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ABSTRACT: Previous studies have demonstrated the presence of grass pollen-specific T cells in grass pollen-allergic patients (GPA) as well as nonallergic subjects (NA). In order to elucidate a possible seasonal variation in proliferation and cytokine production of peripheral blood mononuclear cells (PBMC), PBMC from 13 GPA and 11 NA were stimulated with extracts of Phleum pratense and tetanus toxoid before and during two grass pollen seasons. IL-4, IL-5 and interferon-gamma were determined by ELISAs. PBMC from GPA demonstrated a decreased proliferative response to grass pollen allergens during the pollen season as compared to NA (p < 0.05), but no difference was found in the response to tetanus toxoid. Cells from GPA produced higher amounts of IL-4 and IL-5 than NA (p < 0.05) and the seasonal variation in GPA proliferation was paralleled by the grass pollen-induced production of both IL-4 and IL-5 (p < 0.05). We conclude that during the grass pollen season PBMC from GPA have a reduced ability to proliferate and to produce Th2-type cytokines. This may be due to seasonal migration of the grass pollen-specific T cells from the blood to the tissues of primary allergen exposure.
Experimental and Clinical Immunogenetics 02/1998; 15(3):144-53.
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ABSTRACT: Our investigation aimed to produce and characterize a kiwi extract and to use this extract to investigate a possible cross-reactivity with birch pollen. Kiwi was extracted in two buffers: phosphate-buffered saline (PBS) and borate-buffered saline (BBS). Extraction in BBS produced a double amount of protein, and a more stabile extract. Tandem crossed-immunoelectrophoresis showed that the BBS and PBS extracts had several common, but also a few individual, proteins. The mixture of both extracts was assumed to represent the most complete allergen extract. The allergenic properties of the kiwi extract were investigated by immunoblotting (IB), RAST, and histamine-release (HR) test in 15 birch-pollen-allergic patients (eight of them with clinical kiwi allergy) and one with clinical monoallergy to kiwi. All eight birch-pollen-allergic patients with kiwi allergy and the kiwi-monoallergic patient were positive in kiwi IB binding most frequently to proteins of 10-12 and 20-25 kDa. With our extract, RAST was positive in four kiwi-allergic and one non-kiwi-allergic patient, whereas the HR test was positive in five kiwi-allergic patients and negative in all non-kiwi-allergic patients. RAST and IB inhibition demonstrated cross-reactivity between birch-pollen and kiwi allergens due to a 10-12 kDa protein. In conclusion, a kiwi extract with allergenic properties was produced, and, by the methods used, cross-reactivity was demonstrated between birch-pollen and kiwi allergens.
Allergy 03/1997; 52(2):136-43. · 6.27 Impact Factor
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ABSTRACT: Specific immunotherapy treatment in allergic diseases involves a risk of systemic side effects. A double-blind, placebo-controlled study was performed in 45 patients allergic to pollen to determine whether pretreatment with loratadine could reduce the number and severity of systemic reactions during the dose-increase phase of cluster immunotherapy.
The patients received cluster immunotherapy with a standardized birch (Betula verrucosa) or grass (Phleum pratense) pollen extract adsorbed to aluminum hydroxide. The immunotherapy schedule involved seven visits and 14 injections to reach a maintenance dose of 100,000 standardized quality units. Loratadine, 10 mg, or placebo tablets were administered 2 hours before the first injection at each visit.
A total of 720 injections were given (309 injections in 21 patients receiving loratadine and 411 injections in 24 patients receiving placebo). The median numbers of injections to reach maintenance dose were 15 (range, 14 to 18) in the loratadine group and 16 (range, 14 to 23) in the placebo group (p = 0.037). The numbers of patients with systemic reactions were seven (33%) and 19 (79%) in the loratadine and placebo groups, respectively (p = 0.002). Twenty-five reductions caused by systemic reactions were observed in the placebo group in contrast to nine in the loratadine group (p = 0.047). No life-threatening systemic reactions were observed in either group. Systemic reactions were, however, more severe in the placebo group, mainly because of a significantly higher incidence of urticaria (10 vs 1, p = 0.022).
Pretreatment with loratadine seems to reduce both the number and severity of systemic reactions in specific cluster immunotherapy.
Journal of Allergy and Clinical Immunology 07/1996; 97(6):1207-13. · 11.00 Impact Factor
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ABSTRACT: In a placebo-controlled, randomized, and double-blind 1-day field study, the efficacy and onset of action of capsule acrivastine 8 mg were evaluated in 42 patients suffering from allergic rhinoconjunctivitis elicited by natural grass pollen exposure. Before and for 2 h after treatment, the patients scored the severity of five rhinoconjunctivitis symptoms every 10 min on a 0-5 scale (0 = no symptoms; 5 = very severe symptoms). The number of sneezes was recorded, and every 30 min, measurements of nasal peak flow were made. Before treatment, there was no difference in median total symptom score (mTSS) between the acrivastine group (A) and the placebo group (P) (12 and 12, respectively). Time of onset was estimated by an exponential decay model to be 19 min (95% confidence interval 0-39 min). A statistically significant difference in percent reduction of mTSS between A and P was observed for the first time 46 min after treatment start (A = 22%, P = 0%, P < 0.05). A 50% reduction in total symptom score (TSS) was achieved within 60 min by 38% in A and 17% in P (NS), and within 80 min in 52% and 17%, respectively (P < 0.05). The median time for 50% reduction in TSS (MT50) was 80 min for A and > 120 min for P (P < 0.01). The symptom score of sneezing and number of sneezes were evaluated for periods of 30 min. The difference between A and P became statistically significant from 31-60 and 61-90 min, respectively (P < 0.05 and P < 0.01). Objective and subjective determinants in the different time intervals were well correlated. Improvement of nasal congestion was observed in A at 91-120 min, as measured by nasal peak flow.
Allergy 10/1994; 49(8):630-6. · 6.27 Impact Factor
