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It is not known to what extent intravascular phenotypic alterations in adhesion molecule expression induced by hemodialysis influence the recruitment of granulocytes and their ability to up-regulate CD11b at the local site of inflammation in the interstitium. We used a skin suction chamber technique to address this issue. Two skin blisters were raised on the forearm of eight hemodialysis patients and eight healthy subjects, and blister exudate was collected (time 0). The two blisters were stimulated with buffer (intermediate inflammation) or autologous serum (intense inflammation). Then the patients underwent cuprophane hemodialysis for 4 hours. Ten hours after start of dialysis, the exudate was aspirated from each chamber. Granulocyte count and surface expression of CD11b and CD62L were analyzed in samples from peripheral blood and blister exudate by flow cytometry. Granulocytes from healthy blood donors were incubated in blister fluid from patients and healthy subjects to determine the local chemotactic activity in terms of CD11b up-regulation. The expression of CD11b increased fourfold and CD62L decreased simultaneously in patients and healthy subjects when cells transmigrated to the unstimulated blister at time 0. At the site of intermediate inflammation, granulocytes from patients had a significantly lower capacity to mobilize CD11b compared with cells from healthy subjects (P < 0.001). At the site of intense interstitial inflammation, granulocytes from patients had the capacity to mobilize the receptor and reached values close to those obtained in healthy subjects (P = 0.079). The blister exudate from patients had a similar (at time 0 and intermediate inflammation) or higher (intense inflammation; P < 0.05) capacity to up-regulate CD11b on granulocytes in vitro compared with blister exudate from healthy subjects. Granulocytes from hemodialysis patients seem to require a more intense chemotactic stimulus to up-regulate CD11b at the local site of inflammation in the interstitium compared with corresponding cells from healthy subjects despite the fact that cells transmigrate in a milieu that contains chemotactic factors with an equal or higher capacity to up-regulate CD11b. Granulocytes in hemodialysis patients seem to be more refractory to inflammatory stimuli in the interstitium.

Background: Nearly 60% of birch pollen–allergic patients react exclusively to Bet v 1. With use of the skin blister model, previously only established for installation of crude allergens, we have for the first time characterized the inflammatory response in vivo to recombinant birch pollen allergen, rBet v 1, molecules (rBet v 1 wild type, fragments and trimer). Objective: Our purpose was to examine whether challenge with rBet v 1 derivatives (fragments and trimer) compared with rBet v 1 wild type differs with respect to influx of activated eosinophils and detectable levels of cytokines/chemokines related to allergic inflammation in skin chambers applied to birch pollen–allergic patients. Methods: The skin blister chambers were filled for 2 hours with rBet v 1, the derivatives or PBS and heparin (negative control). The fluids were analyzed after 2 and 8 hours. The number of eosinophils was determined and EG2 and CD69 expression measured by flow cytometry. Cytokines and mediators were analyzed by ELISA and RIA techniques. Results: Comparable numbers of eosinophils were recruited to the chambers challenged with rBet v 1 molecules, but the eosinophils from the rBet v 1 wild-type challenged chambers showed a significantly higher expression of CD69. The levels of eotaxin were similar in all 4 chambers, whereas rBet v 1 wild type induced significantly higher levels of histamine, eosinophil cationic protein, and GM-CSF than the derivatives did. Recombinant Bet v 1 trimer elicited significantly lower levels of IL-4 compared with rBet v1 wild type. Conclusion: Genetically engineered hypoallergenic rBet v 1 derivatives recruited eosinophils analogously with rBet v 1 wild type. However, the derivatives exhibited a lower capacity to activate eosinophils and to release proinflammatory mediators and T helper type 2–derived cytokines. The derivatives may therefore be candidate molecules for specific immunotherapy of birch pollen allergy with reduced risk of inducing allergenic or inflammatory side effects. (J Allergy Clin Immunol 2000;106:101-9.)

Dysregulation of cytokine production in atopic individuals has previously been clearly demonstrated. In the present study we aimed to assess whether a prolonged in vitro exposure of peripheral blood lymphocytes (PBMC) to allergen would result in a, by time, changed cytokine profile in allergic subjects. Blood was taken from 11 atopic asthmatic subjects and nine healthy non-atopic controls during the birch pollen season. PBMC were stimulated with birch pollen allergen (100, 1000 and 10,000 SQ-U/ml). After different times of exposure (1, 3 and 5 weeks) interleukin (IL)-5 and interferon-gamma (IFN-gamma) production was measured. Prior to the IL5 and IFN-gamma determinations, PHA was added to the cultures to ensure maximal release of cytokines. The asthmatic group always displayed a lower IFN-gamma:IL-5 ratio. Significant differences in ratio between the two groups were observed. Furthermore, PBMC challenged in vitro with 10,000 SQ-U/ml resulted in significantly elevated levels of IL-5 in the asthmatic group compared to the control group when determined after 3 and 5 weeks stimulation. In the asthmatic group the balance between IL-5 and IFN-gamma is shifted towards increased IL-5 production following prolonged in vitro stimulation. This might illustrate the in vivo situation, where an increased IL-5 production is of importance in the pathogenesis of asthma.

Background: Microvascular-epithelial exudation of bulk plasma may characterize inflammatory airway diseases. This study compares the acute allergen challenge–induced mast cell and exudative responses in nasal and bronchial airways. The focus is on α 2 -macroglobulin as an index of luminal entry of plasma exudates. Methods: Separate nasal and bronchial allergen challenges were carried out outside the pollen season in eight patients with pollen-induced seasonal allergic rhinitis. The levels of different-sized plasma proteins (albumin molecular weight, 66,000 d and α 2 -macroglobulin molecular weight, 725,000 d) and tryptase were determined in pre- and postchallenge nasal lavage and bronchoalveolar lavage (BAL) fluids. Diluent and increasing doses of allergen were sprayed into the right nasal cavity, and each challenge was followed by a nasal lavage (volume, 15 ml) with a "nasal pool" device (recovery, >80%). Endobronchial allergen challenge (individual doses) and BAL (volume, 2 × 25 ml) were performed in a lobe bronchus through a fiberoptic bronchoscope (recovery, 30%). Saline challenge and BAL were carried out in the contralateral lung as control. Results: The levels of albumin, α 2 -macroglobulin, and tryptase increased dose-dependently in postchallenge nasal lavage fluids ( p 2 -macroglobulin correlated ( r = 0.98, p 2 -macroglobulin and tryptase, but not albumin, were increased in BAL fluids from the allergen-challenged side ( p Conclusion: Local allergen challenge causes luminal entry of tryptase and α 2 -macroglobulin in the nose and bronchi of patients with allergy. We suggest that mast cell and plasma exudation responses may be similar in human nasal and bronchial airways and that albumin levels (in BAL fluids) may not well reflect the exudation process in bronchial airways. (J ALLERGY CLIN IMMUNOL 1995;96:239-46.)