抗磷脂抗体 (aPL) 是一种可识别各种含有磷脂结构的血浆蛋白的自身抗体,如 β2 糖蛋白 I、凝血酶原、膜联蛋白 A5 和在血小板、单核细胞和滋养层细胞上表达的磷脂。现已提出一些病理机制可能导致抗磷脂抗体引起的血栓形成和病态妊娠,[10]Meroni PL, Borghi MO, Raschi E, et al. Pathogenesis of antiphospholipid syndrome: understanding the antibodies. Nat Rev Rheumatol. 2011;7:330-339.http://www.ncbi.nlm.nih.gov/pubmed/21556027?tool=bestpractice.com[11]Mehdi AA, Uthman I, Khamashta M. Antiphospholipid syndrome: pathogenesis and a window of treatment opportunities in the future. Eur J Clin Invest. 2010;40:451-464.http://www.ncbi.nlm.nih.gov/pubmed/20345380?tool=bestpractice.com[12]Giannakopoulos B, Krilis SA. The pathogenesis of the antiphospholipid syndrome. N Engl J Med. 2013;368:1033-1044.http://www.ncbi.nlm.nih.gov/pubmed/23484830?tool=bestpractice.com但目前没有普遍认可的统一机制可解释疾病的所有现象。尤其是 β2 糖蛋白 I,它是由 5 种结构域构成的补体调控蛋白,而且确定是 APS 抗体的主要靶抗原。在最近,人们发现可识别 β2 糖蛋白 I 的结构域 I 中的特定表位抗体与血栓形成的风险增加有关。[13]de Laat B, Derksen RH, Urbanus RT, et al. IgG antibodies that recognize epitope Gly40-Arg43 in domain I of beta 2-glycoprotein I cause LAC, and their presence correlates strongly with thrombosis. Blood. 2005;105:1540-1545.http://www.ncbi.nlm.nih.gov/pubmed/15507529?tool=bestpractice.com
针对血栓形成中的 APS 抗体作用提出的其他机制包括内皮细胞结合、[14]Del Papa N, Raschi E, Catelli L, et al. Endothelial cells as a target for antiphospholipid antibodies: role of anti-beta 2 glycoprotein I antibodies. Am J Reprod Immunol. 1997;38:212-217.http://www.ncbi.nlm.nih.gov/pubmed/9325495?tool=bestpractice.com蛋白 C 抵抗性[15]Malia RG, Kitchen S, Greaves M, et al. Inhibition of activated protein C and its cofactor protein S by antiphospholipid antibodies. Br J Haematol. 1990;76:101-107.http://www.ncbi.nlm.nih.gov/pubmed/2145968?tool=bestpractice.com和补体激活。[16]Erkan D, Lockshin MD. New approaches for managing antiphospholipid syndrome. Nat Clin Pract Rheumatol. 2009;5:160-170.http://www.ncbi.nlm.nih.gov/pubmed/19252521?tool=bestpractice.com[17]Pierangeli SS, Vega-Ostertag ME, Gonzalez EB. New targeted therapies for treatment of thrombosis in antiphospholipid syndrome. Expert Rev Mol Med. 2007;9:1-15.http://www.ncbi.nlm.nih.gov/pubmed/17997880?tool=bestpractice.com现已提出的由 aPL 结合诱导的有关栓塞和炎症介导的几大机制可能是血栓形成和妊娠相关并发症中的抗磷脂抗体的发病机制。[18]Salmon JE, Girardi G. Theodore E. Woodward Award: antiphospholipid syndrome revisited: a disorder initiated by inflammation. Trans Am Clin Climatol Assoc. 2007;118:99-114.http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1863598/http://www.ncbi.nlm.nih.gov/pubmed/18528494?tool=bestpractice.com尤其是补体系统,已经在 APS 小鼠中发现与血栓形成和流产的发病机制有关,[19]Girardi G, Berman J, Redecha P, et al. Complement C5a receptors and neutrophils mediate fetal injury in the antiphospholipid syndrome. J Clin Invest. 2003;112:1644-1654.http://www.jci.org/articles/view/18817http://www.ncbi.nlm.nih.gov/pubmed/14660741?tool=bestpractice.com[20]Lynch AM, Murphy JR, Byers T, et al. Alternative complement pathway activation fragment Bb in early pregnancy as a predictor of preeclampsia. Am J Obstet Gynecol. 2008;198:385;e1-e9.http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2362503/http://www.ncbi.nlm.nih.gov/pubmed/18221926?tool=bestpractice.com并且可抵抗膜联蛋白 A5,这同样是一个重要机制。[21]Rand JH, Wu XX, Lapinski R, et al. Detection of antibody-mediated reduction of annexin A5 anticoagulant activity in plasmas of patients with the antiphospholipid syndrome. Blood. 2004;104:2783-2790.http://www.ncbi.nlm.nih.gov/pubmed/15242878?tool=bestpractice.com[22]Rand JH, Wu XX. Antibody-mediated interference with annexins in the antiphospholipid syndrome. Thromb Res. 2004;114:383-389.http://www.ncbi.nlm.nih.gov/pubmed/15507268?tool=bestpractice.com[23]de Laat B, Wu XX, van Lummel M, et al. Correlation between antiphospholipid antibodies that recognize domain I of beta2-glycoprotein I and a reduction in the anticoagulant activity of annexin A5. Blood. 2007;109:1490-1494.http://www.ncbi.nlm.nih.gov/pubmed/17053060?tool=bestpractice.com