Expression of CD35 (CR1) and CD11b (CR3) on circulating neutrophils and eosinophils from allergic asthmatic children

Complement receptors on neutrophils and eosinophils play a role in activation and adhesion. During asthmatic reactions these receptors have been found elevated on circulating granulocytes. In the present study we compared the expression of CD35 (complement receptor type 1) and CD11b (complement receptor type 3) on neutrophils and eosinophils from asthmatic and non-asthmatic children. This was done in whole blood samples using depolarized light scattering for the discrimination of neutrophils and eosinophils. The non-stimulated expression as well as the upregulated expression of receptors by the chemotactic peptide N-formylmethionyl-leucyl-phenyl-alanine (fMLP) were studied. The results showed that without prior stimulation only the expression of CD35 on neutrophils was significantly elevated in children with asthma (P<0.05). After up-regulation with fMLP, the CD11b expression on neutrophils (P<0.005, fMLP: 0.002 microM) and eosinophils (P<0.05, fMLP: 0.02 microM) was significantly higher in asthmatic children than in the controls. These results indicate that the inducible expression of CD11b on neutrophils and eosinophils from allergic asthmatic children is primed in vivo.     

Allergen challenge primes for IL-5 mRNA production and abrogates β-adrenergic function in peripheral blood T lymphocytes from asthmatics

BACKGROUND: In previous studies, we have found a dysfunctional adenylyl cyclase (AC) system in patients with asthma after allergen provocation, which resulted in a 40-50% decreased generation of intracellular cAMP. In addition, in activated T helper lymphocyte clones, it has been demonstrated that IFN-gamma (TH1-like cytokine) and IL-5 (TH2-like cytokine) are differentially regulated by the AC system. Therefore, we postulate that an increased IL-5/IFN-gamma ratio as observed in asthmatics might be due to a dysfunctional AC system. OBJECTIVE: To assess whether a dysfunctional AC system as observed in asthmatics after allergen provocation, is responsible for an increased IL-5/IFN-gamma cytokine ratio. METHODS: Peripheral blood T lymphocytes of seven asthma patients were stimulated with anti-CD3 plus anti-CD28 MoAbs in the absence and presence of isoproterenol (ISO) and prostaglandin E2 (PGE2) to activate the AC system. Before, 3 h and 24 h after allergen provocation, IFN-gamma and IL-5 mRNAs were detected by semiquantitative RT-PCR. RESULTS: Before allergen provocation, ISO (10-5 mol/L) significantly downregulated IFN-gamma mRNA (P < 0.03, n = 6), and showed a trend to upregulate IL-5 mRNA (P = 0.138, n = 5). Three and 24 h after allergen provocation, ISO was not longer able to modulate IFN-gamma and IL-5. In contrast with the observations with ISO, PGE2 still dose-dependently inhibited IFN-gamma mRNA, both before, 3 h and 24 h after allergen provocation (n = 7). IL-5 mRNA, but not IFN-gamma mRNA, was significantly upregulated in anti-CD3 plus anti-CD28-activated T cells (P < 0.05, n = 5) 24 h after allergen provocation, compared with before allergen provocation. CONCLUSION: Twenty-four hours after allergen provocation, a significant reduction of beta-adrenergic control on IFN-gamma and IL-5 mRNA expression was observed in peripheral blood T lymphocytes, which coincides with a selective priming of IL-5 mRNA production.     

Allergen extracts. Standardization of preparations for bronchial provocation tests. A position paper

Standardization of allergen provocation tests of the airways requires standardization of each of the steps involved, including standardization of the extracts used. The value of international standards is emphasized and so is the determination of a clinically relevant potency. The allergen extracts used for bronchial provocation tests must be compared with qualitatively and quantitatively clinically relevant standards using complementary immunochemical and biological methods. Ideally the same extracts should be used for diagnosis (skin test, specific IgE determinations, provocations) and treatment (immuno-therapy). The importance of the biological compared with the non-biological methods is that the biological methods are established in allergenic patients in order to select a clinically relevant potency of the allergen in question, and this potency ought to be confirmed in clinical trials. Once established the biological potency of an in-house preparation can be reproduced by supplementary in vitro methods. Very few commercial allergen preparations are available which fulfil the above-mentioned criteria.     

Long-term follow-up of indolent mastocytosis in adults

Objective. To evaluate the natural course of indolent mastocytosis in adults. Design. A retrospective long-term follow-up study. Setting. The Department of Endocrinology of a University Hospital. Patients. Sixteen adult patients with a diagnosis of indolent mastocytosis and sufficient biochemical data for statistical analysis. One patient had paediatric-onset cutaneous mastocytosis, whilst the others had adult-onset systemic mastocytosis. Ages at the end of follow-up ranged from 23 to 79, median 50 years. Follow-up periods per patient lasted from 13 to 135 months, median 90 months. Measurements. Urinary excretions of the histamine metabolites N^τ-methylhistamine (MH) and N^τ-methylimidazoleacetic acid (MIMA), and signs and symptoms of the disease. Results. The excretion of MH but not MIMA increased in four patients (ages 37, 45, 61 and 65 years) and decreased in two patients (ages 26 and 48 years), including the only patient with paediatric-onset cutaneous mastocytosis. The excretion of MIMA but not MH increased in none and decreased in one patients (age 51 years). The excretions of both MH and MIMA increased in one patient (age 23 years) and decreased in two patients (ages 65 and 79 years). The excretion of MH and MIMA can be considered to have been stable in one patient (age 49 years). In the five remaining patients, observation periods were rather short. A definite judgement on the course of their disease could not be given. In the two patients in whom the excretion of both MH and MIMA decreased, the enlarged spleen decreased in size, whilst in the other patients, signs and symptoms did not change. There were no accompanying myeloproliferative disorders in any patient. No special treatment aiming at a reduction in mast cell load has been given. Rates of change over the whole follow-up period ranged from -8.4 to +25.1% per year. Conclusion. The natural course of indolent adult-onset mastocytosis is not always progressive. Our data show that the activity of adult-onset indolent mastocytosis, as measured by urinary excretion of MH and MIMA and clinical signs and symptoms, can substantially decline, especially in older patients.     

Anaphylactoid shock following Hymenoptera sting as a presenting symptom of systemic mastocytosis

Abstract. Systemic mastocytosis is a rare and chronic disorder characterized by a pathologically increased number of mast cells in various tissues and overproduction of mast cell mediators. From a group of 15 patients (10 females. 5 males) with systemic mastocytosis five female patients presented with a history of an anaphylactoid shock reaction to wasp sting. Three of them had no demonstrable specific IgE against wasp or bee venom in serum, and a skin test that was only weakly positive for wasp venom. One patient had specific IgE against wasp venom and a clearly positive skin test to wasp venom. The other patient had specific IgE against both wasp and bee venom and a skin test that was only weakly positive to wasp venom. Two patients had to stop a hyposensitization procedure because of systemic side effects. The five patients did not differ from the other patients with systemic mastocytosis with regard to either clinical symptoms and signs or urinary excretion of histamine metabolites. From the latter group two female and three male patients said they had been stung by a wasp in the past. Thus, anaphylactoid shock after Hymenoptera sting can be a presenting symptom of systemic mastocytosis and may be caused by an IgE-as well as a non-IgE-mediated mechanism. In cases of anaphylactoid reaction to Hymenoptera sting, especially when there is no IgE demonstrable in serum or in cases of intolerance of hyposensitization, the diagnosis of systemic mastocytosis should be considered, also in the absence of the clinical hallmarks of urticaria pigmentosa.     

Determination of the stability of diluted allergen extracts using a concentration step prior to EAST inhibition

Background Generally the stability of diluted allergen extracts, as used for skin testing, provocation testing und immunotherapy can not be tneasured using a normal enzyme allergosorbent test (EAST) inhibition method. Objective The aim of this study was to determine the stability of diluted allergen extracts using an ultrafiltration step prior to the standard EAST inhibition procedure, in which the allergen extract was concentrated 100-fold. Methods This eoncentration procedure was validated for Dermatophagoides pteronyssinus, timothy pollen, birch pollen and cat dander extraets and used in a stability study in which three batches were stored for 1 year al 6° C and 25° C. Results There was no difference in relative potency before and after concentration of birch and timothy pollen extracts. D. pteronyssinus and cat dander extracts showed a significant decrease of 25% and 35% of the relative potency after concentration. The mean coeffieient of variation of 12 determinations of the stability study was 11.8%. Conclusion For all allergens the 30BU/mL or approximately 0.00025 mg/mL solution was stable for 12 months at both temperatures, except for D. pteronyssinus which declined rapidly at 25°C.     

Plasma histamine concentrations and complement activation during house dust mite-provoked bronchia] obstructive reactions

Lung function and histamine levels in peripheral venous plasma samples were followed after challenge with house dust mite allergen. In eight patients the mean maximal histamine concentration showed a significant rise during the early obstructive reaction when compared with the concentrations at similar time intervals after inhalation of a control solution. In nine other patients treatment with disodium cromoglycate (DSCG) caused a significant fall in plasma histamine concentrations indicating that histamine liberation plays u role during the early obstructive reaction and was released from the lung compartment. Histamine during early obstructive reactions compared with the pre-inhalation values did show a rise in mean maximal histamine concentration (1.5-4.1 ng/ml) but this was statistically not significant. During the late reaction neither significant increase in histamine nor inhibition by DSCG was found. Measurement of complement degradation products did not support the role of complement activation during cither early or lute bronchial obstructive reactions.     

Cutaneous reactions to captopril

Cutaneous reactions associated with captopril treatment occurred in fifteen out of eighty-nine patients (17%). Dose reduction invariably led to improvement of the reaction but later recurrences were frequent (six patients). In four out of the fifteen patients captopril withdrawal ultimately was necessary. Skin tests and in vitro lymphocyte transformation tests with captopril were performed in these fifteen patients and also in nine captopril-treated control patients without adverse reactions. Positive epicutaneous skin tests were observed in five out of the fifteen patients including the four in whom captopril had to be withdrawn, but in none of the controls. Intracutaneous skin tests were positive in ten of the patients with cutaneous reactions and in two control patients. Captopril-induced in vitro lymphocyte transformation occurred in most patients with cutaneous reactions whereas in control patients captopril suppressed the in vitro lymphocyte proliferative response. Skin biopsies revealed histologic changes consistent with lymphocytic vasculitis. We conclude that epicutaneous skin tests with captopril are helpful in predicting the necessity of captopril withdrawal.