Prevalence of inhaled allergen-specific IgE antibody positivity in the healthy Japanese population

BackgroundMeasurement of allergen-specific IgE antibodies to inhaled allergens is important for the diagnosis and risk evaluation of allergic diseases such as asthma and allergic rhinitis. This study aimed to elucidate the prevalence of allergen sensitization among the healthy population in Japan using serum samples stocked in the Japanese Red Cross for blood donation.MethodsAge- and gender-stratified serum samples (n = 800) from residents in Tokyo aged 20–59 years were randomly selected from the stocked serum obtained for blood donation in 2005. Total and specific IgE antibodies to 17 inhaled allergens were measured by the ImmunoCAP method. Individuals with positive (≥0.35 U_A/mL) specific IgE antibodies to at least one inhaled allergen were defined as atopic. Stocked serums from donors aged 20–29 years in Sapporo, Osaka, Fukuoka, and Okinawa (n = 200 each) were also obtained for the measurement of IgE to six common inhaled allergens, to evaluate regional differences in the rate of positivity.ResultsAmong residents in Tokyo, the prevalence of atopy was 78.0% and highest in men aged 20–29 years (94.0%), which decreased with age. The prevalence of specific IgE antibodies was highest for Japanese cedar pollen (66.8%), followed by cypress pollen (46.8%), Dermatophagoides pteronyssinus (38.3%), and moths (30.1%). Examination of IgE to Japanese cedar pollen, D. pteronyssinus, and moths identified 97.6% of atopic subjects in Tokyo. There were substantial regional differences in the prevalence of pollen IgE positivity.ConclusionsThis study demonstrated an extremely high prevalence of positivity in inhaled allergen-specific IgE antibodies among healthy adults in Japan.     

sICAM-1 and TNF-α in Asthma and Rhinitis: Relationship with the Presence of Atopy

Background. A genetically determined overproduction of specific immunoglobulin E (IgE) underlies many diseases like asthma or allergic rhinitis. IgE as well as tumor necrosis factor-α (TNF-α), and intercellular adhesion molecule-1 (ICAM-1) play a critical role in the induction and maintenance of inflammation. While the correlation between IgE and atopy is inseparable, little is known about the correlation of atopy with markers of inflammation. Objective. We investigated the relationship between the serum concentrations of TNF-α, soluble ICAM-1 (sICAM-1), and the presence of atopy in patients with persistent rhinitis or asthma. Methods. Serum concentrations of sICAM-1, TNF-α, and total IgE were investigated in 64 adults with persistent allergic rhinitis, 17 subjects with nonatopic rhinitis, 90 patients with asthma, and 21 healthy individuals. Atopy was diagnosed on the basis of positive family history, skin prick tests, and serum IgE concentration. Results. Total IgE concentration was significantly higher in patients with atopic rhinitis or asthma when compared with nonatopic patients and healthy individuals and was the highest in patients suffering from severe atopic asthma who were not treated with systemic glucocorticosteroids. Although there were marked alterations in IgE in atopic and nonatopic patients, there were no significant differences between atopic and corresponding groups of nonatopic rhinitic and asthmatic patients in sICAM-1 and TNF-α concentrations. (sICAM-1 in rhinitis: atopic vs. nonatopic patients: 224.02 and 221.08 ng/ml, respectively, p > .05; in mild/moderate asthma: atopic vs. nonatopic: 306.22 and 326.39 ng/ml, respectively, p > .05; severe asthma without oral corticosteroids therapy: atopic vs. nonatopic: 418.03 and 468.09 ng/ml, respectively, p > .05; and severe asthma with oral corticosteroids therapy: atopic vs. nonatopic: 320.66 and 308.09 ng/ml, respectively, p > .05). Conclusions. Concentrations of sICAM-1 and TNF-α are significantly higher in patients with asthma compared with those observed in patients with rhinitis, but they are independent of the presence of atopy.     

Isolated Schistosoma mansoni eggs prevent allergic airway inflammation

Chronic helminth infection with Schistosoma (S.) mansoni protects against allergic airway inflammation (AAI) in mice and is associated with reduced Th2 responses to inhaled allergens in humans, despite the presence of schistosome‐specific Th2 immunity. Schistosome eggs strongly induce type 2 immunity and allow to study the dynamics of Th2 versus regulatory responses in the absence of worms. Treatment with isolated S. mansoni eggs by i.p. injection prior to induction of AAI to ovalbumin (OVA)/alum led to significantly reduced AAI as assessed by less BAL and lung eosinophilia, less cellular influx into lung tissue, less OVA‐specific Th2 cytokines in lungs and lung‐draining mediastinal lymph nodes and less circulating allergen‐specific IgG1 and IgE antibodies. While OVA‐specific Th2 responses were inhibited, treatment induced a strong systemic Th2 response to the eggs. The protective effect of S. mansoni eggs was unaltered in μMT mice lacking mature (B2) B cells and unaffected by Treg cell depletion using anti‐CD25 blocking antibodies during egg treatment and allergic sensitization. Notably, prophylactic egg treatment resulted in a reduced influx of pro‐inflammatory, monocyte‐derived dendritic cells into lung tissue of allergic mice following challenge. Altogether, S. mansoni eggs can protect against the development of AAI, despite strong egg‐specific Th2 responses.     

Variants of endothelin-1 gene in atopic diseases.

BACKGROUND: Several studies suggest that the vasoactive peptide endothelin-1 (ET-1) could be involved in the pathophysiology of atopic asthma and allergic rhinitis. However, a possible involvement of polymorphisms of the corresponding gene in the origin of these conditions has so far not been subjected to a more comprehensive study. OBJECTIVE: This study investigates a possible association of two common polymorphisms in the ET-1 gene (TaqI in intron4 and BsiYI in position 138) with clinically manifested atopic diseases. The genetic linkage of these polymorphisms with the underlying phenotypes of asthma or parameters of atopy including total IgE level was examined, too. METHODS: The study included 456 subjects-270 Czech patients (Caucasians, Central Europe) with clinically manifested atopic diseases and 186 unrelated referent subjects with negative familial history of asthma/atopy. ET-1 genotypes were determined by PCR and restriction analysis by TaqI and BsiYI, respectively. RESULTS: No significant differences were found for the two polymorphisms between atopic patients and healthy subjects, or between subselected asthmatic patients and controls. However, the insertion exonic variant of ET-1 gene showed a significant association with signs of atopy, especially with total serum IgE levels (total IgE levels < or = 150 IU/ml turned out to be associated with DD genotypes, total IgE > 150 IU/ml with II and ID genotypes [OR = 3.76 (95% CI: 1.52-9.34), p = 0.003, Pc = 0.0061). CONCLUSIONS: These findings suggest that ET-1 may participate in the pathogenesis of high total serum IgE level in clinically manifested atopic diseases in our population.     

Differential IgE reactivity to Der p 1 and Der p 2 allergens of Dermatophagoides pteronyssinus in mite-sensitized patients.

Several studies have shown that the presence of IgE antibodies to house dust mites (HDM), particularly Dermatophagoides pteronyssinus (Dpt), is an important risk factor for asthma. Allergen immunotherapy is indicated for patients with IgE antibodies to clinically relevant allergens. The aims of this study were to analyze the levels of specific serum IgE to Der p 1 and Der p 2 allergens in mite-sensitized atopic patients and to compare them with both in vivo (skin prick test) and in vitro (IgE-ELISA) sensitizations to Dpt crude extract. Forty-seven atopic patients with allergic rhinitis with or without intermittent or persistent mild asthma and positive skin prick test (SPT) to Dpt total extract were studied. Thirty age-matched healthy subjects with negative SPT to HDM were included as controls. Levels of total IgE and Dpt-, Der p 1- and Der p 2-specific IgE were measured by ELISAs in SPT-positive atopic patients and SPT-negative control subjects. Among 47 symptomatic atopic patients, 27 (57.4%) were double positive IgE to Der p 1 and Der p 2 allergens, 3 (6.4%) were single positive IgE to Der p 1, 4 (8.5%) were single positive IgE to Der p 2, and 13 (27.6%) were double negative IgE to both allergens. There was a significant correlation between Der p 1- and Der p 2-specific IgE levels, but not between Der p 1- or Der p 2-IgE levels and SPT results. The double negative IgE patients had the smallest skin test reactions although they showed high mean levels of total serum IgE. Therefore, the knowledge of specific IgE levels to Der p 1 and Der p 2 major allergens might support physicians for indication or follow-up in mite-sensitized patients under allergen-specific immunotherapy. These approaches might be important for obtaining improved safety and efficacy of the current clinical practice of allergen immunotherapy.     

A Study of Relation between BCG Scar and Atopy in Schoolchildren of Zanjan City

The prevalence of atopic disease in recent decades has been dramatically increased. It has been suggested that BCG vaccination may protect against development of allergic diseases.The purpose of this study was to identifying relation between scar of BCG vaccine and atopy. This cross-sectional study was done in 1000 children, 10-15 years of age, in Zanjan city. One thousand children (501 girls and 499 boys) were recruited in this study, 137, 121 and 141 cases of asthma, atopic dermatitis and allergic rhinitis, respectively were detected.Three hundred and three subjects had at least one of these disorders, which were diagnosed as atopy. There was reverse correlation between BCG scar and asthma (P=0.013), atopic dermatitis (P<0.01), and atopy (P<0.01). We did not find any association between the diameter of BCG scar and allergic rhinitis. Reverse correlation of asthma, atopic dermatitis and atopy with BCG scar are significant. This relied on history and symptoms of patients. Further studies with skin tests, measurements of total and specific IgE levels and spirometery are recommended.     

The impact of age on prevalence of positive skin prick tests and specific IgE tests

Aging is associated with modifications of the immune system, defined as immunosenescence. This could contribute to a reduced prevalence of allergic disease in the elderly population. In this regard, atopy has rarely been considered in the clinical assessment of the geriatric respiratory patient. This article is a review of the available literature assessing the impact of age on atopy. In the majority of papers, we found a lower prevalence of atopy in the most advanced ages, both in healthy subjects and in individuals affected by allergic respiratory diseases. Unfortunately, no large, longitudinal studies performed in the general population have been conducted to further explore this observation. Although available data seem to favor the decline of allergen sensitization with age, the prevalence of allergic sensitizations in the elderly population with respiratory symptoms is substantial enough to warrant evaluation of the atopic condition. From a clinical perspective, allergic reactions in older adults can have the same or even worse manifestations compared to young people. For this reasons, the evaluation of the atopic condition also in the geriatric patient is recommended. Thus, the role of atopy as it pertains to the diagnosis, therapy (adoption of preventive measure such as removal of environmental allergen or immunotherapy), and prognosis (influence on morbidity and mortality) of chronic respiratory illnesses in the elderly is addressed.     

Allergic transfusion reactions from blood components donated by IgA‐deficient donors with and without anti‐IgA: a comparative retrospective study

Background and Objectives IgA deficiency is common (1/500) and up to 40% of affected individuals will develop anti‐IgA. A few studies suggested that passive transfusion of anti‐IgA was not associated with an increased risk of allergic reactions. This study was designed to assess the safety of transfusing blood components containing anti‐IgA. Materials and Methods IgA‐deficient blood donors with and without anti‐IgA were identified from Héma‐Québec’s (HQ) computerized database. IgA deficiency was confirmed by an ELISA method and the presence of anti‐IgA by a passive hemagglutination assay. Blood donations from IgA‐deficient donors issued to hospitals between March 1999 and December 2004 were retrieved. Medical charts of recipients were reviewed for the occurrence of a suspected transfusion reaction. Presence and nature of transfusion reactions were assessed blindly by an adjudicating committee. Results A total of 323 IgA‐deficient blood products were issued by HQ to 55 hospitals. Of these, 48 agreed to participate [315 blood products (97·5%)]. A total of 272 products were transfused: 174 contained anti‐IgA, and 98 did not. Only two minor allergic reactions occurred in each group. Incidence of allergic reactions was 1·15% in the anti‐IgA group and 2·04% in the group without anti‐IgA (P = 0·91). There was no anaphylactic reaction in either group. Conclusions This study indicates that the proportion of allergic reactions does not appear to be greater in recipients of blood components containing anti‐IgA compared to recipients of non‐anti‐IgA‐containing components. Allowing donations from IgA‐deficient donors with anti‐IgA may therefore be contemplated.     

Immunoglobulin M antibodies are not specific for serodiagnosis of human toxocariasis

Serodiagnosis of human toxocariasis is established by detecting serum anti‐Toxocara IgG antibodies, but there is little knowledge regarding the reactivity of human IgM antibodies against the Toxocara antigens. In this study, we have evaluated the reactivity of IgM antibodies in sera from patients with toxocariasis, patients with other helminth infections, and healthy individuals, against Toxocara larval excretory‐secretory (TES) antigens by enzyme‐linked immunosorbent assay (ELISA) and Western blot (WB). Anti‐Toxocara IgM were detected in 91.4% of sera from patients with toxocariasis, 76% of sera from patients with other helminth infections, and 45.3% of sera from healthy individuals when ELISA was used. Likewise, IgM antibodies were detected in 94.8% of sera from patients with toxocariasis, 65.3% of sera from patients with other helminth infections, and 41% of sera from healthy individuals when WB was used. This reactivity exhibited only a slight decrease when the TES antigens were deglycosylated, showing that not only glycosidic epitopes, but also peptide epitopes are involved in the recognition and binding of IgM antibodies during the immune response against the parasite. The results shown that IgM antibodies are not specific for serodiagnosis of human toxocariasis.     

Robustness into advanced age of atopy-specific mechanisms in atopy-prone families

We evaluated atopy-associated parameters in 1,099 people (aged 6-84 years) from families with history for atopy. All were tested for serum total immunoglobulin E (IgE) and allergen sensitivity by skin prick test. Specific IgE tests were done in randomly selected families. There was a decline with age in serum total IgE values, and relative atopy "incidence rates" were slightly lower among those older than 60 years. However, there was no change with age in sensitivity or severity of atopy. Among those sensitized to ragweed (Ambrosia artemisilfolia), there was no age-associated change in IgE levels specific to Amb a 1, a major allergen extracted from ragweed, and no change in the binding affinity of IgE for the Amb a 1 allergen. Among families with atopic histories, the underlying atopic mechanisms are particularly robust, and the atopic propensity remains into advanced age. In addition, established atopic responses may be focused in an immune system compartment either independent of or minimally influenced by T-cell activity.     

Seroprevalence and risk factors of Toxoplasma gondii infection among healthy blood donors in south‐east of Iran

This prospective cross‐sectional study was aimed to evaluate the prevalence of IgM and IgG anti‐T. gondii antibodies and the associated risk factors among healthy blood donors in Kerman province, south‐eastern Iran. Structured questionnaires (before the donors gave blood) were used to obtain information on risk factors for infection. Totally, 500 serum samples from healthy blood donors of Kerman Blood Transfusion Organization (KBTO) at Kerman, Iran, were screened for IgG and IgM anti‐T. gondii antibodies by enzyme‐linked immunosorbent assay (ELISA) and Roche Elecsys Toxo IgM assay. Real‐time PCR was used to detect DNA of T. gondii in the IgM‐positive samples. Seroprevalence of IgG and IgM anti‐T. gondii antibodies was 28·8% and 3·2%, respectively. In the multiple logistic regression, it could be observed that living in rural regions, having B blood type, being in contact with cats, consuming raw vegetables and raw milk/egg and doing agricultural activities were independent risk factors for Toxoplasma seropositivity. T. gondii DNA was also found in one (9·0%) of IgM‐positive samples. In this study, it was found that T. gondii infection was present among healthy blood donors in south‐east of Iran. Therefore, it is suggested to design screening programmes for preventing transfusion‐transmitted toxoplasmosis.     

IgE antibodies to human growth hormone prior to and during treatment

Clinical manifestations of allergy to biosynthetic hGH were not reported in 245 patients treated for one year. A sensitive radioallergosorbent test showed, however, the presence of anti-hGH IgE antibodies in the sera of 13%. All patients with anti-hGH IgE had also elevated concentrations of total serum IgE, similar to atopic persons (2459 +/- 147 micrograms/l, normal 70 +/- 8, 2p less than 0.0001); 83% of all patients who had specific IgE antibodies to hGH had specific antibodies prior to treatment. Administration of hGH did not consistently change concentrations (up to 8 micrograms/l) or affinities (less than 10(7) to 1.3 X 10(9) l/mol) of the specific reagins. Anti-hGH IgE antibodies were related to atopy. Treatment with biosynthetic hGH did not significantly stimulate specific IgE.     

Antibody profiling in ultrasound normal individuals with positive serology for cystic echinococcosis

Cystic echinococcosis is a zoonotic disease caused by the cestode parasite Echinococcus granulosus. In endemic regions, seropositive individuals to E. granulosus usually and markedly outnumber image‐confirmed cases of cystic echinococcosis, suggesting that some parasite challenges derive in unsuccessful infection establishments. However, it is still unknown whether such parasite‐specific antibodies in healthy individuals might play a role in resistance/susceptibility to the infection. Therefore, we have here analysed the profile of antibodies recognizing E. granulosus antigens in seropositive but ultrasound normal individuals, as well as in surgery‐confirmed patients and healthy donors. Our results showed that ultrasound normal individuals exhibited low avidity IgG antibodies, as well as low levels of parasite‐specific IgG1 and IgG4 antibodies. In addition, they displayed significant levels of specific IgE, and thus, they revealed a uniquely high IgE:IgG4 ratio. Moreover, high levels of parasite‐specific IgM were detected in such individuals, which showed characteristics of natural cross‐reacting antibodies. Therefore, our results indicate that ultrasound normal individuals but seropositive for E. granulosus antigens exhibit a distinctive antibody profile. In this regard, possible associations between their antiparasite antibodies and potential resistance mechanisms to cystic echinococcosis are discussed.     

Laboratory detection of strongyloidiasis: IgG‐, IgG4‐ and IgE‐ELISAs and cross‐reactivity with lymphatic filariasis

Enzyme‐linked immunosorbent assays (ELISAs) were developed for the detection of IgG, IgG₄ and IgE antibodies against Strongyloides stercoralis. A commercial ELISA (IVD Research, USA) was also used, and the sensitivities and specificities of the four assays were determined. Serum samples from 26 patients with S. stercoralis infection and 55 patients with other infections or no infection were analysed. Sensitivities of the IgG₄, IgG, IgE and IgG (IVD) assays were 76·9%, 84·6%, 7·7% and 84·6%, respectively, while the specificities were 92·7%, 81·8%, 100% and 83·6%, respectively. If filariasis samples were excluded, the specificities of the IgG₄‐ELISA and both IgG‐ELISAs increased to 100% and 98%, respectively. A significant positive correlation was observed between IgG‐ and IgG₄‐ELISAs (r = 0·4828; P = 0·0125). IgG‐ and IgG‐ (IVD) ELISAs (r = 0·309) were positively correlated, but was not significant (P = 0·124). Meanwhile there was no correlation between IgG₄‐ and IgG‐ (IVD) ELISAs (r = 0·0042; P = 0·8294). Sera from brugian filariasis patients showed weak, positive correlation between the titres of antifilarial IgG₄ and the optical densities of anti‐Strongyloides IgG₄‐ELISA (r = 0·4544, P = 0·0294). In conclusion, the detection of both anti‐Strongyloides IgG₄ and IgG antibodies could improve the serodiagnosis of human strongyloidiasis. Furthermore, patients from lymphatic filariasis endemic areas who are serologically diagnosed with strongyloidiasis should also be tested for filariasis.     

Allergic symptoms,atopy, and geohelminth infections in a rural area of Ecuador

Geohelminth infections may affect the expression of allergic disease. To investigate the relationship between geohelminth infections, atopy, and symptoms of allergic disease, we studied 4433 schoolchildren from 71 schools in a rural tropical area in Ecuador. Information was collected on allergic symptoms, allergen skin test reactivity, and presence of geohelminth infections. Allergic symptoms were of low prevalence (2.1% had recent wheeze), but prevalence of skin test reactivity was relatively high (18.2%). The presence of geohelminth infections was protective against allergen skin test reactivity (odds ratio 0.62, 95% confidence interval 0.50-0.76, p < 0.001) and symptoms of exercise-induced wheeze (odds ratio 0.59, 95% confidence interval 0.40-0.87, p = 0.008) but not against other wheeze symptoms or symptoms of allergic rhinitis or atopic eczema. Infection intensity with Ascaris lumbricoides or Trichuris trichiura was associated with a reduction in the prevalence of allergen skin test reactivity but not with allergic symptoms. There was no evidence of interactions between geohelminth infection and allergen skin test reactivity on the risks of allergic symptoms. The results suggest that geohelminth infections do not explain the low prevalence of allergic symptoms in the study population.     

Allergic reaction in a cohort of haemophilia A patients using plasma‐derived factor VIII (FVIII) concentrate is rare and not necessarily triggered by FVIII

In contrast to haemophilia B, allergic manifestations are rare complications in haemophilia A (HA) patients treated with factor VIII (FVIII) concentrates. Nevertheless, it can be serious and hamper replacement therapy in these cases. The aims of this study were to evaluate the frequency of allergic reaction in a cohort of HA patients treated only with plasma‐derived FVIII (pdFVIII) concentrates, and assess the possible immune mechanisms involved. History of allergic reaction was retrospectively assessed. Patients with allergic manifestations were followed, and had plasma samples collected in different timepoints in relation to the allergic episode. These samples were analysed for the presence of inhibitor and anti‐FVIII immunoglobulins subclasses. Three of 322 HA patients (0.9%) developed allergic reaction after exposure to pdFVIII products during the last 15 years in our centre. The first patient, with severe HA, without inhibitor, had anti‐pdFVIII IgE and IgG4, but no anti‐recombinant FVIII (rFVIII) IgE. The second patient, with severe HA, and high‐responding inhibitor, presented allergic manifestation with both, pdFVIII concentrate and activated prothrombin complex concentrate. Although anti‐pdFVIII and anti‐rFVIII IgG4 were detected, no anti‐FVIII IgE was present. The third patient, with moderate HA without inhibitor, atopic, had no anti‐FVIII immunoglobulin detected, and allergic symptoms disappeared after switching to rFVIII concentrate. This study corroborates the low incidence of allergic reactions in HA patients. In the three cases presented, the anti‐FVIII immunoglobulin profile demonstrated that the allergic manifestation was triggered by other proteins contained in pdFVIII products, and not directed to FVIII.     

上海粉尘螨变应原及特异性免疫治疗(英文）

我国螨性变态反应的研究开始于1970年代上海第一医学院（现为复旦大学上海医学院）。上海当地的粉尘螨螨种制备的变应原SMU-Df,其过敏活性与国外同种比较,超过许多倍属于最高的,包括美国食品药品管理局参考品、弗吉尼亚大学标准品、丹麦哥本哈根变态反应研究所标准质量品等。SMU-Df 经凝胶层析所显示的蛋白峰曲线型与粉尘螨代谢培养基者基本相似,其变应原性也相仿。过敏病例可用皮肤点刺试验、鼻腔激发试验和血清IgE水平测定方法诊断,80%左右的过敏患者呈阳性反应。粉尘螨注射液是我国第一种由卫生主管部门批准生产的商品变应原,用传统的皮下注射免疫治疗,通过季节性脱敏,大多数患者可减轻过敏症状,具有极好的疗效。尘螨特异性免疫治疗具有远期疗效而无严重不良反应。对于粉尘螨粗抗原的改良处方和不同给药途径进行过研究,尤其舌下含服粉尘螨滴剂制备和临床应用从1992年与国外同步开始,对于儿童尤其适用而无年龄限制,疗效极好。螨苗冲击特异性免疫疗法具有快速改善过敏症状且有远期疗效。粉尘螨变应原具有诱导人体免疫调节作用,不论过敏患者或健康人群都产生免疫应答。     

Analysis of serum cytokine levels in children with chronic cough associated with Toxocara canis infection

Toxocara infection is associated with an increased prevalence of airway symptoms and may be a possible aetiologic agent of chronic cough. The occurrence of toxocariasis in Hungary is mild and/or sporadic. The purpose of this study was to investigate the levels of serum cytokines (IL‐1, IL‐2, IL‐4, IL‐5, IL‐6, IL‐10, IL‐13, IFN‐gamma and TNF‐alpha) and total IgE, the blood eosinophil count, the results of skin prick and non‐specific bronchus provocation tests in Toxocara‐seropositive children with chronic cough relative to those in healthy controls. The patients exhibited moderate eosinophilia, significantly elevated levels of serum total IgE, IL‐6, IL‐10, IL‐13 and IFN‐gamma, and higher skin reactivity to common allergens, whereas the bronchial hyperreactivity was similar in the two groups. The protective proinflammatory cytokines (IL‐6, IFN‐gamma and IL‐13) in association with the anti‐inflammatory cytokine (IL‐10) were simultaneously increased in Toxocara‐infected children with chronic cough. During infections, the activation and suppression of immune processes occur simultaneously and cytokines of Th1/Th2 and regulatory T cells contribute to the regulation of the immune response evoked by helminth infections (depending on the parasite load, the timing and duration of the infection and the status of the host immune system).     

Overview of Serological-Specific IgE Antibody Testing in Children

Allergic diseases are among the most common chronic conditions in the pediatric population. Allergy diagnostic testing is an important part of the evaluation/management of allergic patients because the history may not be precise enough to identify the specific allergen sensitivity. In addition to providing information about specific sensitivities, allergy diagnostic tests have some predictive value in terms of future risk of developing an allergic condition and the severity/persistence of the allergic disease. The two most commonly used methods of confirming allergen sensitization are skin testing and measurement of serum-specific IgE. Both methods have similar diagnostic value in terms of sensitivity and specificity, with both parameters varying with the clinical scenario and allergen tested. Currently, there are three US Food and Drug Administration–cleared, serum-specific IgE assays used in the United States. The three assays report comparable analytic sensitivity, with the coefficients of variation of the precision, reproducibility, and linearity being less than 15%. However, comparative studies have demonstrated significant inter-assay variability, suggesting that they detect different populations of IgE antibody in human sera or do not measure the same antibodies with the same efficiency. Current specific IgE assays utilize allergen extract reagents. Testing with these reagents may identify sensitivity to clinically irrelevant allergens. This diagnostic limitation has spurred the development of molecular diagnostic tests, also referred to as component-resolved diagnostics, which utilize purified native or recombinant allergens to detect IgE sensitivity to individual allergen molecules. These advancements in serum IgE testing may enhance the precision of allergy diagnostic testing, which may decrease the need for oral food challenges and improve the specificity of allergen immunotherapy.     

Cutaneous and serological responses to cat allergen in adults exposed or not to cats

BACKGROUND: The relationship between pet ownership and the risk of developing respiratory allergic sensitization to pet allergens is still controversial. OBJECTIVE: To determine the degree of cutaneous immediate hypersensitivity and the levels of specific IgE and IgG4 antibodies to cat allergen in cat sensitized patients directly or indirectly exposed to this animal. METHODS: We studied 112 adolescents and adults sensitized to cat allergens (43 with and 69 without a cat at home). There were also 52 control subjects, 27 atopic non-sensitized to cat and 25 non-atopic. The degree of immediate hypersensitivity was assessed by using, in duplicate, skin prick test with four five-fold dilutions of cat hair allergen extract with the content of its major allergen Fel d 1 quantified in micrograms plus positive (10 mg/ml histamine chlorhydrate) and negative (saline solution) controls. The resulting wheal areas were analysed by means of Parallel Line Assay. A blood sample was collected from every patient and control subjects for the evaluation of serological cat specific IgE and IgG4 antibodies. RESULTS: Patients with cat at home had a lower cutaneous response than patients without this pet. The difference in the skin sensitivity was estimated in 3.4 times (P<0.01). There was no statistical difference between the levels of cat specific IgE antibodies in the two groups of patients (P=0.065). The levels of Fel d 1 specific IgG4 antibodies showed a statistically significant association with the presence of cat at home, with higher levels in patients owing cat at home than in patients without this pet (P<0.001). CONCLUSION: The results of this study demonstrate that direct cat exposure in adolescents and adults with respiratory allergy is associated with a lower cutaneous response to cat allergenic extract, assessed by SPT and compared with indirect exposure. In patients with cat at home mean levels of specific IgE are statistically comparable whereas the levels of IgG4 are higher in comparison with subjects not exposed to cats. The role of indirect exposure to cat allergens in airways sensitization also in adults is emphasized. Moreover, patients with cat at home show a cutaneous and serological sensitization to cat allergen not higher in comparison with subjects not exposed to cats.