166 Assessment of Chronic Spontaneous Urticaria by Serum-Induced TNF & ALPHA; and MMP-9 Release

Abstract

BackgroundPrevious studies from our group have demonstrated that IgE-mediated basophil activation leads to release of TNFα that in turn can induce matrix metallo-proteinase-9 (MMP-9) release from monocytes. We wished to investigate if serum from chronic spontaneous urticaria-patients with auto-antibodies against IgE/IgE-receptor could induce TNFα and MMP-9 release from donor PBMCs, and if release levels could be used to assess severity and activity of chronic spontaneous urticaria (CSU).MethodsPeripheral blood mononuclear cells (PBMCs) were isolated from whole blood from healthy donors and basophils isolated with MACS Basophil Isolation Kit to 97 to 99% purity. Cells were pulsed 1 hour with or without anti-IgE or with sera from CSU-patients/healthy controls and incubated for a total of 21 h before protein analysis of supernatants. MMP-9 and TNFα in supernatants were measured with commercial ELISAs (R & D), and histamine release determined with HR-test from RefLab ApS.ResultsStimulations with serum-pools demonstrated that CSU-serum, in contrast to healthy controls, was able to induce TNFα-release from isolated basophils. 10 sera from healthy controls and 22 sera from CSU-patients were tested for serum-induced histamine, TNFα and MMP-9 release. The CSU sera were grouped by reaction/no reaction in the autologous skin serum test (ASST), each group consisting of 11 sera. Nine of the 22 CSU-sera were found positive in the HR-test, 6 sera from ASST+ and 3 from ASST- patients. Sera from ASST+ and ASST- patients were observed to induce highly significant MMP-9 and TNFα release from donor PBMCs when compared to sera from healthy controls (P < 0.001). Urticaria assessment score (UAS) did not appear to correlate with release levels for histamine, TNFα or MMP-9 in either group but in the ASST+ group, the ASST score appeared to be positive correlated to histamine and TNFα release and to a smaller degree to MMP-9 release.ConclusionsWe have shown for the first time that serum from CSU-patients, in contrast to serum from healthy controls, can induce TNFα release from isolated basophils, as well as TNFα and MMP-9 from donor PBMCS. Release levels appeared to be positive correlated to ASST reaction in ASST+ patients but not to disease severity for CSU patients in general.