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The present study was designed to discriminate and analyze the presence of direct PMN chemotaxis and leucocyte-induced PMN chemotaxis in filter assay systems of PMN chemotaxis, namely the Wilkinson chamber and the Boyden chamber, which yield a more quantified information on leucocyte chemotaxis than filming of vital cells. The PMN chemotaxis was reduced by approximately 30–35 μm after incubation with vinblastine, 0.01, 0.10 and 1.00 μg/ml respectively, as measured by the leading front method in the Wilkinson chamber. This figure was thought to represent the contribution of the leucocyte-induced antitubulin-sensitive PMN chemotaxis to the casein-induced PMN chemotaxis under the experimental conditions prevailing. The remaining 60 μm antitubulin-insensitive PMN migration into the filter probably represented a combination of direct PMN chemotaxis and stimulated PMN random motility. Since the above-mentioned vinblastine inhibition of PMN chemotaxis was recorded in the absence of serum, complement factors included, the vinblastine-inhibited PMN chemotaxis was thought to be due to the release of a leucocyte-derived cytotaxin. The significance of incubation time and chemotactic parameters was further analyzed in the presence of serum in Boyden chambers, in the intercompartmental filters by means of PMN distribution curves and on the bottom filter by cell numbers. The antitubulin inhibition of PMN chemotaxis was evident in the intercompartmental filter during the initial period of incubation and later by cell counts on the bottom filter. These observations suggested that the antitubulin inhibition of PMN chemotaxis was due to antitubulin inhibition of the direction-finding in a minor proportion of fast-moving PMNs.

Background: Malassezia yeasts play a role in the pathogenesis of atopic eczema/dermatitis syndrome (AEDS). The revised genus Malassezia includes several species which all are natural habitants of the human skin. In this study, we evaluated the presence of immunoglobulin E (IgE) antibodies to different Malassezia spp. in AEDS patients to allow optimization of the characterization of the IgE antibody profile of IgE-associated AEDS. Methods: Ninety-six adult patients, with a clinical diagnosis of AEDS, were included in the study. Seventeen of the patients had IgE antibodies to M. sympodialis, ATCC 42132 (m70 ImmunoCAP, Pharmacia, Diagnostic AB, Uppsala, Sweden). The IgE antibodies to seven Malassezia spp. were measured and inhibition immunoblotting was performed to investigate whether M. sympodialis contains all the allergen components present in the other Malassezia spp. Results: Twenty per cent of 79 AEDS patients with a negative m70 ImmunoCAP test had IgE antibodies to at least one of the other six Malassezia spp. tested. Our inhibition studies indicated that Malassezia spp. to a great extent, share allergenic determinants. However, Malassezia species also contained species-specific allergens. Conclusion: The use of only one species of Malassezia is not sufficient to detect all patients IgE sensitized to Malassezia. To obtain an optimal allergen preparation both common allergenic components as well as species-specific allergens have to be considered.

There have been contradictory reports on the shift in the T-cell cytokine expression pattern of peripheral blood mononuclear cells from patients with atopic dermatitis (AD); more specifically the interleukin (IL)-4 and interferon (IFN)-gamma profiles. The aim of this study was to shed further light on this contradiction by measuring the intracellular cytokines IL-4 and IFN-gamma by flow cytometry on unseparated whole blood to obtain results that, as accurately as possible, reflect the situation in circulating cells in vivo. The patient group including 64 patients with AD was compared with 18 nonatopic healthy adults. The results showed that the percentage of CD4+ T cells expressing IFN-gamma was significantly decreased (P < or = 0.001), as well as the percentage expressing IL-4 (P < 0.05) in AD patients compared with healthy controls. Furthermore, in supernatants from whole blood samples stimulated with phorbol 12-myristate 13-acetate and ionomycin, production of IFN-gamma was significantly decreased, while IL-4 production remained unchanged in AD patients compared with healthy controls. We also investigated if there was a relationship between serum IgE level and Phadiatop, a screening test for atopy, vs. the levels of IL-4 and IFN-gamma, but found no correlation with either. However, there was a significant correlation between disease severity and the level of total IgE (r = 0.67, P < 0.05). In conclusion, our results support the evidence for a decreased ability of peripheral CD4+ T cells to produce IFN-gamma among AD patients.