Spadaro G, et al. - By systematically sampling the 24-hour response of basophils to IgE- and non-IgE-dependent ligands in asthma, researchers decided to determine the possible contribution of these to the diurnal variations of allergic symptoms. Participants were patients with moderate, persistent asthma (n = 10) and matched, nonallergic controls (n = 10). From participants, they obtained leukocytes every 4 hours for 24 hours and then incubated leukocytes with concentrations of anti-IgE, formyl-methionyl-leucylphenylalanine (fMLP), or the Ca²⁺ ionophore, A23187. In basophils from asthmatics but not controls, a significant increase in histamine release induced by anti-IgE was noted at 08:00 vs 20:00. A significantly higher response to fMLP was observed at 08:00 vs 20:00 in controls but not asthmatics. The use of an integrated statistical approach in this study revealed significant circadian variability in basophil responsiveness. Also, using this approach, experts demonstrated the identification of distinct patterns of rhythmicity based on the signal delivered, the activation parameters evaluated, and the disease status.