Salvesen Bodil, Nielsen Erik W, Harboe Morten, Saugstad Ola D, Mollnes Tom E
Institute of Immunology, Medical Faculty, University of Oslo and Rikshospitalet University Hospital, Sognsvannsveien 20, 0027 Oslo, Norway.
Mol Immunol. 2009 Feb;46(4):688-94. doi: 10.1016/j.molimm.2008.09.001. Epub 2008 Oct 31.
Meconium aspiration syndrome has a complex pathophysiology. Meconium activates the complement system and meconium-induced cytokine formation is differentially mediated by complement and CD14. C1-inhibitor (C1-INH) regulates complement and contact-system activation mainly by protease inhibition, but may reduce inflammation by other mechanisms as well.
The aim of the study was to investigate the initial mechanisms of meconium-induced complement activation and to study the effect of C1-INH on the meconium-induced inflammatory reaction.
Human serum from five donors was preincubated with an anti-MBL monoclonal antibody and then incubated with meconium for 30 min at 37 degrees C. Human cord whole blood, anticoagulated with lepirudin, from six donors was preincubated with C1-INH and then incubated with meconium for 30 min and 4h at 37 degrees C. Complement activation products specific for the different pathways were measured by ELISAs: classical pathway C1rs/C1-INH complexes, classical and lectin pathway C4d, alternative pathway C3bBbP, and terminal pathway sC5b-9 complex (TCC). A Bio-Plex Array Reader was used to measure 27 inflammatory mediators.
The anti-MBL monoclonal antibody significantly reduced meconium-induced formation of C4d by 63% (p=0.0159) and TCC by 27% (p=0.0079). C1-INH dose-dependently inhibited meconium-induced formation of C1rs/C1-INH complexes, C4d, C3bBbP, and TCC compared to albumin (p<0.002 for all). C1-INH induced a dose-dependent and substantial inhibition of meconium-induced formation of the proinflammatory cytokines TNFalpha, IL-1 beta, IL-6 and IFN-gamma (p<0.01 for all), the chemokines IL-8, MCP-1, MIP-1 alpha, MIP-1 beta, and eotaxin (p<0.02 for all), the growth factors G-CSF, GM-CSF, basic FGF, and PDGFbb (p<0.05 for all), and the anti-inflammatory cytokine IL-1ra (p<0.001).
Meconium activated the lectin complement pathway as well as the alternative pathway. C1-INH efficiently reduced a broad spectrum of inflammatory mediators even at the lowest concentration. Administration of C1-INH may thus reduce the inflammatory response in MAS.
胎粪吸入综合征具有复杂的病理生理学。胎粪激活补体系统，且胎粪诱导的细胞因子形成由补体和CD14差异介导。C1抑制剂（C1-INH）主要通过抑制蛋白酶来调节补体和接触系统的激活，但也可能通过其他机制减轻炎症。
本研究旨在探讨胎粪诱导补体激活的初始机制，并研究C1-INH对胎粪诱导的炎症反应的影响。
将来自五名供体的人血清与抗MBL单克隆抗体预孵育，然后在37℃下与胎粪孵育30分钟。将来自六名供体的用比伐卢定抗凝的人脐带全血与C1-INH预孵育，然后在37℃下与胎粪孵育30分钟和4小时。通过酶联免疫吸附测定法（ELISA）测量不同途径特异性的补体激活产物：经典途径C1rs/C1-INH复合物、经典和凝集素途径C4d、替代途径C3bBbP以及终末途径sC5b-9复合物（TCC）。使用生物芯片阵列读数仪测量27种炎症介质。
抗MBL单克隆抗体显著降低胎粪诱导的C4d形成63%（p=0.0159），TCC形成27%（p=0.0079）。与白蛋白相比，C1-INH剂量依赖性地抑制胎粪诱导的C1rs/C1-INH复合物、C4d、C3bBbP和TCC的形成（所有p<0.002）。C1-INH剂量依赖性地显著抑制胎粪诱导的促炎细胞因子TNFα、IL-1β、IL-6和IFN-γ的形成（所有p<0.01）、趋化因子IL-8、MCP-1、MIP-1α、MIP-1β和嗜酸性粒细胞趋化因子（所有p<0.02）、生长因子G-CSF、GM-CSF、碱性FGF和血小板衍生生长因子bb（所有p<0.05）以及抗炎细胞因子IL-1ra（p<0.001）。
胎粪激活凝集素补体途径以及替代途径。即使在最低浓度下，C1-INH也能有效减少多种炎症介质。因此，给予C1-INH可能会减轻胎粪吸入综合征中的炎症反应。
