IL-1α and -1β induce endothelial degranulation and contribute to WVF exocytosis in TTP. (A) VWF concentrations in cell supernatants after stimulations with IL-1α (10 ng/mL), IL-1β (10 ng/mL), and PBS with/without MAPTAM (1 μmol/L). Thrombin (4 IU/mL) is used as positive control. IL-1α: 10.7 (8.5-15.5) ng/mL; IL-1β: 10.7 (6.6-16.3) ng/mL; PBS: 4.8 (1.6-5.6) ng/mL; IL-1α + MAPTAM: 1.2 (0.97-1.4) ng/mL; IL-1β + MAPTAM: 0.7 (0.23-1.2) ng/mL. (B) VWF concentrations in cell supernatants after stimulations with IL-1α (10 ng/mL), or (C) IL-1β (10 ng/mL) for 15, 30, and 60 minutes. (D) Calcium flux after stimulation with IL-1α (10 ng/mL), IL-1β (10 ng/mL), and PBS over 20 seconds. AUC of IL-1α: 62.2 (95% CI, 60.7-63.7) × 10¹⁰ AU; IL-1β: 64.5 (95% CI, 63.3-65.7) × 10¹⁰ AU; and PBS: 8.0 (95% CI, 7.9-8.2) × 10¹⁰ AU. (E) VWF concentrations in cell supernatants after stimulations with TTP plasma (1%, n = 6), control plasma (1%, n = 6), and PBS, with/without anakinra (10 μg/L). TTP: 105.0 (95.0-140.5) ng/mL; and TTP + anakinra: 65.0 (53.5-84.5) ng/mL. (F) Calcium flux after stimulations with TTP plasma (1%), control plasma (1%), and PBS, with/without anakinra (10 μg/L) over 20 seconds. AUC of TTP: 13.6 (95% CI, 12.9-14.2) × 10¹⁰ AU; TTP + anakinra: 5.9 (95% CI, 5.8-6.1) × 10¹⁰ AU; control 3.4 (95% CI, 3.3-3.6) × 10¹⁰ AU; and control + anakinra: 1.4 (95% CI, 1.3-1.4) × 10¹⁰ AU (ns: P > .05; ∗P < .05 and ∗∗P < .01). AU, arbitrary unit; AUC, area under the curve; CI, confidence interval.