Pengo Vittorio, Zardo Lorena, Cattini Maria Grazia, Bison Elisa, Pontara Elena, Altinier Sara, Cheng Chunyan, Denas Gentian
Cardiology Clinic, Thrombosis Centre, Department of Cardiac, Thoracic and Vascular Sciences, University of Padua, Padova, Italy.
Castelfranco Veneto General Hospital - ULSS 2 Treviso, Treviso, Italy.
TH Open. 2020 Mar 9;4(1):e40-e44. doi: 10.1055/s-0040-1705091. eCollection 2020 Jan.
Lupus anticoagulant is a misnomer as it is commonly associated with thromboembolic events. In few cases, the name retains its literal meaning when it characterizes patients with a bleeding disorder. We describe a patient with lupus anticoagulant, hypoprothrombinemia, and major bleeding (lupus anticoagulant/hypoprothrombinemia syndrome). Immunological studies revealed a huge amount of circulating monoclonal immunoglobulin M lambda (IgMλ) antiphosphatidylserine/prothrombin antibodies (14,400 U/mL). Affinity purified monoclonal antibodies (440 U/mL) prolonged the coagulation time of normal plasma by 12.2 seconds (diluted Russell viper venom time) and 25.5 seconds (silica clotting time). The original patient's plasma mixed 1:1 with normal plasma showed a marked prolongation of coagulation times (lupus cofactor) from a ratio of 2.94 to 5.23 in diluted Russel viper venom time and from 2.30 to 3.00 using the silica clotting time. Human prothrombin added to original patient's plasma caused a marked prolongation of coagulation times in diluted Russell viper venom test thus unequivocally explaining the lupus cofactor phenomenon. In conclusion, we have shown that lupus anticoagulant/hypoprothrombinemia syndrome is attributable to monoclonal IgMλ antibodies directed to phosphatidylserine/prothrombin and that prothrombin is the protein responsible for the observed lupus cofactor phenomenon.
狼疮抗凝物这一名称并不准确，因为它通常与血栓栓塞事件相关。在少数情况下，当它用于描述有出血性疾病的患者时，该名称保留了其字面意义。我们描述了一名患有狼疮抗凝物、低凝血酶原血症和严重出血的患者（狼疮抗凝物/低凝血酶原血症综合征）。免疫学研究发现大量循环的单克隆免疫球蛋白Mλ（IgMλ）抗磷脂酰丝氨酸/凝血酶原抗体（14,400 U/mL）。亲和纯化的单克隆抗体（440 U/mL）使正常血浆的凝血时间延长了12.2秒（稀释蝰蛇毒时间）和25.5秒（硅土凝血时间）。原患者的血浆与正常血浆按1:1混合后，稀释蝰蛇毒时间的凝血时间比值从2.94显著延长至5.23，硅土凝血时间从2.30延长至3.00（狼疮抗凝因子）。向原患者血浆中加入人凝血酶原，在稀释蝰蛇毒试验中导致凝血时间显著延长，从而明确解释了狼疮抗凝因子现象。总之，我们已经表明狼疮抗凝物/低凝血酶原血症综合征归因于针对磷脂酰丝氨酸/凝血酶原的单克隆IgMλ抗体，并且凝血酶原是导致观察到的狼疮抗凝因子现象的蛋白质。
