This episode digs into the pathophysiology of urticaria vasculitis from anti-C1q to the story of bradykinin. · Intro 0:11* · In this episode 0:22 · Review of episode 83 1:23 · Listen to previous episode, The Complement System for Dunces) 4:09 · Anti-C1q antibodies 6:26 · Lupus, anti-C1q and lupus nephritis 9:33 · What happens when you inject anti-C1q in a mouse? 12:56 · The allergy component: anti-C1q, urticaria and angioedema 17:36 · Bradykinin-mediated angioedema and C1q deficiency 24:20 · What is the kinin kallikrein system? 26:21 · French researchers in 1909: human urine injected in dogs 27:30 · How is this relevant to urticarial vasculitis? 31:08 · SERPING1 gene mutation 31:23 · Summary 32:06 · COPD association with urticarial vasculitis 33:51 · Coming up in episode 85 35:28 · Thanks for listening 35:45 Disclosures: Brown reports no relevant financial disclosures. We’d love to hear from you! Send your comments/questions to Dr. Brown at [email protected]). Follow us on Twitter @HRheuminations) @AdamJBrownMD) @HealioRheum). References: Busse P, et al. J Allergy Clin Immunol Pract. 2022;doi:10.1016/j.jaip.2021.11.011.) Davis MDP, et al. J Allergy Clin Immunol Pract. 2018;doi:10.1016/j.jaip.2018.05.006.) Dorn JM, et al. Ann Allergy Asthma Immunol. 2023;doi:10.1016/j.anai.2023.06.014.) Marzano AV, et al. J Allergy Clin Immunol. 2022;doi:10.1016/j.jaci.2022.02.007.) Siegert CE, et al. Clin Immunol Immunopathol. 1993;doi:10.1006/clin.1993.1066.) Stojan G, et al. Lupus. 2016;doi:10.1177/0961203316645205.) Venzor J, et al. Clin Rev Allergy Immunol. 2002;doi:10.1385/CRIAI:23:2:201.) Wisnieski JJ, et al. Medicine. 1995;doi:10.1097/00005792-199501000-00003.)