IgE, allergies and helminth parasites: a new perspective on an old conundrum

IgE-Mediated Activation of Mast Cells and Basophils in Health and Disease

Type 2-mediated immune responses protect the body against environmental threats at barrier surfaces, such as large parasites and environmental toxins, and facilitate the repair of inflammatory tissue damage. However, maladaptive responses to typically nonpathogenic substances, commonly known as allergens, can lead to the development of allergic diseases. Type 2 immunity involves a series of prototype TH2 cytokines (IL-4, IL-5, IL-13) and alarmins (IL-33, TSLP) that promote the generation of adaptive CD4+ helper Type 2 cells and humoral products such as allergen-specific IgE. Mast cells and basophils are integral players in this network, serving as primary effectors of IgE-mediated responses. These cells bind IgE via high-affinity IgE receptors (FcεRI) expressed on their surface and, upon activation by allergens, release a variety of mediators that regulate tissue responses, attract and modulate other inflammatory cells, and contribute to tissue repair. Here, we review the biology and effector mechanisms of these cells, focusing primarily on their role in mediating IgE responses in both physiological and pathological contexts.

Microbial natural compounds and secondary metabolites as Immunomodulators: A review

Immunomodulatory therapies are beneficial strategies for the improvement of immune system function. Today, due to the increasing prevalence of immune disorders, cancer, and new viral diseases, there is a greater need to introduce immunomodulatory compounds with more efficiency and fewer side effects. Microbial derivatives are fertile and attractive grounds for discovering lots of novel compounds with various medical properties. The discovery of many natural compounds derived from bacterial sources, such as secondary metabolites with promising immunomodulating activities, represents the importance of this topic in drug discovery and emphasizes the necessity for a coherent source of study in this area. Considering this need, in this review, we aim to focus on the current information about the immunomodulatory effects of bacterial secondary metabolites and natural immunomodulators derived from microorganisms.

Longitudinal cytokine and multi-modal health data of an extremely severe ME/CFS patient with HSD reveals insights into immunopathology, and disease severity

Introduction

Myalgic Encephalomyelitis/Chronic Fatigue Syndrome (ME/CFS) presents substantial challenges in patient care due to its intricate multisystem nature, comorbidities, and global prevalence. The heterogeneity among patient populations, coupled with the absence of FDA-approved diagnostics and therapeutics, further complicates research into disease etiology and patient managment. Integrating longitudinal multi-omics data with clinical, health,textual, pharmaceutical, and nutraceutical data offers a promising avenue to address these complexities, aiding in the identification of underlying causes and providing insights into effective therapeutics and diagnostic strategies.

Methods

This study focused on an exceptionally severe ME/CFS patient with hypermobility spectrum disorder (HSD) during a period of marginal symptom improvements. Longitudinal cytokine profiling was conducted alongside the collection of extensive multi-modal health data to explore the dynamic nature of symptoms, severity, triggers, and modifying factors. Additionally, an updated severity assessment platform and two applications, ME-CFSTrackerApp and LexiTime, were introduced to facilitate real-time symptom tracking and enhance patient-physician/researcher communication, and evaluate response to medical intervention.

Results

Longitudinal cytokine profiling revealed the significance of Th2-type cytokines and highlighted synergistic activities between mast cells and eosinophils, skewing Th1 toward Th2 immune responses in ME/CFS pathogenesis, particularly in cognitive impairment and sensorial intolerance. This suggests a potentially shared underlying mechanism with major ME/CFS comorbidities such as HSD, Mast cell activation syndrome, postural orthostatic tachycardia syndrome (POTS), and small fiber neuropathy. Additionally, the data identified potential roles of BCL6 and TP53 pathways in ME/CFS etiology and emphasized the importance of investigating adverse reactions to medication and supplements and drug interactions in ME/CFS severity and progression.

Discussion

Our study advocates for the integration of longitudinal multi-omics with multi-modal health data and artificial intelligence (AI) techniques to better understand ME/CFS and its major comorbidities. These findings highlight the significance of dysregulated Th2-type cytokines in patient stratification and precision medicine strategies. Additionally, our results suggest exploring the use of low-dose drugs with partial agonist activity as a potential avenue for ME/CFS treatment. This comprehensive approach emphasizes the importance of adopting a patient-centered care approach to improve ME/CFS healthcare management, disease severity assessment, and personalized medicine. Overall, these findings contribute to our understanding of ME/CFS and offer avenues for future research and clinical practice.

The immunomodulatory role of withania somnifera (L.) dunal in inflammatory diseases

Withania somnifera (L.) Dunal (Solanaceae) (also known as Ashwagandha) is a botanical drug that has been used for centuries to treat many chronic diseases like high blood pressure, arthritis, diabetes, Alzheimer's disease, and depression. As many botanical drugs, w. Somnifera possesses anti-inflammatory, antioxidant, anticarinogenic, anti-diabetic, and anti-asthmatic properties. W. somnifera is often compared to the ginseng plant due to its ability to reduce stress, improve cognitive functions (e.g., memory), and promote a healthy immune system. It promotes immunomodulatory effects whose function is to balance the humoral and cellular responses of the adaptive immune system. The therapeutic effect of w. Somnifera is attributed to active ingredients like alkaloids, steroidal lactones (such as withanolides, withaferins), and steroidal saponins. Although w. Somnifera is safe and highly recommended for treating various diseases, the current knowledge and understanding of its operational mechanisms are limited. One of the proposed mechanisms states that w. Somnifera promotes cellular-mediated immunity or initiates chemical interactions that contribute to therapeutic effects. Withania somnifera has been shown to play a significant role in immunological diseases by modulating several cytokines, increasing T-cell proliferation and enhancing macrophages functions. In this review, we will discuss the latest therapeutic effects of w. Somnifera on a number of diseases through modulating immunological markers and which specific components of w. Somnifera induce these therapeutic activities. We will also focus on the chemical properties in w. Somnifera components and their immunomodulatory role in type 2 allergic diseases where type 2 inflammation is highly imbalanced.

Exposure to polycyclic aromatic hydrocarbons and serum total IgE in the Korean adults: the Third Korean National Environmental Health Survey (2015-2017)

Background

Polycyclic aromatic hydrocarbons (PAHs) have become common pollutants with industrial development. Although the effect of exposure to PAHs on allergic disease in humans has been evaluated, evidence of an association is sparse. The association between PAH exposure and serum total immunoglobulin E (IgE) levels was evaluated in Korean adults.

Methods

In total, this study included 3,269 participants in the Third Korean National Environmental Health Survey (2015-2017). Four urinary PAH metabolites were used to assessed exposure to PAHs: 1-hydroxypyrene, 1-hydroxyphenanthrene, 2-naphthol, and 2-hydroxyfluorene. The analyses were performed on 3 cutoff levels (100 IU/mL, 114 IU/mL, and 150 IU/mL) set as the total IgE elevation. Prevalence of total IgE elevation by PAH exposure group and general characteristics (age, sex, BMI, smoking, alcohol drinking, and occupation) were analyzed using the Rao-Scott χ² test. Multiple logistic regression analyses were conducted to calculate adjusted odds ratios (ORs) for total IgE elevation by PAH exposure groups.

Results

Total IgE elevation differed significantly by age, sex, smoking status, alcohol drinking status, and occupation. For 2-hydroxyfluorene, the fourth quartile showed a significant association with IgE elevation compared to the first quartile in the analyses of cutoff-level 100 IU/mL (OR: 1.372, 95% confidence interval [CI]: 1.007-1.869) and 114 IU/mL (OR: 1.643, 95% CI: 1.167-2.312). In the analysis of cutoff-level 150 IU/mL, the adjusted ORs of the third and fourth quartile of 2-hydroxyfluorene were significantly higher than the first quartile (3rd quartile: OR: 1.478, 95% CI: 1.034-2.113; 4th quartile: OR: 1.715, 95% CI: 1.161-2.534). However, there were no significant positive associations for the other metabolites.

Conclusions

This study implied that PAHs exposure is associated with total IgE elevation in Korean adults. More research is needed to confirm the effect of exposure to PAHs on serum IgE and allergic diseases.

Do Intestinal Unicellular Parasites Have a Role in the Inflammatory and Redox Status among the Severely Obese?

The diagnosis of obesity comprises subjects with totally different phenotypes and metabolic profiles. Systemic inflammation and oxidative stress derived from the white adipose tissue are suggested as the link between this disease and the development of insulin resistance and metabolic comorbidities. The presence of unicellular eukaryotic parasites colonizing the human gut ecosystem is a common circumstance, and yet their influence on the inflammatory and redox status of the obese host has not been assessed. Herein, a set of inflammatory and redox biomarkers were assessed together with a parasitological analysis of 97 severely obese subjects. Information was also collected on insulin resistance and on the antioxidant composition of the diet. The global prevalence of intestinal unicellular parasites was 49.5%, with Blastocystis sp. the most prevalent protozoan found (42.3%). Colonized subjects displayed a higher total antioxidant capacity and a trend towards higher extracellular superoxide dismutase activity, regardless of their insulin resistance status, along with lower reduced glutathione/oxidized glutathione (GSH/GSSG) ratios in plasma in the insulin-resistant subgroup. No changes in malondialdehyde levels, or in inflammatory cytokines in plasma, were found in regard to the colonization status. In conclusion, enteric eukaryotic unicellular parasites may play an important role in modulating the antioxidant defenses of an obese host, thus could have beneficial effects with respect to the development of systemic metabolic disorders.

A New Role for Old Friends: Effects of Helminth Infections on Vaccine Efficacy

Vaccines are one of the most successful medical inventions to enable the eradication or control of common and fatal diseases. Environmental exposure of hosts, including helminth infections, plays an important role in immune responses to vaccines. Given that helminth infections are among the most common infectious diseases in the world, evaluating vaccine efficiency in helminth-infected populations may provide critical information for selecting optimal vaccination programs. Here, we reviewed the effects of helminth infections on vaccination and its underlying immunological mechanisms, based on findings from human studies and animal models. Moreover, the potential influence of helminth infections on SARS-CoV-2 vaccine was also discussed. Based on these findings, there is an urgent need for anthelmintic treatments to eliminate helminth suppressive impacts on vaccination effectiveness during implementing mass vaccination in parasite endemic areas.

Antibody response to Schistosoma haematobium and other helminth species in malaria-exposed populations from Burkina Faso

Infection with helminths in sub-Saharan Africa could modulate the immune response towards Plasmodium falciparum as well as susceptibility to malaria infection and disease. The aim of this study is to assess the antibody responses to helminths species in malaria-exposed populations from Burkina Faso. Plasma samples were collected in rural villages inhabited by Fulani, Mossi and Rimaibe communities, and IgG against parasitic helminths were measured by ELISA. The prevalence of IgG against antigens of Strongyloides stercoralis, Wuchereria bancrofti and Schistosoma haematobium (Soluble Egg Antigen, SEA) was 5%, 16% and 63% respectively, in line with estimates of infection prevalence in the region for the three parasites. Anti-SEA IgG prevalence was highest at 10-20 years of age, higher in males than females, and did not show differences between ethnic groups. However, the Fulani showed lower levels of anti-SEA IgG suggesting that lighter S. haematobium infections may occur in the ethnic group known for a marked lower susceptibility to P. falciparum. The present data support the use of serological methods for integrated surveillance of neglected tropical diseases such as soil-transmitted helminths, lymphatic filariasis and bilharzia. Furthermore, as helminth infections might promote downregulation of immune responses against intracellular pathogens, the observation of lower anti-SEA IgG levels in the malaria resistant Fulani population warrants further investigation into the immunological cross-talk between S. haematobium and P. falciparum in this geographical region.

Plasma cells: You are what you eat

Plasma cells are terminally differentiated B lymphocytes that constitutively secrete antibodies. These antibodies can provide protection against pathogens, and their quantity and quality are the best clinical correlates of vaccine efficacy. As such, plasma cell lifespan is the primary determinant of the duration of humoral immunity. Yet dysregulation of plasma cell function can cause autoimmunity or multiple myeloma. The longevity of plasma cells is primarily dictated by nutrient uptake and non-transcriptionally regulated metabolic pathways. We have previously shown a positive effect of glucose uptake and catabolism on plasma cell longevity and function. In this review, we discuss these findings with an emphasis on nutrient uptake and its effects on respiratory capacity, lifespan, endoplasmic reticulum stress, and antibody secretion in plasma cells. We further discuss how some of these pathways may be dysregulated in multiple myeloma, potentially providing new therapeutic targets. Finally, we speculate on the connection between plasma cell intrinsic metabolism and systemic changes in nutrient availability and metabolic diseases.

Biodiversity of protists and nematodes in the wild nonhuman primate gut

Documenting the natural diversity of eukaryotic organisms in the nonhuman primate (NHP) gut is important for understanding the evolution of the mammalian gut microbiome, its role in digestion, health and disease, and the consequences of anthropogenic change on primate biology and conservation. Despite the ecological significance of gut-associated eukaryotes, little is known about the factors that influence their assembly and diversity in mammals. In this study, we used an 18S rRNA gene fragment metabarcoding approach to assess the eukaryotic assemblage of 62 individuals representing 16 NHP species. We find that cercopithecoids, and especially the cercopithecines, have substantially higher alpha diversity than other NHP groups. Gut-associated protists and nematodes are widespread among NHPs, consistent with their ancient association with NHP hosts. However, we do not find a consistent signal of phylosymbiosis or host-species specificity. Rather, gut eukaryotes are only weakly structured by primate phylogeny with minimal signal from diet, in contrast to previous reports of NHP gut bacteria. The results of this study indicate that gut-associated eukaryotes offer different information than gut-associated bacteria and add to our understanding of the structure of the gut microbiome.

Total serum IgE levels among adults patients with intermittent and persistent allergic asthmas

Background: Obesity with knee osteoarthritis (OA) is related to chronic pain causing physical inactivity that leads to decreased cardiorespiratory endurance and quality of life. Aquatic and land-based exercises are effective in improving physical activity. The aim of this study is to compare between aquatic and land-based exercise to improve cardiorespiratory endurance and quality of life in obese patients with knee osteoarthritis.Methods: A single-blind, randomized, controlled trial was conducted on thirty-three obese patients with knee OA who visited Obesity Clinic of Medical Rehabilitation Cipto Mangunkusumo Hospital, from October 2016 to January 2017, subjects were divided into aquatic or land-based exercise group. Aerobic and knee-strengthening exercises were given. Cardiorespiratory endurance was assessed using the Borg Scale, whereas both the BORG CR-10 and SF-36 questionnaires were used to assess quality of life.Results: After intervention, there were significant improvements in the land-based exercise group in the rating of perceived exertion (p=0.02), role limitations due to physical health (p=0.024), role limitations due to emotional problems (p=0.041), energy/fatigue (p=0.016), and the decline in pain (p=0.049) parameters. While in the aquatic exercise, there were significant improvements in leg fatigue (p=0.016), energy/fatigue (p=0.025), emotional well-being (p<0.001), and general health (p=0.045) parameters. Despite this, there were no significant differences between two groups regarding cardiorespiratory endurance and quality of life.Conclusion: This study found that patients could start aquatic exercise to reduce leg fatigue and enhance general health and energy. After that, exercise could be continued in land-based settings to improve cardiorespiratory endurance and quality of life.

Cell Type-Specific Immunomodulation Induced by Helminthes: Effect on Metainflammation, Insulin Resistance and Type-2 Diabetes

Recent epidemiological studies have documented an inverse relationship between the decreasing prevalence of helminth infections and the increasing prevalence of metabolic diseases ("metabolic hygiene hypothesis"). Chronic inflammation leading to insulin resistance (IR) has now been identified as a major etiological factor for a variety of metabolic diseases other than obesity and Type-2 diabetes (metainflammation). One way by which helminth infections such as filariasis can modulate IR is by inducing a chronic, nonspecific, low-grade, immune suppression mediated by modified T-helper 2 (Th2) response (induction of both Th2 and regulatory T cells) which can in turn suppress the proinflammatory responses and promote insulin sensitivity (IS). This article provides evidence on how the cross talk between the innate and adaptive arms of the immune responses can modulate IR/sensitivity. The cross talk between innate (macrophages, dendritic cells, natural killer cells, natural killer T cells, myeloid derived suppressor cells, innate lymphoid cells, basophils, eosinophils, and neutrophils) and adaptive (helper T [CD4⁺] cells, cytotoxic T [CD8⁺] cells and B cells) immune cells forms two opposing circuits, one associated with IR and the other associated with IS under the conditions of metabolic syndrome and helminth-mediated immunomodulation, respectively.

Elevated total serum immunoglobulin E (>1000 IU/mL): implications?

Atopic eczema, allergic broncho-pulmonary aspergillosis, helminthic infections and rare primary immunodeficiencies are known to elevate total serum immunoglobulin E (IgE) above 1000 IU/mL. However, of 352 patients with IgE >1000 IU/mL seen in our hospital over a 5-year period, less than 50% had these conditions. Markedly elevated IgE levels in the rest of the patients were associated with asthma, allergic rhinitis and food allergy, instances where the test is of limited diagnostic utility.

Different clinical allergological features of Taenia solium infestation

The tapeworm Taenia (T.) solium can be responsible for two different conditions: taeniasis and cysticercosis. Helminth infections in human host cause an immune response associated with elevated levels of IgE, tissue eosinophilia and mastocytosis, and with the presence of CD4+ T cells that preferentially produce IL-4, IL-5, and IL-13. Individuals exposed to helminth infections may have allergic inflammatory responses to parasites and parasite antigens. PubMed search of human cases of allergic reactions occurring during T. solium infestation was performed combining the terms (allergy, urticaria, angioedema, asthma, anaphylaxis) with T. solium. A study was considered eligible for inclusion in the review if it reported data on patients with T. solium infestation who had signs or symptoms of allergy. In literature we found six articles reporting the association between an allergic reaction and T. solium infestation: two cases of urticaria, two cases of relapsing angioedema, one case of asthma and two cases of anaphylaxis. Despite the large diffusion of T. solium infestation, we found only a few cases of concomitant allergic reaction and the presence of Taenia in the host. The association between T. solium infestation and allergic manifestations has never been clearly demonstrated, and in absence of a well-documented causality the hypotheses are merely speculative. Therefore, the association between Taenia infection and allergy needs to be thoroughly studied to better clarify if this association may really exist and which is the pathogenetic mechanism supported.

Influence of levamisole and Freund's adjuvant on mouse immunisation with antigens of adults of the liver fluke Fasciola hepatica Linnaeus, 1758

We have studied the influence of both levamisole (AL) and Freund's adjuvant (AF) on the immunisation of mice with the secretory antigens of adults of the liver fluke Fasciola hepatica Linnaeus, 1758. Total IgG antibodies were detected in all groups where the F. hepatica antigen was administered, been levels of IgG1 increased respect to IgG2a antibodies. During immunisation, IL-4 and IFN-γ were only detected in AL and AF groups, but after infection, IL-4 boosted in all groups. IFN-γ increased two fold in AF and AL groups compared to the saline solution (AS) group. Worm recovering was of 32-35% in groups administered without antigen whereas in AS, AL and AF groups recovering was of 25%, 12% and 8%, respectively. Macroscopical lesions in the liver were scarce in AL and AF groups. Our data suggest that immunisation of mice with antigens of F. hepatica enhances the immune response avoiding both liver damage and worm establishment after challenge infection. The murine model of fasciolosis has appeared to be useful to elucidate the mechanism by which the parasite modulates immune responses toward a Th2 type but also the development of Th1 type-inducing vaccines.

Immune responses in children infected with the pinwormEnterobius vermicularisin central Greece

Previous studies have suggested an immunomodulatory and even protective role forEnterobius vermicularis, the least pathogenic human intestinal helminth. Here, in a study using haematological and serological parameters, we tested a total of 215 children from central Greece, with a mean age of 8.39, of whom 105 (48.84%) were infected withE. vermicularisand 110 (51.16%) were matched healthy controls. In particular, we analysed eosinophil counts (EO), serum eosinophil cationic protein (ECP), total and specific serum immunoglobulin E (IgE) and the ECP/EO ratio. The atopic status and the potential occurrence of clinically expressed allergic diseases were both taken into account. Eosinophils, ECP and IgE were found to be higher in infected than in uninfected children, indicating a type-2 immune response activation during infection. Atopic infected children exhibited higher IgE levels compared to non-atopic ones. EO and ECP were found to be lower in atopic children who had a history of allergic disease than in those with no such history. The type-2 oriented immune response elicited againstE. vermiculariscould contribute to a balanced activation of the immune system in the examined children. Interestingly, although the atopic children showed a stronger activation, they did not exhibit any symptoms and, moreover, there seemed to be some indication of immunosuppression in those children with a positive history of allergic disease.

Immunity to gastrointestinal nematodes: mechanisms and myths

Immune responses to gastrointestinal nematodes have been studied extensively for over 80 years and intensively investigated over the last 30–40 years. The use of laboratory models has led to the discovery of new mechanisms of protective immunity and made major contributions to our fundamental understanding of both innate and adaptive responses. In addition to host protection, it is clear that immunoregulatory processes are common in infected individuals and resistance often operates alongside modulation of immunity. This review aims to discuss the recent discoveries in both host protection and immunoregulation against gastrointestinal nematodes, placing the data in context of the specific life cycles imposed by the different parasites studied and the future challenges of considering the mucosal/immune axis to encompass host, parasite, and microbiome in its widest sense.

Changing patterns of antigen exposure and their impact on the prevalence of allergy

Industrial development has advanced at a varying pace in different parts of the world over the past 200 years. Inhabitants of the most industrially advanced regions have experienced major changes in patterns of antigen exposure to infectious agents and to environmental biologic substances. This article analyzes the major factors that affect the amounts and variety of antigens to which the immune system of a young child is exposed. Depending on individual living environments and lifestyles, the types of antigen exposure of young children are graded into five patterns: 'primitive', 'pre-modern', 'early modern', 'modern', and 'ultramodern'. These patterns represent increasing deviation from the pattern of human immune system exposure to antigens prior to the industrial revolution. This article further discusses how such changes in antigen exposure have affected the immunologic system, especially with regard to the development of total IgE and allergic response-relevant antigen-specific IgE, and how the patterns of antigen exposure are related to the propensity to develop allergy.

Use of humanised rat basophilic leukaemia cell line RS-ATL8 for the assessment of allergenicity of Schistosoma mansoni proteins

Background

Parasite-specific IgE is thought to correlate with protection against Schistosoma mansoni infection or re-infection. Only a few molecular targets of the IgE response in S. mansoni infection have been characterised. A better insight into the basic mechanisms of anti-parasite immunity could be gained from a genome-wide characterisation of such S. mansoni allergens. This would have repercussions on our understanding of allergy and the development of safe and efficacious vaccinations against helminthic parasites.

Methodology/Principal Findings

A complete medium- to high-throughput amenable workflow, including important quality controls, is described, which enables the rapid translation of S. mansoni proteins using wheat germ lysate and subsequent assessment of potential allergenicity with a humanised Rat Basophilic Leukemia (RBL) reporter cell line. Cell-free translation is completed within 90 minutes, generating sufficient amounts of parasitic protein for rapid screening of allergenicity without any need for purification. Antigenic integrity is demonstrated using Western Blotting. After overnight incubation with infected individuals' serum, the RS-ATL8 reporter cell line is challenged with the complete wheat germ translation mixture and Luciferase activity measured, reporting cellular activation by the suspected allergen. The suitability of this system for characterization of novel S. mansoni allergens is demonstrated using well characterised plant and parasitic allergens such as Par j 2, SmTAL-1 and the IgE binding factor IPSE/alpha-1, expressed in wheat germ lysates and/or E. coli. SmTAL-1, but not SmTAL2 (used as a negative control), was able to activate the basophil reporter cell line.

Conclusion/Significance

This method offers an accessible way for assessment of potential allergenicity of anti-helminthic vaccine candidates and is suitable for medium- to high-throughput studies using infected individual sera. It is also suitable for the study of the basis of allergenicity of helminthic proteins.

Infection with parasitic helminths is characterised by a marked elevation of total and parasite-specific Immunoglobulin E (IgE). It is widely believed that this IgE response has evolved to protect hosts against large metazoan parasites. Such a protective function has been well characterised in particular against members of the genus Schistosoma. However, with a few notable exceptions, the molecular targets of the IgE response and the downstream immunological mechanisms leading to host protection are not well understood. The molecular targets of a specific IgE response are by definition called allergens. While almost 3,000 different allergens, contained in e.g. plant pollen or seeds, moulds or animal materials, have been characterised at the molecular level, and are listed and described in databases such as the Allergome database (www.allergome.org), only a few dozen allergens have been characterised in parasitic helminths. A more detailed understanding of the molecular targets of the anti-helminth IgE response can not only be expected to further our basic understanding of protective immune responses and allergy in general–such knowledge can also be expected to have important repercussions on the production of safe and effective anti-helminthic vaccines. This research describes a novel approach suitable for genome-wide functional identification of allergens in S. mansoni and other parasites, paving the way for the identification of the Schistosoma allergome.

The autoimmune model of schizophrenia

Schizophrenia is of mysterious causation. It is not infectious, not congenital, but shows familial aggregation, the Mendelian genetics indicating involvement of multiple codominant genes with incomplete penetrance. This is the pattern for autoimmune diseases, such as Graves' disease of the thyroid, where forbidden clones of B lymphocytes develop, and cause thyrotoxicosis by secreting autoantibodies that react with the thyroid gland's receptor for thyroid-stimulating hormone from the pituitary gland. In 1982, Knight postulated that autoantibodies affecting the function of neurons in the limbic region of the brain are a possible cause of schizophrenia. Today, this is even more probable, with genes predisposing to schizophrenia having being found to be immune response genes, one in the MHC and two for antibody light chain V genes. Immune response genes govern the immune repertoire, dictating the genetic risk of autoimmune diseases. The simplest test for an autoimmune basis of schizophrenia would be trial of immunosuppression with prednisone in acute cases. The urgent research need is to find the microbial trigger, as done by Ebringer for rheumatoid arthritis and for ankylosing spondylitis. This could lead to prophylaxis of schizophrenia by vaccination against the triggering microbe.

Mast cells as cellular sensors in inflammation and immunity

Mast cells are localized in tissues. Intense research on these cells over the years has demonstrated their role as effector cells in the maintenance of tissue integrity following injury produced by infectious agents, toxins, metabolic states, etc. After stimulation they release a sophisticated array of inflammatory mediators, cytokines, and growth factors to orchestrate an inflammatory response. These mediators can directly initiate tissue responses on resident cells, but they have also been shown to regulate other infiltrating immune cell functions. Research in recent years has revealed that the outcome of mast cell actions is not always detrimental for the host but can also limit disease development. In addition, mast cell functions highly depend on the physiological context in the organism. Depending on the genetic background, strength of the injurious event, the particular microenvironment, mast cells direct responses ranging from pro- to anti-inflammatory. It appears that they have evolved as cellular sensors to discern their environment in order to initiate an appropriate physiological response either aimed to favor inflammation for repair or at the contrary limit the inflammatory process to prevent further damage. Like every sophisticated machinery, its dysregulation leads to pathology. Given the broad distribution of mast cells in tissues this also explains their implication in many inflammatory diseases.

Strongyloides stercoralis excretory/secretory protein strongylastacin specifically recognized by IgE antibodies in infected human sera

The infective, microscopic Strongyloides stercoralis larvae in contaminated soil can penetrate human skin with the help of excretory/secretory proteases. These proteases play a critical role in infection and transmigration of the parasite to the intestines. Strongylastacin is similar to astacin (from the digestive gland of the crayfish Astacus astacus), a multi-domain protein with a signal peptide, a pro-enzyme, a catalytic domain containing the zinc binding consensus astacin family signature sequence HEXXHXXGFXHEXXRXDR, and a second conserved zinc binding motif SIMHY at N- terminal region. An EGF-1 like domain and a CUB domain are located at the COOH- terminal. In this study, the excretory/secretory Strongylastacin gene from S. stercoralis infective larval stage was cloned and expressed as a 45 kDa in Escherichia coli. Immunoblot analysis showed the presence of natural IgG antibodies against strongylastacin in six infected and six non-endemic normal sera. These findings were confirmed in an ELISA of 32 S. stercoralis infected and 32 presumed normal human sera; all contained natural anti-strongylastacin IgG antibodies. By contrast, IgE antibodies specific to strongylastacin were present in sera from individuals infected with S. stercoralis but not in uninfected control sera. Moreover, recombinant strongylastacin did not cross-react with IgE antibodies either from patients infected with filaria or patients with tropical pulmonary eosinophilic (TPE) who had increased IgE antibodies. The present authors conclude that strongylastacin, an excretory/secretory antigen, elicits specific IgE antibodies in S. stercoralis infected humans. Non-specific IgG antibodies to strongylastacin are present in both infected and normal humans. Further investigation is needed to understand the role of the host protective response against strongylastacin.

The role of platelets in defence against pathogens

Many more platelets are present in healthy mammals than are necessary for routine haemostasis. Thus, they could have other functions. Platelets have many of the attributes of innate immune function including Toll-like receptors. They also contain a wide range of anti-microbial peptides in storage granules. Platelets play an important role in bacterial infections, both in disease progress and in defence mechanisms depending on circumstances. Similar mechanisms are used in defence against fungi. Platelets are also involved in viral diseases, either in protecting from the immune system or in killing viruses that activate platelets. Finally, platelets have a role in defence against parasitic diseases, in particular malaria, that should not be ignored, and may aggravate some of the worst aspects. Platelets also have receptors for IgE and are implicated via parasitic disorders in development and problems of allergy.

Therapeutic targets for persistent airway inflammation in refractory asthma

The management of refractory asthma remains a compelling clinical problem that contributes significantly to the morbidity of patients as well as posing a financial burden to the health system. Treatment failure in this group of patients is associated with continued airway inflammation and dampening of the inflammatory cascade is the focus of much research in this area. Continued airway inflammation has been associated with higher patient morbidity and is being increasingly measured using markers of systemic and local inflammation in order to target therapy more effectively. This review focuses on the published evidence for both established and novel treatments in refractory asthma that act to control this pathological inflammatory process. No clear treatment yet exists to control this process and further research into inhibiting newly elucidated inflammatory pathways or new drugs more effectively or accurate targeting existing pathways are discussed along with the clinical evidence and the relative merits of each treatment.

Towards a differential definition of atopy: Anisakis simplex and the relationship between parasites and arthropods in respiratory allergy

Protective as well as enhancing effects of parasite infections on allergic disease have been postulated. Previous studies on this relationship focused frequently on skin test reactivity against aeroallergens, being house dust mites (HDM) the main agents responsible for a positive atopy outcome. We aimed to analyse the possible relationship between human parasite infection induced Anisakis simplex urticaria and respiratory allergy. A total of 86 patients with gastro-allergic Anisakiasis and 203 patients with chronic urticaria sensitized against A. simplex were studied for sensitization against aeroallergens and evaluated for rhinoconjunctivitis or bronchial asthma (RCBA). We compared the results with a control group of 250 consecutive patients referred for evaluation of allergic RCBA and atopy prevalence data of our region. Whereas no effect of A. simplex related disease on the overall allergic respiratory disease could be detected, a highly significant higher prevalence of RCBA associated HDM sensitization, but diminished allergy against other common aeroallergens (pollen, mould or dander) was observed in these groups. The relationship between A. simplex parasitism-associated acute or chronic urticaria on one side and allergic respiratory disease on the other side depends on the definition of atopy. We propose a differential definition of atopy, with a special emphasis on arthropod related sensitization.

Determinants of exhaled nitric oxide levels in healthy, nonsmoking African American adults

BACKGROUND

Asthma is a significant cause of morbidity and mortality for African Americans. Fraction of exhaled nitric oxide (FeNO) levels are increased in patients with asthma, and airway levels of nitric oxide metabolites regulate airway inflammation and airway diameter. More needs to be known about the factors that regulate FeNO. There is a need for FeNO reference values for African Americans.

OBJECTIVE

We sought to establish reference values and identify factors associated with FeNO levels in healthy African American adults.

METHODS

FeNO levels were measured in 895 healthy, nonsmoking African Americans between the ages of 18 and 40 years. FeNO measurements were repeated in 84 subjects. Factors potentially associated with FeNO were measured, including blood pressure, height, weight, and serum total IgE, eosinophil cationic protein, C-reactive protein, and nitrate levels. Data on respiratory symptoms, including upper respiratory tract infection (URI) symptoms, were collected. Univariate and multivariate analyses of the relationship between these variables and FeNO levels were performed.

RESULTS

In healthy, nonsmoking African Americans FeNO levels were stable during repeated measurements (intraclass correlation coefficient, 0.81). Sex (P < .0001), serum total IgE levels (P < .0001), and current URI symptoms (P = .0002) contributed significantly to FeNO variability but together accounted for less than 50% of the variation in FeNO levels.

CONCLUSION

The high correlation between repeated measurements of FeNO and the low correlation coefficients of known factors associated with FeNO suggest that other factors might contribute substantially to variability of FeNO levels in African Americans.

Safety of anti-immunoglobulin E therapy with omalizumab in allergic patients at risk of geohelminth infection

Background

Although the role of immunoglobulin E (IgE) in immunity against helminth parasites is unclear, there is concern that therapeutic antibodies that neutralize IgE (anti-IgE) may be unsafe in subjects at risk of helminth infection.

Objective

We conducted an exploratory study to investigate the safety of omalizumab (anti-IgE) in subjects with allergic asthma and/or perennial allergic rhinitis at high risk of intestinal helminth infection. The primary safety outcome was risk of infections with intestinal helminths during anti-IgE therapy.

Methods

A randomized, double-blind, placebo-controlled trial was conducted in 137 subjects (12–30 years) at high risk of geohelminth infection. All subjects received pre-study anthelmintic treatment, followed by 52 weeks' treatment with omalizumab or placebo.

Results

Of the omalizumab subjects 50% (34/68) experienced at least one intestinal geohelminth infection compared with 41% (28/69) of placebo subjects [odds ratio (OR) 1.47, 95% confidence interval (CI) 0.74–2.95, one-sided P = 0.14; OR (adjusted for study visit, baseline infection status, gender and age) 2.2 (0.94–5.15); one-sided P = 0.035], providing some evidence for a potential increased incidence of geohelminth infection in subjects receiving omalizumab. Omalizumab therapy was well tolerated, and did not appear to be associated with increased morbidity attributable to intestinal helminths as assessed by clinical and laboratory adverse events, maximal helminth infection intensities and additional anthelmintic requirements. Time to first infection (OR 1.30, 95% CI 0.79–2.15, one-sided P = 0.15) was similar between treatment groups. Infection severity and response to anthelmintics appeared to be unaffected by omalizumab therapy.

Conclusions

In this exploratory study of allergic subjects at high risk of helminth infections, omalizumab therapy appeared to be safe and well tolerated, but may be associated with a modest increase in the incidence of geohelminth infection.

Initial support for the hypothesis that PAR2 is involved in the immune response to Nippostrongylus brasiliensis in mice

Protease-activated receptor 2 (PAR(2)) is a cell surface receptor that detects trypsin and trypsin-like enzymes. Although the precise pathophysiological roles of PAR(2) are yet to be determined, the receptor has been broadly implicated in inflammation and allergy. However, no studies have investigated the possible roles of PAR(2) in hosts infected by parasitic helminths. Therefore, in this preliminary investigation, we compared the infectivity of the nematode Nippostrongylus brasiliensis in mice lacking the PAR(2) gene (PAR2-/- ) and in their 'background-strain' controls (129SV). PAR2-/- mice displayed elevated fecal egg counts and decreased levels of total serum IgE, after a subcutaneous infection with 900 infective third-stage N. brasiliensis larvae compared with 129SV mice that were not susceptible to infection. In addition, in a separate study in BALB/c mice, two immunological hallmarks of parasite infection, IgE- and IL-10-expressing lymphocytes, were shown to be augmented after the coadministration of the classic antigen ovalbumin with the PAR(2)-activating peptide SLIGRL (single letter amino acid sequence) but not the inactive reverse peptide LRGILS. These findings provide initial support for the proposal that PAR(2) is a recognition receptor for nematode-derived proteases.

Immunological cross-reactivity analysis on recombinant histamine-releasing factors from Schistosoma japonicum, Clonorchis sinensis, and Wistar rat

Studies have demonstrated a declined incidence of allergic disorders in the population with helminthic infection. Though several hypotheses have been proposed to explain how helminthic infection protected people against allergies, the underlying mechanisms remain poorly understood. A human histamine-releasing factor (HRF) has been proved to be closely related to the development of allergic disorders and the homologues are ubiquitously expressed in all eukaryotic organisms including parasites. To study the role of this HRF in the relationship between parasitic infection and allergic diseases with experimental model of rats, the cDNA of the homologues of the human HRF from Wistar rat, Schistosoma japonicum, and Clonorchis sinensis containing a coding region of 519, 510, and 510 bp, respectively, were cloned. In addition, the cross-reactivity between recombinant rat HRF (rRHRF) and recombinant S. japonicum HRF (rSjHRF) as well as that between rRHRF and recombinant C. sinensis HRF (rCsHRF) was identified with ELISA and Western blotting. Based on their detected cross-reactivities, a hypothesis was put forward that the anti-parasitic HRFs antibodies could inhibit the effects of host HRF and those of parasitic HRFs and thus decreased the host sensitivities to allergens.

Relationship between IgE and specific aeroallergen sensitivity in Alaskan native children

BACKGROUND

The relationship between atopic disease and serum IgE levels varies among populations and geographic regions. The close association of atopy with IgE may not occur in subarctic populations as it does in developed countries in temperate climates.

OBJECTIVE

To evaluate the relationship between total and specific IgE concentrations and clinical atopy in 5- to 8-year-old Alaskan native children.

METHODS

Medical record reviews, interviews, physical examinations, serum IgE measurements, and radioallergosorbent testing (RAST) were performed.

RESULTS

The IgE geometric mean was 122.1 IU/mL. Fifty-eight percent of patients had IgE levels greater than 70 IU/mL, and 17% had levels greater than 1,000 IU/mL; 14% had RAST values greater than 0.35 kU/L. Both IgE levels greater than 70 IU/mL and greater than 1,000 IU/mL were associated with RAST values greater than 0.35 IU/L (P = .004) and early wheezing (P = .005) but not with current wheezing, asthma, eczema, or a history of allergies. A RAST value greater than 3.51 kU/L was associated with eczema (P = .04) but not with allergies or wheezing. Children with current wheezing were more likely to have allergies (P = .03) but not eczema, an IgE level greater than 70 IU/mL, or a positive RAST value. Children hospitalized with respiratory syncytial virus (RSV) were not more likely than controls to have current wheezing.

CONCLUSIONS

Elevated serum IgE concentrations, including levels greater than 1,000 IU/mL, are common among Alaskan native children; positive RAST reactions to aeroallergens are not. The IgE levels do not relate to wheezing, eczema, a history of allergies, or past hospitalization for RSV infection but likely reflect infections other than RSV and environmental factors in subarctic indigenous populations.

Early stages of Ascaris suum induce airway inflammation and hyperreactivity in a mouse model

The inflammatory and functional changes that occur in murine lung after infection with 2500 infective Ascaris suum eggs were studied in this work. A sequential influx of neutrophils, mononuclear cells and eosinophils occurred into airways concomitantly with migration of larvae from liver to the lungs. Histological analysis of the lung showed a severe intra-alveolar haemorrhage at the peak of larval migration (day 8) and the most intense inflammatory cell infiltrate on day 14. Ascaris L3 were found in alveolar spaces and inside bronchioles on day 8. The number of eosinophils was elevated in the blood on days 8 and 14. The peak of eosinophil influx into the lung was at day 14, as indicated by the high levels of eosinophil peroxidase activity, followed by their migration into the airways. The antibody response against egg and larval antigens consisted mainly of IgG1 and IgM, and also of IgE and anaphylactic IgG1, that cross-reacted with adult worm antigens. Total IgE levels were substantially elevated during the infection. Measurement of lung mechanical parameters showed airway hyperreactivity in infected mice. In conclusion, the murine model of A. suum infection mimics the Th2-induced parameters observed in pigs and humans and can be used to analyse the immunoregulatory properties of this helminth.

The role of human mast cell-derived cytokines in eosinophil biology

Eosinophil-mediated diseases, such as allergic asthma, eosinophilic fasciitis, and certain hypersensitivity pulmonary disorders, are characterized by eosinophil infiltration and tissue injury. Mast cells and T cells often colocalize to these areas. Recent data suggest that mast cells can contribute to eosinophil-mediated inflammatory responses. Activation of mast cells can occur by antigen and immunoglobulin E (IgE) via the high-affinity receptor (FcepsilonRI) for IgE. The liberation of proteases, leukotrienes, lipid mediators, and histamine can contribute to tissue inflammation and allow recruitment of eosinophils to tissue. In addition, the synthesis and expression of a plethora of cytokines and chemokines (such as granulocyte-macrophage colony-stimulating factor [GM-CSF], interleukin-1 [IL-1], IL-3, IL-5, tumor necrosis factor-alpha [TNF-alpha], and the chemokines IL-8, regulated upon activation normal T cell expressed and secreted [RANTES], monocyte chemotactic protein-1 [MCP-1], and eotaxin) by mast cells can influence eosinophil biology. Stem cell factor (SCF)-c-kit, cytokine-cytokine receptor, and chemokine-chemokine receptor (CCR3) interactions leading to nuclear factor kappaB (NF-kappaB), mitogen-activated protein kinase (MAPK) expression, and other signaling pathways can modulate eosinophil function. Eosinophil hematopoiesis, activation, survival, and elaboration of mediators can all be regulated thus by mast cells in tissue. Moreover, because eosinophils can secrete SCF, eosinophils can regulate mast cell function in a paracrine manner. This two-way interaction between eosinophils and mast cells can pave the way for chronic inflammatory responses in a variety of human diseases. This review summarizes this pivotal interaction between human mast cells and eosinophils.

Impeded establishment of the infective stage of Trichinella in the intestinal mucosa of mice by passive transfer of an IgA monoclonal antibody

Our previous study showed that the IgA monoclonal antibody (mAb) HUSM-Tb1 forms immunoprecipitates on the cuticular surface of infective larvae of Trichinella britovi, and that intraperitoneal injection of this mAb to mice 5 hr before challenge infection confers a high level of protection against intestinal T. britovi. The same treatment produced a similar effect in BALB/c mice inoculated orally with Trichinella pseudospiralis larvae, indicating that the effects may be seen upon most members of the genus Trichinella. Worms recovered from the intestinal mucosa at 1 hr after challenge infection with T. pseudospiralis was few in mice passively immunized with the mAb, whereas a substantial number of worms were recovered from the mucosa of control groups. These results suggest that the IgA mAb impedes establishment of infective Trichinella worms in the intestinal mucosa. Trichinella worms inoculated orally into BALB/c mice vaccinated with ultraviolet-irradiated muscle larvae 3 weeks earlier were expelled between days 4 and 7 after challenge infection. Although the mAb HUSM-Tb1 originated from the mesenteric lymph node cells of mice vaccinated repeatedly with such irradiated larvae, IgA-mediated expulsion does not seem to play an important role in this vaccination model.

Development of a new monoclonal antibody to ovine chimeric IgE and its detection of systemic and local IgE antibody responses to the intestinal nematode Trichostrongylus colubriformis

The J558L cell line, previously transfected with the ovine Cepsilon gene, was induced to secrete a chimeric IgE protein composed of the ovine heavy chain and a mouse light chain with MW of approximately 80 and 26 kDa, respectively. After purification, the chimeric protein was used to immunise BALB-c mice and monoclonal antibodies (mAbs) were generated. The mAb 2F1, which had greatest anti-IgE activity in preliminary screens, was chosen for further characterisation and an examination of systemic and local IgE responses to the intestinal nematode, Trichostrongylus colubriformis. The chimeric IgE protein was not recognised in enzyme linked immunosorbent assay (ELISA) by mAbs raised against ovine IgG1, IgG2, IgA or IgM. However, 2F1 was highly specific to the chimeric IgE protein, and did not cross-react with ovine IgG1, IgG2 or IgA. Western blot analysis also showed that 2F1 and secretory IgA (sIgA) did not cross-react, and that 2F1 and the anti-IgA mAb identified different MW bands from colostrum (approximately 200 and 400 kDa, respectively). 2F1 bound to mucosal mast cells (MMC) isolated from the intestines of lambs infected with T. colubriformis, but cultured bone marrow-derived mast cells (BMMC) required prior incubation with the chimeric IgE protein for this binding to occur. Distinctive staining of plasma cells and putative mast cells were observed using 2F1 on immunohistological sections of mesenteric lymph node and jejunum.ELISA incorporating 2F1 was able to detect >0.4 ng chimeric protein. Total IgE in ovine colostrum and intestinal homogenates was quantified using a capture ELISA, with known amounts of chimeric protein used to produce a standard curve. Colostrum from outbred Merino ewes had 0.55-11.05 ng ml(-1) total IgE, and their lambs, at necropsy after infection with a total of 18,000 T. colubriformis infective larvae over a 9-week period, had 45-620 ng g(-1) total IgE in intestinal tissue. Compared to genetically susceptible lambs, antigen-specific levels of IgE were significantly higher in genetically resistant lambs after infection with 4500 T. colubriformis infective larvae (TcL3) per week for 9 weeks (161.4 versus 44.8 geometric mean titres; P=0.043). In western blots, distinctive bands (19-21 and 27 kDa) from T. colubriformis larval antigen were differentially recognised by IgE, as identified by 2F1, in intestinal homogenates from genetically resistant animals. These results have demonstrated the value of 2F1 for quantification of IgE responses in samples derived from ovine fluids and tissues using ELISA, western blots and immunohistology. In this respect, it recognises native ovine IgE and does not require pre-treatment of the sample with denaturing agents or ammonium sulphate.

Comparative cytokine profile of human skin mast cells from two compartments--strong resemblance with monocytes at baseline but induction of IL-5 by IL-4 priming

Although known as heterogenous, mast cells (MC) are believed to induce allergic inflammation, partially by secretion of T helper cell type 2 (Th2) cytokines. We show here that MC purified from two human skin compartments produce cytokines that are primarily associated with inflammation and innate immunity [interleukin (IL)-1beta, IL-6, IL-8, tumor necrosis factor alpha (TNF-alpha)]. Although these are detectable even without stimulation, immunoglobulin (Ig)E receptor cross-linking is able to enhance only TNF-alpha production, but phorbol 12-myristate 13-acetate additionally promotes IL-1beta and IL-8. With the exception of TNF-alpha, the presence of serum has a positive impact on cytokine production. Although IL-13 transcripts (but not those for IL-4 and -5) are produced by skin MC, all Th2 cytokines remain undetectable in the supernatants or lysates of MC from foreskin and breast skin by all treatments. Therefore, rather than sharing similarity with Th2 cells, the cytokine profile of skin MC at baseline resembles that of monocytes. Of note, MC precultured in the presence of IL-4 [alone or plus stem cell factor (SCF)] before anti-IgE stimulation, acquired the ability to produce IL-5, and IL-1beta was concomitantly suppressed. Additionally, strong up-regulation of IL-6 by SCF was observed, which was inhibited by IL-4. In summary, we present a detailed analysis of the cytokine array of human skin MC immediately upon isolation; demonstrate that MC from different skin compartments, although producing the same pattern of cytokines, display quantitative differences in several aspects; and provide further evidence that MC possess a proinflammatory capacity, which can, however, be altered by microenvironmental stimuli, substantiating the marked plasticity of the cells.

Immunoglobulin profiles in a murine intermediate host model of resistance for Echinococcus granulosus infection

We have shown previously that primary infection of Chinese Kunming (CKM) mice with Echinococcus granulosus oncospheres is protective against subsequent challenge. Nine groups of mice were infected with the oncospheres of E. granulosus by different routes (intraperitoneal, subcutaneous or intravenous injection). After infection, serum was collected after different periods of time and serum antibodies were tested by ELISA against oncospheral proteins and hydatid cyst fluid antigens. The results indicated that CKM mice produced low levels of antibodies before a secondary challenge infection given 3 weeks later by a different route. Most mice did not evoke significant antibody responses against oncospheral antigens until 5 weeks after infection. The level of IgG, especially IgG1 against oncospheral antigens increased from week 4 post-infection (p.i.), to a maximum at week 9 p.i. In addition, antibodies against hydatid cyst fluid antigens increased at the same time as the recognition of oncospheral antigens. Immunoblots using hydatid cyst fluid showed that the first antigen that was recognized - an 8-kDa protein, possibly the smallest subunit of Antigen B - appeared 5-6 weeks p.i. and reactivity to this molecule was intensive at week 9 p.i. The results suggest that protection against secondary infection was not principally antibody-mediated during the initial phases of infection, when cellular immune responses may play a pivotal role in the protective mechanism.

Concepts in immunology and diagnosis of hydatid disease

Echinococcosis is a cosmopolitan zoonosis caused by adult or larval stages of cestodes belonging to the genus Echinococcus (family Taeniidae). The two major species of medical and public health importance are Echinococcus granulosus and E. multilocularis, which cause cystic echinococcosis (CE) and alveolar echinococcosis (AE), respectively. Both CE and AE are both serious diseases, the latter especially so, with a high fatality rate and poor prognosis if managed inappropriately. This review discusses new concepts and approaches in the immunology and diagnosis of CE, but comparative reference has also been made to AE infection and to earlier pivotal studies of both diseases. The review considers immunity to infection in the intermediate and definitive hosts, innate resistance, evasion of the immune system, and vaccination of intermediate and definitive hosts, and it particularly emphasizes procedures for diagnosis of CE and AE, including the value of immunodiagnostic approaches. There is also discussion of the new advances in recombinant and related DNA technologies, especially application of PCR, that are providing powerful tools in the fields of vaccinology and molecular diagnosis of echinococcosis.

Negative association of Enterobius infestation with asthma and rhinitis in primary school children in Taipei

BACKGROUND

The relationship between allergy and parasites has been controversial, especially in non-tropical countries. Enterobius vermicularis (human pinworm) is the most prevalent intestinal parasite in industrialized countries.

OBJECTIVE

To examine the association between pinworm infestation and allergy in primary school children.

METHOD

Peri-anal tape test for pinworm is routinely performed in Taipei primary schools. We collected data from school records and questionnaires distributed to all children in four primary schools grades 1 through 6 (n = 3107).

RESULTS

The prevalence of physician-diagnosed asthma (9.3% vs. 14.1%, P = 0.007) and allergic rhinitis (27.4% vs. 38.3%, P = 0.001) was lower in pinworm-positive compared to uninfested children. Pinworm was not correlated with atopic dermatitis or parent allergy. With logistic regression controlling for sex, parent allergy and lower respiratory infection, current asthma (OR = 0.25, 95% CI 0.10-0.63) and rhinitis (OR = 0.61, 95% CI 0.45-0.84) were negatively associated with pinworm. Among children in grades 3-6 who had no asthma or rhinitis before age 7, those with early infestation (pinworm diagnosis at or before grade 1) had a lower risk of having diagnosis of rhinitis during school years, compared to the uninfected group (5.4% vs. 12.3%, P = 0.03; adjusted OR = 0.47, 95% CI 0.21-1.02).

CONCLUSIONS

We identified a negative association between pinworm infestation and allergic airway diseases, which could in part be attributed to protective effect of pinworm infestation on development of allergic symptoms. Other mechanisms of association could not be ruled out.

Gastro-allergic anisakiasis as a consequence of simultaneous primary and secondary immune response

Gastro-allergic anisakiasis has been reported as an entity in which an acute parasitism by Anisakis simplex is accompanied by an immunoglobulin (Ig)E-mediated systemic allergic reaction. Serum samples were obtained from 24 patients within 24 h after the onset of symptoms (day 0) and after 1 month (day 30) and in 13 patients after 6 months. Total IgE was assessed by the Imx method. Specific IgE was assessed by CAP-FEIA. Specific IgM, IgG, IgG4 and IgA antibodies were assessed by enzyme-linked immunosorbent assay against crude extract (CE) and excretory-secretory products (ESP). IgE immunoblotting (IB) was directed against CE or ESP (day 0 and day 30). We found a rise of total IgE, specific IgE, number of bands in IgE-IB, IgG and IgG4 between day 0 and day 30 with a fall to near basal levels after 6 months. IgM levels were highest at day 0, falling over the next 6 months and IgA levels remained almost unchanged. Correlation studies revealed a parallel stimulation of nearly all Ig isotypes, except IgM anti-ESP, whose antibody levels correlated negatively with specific IgG levels. We found an extension of the IgE antibody repertoire in IB. We conclude that the allergic IgE-mediated reaction in the course of gastro-allergic anisakiasis involves a parallel secondary Th2 type memory response and a primary immunologic stimulation of both Th2 and Th1 lymphocyte subsets against previously unrecognized antigens.

Infection of mice with the helminth Strongyloides stercoralis suppresses pulmonary allergic responses to ovalbumin

Asthma and helminth infections induce similar immune responses characterized by the presence of peripheral blood eosinophilia and elevated serum IgE levels. Epidemiological surveys have reported either increases or decreases in the development of atopic diseases and asthma based on the prevalence of helminth infections in the population. The aim of this study was to determine if a pre-existing helminth infection would increase or decrease subsequent allergic responses to an unrelated allergen in the lungs. BALB/cByJ mice were infected with the nematode parasite Strongyloides stercoralis prior to ovalbumin (OVA) immunization and intratracheal challenge. Bronchoalveolar lavage (BAL) and fluid (BALF) were collected 3 days post-challenge and cellular and humoral immune responses were measured. Intracellular cytokine staining revealed increased IL-4 and IL-5 producing cells in BAL from mice infected with S. stercoralis before OVA sensitization. Increased IL-5 protein levels and decreased IFN-gamma protein levels were also observed in the BALF. There was, however, no increase in airway eosinophil accumulation in mice infectd with parasites before sensitization with OVA as compared to mice exposed to OVA alone. Furthermore, eotaxin levels in the lungs induced by OVA was suppressed in mice infected with the parasite before OVA sensitization. The development of OVA specific IgE responses in BALF was also impaired in mice infected with the parasite before sensitization with OVA. These results suggest that a pre-existing helminth infection may potentiate a systemic Type 2-type response yet simultaneously suppress in the lungs allergen-specific IgE responses and eotaxin levels in response to subsequent exposure to allergens.

The association of skin test reactivity, total serum IgE levels, and peripheral blood eosinophilia with asthma in Kuwait

There is evidence that elevated serum immunoglobulin E (IgE) and eosinophilia correlate well with allergic skin test reactivity. These parameters have been used as alternative methods to characterize atopic subjects. Skin test reactivity is the only measure used routinely in clinical practice in Kuwait to reflect atopy in asthma patients. This study examines the usefulness of the two other parameters of atopy in patients with asthma, and to determine the most common allergens involved in Kuwait. Between 1998 and 1999, 101 asthma patients and 33 healthy controls were recruited for this study. Skin sensitivity test, serum total and specific IgE, total blood eosinophil count (B-EOS), and eosinophil cationic protein (ECP) tests were performed in patients and controls. Nine allergens known to be prevalent in this environment were selected for the skin test and specific IgE test. Spirometry was also measured. These parameters were repeated after 4 weeks of therapy in the patients only. Skin test reaction was positive in 81% of the patients, while total IgE above 200 kU/L was obtained in 63% of cases. B-EOS above 300 x 10(3)/L was found in 75% of cases. House dust mite reactivity (positivity) was the most frequently encountered skin allergy, occurring in 28% of the patients. IgE correlated positively with B-EOS and ECP. B-EOS similarly correlated positively with ECP. There was a negative correlation between ECP and forced expiratory volume in 1 sec (FEV1) (% predicted) as expected. At least one positive parameter of atopy was found in 95% of the patients. In 48% of the patients, all three parameters of atopy were found to be positive. Skin test reactivity and elevated IgE were found together in 62% of the cases. This study reveals a significant degree of allergy among patients with asthma in this environment. Skin testing was found to be the most effective measure of atopy in this environment, and correlates well with the other more sensitive newer tests.

Usefulness of currently available methods for the diagnosis of Anisakis simplex allergy

BACKGROUND

Serodiagnosis of anisakiosis and Anisakis allergy is difficult since many Anisakis antigens show cross-reactivity complications. In the present study, we assess the usefulness of the major immunologic methods currently available for the diagnosis of Anisakis allergy.

METHODS

Four tests (skin prick test, CAP-FEIA system, Western blotting, and an antigen-capture ELISA using O-deglycosylated antigen bound by the monoclonal antibody UA3) were applied to Anisakis-free subjects and subjects with confirmed Anisakis allergy.

RESULTS

The skin prick test, CAP-FEIA, and the antigen-capture ELISA identified Anisakis allergy sera with 100% sensitivity, while Western blotting showed 96%/ sensitivity. The antigen-capture ELISA also showed 100% specificity, but CAP-FEIA showed a specificity of only 50%. In Western blotting, none of the bands detected were specific for either Anisakis-free or Anisakis allergy subjects. The skin prick test was not applied to the Anisakis-free subjects, so its specificity could not be determined.

CONCLUSIONS

On the basis of these results, we suggest that the most appropriate procedure for diagnosis of Anisakis allergy suspected on clinical grounds is the antigen-capture ELISA using UA3, or, alternatively, a preliminary skin prick test with a positive result subsequently confirmed by UA3-ELISA.