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Notes: Background Diagnostic procedures using natural extracts show only limited quantitative correlation between in vivo and in vitro results. Highly pure recombinant allergens might show more predictive findings.Objective The aim of this study was to compare natural birch pollen extract (BPE) and recombinant Betula verrucosa (rBet v 1) for their diagnostic value comparing skin prick tests (SPTS) and nasal provocation tests (NPTS) with specific IgE in the serum.Methods Thirty-four patients allergic to birch pollen and five healthy controls were investigated. SPT and NPT were performed with BPE and rBet v 1 at different concentrations. Specific serum IgE was measured by the Pharmacia CAP system.〈section xml:id="abs1-2"〉〈title type="main"〉Results Commercial BPE and rBet v 1 (10 μg/mL) were able to elicit similar allergenic reactions in vivo and IgE binding in vitro. SPT reflects immediate-type allergy as determined by NPT to a higher degree than specific IgE, for both reagents. To cause allergic reactions in NPT, higher amounts of rBet v 1 were needed than for skin tests and the sensitivity was lower than with BPE.〈section xml:id="abs1-3"〉〈title type="main"〉Conclusion rBet v 1 alone is sufficient for a reliable diagnosis of birch pollen allergy in most patients and induces comparable skin test reactivity as BPE, but less allergic reactions in nasal provocations.

Notes: Background In diagnosis of type I allergy recombinant allergens have potential advantages over conventional allergenic extracts, both regarding specificity and reproducibility.Objectives We therefore decided to study honey bee venom (BV) and its major allergen phospholipase A2 (PLA) in native and recombinant form for diagnosis of bee sting allergy.Method We investigated 85 patients with a history of a recent systemic allergic bee sting reaction and positive intracutaneous skin test to BV, and 21 controls with no history of allergic bee sting reaction and negative skin test to BV. Intracutaneous skin tests and determination of specific IgE by ImmunoCAPR to BV, native PLA (nPLA) and recomhinant PLA (rPLA) were done in all patients and controls.Results In skin testing 84 (99%) of the 85 patients reacted to nPLA and 81 (95%) to rPLA, while none of the 21 controls was positive with nPLA or rPLA. Specific serum IgE to BV could be detected in 82 of the patients (96%), to nPLA in 73 (86%) and to rPLA in 66 (78%). Four (19%) of the controls had a positive CAP to BV, one (4.8%) to nPLA and none to rPLA. Analysis of discordant results in CAP showed, that most patients with specific IgE to BV, but not to nPLA and rPLA, had positive skin tests to both PLA preparations and low levels of BV specific IgE. Patients with specific IgE to nPLA but not to rPLA were usually sensitized to minor allergens of BV which contaminated the commercial nPLA.Conclusions PLA is the major allergen in BV. While diagnostic tests with BV are more sensitive, the specificity of tests with PLA, especially rPLA is clearly increased as compared with BV.

Notes: Background The synthesis of IgE is regulated by cytokines secreted from T-helper cells. The studies on cytokine secretion by peripheral blood mononuclear cells (PBMC) upon stimulation with antigen or allergen are ditficult due to low levels of cytokines, especially of inlerieukin-4 (IL-4).Objective ln this study we tried lo establish a culture system, which could enable the measurement of the cytokine profiles in specifically activated cultures.Methods Three methods to potentiate cytokine secretion were evaluated: PBMC from bee venom or house dust mite (Dermatophagoides pteronyssinus) allergic patients as well as normal subjects were stimulated either with the major bee venom allergen phosphoiipase A2 (PLA) or with the major D. pteronyssinus allergen (Der p 1) or with the control antigens tetanus toxoid (TT) and purified protein derivate (PPD). After 7 days of culture the cells were restimulated either wilh pkistie bound 0KT3 F(ab)2 monoclonal antibodies (MoAbs), with the appropriate antigen + antigen presenting cells or with IL-2. The secretion of cylokines (IL-4, IFNγ) was measured after restimulation of the cultures (day 8).Results While OKT3 F(ab)2 was unable lo activate resting T cells, it could restimulate preactivaled cells. Restimulalion with OKT3 F(ab)2 induced higher IL-4 and IFN7 secretion than restimulation with IL-2 or antigen. TT and PLA stimulated a similar cytokine secretion prolile in normal and PLA allergic subjects with substantial levels of both lL-4 and IFNγ. In contrast, PPD induced virtually only IFNγ secretion. Der p 1 stimulated mainly IL-4 seerclion but also IFNγ production in some mite allergic palienis.Conclusion We have established a cell culture system, which combines antigen specificity with a strong cytokine inducing signial provided by anti-CD3 MoAbs. TH-1 and TH-2 characteristic cytokine patterns can be observed in short-term PBMC cultures already after 8 days of culture.

Notes: Background We report the results of a study comparing the recombinant Aspergiilus fumigatus allergen I (rAsp f I) to commercial A. jumigatus extracts in serological assays, Pharmacia CAP System and skin tests.Objective The study was designed to test the feasibility of using recombinant allergens in an automated serology system for determination of allergen-specific IgE.Methods Patients with allergic bronchopulmonary aspergillosis (ABPA), asthmatics with A. fumigatus allergy and control subjects, who included allergic asthmatics without allergy to A. fumigatus and healthy subjects, were investigated. All subjects were characterized with respect to their total IgE level, radio allergosorbent test to A. fumigatus and skin test reactivity to both commercial A. fumigatus extracts and recombinant rAsp f I protein.Results All patients with ABPA (n = 30) showed positive skin test reactions with commercial A. fumigatus extracts, and 24 were sensitized to r Asp f I by the same criterion. The 10 patients with asthma and A. fumigatus allergy showed positive skin reactions to at least one commercial extract, and five reacted to r Asp f I. AU control subjects (H= 19) scored negatively in skin tests to A. fumigatus extracts and r Asp f I, and showed no detectable rAsp f I-specific IgE. ImmunoCAP carrying immobilized r Asp f I were evaluated using sera from all individuals described and the results compared with those obtained with the r Asp f I-specific ELISA for IgE. The data obtained with the two r Asp f I-specific detection systems correlated closely (r= 0.997) and were in perfect agreement with the skin test results.Conclusion The data show that r Asp f I can be used as immobilized allergen in the Pharmacia CAP System indicating the feasibility of using recombinant allergens for an automated serological diagnosis of allergic diseases. However, every recombinant allergen needs to be evaluated individually for its performance if applied to a new diagnostic technology.

Notes: In the first part of this study peripheral blood lymphocyte subpopulations. Iheir activation slate and various serum parameters were measured in extrinsic and intrinsic atopic dermatitis (AD) patients compared to normal individuals. Beside the characteristic eosinophilia, significantly increased numbers of CD4+ T cells with increased expression of IL-2 receptors (IL-2R) and HLA-DR were noted in the AD patients. In addition, extrinsic AD patients showed increased numbers of CD23+ B cells and decreased numbers of CD16+ natural killer cells. Moreover, increased serum levels of eosinophil canonic protein (ECP) and soluble 1L-2R as well as soluble factors lhat prolong survival of eosinophils in vitro could be demonstrated. In the second section of this study we determine how these blood immunological parameters relate to the clinical severity of the skin lesions of AD, by weekly analysis of 12 AD patients attending a high altitude clinic for 3 to 6 weeks. The patients were divided into two groups on the basis of treatment with topical steroids, but during the observation period a significant improvement in clinical status was observed in all AD patients independent of topical steroid therapy. A progressive decrease in eosinophil and activated T cell numbers. soluble IL-2R levels and serum eosinophil survival prolonging activity could be demonstrated, which closely correlated with the clinical severity of the AD.

Notes: Background Priming of eosinophils with granulocyte-macrophage colony-stimulating factor (GM-CSF) and subsequent stimulation with platelet-activating factor (PAF) or the anaphylatoxin C5a is associated with a rapid production of leukotrienes (LTs) and release of eosinophil cationic protein (ECP).Objective This study was designed to determine the effects of the sesquiterpene esters petasin, isopetasin and neopetasin on LT generation and ECP release in eosinophils in vitro.Methods The model of eosinophil activation described above was used to induce LT production and ECP release. Cells were incubated with petasins and control inhibitors prior to priming and stimulation. To analyse intracellular steps of eosinophil activation and determine potential drug targets, some key signalling events were studied. Activity of cytosolic phospholipase A2 (cPLA2) was measured by analysing the generation of arachidonic acid (AA). Translocation of 5-lipoxygenase (5-LO) was observed using immunofluorescence microscopy. Intracellular calcium concentrations [Ca2+]i were measured by a bulk spectrofluorometric assay.Results Whereas all three compounds inhibited LT synthesis, ECP release from eosinophils was blocked by petasin only, but not isopetasin or neopetasin. Similarly, PAF- or C5a-induced increases in [Ca2+]i were completely abrogated by petasin only, whereas isopetasin and neopetasin had significant lower blocking efficacy. Moreover, only petasin, but not isopetasin or neopetasin, prevented increases in cPLA2 activity and 5-LO translocation from the cytosolic compartment to the nucleus envelope in calcium ionophore-stimulated eosinophils.Conclusion These data suggest that different petasins may at least partially block different intracellular signalling molecules. To reduce LT synthesis, isopetasin and neopetasin may act at the level of or distal to 5-LO. In contrast, petasin may inhibit inflammatory effector functions in human eosinophils by disrupting signalling events at the level of or proximal to phospholipase Cβ (PLCβ), besides its potential inhibitory activity within mitogen-activated protein kinase (MAPK) and LT pathways.

Notes: Background For many years, fungal spores have been recognized as potential causes of respiratory allergies. All fungal allergens cloned so far represent either secreted or cytoplasmatic proteins, but nothing is known about the involvement of fungal surface proteins in allergic diseases.Methods A phage surface displayed cDNA-library from the mould Cladosporium herbarum was constructed and phage displaying IgE-binding proteins were selectively enriched with immobilized serum IgE from C. herbarum-sensitized individuals. Inserts encoding putative allergens were sequenced, subcloned and used to produce recombinant proteins. Allergenicity of the proteins was evaluated by IgE binding in Western blots, enzyme-linked immunosorbent assay (ELISA) and skin prick test in a total of 84 patients sensitized to either C. herbarum or Aspergillus fumigatus and three healthy controls.Results After four rounds of affinity selection, the cDNA-library was enriched for clones displaying IgE-binding molecules. Sequencing of inserts showed that one clone contained an open reading frame predicting a protein of 105 amino acids and a calculated molecular weight of 10.5 kDa showing the classical signature of members of the hydrophobin family. The recombinant protein, termed HCh-1, was able to bind IgE from six patients sensitized to fungi in vitro. Two of those patients were also included in a skin prick test survey and showed strong type I skin reactions to HCh-1, demonstrating the allergenic nature of C. herbarum hydrophobin and indicating a prevalence of sensitization in the range of 8–9%. In contrast, the hydrophobin HYP1 from Aspergillus fumigatus was not recognized by the sera of the same patients and controls investigated with HCh-1.Conclusion C. herbarum hydrophobin represents the first component of the cell wall of fungi demonstrated to act as a rare but clinically relevant allergen in vitro and in vivo.

Notes: Age-related changes in antibody response and tolerance inducibility are polymorphic; in this paper isotype changes in ageing C57BL/6 mice are examined Female C57BL/6 mice of various ages were immunized with either heat-aggregated RGG (a-RGG) or phosphorylcholine conjugate of RGG (PC-RGG); other animals of the same ages were given aggregate free RGG, followed by injections with either aggregated RGG or haptenated RGG. Sera from these four groups were analysed for antibody isotype. The data presented here indicate that age-related changes in isotype predominance and magnitude are different for different determinants. The capacity to be down-regulated appeared to undergo different age-related changes with different isotypes: there is split tolerance in isotypes. Age-dependent changes in T- and B-cell tolerance could be deduced by comparing responses of animals to hapten and to carrier determinants. In 5-week-old animals tolerance to hapten was more profound than tolerance to carrier. It was concluded that T-cell regulation dominated the response at this age. With advancing age, i.e. by 95 weeks, tolerance is observed in response to hapten but not in response to carrier determinants. We concluded that suppressor cells were induced by aggregate free RGG and affected the response of ‘naive’ but not of ‘experienced’ B cells.

Notes: Difficult-to-treat asthma (DTA) represents a heterogeneous subgroup of asthma. Up to now, the lack of specific diagnosis not only complicates appropriate specification and control of asthma, but also makes targeted research difficult. The aim of this study is to categorize this heterogeneous group of DTA patients (n = 27; referring to the GINA guidelines) based on the distinct leucocyte redistribution (LR) after glucocorticoid (GC) treatment. Furthermore, the effect of adjuvant therapies was investigated for its impact on LR. The frequency of CD3+, CD4+, CD8+, CD14+, CD19+ and NK cells was analysed in peripheral blood before and 3 h after systemic GC treatment, along with the markers of activation HLA-DR and CD25. Within 3 h of GC administration, a significant average decrease of 16% in CD3+CD4+ (P ≤ 0.001) and a 12% increase in NK-cell frequency (P ≤ 0.001) clearly distinguished two groups of patients: LR-responsive and LR-unresponsive patients. The CD3+CD8+ T-cell number and activation marker remained unchanged. Patients who received adjuvant therapy, such as methotrexate or interferon-α, because of poor clinical response to GC showed an LR similar to that showed by responsive patients. DTA patients comprise at least two immunologically distinct groups: patients showing an immediate decrease in CD3+CD4+ T cells and an increase in NK cells following GC administration and patients lacking an immediate change. Analysis of LR not only may allow the identification of immunologic steroid resistance, but also may be of value for immunologic determination of effective steroid doses.