Long-term safety of replication-defective smallpox vaccine (MVA-BN) in atopic eczema and allergic rhinitis

BACKGROUND

Availability of a safe smallpox vaccine may be necessary under certain circumstances. Use of the old life virus vaccine was associated with serious adverse events, particularly in the setting of atopic eczema (AE) and immunodeficiency. Modified virus Ankara (MVA)-BN, a highly attenuated strain of vaccinia virus, was developed for vaccination with improved safety profile.

METHODS

A phase 1 study was conducted in 60 subjects without history of smallpox vaccination to gain experience with smallpox vaccination using this strain in healthy and atopic subjects. Healthy subjects, subjects with a history of AE, subjects with mild active AE and subjects with mild allergic rhinitis without AE were equally allocated into four groups. MVA-BN was injected s.c. in a dose of 10⁸ TCID₅₀ twice in a 4-week interval.

RESULTS

No serious or unexpected adverse reactions were reported. All subjects experienced mild to moderate pain and redness at the injection site. Dermatologic examinations did not reveal any unfavourable reactions to the study medication, particularly no sign or exacerbation of eczema for as long as 196 days. All subjects seroconverted after two vaccinations and no significant difference in antibody titres between the four different groups was observed.

CONCLUSIONS

A good safety profile of the MVA-BN vaccine was shown. The absence of adverse events in subjects with atopic disorders appears promising for the development of a safe smallpox vaccine for patients with AE or other atopic diseases.

Pollen derived low molecular compounds enhance the human allergen specific immune response in vivo

BACKGROUND

Besides allergens, pollen release bioactive, low molecular weight compounds that modulate and stimulate allergic reactions. Clinical relevance of these substances has not been investigated to date.

OBJECTIVE

To elucidate the effect of a non-allergenic, low molecular weight factors from aqueous birch pollen extracts (Bet-APE < 3 kDa) on the human allergic immune response in vivo.

METHODS

Birch and grass pollen allergic individuals underwent skin prick testing with allergen alone, allergen plus Bet-APE < 3 kDa, or allergen plus pre-identified candidate substances from low molecular pollen fraction. Nasal allergen challenges were performed in non-atopic and pollen allergic individuals using a 3 day repeated threshold challenge battery. Subjects were either exposed to allergen alone or to allergen plus Bet-APE< 3 kDa. Local cytokine levels, nasal secretion weights, nasal congestion and symptom scores were determined.

RESULTS

Skin prick test reactions to pollen elicited larger weals when allergens were tested together with the low molecular weight compounds from pollen. Similar results were obtained with candidate pollen-associated lipid mediators. In nasal lining fluids of allergic patients challenged with allergen plus Bet-APE < 3 kDa, IL-8 and IgE was significantly increased as compared to allergen-only challenged patients. These patients also produced increased amounts of total nasal secretion and reported more severe rhinorrhea than the allergen-only challenged group.

CONCLUSIONS

Low molecular compounds from pollen enhance the allergen specific immune response in the skin and nose. They are therefore of potential clinical relevance in allergic patients.

Pollen-derived nonallergenic substances enhance Th2-induced IgE production in B cells

BACKGROUND

B cells play a central role in IgE-mediated allergies. In damaged airway epithelium, they are exposed directly to aeroallergens. We aimed to assess whether direct exposure of B cells to pollen constituents affects allergic sensitization.

METHODS

B cells from murine splenocytes and from blood samples of healthy donors were incubated for 8 days under Th2-like conditions with aqueous ragweed pollen extracts (Amb-APE) or its constituents. Secreted total IgM, IgG, and IgE was quantified by ELISA. Additionally, birch, grass, or pine-pollen extracts were tested. The number of viable cells was evaluated by ATP measurements. B-cell proliferation was measured by CFSE staining. IgE class switch was analyzed by quantitation of class switch transcripts. In an OVA/Alum i.p.-sensitization mouse model, Amb-APE was intranasally instilled for 11 consecutive days.

RESULTS

Upon Th2 priming of murine B cells, ragweed pollen extract caused a dose-dependent increase in IgE production, while IgG and IgM were not affected. The low-molecular-weight fraction and phytoprostane E1 (PPE1) increased IgE production, while Amb a 1 did not. PPE1 enhanced IgE also in human memory B cells. Under Th1 conditions, Amb-APE did not influence immunoglobulin secretion. The IgE elevation was not ragweed specific. It correlated with proliferation of viable B cells, but not with IgE class switch. In vivo, Amb-APE increased total IgE and showed adjuvant activity in allergic airway inflammation.

CONCLUSIONS

Aqueous pollen extracts, the protein-free fraction of Amb-APE, and the pollen-contained substance PPE1 specifically enhance IgE production in Th2-primed B cells. Thus, pollen-derived nonallergenic substances might be responsible for B-cell-dependent aggravation of IgE-mediated allergies.

What can reunification of East and West Germany tell us about the cause of the allergy epidemic?

The increase of allergies in East Germany--reaching West German prevalence shortly after the reunification--is considered a model for the allergy epidemic in the western world. Whether such a pattern was observed in all comparison studies and for all allergic manifestations is not known because a complete overview is missing. Hints about possible causal factors for the allergy epidemic could be gained by identifying known risk factors, which explain the observed pattern of allergy development in Germany. Again, an overview about these efforts is missing. We identified 14 cross-sectional studies conducted after 1989 and calculated prevalence ratios (West/East) for asthma, hayfever, eczema and allergic sensitization. Additionally, a tabular overview about the explanatory power of risk factors hypothesized in the nineties and covering outdoor exposure, indoor factors, early childhood influences, nutrition as well as awareness is given. At the time of the German reunification, the prevalence ratio West/East was largest for hayfever and sensitization to birch pollen, less pronounced for the other phenotypes and even less than one for atopic eczema. Hayfever and sensitization to birch pollen also showed the steepest increase in East Germany afterwards. Single-room heating with fossil fuels and living as only child in a family were identified as explaining up to 23.5% of the excess trend in East compared to the trend in West. Hayfever as most typical atopic disease showed the difference in allergy pattern between East and West Germany clearest. Risk factors identified for these phenotypes are completely different (single child) or even act in the opposite direction (single-room heating) from classical risk factors for airway diseases. This might be the most important lesson from the West/East German experience. It already stimulated many other studies focussing on protective factors such as microbial stimulation.

Pollen-derived adenosine is a necessary cofactor for ragweed allergy

BACKGROUND

Ragweed (Ambrosia artemisiifolia) is a strong elicitor of allergic airway inflammation with worldwide increasing prevalence. Various components of ragweed pollen are thought to play a role in the development of allergic responses. The aim of this study was to identify critical factors for allergenicity of ragweed pollen in a physiological model of allergic airway inflammation.

METHODS

Aqueous ragweed pollen extract, the low molecular weight fraction or the major allergen Amb a 1 was instilled intranasally on 1-11 consecutive days, and allergic airway inflammation was evaluated by bronchoalveolar lavage, lung histology, serology, gene expression in lung tissue, and measurement of lung function. Pollen-derived adenosine was removed from the extract enzymatically to analyze its role in ragweed-induced allergy. Migration of human neutrophils and eosinophils toward supernatants of ragweed-stimulated bronchial epithelial cells was analyzed.

RESULTS

Instillation of ragweed pollen extract, but not of the major allergen or the low molecular weight fraction, induced specific IgG1 , pulmonary infiltration with inflammatory cells, a Th2-associated cytokine signature in pulmonary tissue, and impaired lung function. Adenosine aggravated ragweed-induced allergic lung inflammation. In vitro, human neutrophils and eosinophils migrated toward supernatants of bronchial epithelial cells stimulated with ragweed extract only if adenosine was present.

CONCLUSIONS

Pollen-derived adenosine is a critical factor in ragweed-pollen-induced allergic airway inflammation. Future studies aim at therapeutic strategies to control these allergen-independent pathways.

Comparison of Molecular Multiplex and Singleplex Analysis of IgE to Grass Pollen Allergens in Untreated German Grass Pollen-Allergic Patients

BACKGROUND

The ImmunoCAP ISAC 112 platform is the only commercially available molecular allergy IgE multiplex test. Data on the comparison of this rather novel test with the molecular singleplex ImmunoCAP IgE platform are lacking.

OBJECTIVE

To compare the multiplex ISAC 112 platform and the singleplex ImmunoCAP platform in regard to IgE to grass pollen allergens in untreated grass pollen-allergic patients in Germany.

METHODS

Serum samples from 101 adults with grass pollen allergy were analyzed for specific IgE (sIgE) to 8 allergenic molecules from timothy grass pollen and to the 112 allergenic molecules included in the ISAC panel. The results for the multiplex and singleplex tests were subsequently analyzed statistically.

RESULTS

Comparison of sIgE to grass pollen allergens detected by ISAC 112 and the singleplex ImmunoCAP assay revealed the following correlation coefficients: 0.88 (rPhl p 1), 0.96 (rPhl p 2), 0.70 (nPhl p 4), 0.94 (rPhl p 5b), 0.92 (rPhl p 6), 0.85 (rPhl p 11), and 0.78 (rPhl p 12).

CONCLUSION

Molecular testing with ISAC 112 correlates well with the ImmunoCAP platform for respective molecular timothy grass pollen allergens.

Mechanisms of peripheral tolerance to allergens

The immune system is regulated to protect the host from exaggerated stimulatory signals establishing a state of tolerance in healthy individuals. The disequilibrium in immune regulatory vs effector mechanisms results in allergic or autoimmune disorders in genetically predisposed subjects under certain environmental conditions. As demonstrated in allergen-specific immunotherapy and in the healthy immune response to high-dose allergen exposure models in humans, T regulatory cells are essential in the suppression of Th2-mediated inflammation, maintenance of immune tolerance, induction of the two suppressive cytokines interleukin-10 and transforming growth factor-β, inhibition of allergen-specific IgE, and enhancement of IgG4 and IgA. Also, suppression of dendritic cells, mast cells, and eosinophils contributes to the construction of peripheral tolerance to allergens. This review focuses on mechanisms of peripheral tolerance to allergens with special emphasis on recent developments in the area of immune regulation.

Itch and the brain

The sensation of itch - defined as unpleasant sensation inducing the urge to scratch - is processed by a network of different brain regions contributing to the encoding of sensory, emotional, attention-dependent, cognitive-evaluative and motivational patterns. Patients with atopic eczema show different activation patterns and kinetics compared to healthy volunteers. This review summarizes current studies investigating itch in the brain.

Toxicity and elemental composition of particulate matter from outdoor and indoor air of elementary schools in Munich, Germany

Outdoor particulate matter (PM(10)) is associated with detrimental health effects. However, individual PM(10) exposure occurs mostly indoors. We therefore compared the toxic effects of classroom, outdoor, and residential PM(10). Indoor and outdoor PM(10) was collected from six schools in Munich during teaching hours and in six homes. Particles were analyzed by scanning electron microscopy and X-ray spectroscopy (EDX). Toxicity was evaluated in human primary keratinocytes, lung epithelial cells and after metabolic activation by several human cytochromes P450. We found that PM(10) concentrations during teaching hours were 5.6-times higher than outdoors (117 ± 48 μg/m(3) vs. 21 ± 15 μg/m(3), P < 0.001). Compared to outdoors, indoor PM contained more silicate (36% of particle number), organic (29%, probably originating from human skin), and Ca-carbonate particles (12%, probably originating from paper). Outdoor PM contained more Ca-sulfate particles (38%). Indoor PM at 6 μg/cm(2) (10 μg/ml) caused toxicity in keratinocytes and in cells expressing CYP2B6 and CYP3A4. Toxicity by CYP2B6 was abolished with the reactive oxygen species scavenger N-acetylcysteine. We concluded that outdoor PM(10) and indoor PM(10) from homes were devoid of toxicity. Indoor PM(10) was elevated, chemically different and toxicologically more active than outdoor PM(10). Whether the effects translate into a significant health risk needs to be determined. Until then, we suggest better ventilation as a sensible option.

PRACTICAL IMPLICATIONS

Indoor air PM(10) on an equal weight base is toxicologically more active than outdoor PM(10). In addition, indoor PM(10) concentrations are about six times higher than outdoor air. Thus, ventilation of classrooms with outdoor air will improve air quality and is likely to provide a health benefit. It is also easier than cleaning PM(10) from indoor air, which has proven to be tedious.

Acupuncture compared with oral antihistamine for type I hypersensitivity itch and skin response in adults with atopic dermatitis: a patient- and examiner-blinded, randomized, placebo-controlled, crossover trial

BACKGROUND

Itch is the major symptom of atopic dermatitis (AD). Acupuncture has been shown to exhibit a significant effect on experimental itch in AD. Our study evaluated acupuncture and antihistamine itch therapy (cetirizine) on type I hypersensitivity itch and skin reaction in AD using a patient and examiner-blinded, randomized, placebo-controlled, crossover trial.

METHODS

Allergen-induced itch was evaluated in 20 patients with AD after several interventions in separate sessions: preventive (preceding) and abortive (concurrent) verum acupuncture (VAp and VAa), cetirizine (10 mg, VC), corresponding placebo interventions (preventive, PAp, and abortive, PAa, placebo acupuncture; placebo cetirizine pill, PC) and a no-intervention control (NI). Itch was induced on the forearm and temperature modulated over 20 min, using our validated model. Outcome parameters included itch intensity, wheal and flare size and the D2 attention test.

RESULTS

Mean itch intensity (SE: 0.31 each) was significantly lower following VAa (31.9) compared with all other groups (PAa: 36.5; VC: 36.8; VAp: 37.6; PC: 39.8; PAp: 39.9; NI: 45.7; P < 0.05). There was no significant difference between VAp and VC (P > 0.1), although both therapies were significantly superior to their respective placebo interventions (P < 0.05). Flare size following VAp was significantly smaller (P = 0.034) than that following PAp. D2 attention test score was significantly lower following VC compared with all other groups (P < 0.001).

CONCLUSIONS

Both VA and cetirizine significantly reduced type I hypersensitivity itch in patients with AD, compared with both placebo and NI. Timing of acupuncture application was important, as VAa had the most significant effect on itch, potentially because of counter-irritation and/or distraction. Itch reduction following cetirizine coincided with reduced attention.

Can immunoglobulin E-measurement replace challenge tests in allergic rhinoconjunctivits to grass pollen?

BACKGROUND

There is minimal data available concerning the dose-response relationship between allergen exposure and clinical reactivity for outdoor aeroallergens, such as timothy grass pollen. Timothy pollen-specific IgE (sIgE) determinations might assist in predicting the clinical reactivity in patients with allergic rhinoconjunctivitis (ARC).

METHODS

Allergen-sIgE antibody levels of timothy grass pollen were correlated with individual threshold doses eliciting allergic reactions in skin prick test (SPT), conjunctival (CPT) and nasal (NPT) provocation tests in patients suffering from pollen-induced rhinoconjunctivitis and healthy controls.

RESULTS

One hundred and four patients with ARC (median age: 27 years; range: 18-64; females: 58%) and 36 controls (25 years (22-77); females: 70%) were included in the study. Ninety-six percent of the patients showed a positive reaction in the nasal and 57% showed a positive reaction in the conjunctival provocation. With regarding to titrated SPT, 98% of the patients showed a positive skin test reaction; correlating with the level of sIgE for timothy (P < 0.001). For both provocation protocols, there was no correlation between the provocation concentration at the reaction and the level of sIgE for timothy. The ratio of sIgE/total IgE correlated with the dilution level of SPT (P < 0.002) and CPT (P < 0.01), respectively.

CONCLUSION AND CLINICAL RELEVANCE

A dose-response relationship between the levels of sIgE and clinical outcome of timothy allergen exposure could not be established. Although IgE-determination remains an important key element in allergy diagnosis, provocation tests are procedures of choice if the clinical relevance of an allergen has to be confirmed.

Projections of the effects of climate change on allergic asthma: the contribution of aerobiology

Climate change is unequivocal and represents a possible threat for patients affected by allergic conditions. It has already had an impact on living organisms, including plants and fungi with current scenarios projecting further effects by the end of the century. Over the last three decades, studies have shown changes in production, dispersion and allergen content of pollen and spores, which may be region- and species-specific. In addition, these changes may have been influenced by urban air pollutants interacting directly with pollen. Data suggest an increasing effect of aeroallergens on allergic patients over this period, which may also imply a greater likelihood of the development of an allergic respiratory disease in sensitized subjects and exacerbation of symptomatic patients. There are a number of limitations that make predictions uncertain, and further and specifically designed studies are needed to clarify current effects and future scenarios. We recommend: More stress on pollen/spore exposure in the diagnosis and treatment guidelines of respiratory and allergic diseases; collection of aerobiological data in a structured way at the European level; creation, promotion and support of multidisciplinary research teams in this area; lobbying the European Union and other funders to finance this research.

The allergen Bet v 1 in fractions of ambient air deviates from birch pollen counts

BACKGROUND

Proof is lacking that pollen count is representative for allergen exposure, also because allergens were found in nonpollen-bearing fractions of ambient air.

OBJECTIVE

We monitored simultaneously birch pollen and the major birch pollen allergen Bet v 1 in different size fractions of ambient air from 2004 till 2007 in Munich, Germany.

METHODS

Air was sampled with a ChemVol high-volume cascade impactor equipped with stages for particulate matter (PM)>10 microm, 10 microm>PM>2.5 microm, and 2.5 microm>PM>0.12 microm. Allergen was determined with a Bet v 1-specific ELISA. Pollen count was assessed with a Burkard pollen trap. We also measured the development of allergen in pollen during ripening.

RESULTS

About 93 +/- 3% of Bet v 1 was found in the PM > 10 microm fraction, the fraction containing birch pollen. We did not measure any Bet v 1 in 2.5 microm > PM > 0.12 microm. Either in Munich no allergen was in this fraction or the allergen was absorbed to diesel soot particles that also deposit in this fraction. Pollen released 115% more Bet v 1 in 2007 than in 2004. Also within 1 year, the release of allergen from the same amount of pollen varied more than 10-fold between different days. This difference was explained by a rapidly increasing expression of Bet v 1 in pollen in the week just before pollination. Depending on the day the pollen is released during ripening, its potency varies.

CONCLUSION

In general, pollen count and allergen in ambient air follow the same temporal trends. However, because a 10-fold difference can exist in allergen potency of birch pollen, symptoms might be difficult to correlate with pollen counts, but perhaps better with allergen exposure.

Influence of acupuncture on type I hypersensitivity itch and the wheal and flare response in adults with atopic eczema - a blinded, randomized, placebo-controlled, crossover trial

BACKGROUND

Itch is a major symptom of allergic skin disease. Acupuncture has been shown to exhibit a significant effect on histamine-induced itch in healthy volunteers. We investigated the effect of acupuncture on type I hypersensitivity itch and skin reaction in a double-blind, randomized, placebo-controlled, crossover trial.

METHODS

An allergen stimulus (house dust mite or grass pollen skin prick) was applied to 30 patients with atopic eczema before (direct effect) and after (preventive effect) two experimental approaches or control observation: acupuncture at points Quchi and Xuehai [verum acupuncture (VA), dominant side], 'placebo-point' acupuncture (PA, dominant side), no acupuncture (NA). Itch intensity was recorded on a visual analogue scale. After 10 min, wheal and flare size and skin perfusion (via LASER-Doppler) were measured at the stimulus site, and the validated Eppendorf Itch Questionnaire (EIQ) was answered.

RESULTS

Mean itch intensity was significantly lower in VA (35.7 +/- 6.4) compared to NA (45.9 +/- 7.8) and PA (40.4 +/- 5.8) regarding the direct effect; and significantly lower in VA (34.3 +/- 7.1) and PA (37.8 +/- 5.6) compared to NA (44.6 +/- 6.2) regarding the preventive effect. In the preventive approach, mean wheal and flare size were significantly smaller in VA (0.38 +/- 0.12 cm(2)/8.1 +/- 2.0 cm(2)) compared to PA (0.54 +/- 0.13 cm(2)/13.5 +/- 2.8 cm(2)) and NA (0.73 +/- 0.28 cm(2)/15.1 +/- 4.1 cm(2)), and mean perfusion in VA (72.4 +/- 10.7) compared to NA (84.1 +/- 10.7). Mean EIQ ratings were significantly lower in VA compared to NA and PA in the treatment approach; and significantly lower in VA and PA compared to NA in the preventive approach.

CONCLUSIONS

Acupuncture at the correct points showed a significant reduction in type I hypersensitivity itch in patients with atopic eczema. With time the preventive point-specific effect diminished with regard to subjective itch sensation, whereas it increased in suppressing skin-prick reactions.

[Mucocutaneous candidiasis]

Infection with the yeast candida is a quite common disease. Its occurrence might be harmless, however, Candida infections often present with an underlying systemic disease. Thus, candidiasis in some cases can be considered as an indicator for e.g. diabetes mellitus or immune deficiency (i.e. HIV or leukaemia). Of note, we have to distinguish the colonisation and the infection with Candida because only the presence of the yeast together with clinical symptoms is an indication for treatment. The latter has to be adapted according to age, localisation and potentially underlying systemic disease. A special form of Candidiasis constitutes the chronic mucocutaneous candidiasis which can occur in line with hereditary immune deficiencies or also isolated. In the present review we discuss the current status of diagnostic and therapy of mucocutaneous candidiasis as well as the (patho-) immunologic background of yeast infections using the example of a special case of chronic mucocutaneous candidiasis.

Pollen-derived low-molecular weight factors inhibit 6-sulfo LacNAc+ dendritic cells' capacity to induce T-helper type 1 responses

BACKGROUND

Evidence is accumulating that the pollen exsudate contains an array of non-allergenic, pro-inflammatory and immunomodulatory substances acting on the innate and adaptive immune system. In this context, pollen-associated E(1)-phytoprostanes (PPE(1)) were shown to licence human monocyte-derived dendritic cells for T-helper type 2 (Th2) polarization of naïve T cells.

OBJECTIVE

This study aims at analysing the impact of pollen-associated lipid mediators on cytokine secretion and maturation of 6-sulfo LacNAc(+) dendritic cells (slanDCs), the most abundant native dendritic cell (DC) in human peripheral blood, and further dissecting the biologically active substance(s) within aqueous pollen extracts.

RESULTS

Aqueous birch pollen extracts dose-dependently inhibited the lipopolysaccharide (LPS)-induced IL-12 p70 production, while the levels of IL-6 remained unaffected. PPE(1) inhibited secretion of both IL-12 p70 and IL-6. Aqueous pollen extracts, but not PPE(1) or F(1)-phytoprostanes significantly reduced the LPS-induced surface expression of the maturation markers CD80, CD83, CD40 and CCR-7, an effect that was independent of proteins and that was still present in a 3 kDa cut-off fraction of the pollen extract. These effects were observed irrespective of the atopy status of the donors. Finally, slanDCs exposed to aqueous pollen extracts were impaired in eliciting an IFN-gamma response in naïve CD4(+) T cells.

CONCLUSION

Our data show that slanDCs, a subset of human blood DCs with constitutively high potency to induce Th1 responses, are susceptible to the Th2 polarizing effect of low molecular weight, non-protein factors derived from pollen.

Differences in allergy trends between East and West Germany and possible explanations

BACKGROUND

At the time of the German reunification in 1990, manifestations of most allergic diseases were less prevalent in East than in West Germany. It was hypothesized that these East-West differences would diminish with lifestyle and pollution changes in East Germany.

OBJECTIVE

To investigate whether changes in the prevalence of asthma, hayfever, eczema or allergic sensitization in East Germany approached the levels seen in West Germany and to identify possible lifestyle or environmental factors that may influence this.

METHODS

Between 1991 and 2000, 6-year-old children from four areas in East Germany participated in an annual survey. Every 3rd year, a parallel survey was performed in four areas of West Germany. In total, 31 903 children were included. Parents completed a questionnaire regarding lifestyle factors and diagnoses and symptoms of asthma, hayfever and eczema. In sub-areas, eczema was clinically assessed by a dermatologist. Specific IgE sensitization was determined for 6121 children. Logistic regression was used to analyse differences in time trends and the influence of lifestyle and pollution changes.

RESULTS

Lifestyle and pollution changed significantly differently between East and West Germany. The trends in hayfever and in strong (specific IgE >3.5) sensitization against pollen, and particularly birch pollen, were steeper in East than in West Germany. The trend towards marked pollen sensitization was four times stronger (95% confidence interval 1.2-13.9) in East than in West Germany. Increasing numbers of only children, less single-room heating with fossil fuels and increasing importance of traffic-related pollution in East Germany partly explained these differences in time trends.

CONCLUSIONS

Hayfever and sensitization against pollen were the most sensitive allergic manifestations to changes experienced specifically in East Germany. Influences of lifestyle (single-room heating, living as a single child) were important in explaining different trend developments.

Integrated water resources management in central Asia: nutrient and heavy metal emissions and their relevance for the Kharaa River Basin, Mongolia

Within the framework of Integrated Water Resources Management (IWRM) the nutrient and heavy metal levels within the Kharaa river basin were investigated. By the application of the MONERIS model, which quantifies nutrient emissions into river basins, various point and diffuse pathways, as well as nutrient load in rivers, could be analysed. Despite seasonal variations and inputs of point sources (e.g. Wastewater Treatment Plant Darkhan) the nutrient concentrations in most of the subbasins are on a moderate level. This shows evidence for a nutrient limited ecosystem as well as dilution effects. However, in the middle and lower reaches heavy metal concentrations of arsenic and mercury, which are linked to mining activities in many cases, are a point of concern. Thus measures are necessary to protect the valuable chemical and ecological status of the Kharaa River and its tributaries. As a result of the growing economic pressure Mongolia will enhance the agricultural production by irrigation. Until 2015 about 60% of the agricultural land shall be irrigated. In addition the gold mining activities shall increase by 20% a year. Both sectors have a high demand for water quantity and quality. The model MONERIS allows the assessment of measures which are inevitable to protect the water quality under shrinking water availability.

Temperature modulated histamine-itch in lesional and nonlesional skin in atopic eczema - a combined psychophysical and neuroimaging study

BACKGROUND

Itch is the major symptom of many allergic diseases; yet it is still difficult to measure objectively. The aim of this study was to use an evaluated itch stimulus model in lesional (LS) and nonlesional (NLS) atopic eczema (AE) skin and to characterize cerebral responses using functional magnetic resonance imaging (fMRI).

METHODS

Thermal modulation was performed on a histamine stimulus in randomized order on LS or NLS in rapid alternating order from 32 degrees C (warm) to 25 degrees C (cold). Subjective itch ratings were recorded. Additionally, fMRI measurements were used to analyze the cerebral processing (n = 13). Healthy skin (HS) of age-matched volunteers served as control (n = 9).

RESULTS

Mean VAS itch intensity was significantly (P < 0.0001) higher during the relative cold [55.2 +/- 8.3% (LS); 48.6 +/- 8.2% (NLS)] compared to the relative warm blocks [36.0 +/- 7.3% (LS); 33.7 +/- 7.6% (NLS)]. Compared to HS, the itch response was delayed in LS and NLS. Itch intensity was perceived highest in LS, followed by NLS and HS. For NLS, fMRI revealed at the beginning of the itch provocation a cerebral deactivation pattern in itch processing structures (thalamus, prefrontal, cingulate, insular, somatosensory and motor cortex). During the course of stimulation, the cerebral deactivation was reduced with time and instead an activation of the basal ganglia occurred. In contrast LS showed an activation instead of deactivation pattern already at the beginning of the stimulation in the above mentioned structures.

CONCLUSIONS

Moderate short-term temperature modulation led to a reproducible, significant enhancement of histamine-induced itch with the strongest effect in LS. The differences in itch perception and itch kinetics between healthy volunteers and NLS in patients point towards an ongoing central inhibitory activity patients with AE, especially at the beginning of the itch provocation.

Common variants in FCER1A influence total serum IgE levels from cord blood up to six years of life

BACKGROUND

In a recent genome wide scan, a functional promoter variant (rs2251746) in the gene encoding the alpha chain of the high affinity receptor for immunoglobulin E (IgE) (FCER1A) was identified as major determinant of serum IgE levels.

OBJECTIVE

The aim of this study was to investigate the role of rs2251746 on total IgE levels measured at different stages of life from birth (cord blood) up to the age of 6 and to evaluate its interaction with the environmental influences in two German birth cohorts.

METHOD

Data from two German birth cohorts were analysed (n = 1043 for the LISA cohort and n = 1842 for the GINI cohort). In the studies, total serum IgE was measured from cord blood, and blood samples taken at the age of 2/3 and 6 years. In a subgroup of the LISA study, house dust samples were collected at age of 3 months and the amount of endotoxin was determined. Random effect models were used to analyse the longitudinal health outcomes.

RESULTS

In the two cohorts, the heterozygote and the rare homozygote of rs2251746 was consistently associated with lower total IgE levels from birth up to the age of 6 years with an allele-dose effect (P < 0.02 for blood samples taken at each time point in both cohorts). No interaction between the two FCER1A encoding gene and environmental exposures including endotoxin, worm infestation and day care centre attendance during early childhood were observed.

CONCLUSION

Common variants in FCER1A strongly influence basal IgE production independently from environmental stimuli. These effects can be observed already in cord blood pointing to altered gene expression in foetus.

Impact of urbanization on the proteome of birch pollen and its chemotactic activity on human granulocytes

BACKGROUND

Epidemiologic studies reveal a dramatic increase in allergies in the last decades. Air pollution is considered to be one of the factors responsible for this augmentation. The aim of this study was to analyze the impact of urbanization on birch pollen. The birch pollen proteome was investigated in order to identify differences in protein abundance between pollen from rural and urban areas. The allergenicity of birch pollen from both areas was evaluated by assessing its chemotactic potency as well as its protein and allergen contents.

METHODS

Difference gel electrophoresis (DIGE) was used to analyze the pollen proteome. The chemotactic activity of aqueous pollen extracts was determined by migration assays of human neutrophils.

RESULTS

DIGE revealed 26 differences in protein spot intensity between pollen from urban and rural areas. One of these proteins was identified by de novo sequencing as the 14-3-3 protein, which resembles a stress-induced factor in other plant species. Furthermore, extracts from pollen collected in urban areas had higher chemotactic activity on human neutrophils compared to pollen from rural sites.

CONCLUSIONS

The present study points to an impact of air pollution on allergen carrier proteome and release of chemotactic substances. The increment in proinflammatory substances such as pollen-associated lipid mediators might contribute to the described urban-rural gradient of allergy prevalence. Furthermore, our study suggests that allergenicity is determined by more than the sole allergen content.

[Sensitization to airborne ragweed pollen--a cause of allergic respiratory diseases in Germany?]

BACKGROUND AND OBJECTIVE

Allergic skin and respiratory diseases show a high prevalence in most industrial countries. In addition, during the last years ragweed colonization has increased in Europe. Ambrosia pollen ( AMBROSIA ARTEMISIIFOLIA L. - common ragweed) are highly allergenic. Due to the late flowering time (august/September) of ragweed this can result in increasing health threats for allergic populations. This is of particular importance for those who already are sensitive to some grass or tree pollen. These individuals can then suffer from allergies during nearly the whole year. The present study examined the prevalence of sensitization to ragweed in German children and possible health implications.

METHODS

Between 2004 and 2007 sera of 1323 10-years old children in Baden Württemberg were tested in-vitro for specific IgE-antibodies against common aeroallergens including ragweed pollen.

RESULTS

Specific IgE-antibodies to extracts of common ragweed pollen were present in 10 - 17 % of the tested sera depending on the year of investigation.

CONCLUSION

The determined specific IgE-antibodies may be the result of a direct sensitization to ragweed pollen or correspond to cross-reactivity to other plants of the asteraceae subfamily or some nutritional allergens. The detection of sensitization to ragweed pollen does not prove actual allergic disease. However, a ragweed derived allergy should be considered in the differential diagnosis when allergic symptoms are present in direct connection to the flowering-time of ragweed. Ragweed plants should be removed and the spread of the plant 'restricted', as experiences in other countries with already wide spreading show.

Serine protease inhibitor lymphoepithelial Kazal type-related inhibitor tends to be decreased in atopic dermatitis

BACKGROUND

A pathogenic role of serine protease inhibitor lymphoepithelial Kazal type-related inhibitor (LEKTI) in atopic dermatitis (AD) is currently in intense debate. Analyses of an association between genetic polymorphisms of SPINK5 and atopic diseases revealed contradictory results. Herein, we assessed the role of LEKTI in AD at an expressional and functional level.

METHODS

The expression of LEKTI and its inhibitory capacity was measured by real-time polymerase chain reaction and hydrolytic activity assay, respectively, in keratinocyte cell cultures of three AD patients in comparison to cultures of healthy individuals (5x) and Netherton (NS) patients (3x).

RESULTS

Expression of LEKTI was significantly decreased in AD vs. healthy volunteers. Due to reduced protease inhibition, trypsin-like hydrolytic activity in AD was slightly increased, although not significantly.

CONCLUSIONS

Even though the number of investigated subjects was small and hydrolytic activity was only slightly increased, the results denote that LEKTI might be diminished in AD. The study also disclosed the necessity of functional analyses in addition to genetic investigations to gain further and more detailed insights into the role of LEKTI in AD.

Ragweed sensitization in Europe - GA(2)LEN study suggests increasing prevalence

Ambrosia has now reached threshold for high prevalence allergen in Europe.