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R Urbanek

Publications and source records attributed to R Urbanek.

At least 19 recordsLinked to original sources
PubMed2006

Absence of systemic immunologic changes during dose build-up phase and early maintenance period in effective specific sublingual immunotherapy in children.

BACKGROUND: Sublingual immunotherapy (SLIT) has been reported to be a safe treatment for inhalant allergies in children. Yet the immunologic mechanisms resulting in clinical improvement are poorly understood. OBJECTIVE: To identify early systemic immunologic changes during the first 8 weeks of clinically effective SLIT to grass pollen, tree pollen or house dust mite in paediatric patients with allergic rhinoconjunctivitis and/or asthma. METHODS: Peripheral blood mononuclear cells and plasma samples of 13 children with reduced symptoms after 1 year of SLIT were obtained before therapy and at 2 and 8 weeks after the initiation of SLIT. Allergen-specific lymphocyte proliferation assays were performed, and allergen-induced cytokine production (IL-2, IL-4, IL-10, IFN-gamma, and TGF-beta(1)) was measured by ELISA and flow cytometry. Allergen-specific IgE, IgG1, IgG4, and IgA levels in plasma samples were determined in ELISA. RESULTS: During the first 8 weeks of successful SLIT, allergen-specific lymphoproliferation (n=13) as well as levels of allergen-specific intracellular (n=8) and secreted cytokines (n=9) did not change significantly. In addition, no alterations in levels of allergen-specific Igs (n=7) were observed. CONCLUSION: We could not find any early systemic immunologic changes during the first 8 weeks of clinically effective SLIT to inhalant allergens in paediatric patients with allergic rhinoconjunctivitis and/or asthma.

Administration, Sublingual↗
PubMed2006

Most of diaplacentally transferred allergen is retained in the placenta.

BACKGROUND: Transplacental transfer of nutritive and inhalant allergens has been described being potentially responsible for a series of events leading to antigen-specific immune responses in the fetus. As such, cord blood T cell responses appear ubiquitously. However, studies failed to reveal a consistent dose-response relationship between antenatal allergen exposure and allergen-specific cellular reactivity in cord blood. OBJECTIVE: To examine the transfer process of allergens (ovalbumin (OVA), beta-lactoglobulin (BLG), birch pollen allergen Bet v1) in placental tissue (BeWo cell line, ex vivo placenta model). METHODS: The choriocarcinoma cell line BeWo was used to study the allergen uptake and transfer experiments in vitro. In the ex vivo placenta model the contribution of different placental compartments was evaluated. For this, immuno-histochemistry, immuno-electronmicroscopy and ELISA techniques were applied using monoclonal antibodies to Bet v1, OVA and -BLG. RESULTS: In vitro transfer studies on a BeWo cell-layer revealed an intracellular allergen uptake and a trans-trophoblastic allergen transfer, which was temperature- and concentration dependent, pH sensitive and asymmetric. Allergen-specific staining of placental tissue after allergen perfusion (BLG) demonstrated bulk of the allergen in the syncytio-trophoblastic cell layer and minor staining in the villous stroma and in the endothelium of fetal vessels. Immunogold staining revealed an accumulation of the perfused allergen in the trophoblastic basement membrane. CONCLUSION: In vitro/ex vivo trans-trophoblastic and trans-placental allergen transfer is shown with an accumulation of most of the allergen in placental tissues, potentially explaining the missing direct dose-response relationship between prenatal (maternal) allergen exposure and allergen-specific cellular reactivity in cord blood.

Allergens↗
PubMed2006

Early exposure to latex products mediates latex sensitization in spina bifida but not in other diseases with comparable latex exposure rates.

BACKGROUND: The high prevalence of latex sensitization in patients with spina bifida (SB) has been attributed to repeated and early exposure to latex products. Other diseases such as gastroschisis/omphalocoele and post-haemorrhagic/congenital hydrocephalus are also associated with repeated and early latex exposure. OBJECTIVE: The aim of the study was to evaluate whether the high prevalence of latex sensitization in patients with SB is rather related to the underlying disease itself than to disease-associated known risk factors. METHODS: We compared children with SB (n=35), children with gastroschisis/omphalocoele (G/O, n=20) and children with post-haemorrhagic/congenital hydrocephalus (PH, n=45). All children with SB and PH had a ventriculo-peritoneal shunt since a very young age. Patients who underwent three or less surgical procedures matched in terms of age, number of operations, atopy and gender distribution, and were analysed for IgE sensitization rates to latex. RESULTS: In the SB group, 16 of 35 patients (46%) showed elevated latex-specific IgE antibodies in contrast to one of 20 patients (5%) in the G/O group and four of 45 patients (8.9%) in the PH group (P<0.0005 and P<0.005, Fisher's exact test). Comparing matched control groups (<or=3 operations), the effects remained significant (P<0.05 and P<0.01). CONCLUSION: This study suggests that the SB population bears a disease-associated propensity for latex sensitization. This effect cannot be explained exclusively by a higher number of operations and differences related to atopy, age or gender.

Adolescent↗
PubMed2006

Five-year follow-up on the PAT study: specific immunotherapy and long-term prevention of asthma in children.

BACKGROUND: A 3-year course of specific immunotherapy (SIT) in children with hay fever to grass and/or birch pollen significantly reduced the risk of developing asthma. To investigate the long-term preventive effect, we performed a follow up--2 years after termination of immunotherapy. METHODS: A total of 183 children, aged 6-14 years with grass and/or birch pollen allergy could be investigated 2 years after discontinuation of SIT or no treatment. Conjunctival provocation tests (CPTs) and methacholine bronchial provocation tests were carried out during the season and winter after 5 years. The development of asthma was assessed by clinical evaluation. RESULTS: The significant improvement in hay fever and CPT results observed after 3 years of SIT persisted at the 5-year follow-up. No difference in bronchial responsiveness to methacholine was found after 5 years because of spontaneous improvement during the follow-up period in the control patients. The immunotherapy-treated children had significantly less asthma after 5 years as evaluated by clinical symptoms [odds ratio 2.68 (1.3-5.7)] in favor of SIT for prevention of development of asthma and significantly less patients reported an increase in asthma scores (P < 0.01). CONCLUSION: Immunotherapy for 3 years with standardized allergen extracts of grass and/or birch shows long-term clinical effect and preventive effect on development of asthma in children with seasonal rhinoconjunctivitis.

Adolescent↗
PubMed2004

Maternally delivered nutritive allergens in cord blood and in placental tissue of term and preterm neonates.

BACKGROUND: The proliferation of cord blood mononuclear cells in response to nutritive and inhalant allergens implies intrauterine exposure with resulting T cell priming. However, the mechanisms triggering these fetal allergen-specific immune responses are incompletely understood. METHODS: We studied the placental release of endogenous beta-lactoglobulin (BLG) and ovalbumin (OVA) by the use of an open ex vivo placental perfusion model. Preterm and term placentas were obtained immediately after delivery to recover functionally active fetal and maternal circulations. Fetal and maternal perfusate samples were collected throughout the perfusion experiments with medium. Matched cord blood samples were collected separately. All samples were tested for the presence of OVA and BLG by allergen-specific ELISAs. RESULTS: In 16 out of 19 placentas, the nutritive allergens could be detected both in fetal and maternal perfusate samples. Fetal wash out levels of the allergens BLG and OVA from the placental tissue of preterm and term deliveries were observed in traces and up to 44.4 and 2.6 ng/mL, respectively. In cord blood of preterm and term neonates, BLG and OVA could be detected at concentrations up to 16.7 and 5 ng/mL, respectively. CONCLUSION: These findings provide direct evidence for the release of tiny amounts of nutritive allergens from placental tissue indicating diaplacental allergen transfer and fetal exposure to nutritive allergens in vivo.

Allergens↗
PubMed2004

Increased prevalence of latex-sensitization among children with chronic renal failure.

BACKGROUND: Type-I-allergy to natural rubber latex (NRL) has been shown to be more prevalent among certain groups of patients. Children suffering from chronic renal failure (CRF) could be a suspected risk group because of their intense exposure to latex through catheters, gloves and anesthetic equipment during frequent hospitalizations from early life on. We investigated the prevalence of latex-sensitization among this group of patients and sought to identify risk factors. METHODS: Ninety-three patients (mean age 10.5 years) suffering from CRF were assessed by questionnaire-based history (details on renal disease, number and kind of surgical procedures, family and personal history of atopic diseases, allergic reactions to NRL, and the use of pacifiers) and by measurement of total and latex-specific serum immunoglobulin (Ig)E. RESULTS: Ten of 93 (10.8%) patients showed elevated latex-specific IgE-levels. One of 10 patients reported clinical symptoms to latex-allergen, but no allergic reactions to NRL during medical care were reported. Sensitized patients were significantly more likely to be atopic, reflected by a positive history of other allergies as well as elevated total serum IgE-levels, and had a significantly higher number of urogenital surgeries (P = 0.02 in all cases, Fisher's exact and Wilcoxon test, respectively). CONCLUSION: This study demonstrates that children with CRF are at increased risk of latex-hypersensitivity. Significant associations with atopy and repeated surgeries were observed. Larger studies are required to elucidate whether these children are also at increased risk of anaphylaxis and therefore deserve preventive measures.

Adolescent↗
PubMed2002

Materno-fetal passage of nutritive and inhalant allergens across placentas of term and pre-term deliveries perfused in vitro.

BACKGROUND: The pre- and postnatal environment appears to be of crucial importance for the manifestation of allergic diseases, which often begin during infancy. Although T cell reactivity of fetal origin to a range of common allergens is present in most cord blood samples, the immunological basis remains unclear. OBJECTIVE: In order to test the hypothesis of transplacental allergen transfer we studied double-sided open ex vivo perfusion experiments of isolated placental cotyledons with the nutritive allergens beta-lactoglobulin (BLG) and ovalbumin (OVA) and the inhalant major birch pollen allergen Bet v1. METHODS: Placentas of full-term and pre-term newborns were obtained immediately after delivery to recover functionally active maternal and fetal circulations. Thus, a fetal artery and a fetal vein were cannulated and perfused with pure medium (fetoplacental circulation), whereas the intervillous space of placentas was flushed with allergen containing medium by puncture of the basal plate (maternoplacental circulation). Samples that were collected throughout the perfusion experiment from fetal venous outflow were tested by allergen-specific enzyme-linked immunosorbent assays (ELISA) for the presence of allergens indicative of materno-fetal transplacental passage. RESULTS: We observed transplacental transfer of BLG, OVA and Bet v1 in placentas of term as well as premature deliveries. The respective allergen was readily detectable in fetal effluent at the beginning of the perfusion experiment and allergen levels reached a plateau after about 2 h. The steady state transfer rate of BLG and OVA in term placentas was 0.012% +/- 0.001 and 0.013% +/- 0.001 of total dose, i.e. 130.21 +/- 7.41 ng/mL and 115.83 +/- 6.07 ng/mL, respectively. The observed transfer rate of Bet v1 after 2h of perfusion was 0.155% +/- 0.034 of total dose, that is 2.41 +/- 1.36 ng/mL. Transplacentally transferred concentration of BLG and OVA in pre-term placentas increased continuously throughout perfusion time from 5.32 +/- 0.92 ng/mL at 1 min to 87.53 +/- 21.93 ng/mL at 120 min and 1.35 +/- 0.31 ng/mL at 1 min to 112.87 +/- 5.25 ng/mL at 150 min, respectively. CONCLUSION: Allergen-specific cord blood reactivity may be attributed to low levels of allergens crossing the human placenta and providing the fetus with the necessary stimulus for T cell priming.

Allergens↗
PubMed2002

Parental farming protects children against atopy: longitudinal evidence involving skin prick tests.

BACKGROUND: There is growing evidence that the development of allergic sensitization can be influenced by environmental co-factors. Studies showed that growing up on a farm can protect children against allergic sensitization. However, little is known whether this 'farming effect' can only be observed in early lifetime or whether it also plays a role in later childhood. OBJECTIVE: The aim of our study was to test whether a farming environment is negatively associated with a new occurrence of skin prick test (SPT) positivity in school children. As a secondary outcome we investigated whether children living on a farm lose their allergic sensitization more frequently than other children. METHODS: In a longitudinal design, 1150 elementary school children (mean age 7.8 years, SD 0.7) were recruited from nine different areas of Austria in 1994. A questionnaire and an SPT involving seven common aero-allergens were performed at study entry and at follow-up 3 years later. RESULTS: A total of 844 children, who underwent two SPTs, were included in the analyses; 15.1% of their families reported working on a farm. Adjusting for potential confounders (parental education, number of siblings, sex, family history of allergy), parental farming was inversely related to the prevalence and new occurrence of SPT positivity [no farming 12.2%, part-time farming 6%, full-time farming 2.2% incidence; odds ratio (OR) farming vs. non-farming 0.34, 95% confidence interval (CI) 0.12-0.98]. Furthermore, children living in a farming environment were more likely to lose their SPT positivity during follow-up (no farming 14.6%, part-time farming 50%, full-time farming 60% loss of sensitization; OR farming vs. non-farming 8.06; 95% CI 2.05-31.75). No difference in the pattern of sensitization to specific allergens could be observed between farming and non-farming children. CONCLUSION: A farming environment has a strong negative effect on the development of allergic sensitization. Furthermore, the study provides evidence that atopic children living on a farm lose their SPT positivity more frequently than children from non-farming environments.

Agriculture↗
PubMed2002

Particulate matter and lung function growth in children: a 3-yr follow-up study in Austrian schoolchildren.

The effects of particulate matter <10 microm in diameter (PM10) and other air pollutants on lung function were assessed in 975 schoolchildren, from eight communities in Lower Austria between 1994-1997. In each community, air pollution data were collected. Spirometry was performed twice a year. PM10 concentration (mean concentration between two subsequent lung-function measures in spring and autumn (summer interval) or between autumn and spring (winter interval)) showed a mean value of 17.36 microg x m(-3) in the summer interval and 21.03 microg m(-3) in the winter interval. A slower increase in the forced expiratory volume in one second (FEV1) and midexpiratory flow between 25 and 75% of the forced vital capacity (MEF25-75) with age in children exposed to higher summer PM10 was observed in the 3-yr study period. After adjusting for potential confounders (sex, atopy, passive smoking, initial height, height difference, site, initial lung function) an increase of summer PM10 by 10 microg x m(-3) was associated with a decrease in FEV1 growth of 84 mL x yr(-1) and 329 mL x s(-1) x yr(-1) for MEF25-75. Nitrogen dioxide and ozone also showed a negative effect on lung-function growth, confirming previous work. The authors concluded that long-term exposure to particulate matter <10 microm in diameter had a significant negative effect on lung-function proxy for the development of large (forced expiratory volume in one second) and small (midexpiratory flow between 25 and 75% of the forced vital capacity) airways, respectively, with strong evidence for a further effect of ozone and nitrogen dioxide on the development of forced vital capacity and forced expiratory volume in one second.

Air Pollutants↗
PubMed2001

CD14(dim)/CD16(bright) monocytes in hemophagocytic lymphohistiocytosis.

Hemophagocytic lymphohistiocytosis (HLH) is an extremely rare and highly lethal chronic inflammatory disease, which is mediated by proinflammatory cytokines. In the peripheral blood of a boy suffering from HLH, a chronic expansion of CD14(dim)/CD16(bright) inflammatory monocytes was detected. Compared with CD14(bright) monocytes, their immunophenotype correlated with more mature monocytic cells differentiating to macrophages: they showed lower expression of CD11b, CD64 and CD35. Such CD14(dim)/CD16(bright) monocytes produce the inflammatory cytokines IL-1beta, IL-6 and TNF-alpha. They fit in well with the pathophysiological concept of HLH as an inflammatory state of lymphocytes and of the monocyte/macrophage system. In the presented patient the percentage of these circulating inflammatory monocytes decreased over time during clinical response to immunosuppressive therapy. This finding may indicate that CD14(dim)/CD16(bright) monocytes represented the degree of inflammation in this extremely rare and highly lethal disease.

Adolescent↗
PubMed2001

Cow's milk-specific cellular and humoral immune responses and atopy skin symptoms in infants from atopic families fed a partially (pHF) or extensively (eHF) hydrolyzed infant formula.

BACKGROUND: Hydrolyzed milk formulas are recommended to feed infants at high risk of atopy if breast-feeding is not possible. We studied the specific cellular and humoral immune response to cow's milk proteins and occurrence of atopic dermatitis under different feeding regimens: two hydrolyzed infant milk formulas (partially [pHF] and extensively hydrolyzed [eHF]) and under exclusive breast-feeding (BF). METHODS: Seventy-two infants from families with atopic symptoms were randomized in the pHF and eHF groups, respectively. At 6 and 12 months of age, peripheral blood mononuclear cell proliferation along with specific IgG and IgE to cow's milk proteins was determined in infants fed pHF or eHF, respectively, and those who had not yet received any formula at 6 months of age (BF). Cases of atopic dermatitis were recorded throughout the first 12 months of life, and their severity was evaluated with SCORAD points. RESULTS: A significantly decreased proliferation to cow's milk caseins was found in the pHF group compared to the exclusively breast-fed group. Medians of stimulation indexes for CAS at 6 months were as follows: pHF 1.18; n=24; BF 1.70; n=24 (P=0.033, Mann-Whitney U-test). Higher levels of plasma IgG antibodies to BCAS were found in infants fed pHF than in those fed eHF at 12 months. Optical density (OD): (25th percentile; median; 75th percentile): pHF: 0.00; 0.14; 0.38; n=30; eHF: 0.00; 0.03; 0.14; n=28; P=0,089, Mann-Whitney U-test. Cow's milk-specific IgE was detected at 6 months as follows: BF: 3 of 24; eHF: 2 of 21; pHF: 0 of 23. The number of cases of atopic dermatitis and their severity did not differ among the groups during the first 12 months. CONCLUSIONS: Feeding pHF appears to suppress cow's milk-specific cellular responses and stimulate specific IgG production. Specific IgE sensitization can occur also with breast-feeding.

Animals↗
PubMed2000

[The effect of inhalable dust particles (PN10) on lung function and respiratory symptoms of school children in Lower Austria].

The effect of PM10 (particulate matter less than 10 microns in diameter) on respiratory symptoms and lung function was evaluated in 881 children (aged 8 to 11 years) in 8 communities in Lower Austria. In each community, air pollution data (PM10, SO2, NO2, O3) were collected. The examination of each child included a questionnaire (spring 1996), and two lung function tests (autumn 1995, spring 1996). Statistically significant relationships were observed between PM10 levels (annual mean, 15.8-26.9 micrograms/m3) and parameters of lung function (adjusted for sex, height, atopy, passive smoking, altitude, temperature). A 10 micrograms/m3 increase in the last two weeks' mean PM10 in spring 1996 was associated with a 0.05% decrease in FVC, a 0.05% decrease in FEV1, a 0.15% decrease in MEF50, and a 0.13% decrease in MEF75-25. Furthermore, a 10 micrograms/m3 increase in last year's mean PM10 was associated with a 0.07% decrease in FVC. No association between the prevalence of respiratory symptoms and the last year's mean PM10-exposure was found. Our study demonstrates a small effect of low-level particulate air pollution on lung function of healthy school children.

Age Factors↗
PubMed2000

[Project for supporting visually handicapped aged persons: developing a guide for the community of Münster].

In this paper we wish to outline both the function and the role of projects as part of a course in "Nursing Education" (Pflegepädagogik) at the Fachhochschule Münster, as well as to present a specific project which has enabled the students to gain experience in project management and qualitative research. The project target group were visually handicapped old people for whom a guide was produced as a health promotion strategy within the framework of governmental health objectives in the state of Northrhine-Westfalia.

Aged↗
PubMed2000

Eosinophil cationic protein and eosinophil protein X in the nasal lavage of children during the first 4 weeks of life. SPACE Collaborative Study Team.

Eosinophil cationic protein (ECP) and eosinophil protein X (EPX) are well established as markers of eosinophil activation. We analyzed ECP and EPX concentrations in nasal lavage fluids (NALF) of 378 neonates during their first 4 weeks of life. Inclusion criteria were a positive history of parental allergy and a positive skin prick test or specific IgE (RAST class > or = 2) against at least one out of a panel of common aeroallergens in one or both parents. Twenty-four infants with no history of parental allergy were used as controls. A volume of 2 ml of 0.9% saline was instilled into each nostril and immediately recovered by a suction device. ECP and EPX were analyzed by radioimmunoassay. In 65 samples of three consecutive lavages, EPX was detected in nine samples (13.8%) in the control group, whereas it was detected in 197/360 samples (54.7%) in the study population. The corresponding figures for ECP were 17/65 (26.2%) in the control group and 173/365 (47.4%) in the study group. Both proteins showed a skewed distribution (median/5-95th percentiles for ECP: 0 microg/l [0-69.4] and EPX: 6.6 microg/l [0-73.2]). The differences between the control group and the study group were statistically significant, regardless of the allergic disease of the parents. In children of allergic parents, activation proteins of the eosinophil granulocyte are released on the nasal mucosal surface in about 50% of the studied population at the age of 4 weeks. This early onset of eosinophil activation in the nasal respiratory epithelium may reflect a genetic predisposition to allergy or early exposure to allergens.

Blood Proteins↗
PubMed2000

Eosinophil-derived proteins in nasal lavage fluid of neonates of allergic parents and the development of respiratory symptoms during the first 6 months of life. Collaborative SPACE team. Study on the Prevention of Allergy in Children in Europe.

BACKGROUND: Eosinophilic airways inflammation forms the pathophysiologic basis for a proportion of children at risk of developing recurrent wheezing. Early preventive measures and/or anti-inflammatory treatment may be guided by the identification of such children. METHODS: We studied upper-airways inflammation by nasal lavage in a cohort of 397 infants within the first 4 weeks of life. They participated in an international multicenter study on the prevention of allergy in Europe (SPACE-Biomed II Program). A volume of 2 ml of prewarmed 0.9% saline was instilled into each nasal cavity and immediately re-collected by a suction device. The average recovery was 502 microl (SD: 311 microl). The concentrations of eosinophil cationic protein (ECP) and eosinophil protein X (EPX) were determined by RIA analysis. RESULTS: ECP was detectable (>2 microg/l) in 47% of samples (173/365) and EPX (>3 microg/l) in 54.7% (197/360). Children with a doctor's diagnosis of a wheezy bronchitis within the first 6 months of life (n = 40) had significantly higher ECP and EPX concentrations in the nasal lavage at 4 weeks of age (median ECP: 14 microg/l; 5-95th percentile: 0-122.4 microg/l) than children without such diagnosis (median ECP: 0 microg/l; 5-95th percentile: 0-86.6 microg/l; P<0.05). Corresponding figures for EPX were 12.14 microg/l (0-148.98 microg/l) vs 7.5 microg/l (0-81.46 microg/l; P<0.05). No associations between nasal ECP/EPX and the development of food allergy or eczema were observed. CONCLUSIONS: Increased nasal ECP and EPX in the first 4 weeks of life are associated with wheezing in 6-month-old infants at increased risk of atopic disease. We suggest that this might be related to a general tendency for a Th2 cytokine pattern in these young infants and subsequent trafficking of eosinophils into the nasal mucosa, or it might be a consequence of intrauterine allergen exposure.

Blood Proteins↗
PubMed2000

Culture conditions for the detection of allergen-specific T-cell reactivity in cord blood: influence of cell number.

Raised T-cell proliferation of cord blood mononuclear cells (CBMC) in response to various ingestant and inhalant allergens has been reported in newborns, suggesting a prenatal allergen contact. In general, for in vitro proliferation assays a concentration of 50 x 10(3) or 100 x 10(3) cells/well are used. The aim of this study was to analyze whether cell concentration influences T-cell reactivity in cord blood cells and to study differences of T-cell reactivity triggered by inhalant and ingestant allergens. CBMC from 51 neonates (34 females: 22 with and 29 without a family history of allergy, i.e. FH+ or FH-) were incubated with interleukin-2 (IL-2), beta-lactoglobulin (beta-LG), ovalbumin (OVA), house dust mite allergen Dermatophagoides pteronyssinus (Der p 1), and timothy grass allergen Phleum pratense (Ph1 p 1) for 7 days. The cell concentration ranged from 6.25 x 10(3) to 100 x 10(3) cells/well. Proliferation was assessed by incorporation of [3H]-thymidine and was expressed as counts per minute (c.p.m.). In unstimulated cells, a decreasing cell concentration paralleled a steep drop of background activity. In response to IL-2, a decreasing cell concentration led to a slow decrease of c.p.m. The corresponding mean stimulation indices (SI) were 9, 32, 77, 47, and 21 for 100 x 10(3), 50 x 10(3), 25 x 10(3), 12.5 x 10(3), and 6.25 x 10(3) cells/well, respectively. In addition, the highest number of positive proliferative responses to specific allergens were obscured at lower cell concentrations. For beta-LG, the maximal number of positive responses were obtained between 25 x 10(3) (n = 44) and 12.5 x 10(3) (n = 46) cells/well, for OVA at 25 x 10(3) (n = 3) cells/well, for Der p 1 at 50 x 10(3) (n = 5) cells/well, and for Ph1 p 1 between 25 x 10(3) and 12.5 x 10(3) (n = 5) cells/well. Positive proliferation in at least one of the tested assays was observed in 100% of samples in response to beta-LG, in 22% in response to Ph1 p 1, and in 14% in response to OVA and Der p 1. T-cell reactivity did not differ between samples of newborns with or without a family history of atopy. Therefore, sensitivity of T-cell proliferation measurement is highly influenced by background proliferation of unstimulated cells. Hence, proliferation assays with lower cell numbers unmask T-cell reactivity in response to ingestant and inhalant allergens. We suggest the use of concentrations of 12.5 x 10(3)-50 x 10(3) cells/well in proliferation experiments.

Allergens↗
PubMed2000

Transplacental priming of the human immune system with environmental allergens can occur early in gestation.

BACKGROUND: Allergen-specific T cells play an important role in the allergic immune response to various environmental allergens. In vitro studies have shown that T-cell responses to these allergens do occur prenatally. Some allergens (milk proteins) appear to lead more often to fetal T-cell priming than others (house dust mite allergen, ovalbumin, and birch and grass pollen allergens). OBJECTIVE: We sought to determine the window of opportunity for prenatal T-cell priming with inhalant and nutritive allergens. METHODS: The T-cell reactivity of cord blood cells derived through cordocentesis from unborn (n = 62) and term babies (n = 114) in response to inhalant allergens (birch pollen major allergen, recombinant Bet v 1, and timothy grass major allergen, recombinant Phl p 1) was investigated. RESULTS: The results demonstrate that allergen-specific T-cell reactivity is as common in preterm as in term infants (Bet v 1, 8% and 5%, respectively; Phl p 1, 20% and 25%, respectively). CONCLUSIONS: Our data support the hypothesis that differential handling of the allergenic proteins by the feto-placental barrier and possibly by antigen-presenting cells may directly modulate the ensuing T-cell immune response.

Administration, Inhalation↗