明显增加，可考虑作为活动的指标之一，但与病情的轻重程度无关。     

Subclass composition and J-chain expression of the 'compensatory' gastrointestinal IgG cell population in selective IgA deficiency.

The subclass distribution of IgG-producing immunocytes was examined by two-colour immunohistochemistry in gastrointestinal mucosa of 14 patients with selective serum IgA deficiency providing the following biopsy material: gastric (n = 1); jejunal (n = 12); colonic (n = 1); and rectal (n = 2). All except two patients suffered from various infections, and coeliac disease was observed in six of them. Control reference data were based on biopsies from immunologically intact subjects, including histologically normal jejunal (n = 10) and large bowel (n = 10) mucosa and stomach mucosa with slight chronic gastritis (n = 8). The total mucosal population of immunoglobulin-producing cells per 500 microns gut length unit was only slightly decreased in IgA deficiency because of an increased number of IgG (30%) and especially IgM (71%) immunocytes. The IgG1 immunocyte proportion in the proximal gut (median 87%) was higher than that in the comparable controls (gastric 69%, jejunal 66%). A similar trend was seen in the distal gut (69%) compared with controls from the large bowel mucosa (55%). Conversely, IgG2 and IgG3 cell proportions were significantly decreased compared with the respective controls from the proximal gut. The same was true for IgG4, which also was significantly reduced in jejunal mucosa. Paired staining for cytoplasmic J chain and immunoglobulin isotype showed 71% positivity for jejunal IgG-producing cells in IgA deficiency, which was somewhat reduced compared with comparable controls (89%). J chain appeared to be preferentially expressed by IgG1 cells (75%), but was also found in IgG2 (70%), IgG3 (32%) and IgG4 cells (33%). IgM-producing cells showed a J-chain positivity (99%) in IgA deficiency similar to normal (100%). Our results suggested that the block in mucosal B cell differentiation to IgA expression in the proximal gut is mainly located immediately upstream to the CH alpha 1 gene, giving excessive terminal maturation of J-chain-positive IgG1 immunocytes.     

Subclass distribution of IgG antibodies to the rat oesophagus stratum corneum (so-called anti-keratin antibodies) in rheumatoid arthritis.

Serum IgG, labelling the stratum corneum of the rat oesophagus epithelium, so-called anti-keratin antibodies (AKA) constitute the most specific marker for the diagnosis of rheumatoid arthritis. In this study, we investigated 31 IgG AKA-positive rheumatoid sera and 21 control sera from patients with non-rheumatoid inflammatory rheumatic diseases. The serum level of IgG1,2,3 and 4 was determined by radial immunodiffusion and the subclass distribution of IgG AKA by a three-step semi-quantitative immunofluorescence assay using standard monoclonal antibodies specific for each of the four human IgG subclasses. In the rheumatoid sera, the serum level of IgG1 was found to be significantly increased and the level of IgG2 significantly decreased with regard to the control sera, while the levels of IgG3 and 4 as well as total IgG were in the normal range. IgG1,2,3, and 4 AKA were detected in 27 (87%), 6 (19%), 4 (13%) and 11 (35%) of the 31 rheumatoid sera, respectively, and were found to be independent of the clinical and biological indices of the disease. In spite of inter-individual heterogeneity, two predominant profiles were distinguished: IgG1 (alone) and IgG(1 + 4), which together represented 18 sera (58%). The large predominance of IgG1 AKA and the quasi-absence of IgG2 AKA suggest that the recognized antigen may be partly comprised of protein. Moreover, the high frequency of occurrence of IgG4 AKA might result from chronic exposure to the eliciting antigen, which could be a genuine autoantigen since we demonstrated that it is also present in the stratum corneum of human epidermis.