A new variant of the basophil activation test for allergen-induced basophil CD63 upregulation. The effect of cetirizine.

OBJECTIVE: The aim of our study was to determine the diagnostic usefulness of a newly developed basophil activation test (BAT) in patients allergic to Dermatophagoides pteronyssinus and pollens. We also analyzed the influence of cetirizine on CD63 upregulation. This popular antihistamine strongly inhibits skin tests, but its impact on BAT sensitivity remains unknown and deserves at least preliminary determination. METHODS: The study sample comprised 22 patients allergic to house dust mite and pollens and 19 healthy controls. All participants underwent skin prick testing and the newly developed flow-cytometric basophil activation test. The protocol for allergen-induced basophil CD63 upregulation consisted of whole blood samples that were processed and stained with anti-CCR3/CD63 antibodies added to the buffer at the beginning of stimulation. Skin prick tests and BAT were performed twice--before and 2 hours after ingestion of 10 mg of cetirizine. RESULTS: The new BAT is characterized by its short processing time, easy basophil gating, and strong CD63 upregulation with very high sensitivity and excellent specificity. Our results suggest that allergen-induced CD63 upregulation by higher doses of allergens is not inhibited 2 hours after administration of cetirizine (unlike skin prick tests). CONCLUSION: The BAT is a very useful and precise method for the diagnosis of allergy to aeroallergens. It is not influenced by cetirizine.

Production of leukotriene C4 by peripheral blood leukocytes stimulated with anti-fcepsilonRI antibody, PMA, and fMLP does not correlate with irreversible airway obstruction in asthmatics.

BACKGROUND: Airway remodeling has recently emerged as a major problem in an increasing percentage of patients with asthma. Reasons for great diversity in the progression of irreversible bronchoconstriction among asthmatics remain unclear. OBJECTIVE: The aim of this study was to assess whether the potential ability of leukocytes to produce cysteinyl leukotrienes in response to various stimuli is correlated with magnitude of irreversible airway obstruction in asthmatics. MATERIALS AND METHODS: The study sample comprised 76 asthmatics (34 males, mean +/- SD age 52 +/- 13 years), and 35 healthy controls (18 males, 38.2 +/- 15 years). Each subject underwent 2 pulmonary function tests: before and after bronchodilator administration. In addition, approximate annual decline in forced expiratory volume in 1 second (FEV1) (% of predicted) was calculated. Leukotriene C4 (LTC4) production was assessed combining a cellular antigen stimulation test and enzyme-linked immunosorbent assay using Bulhmann Laboratories AG kits. Leukocytes isolated from peripheral blood were stimulated with anti-FcepsilonRI antibody, N-formyl-methionyl-leucyl-phenylalanine (fMLP) and phorbol 12-myristate 13-acetate (PMA). In separate tubes each subject's leukocytes were tested for spontaneous LTC4 production. Finally, stimulated LTC4 production was expressed in pg/mL after subtraction of values of spontaneous production. RESULTS: In asthmatics, baseline FVC% and FEV% values ranged from 24.4% to 122.4% (mean, 75.5%) and from 23.4% to 126.6% (mean, 74.4%), respectively. There were no significant differences between asthmatics and controls in LTC4 production stimulated by anti-FcepsilonRI antibody (P = .79), fMLP (P = .33) or PMA (P = .86). We found no correlation between stimulated LTC4 production and spirometric parameters at baseline or after bronchodilator administration or annual decline in FEV1%. CONCLUSION: Our results do not confirm the hypothesis that airway remodeling in asthma might be related to enhanced ability of leukocytes to produce cysteinyl leukotrienes in response to various stimuli.