Thrombotic microangiopathies (TMAs) occurring in the postpartum period may be difficult to manage. They present as the combination of mechanical hemolytic anemia and consumption thrombocytopenia due to endothelial dysfunction. The cause of this endothelial aggression can be multiple: thrombocytopenic thrombotic purpura (TTP), HELLP syndrome, antiphospholipid syndrome, atypical hemolytic and uremic syndrome or acute fatty liver of pregnancy. TTP results from a severe deficiency of ADAMTS13, which is a protease cleaving specifically von Willebrand factor chiefly produced by liver cells. There are two main causes, the production of anti-ADAMTS13 auto-antibodies and, more rarely, a genetic deficiency in ADAMTS13. First-line treatment is based on plasma exchange. HELLP syndrome occurs in the third trimester of pregnancy usually in association with preeclampsia and represents a form of TMA characterized by damage to the sinusoidal capillaries of the liver. Prompt delivery is the main treatment. We present a case illustrating the challenges in discriminating between different postpartum TMAs, with a focus on the distinction between TTP and HELLP syndrome. Specifically, we highlight how acute liver failure (ALF) stemming from HELLP may lead to TTP with a spectacular response to plasma exchanges. A 28-year-old, 33 + 4 weeks pregnant woman presented with severe preeclampsia complicated by ALF in the setting of partial liver necrosis, disseminated intravascular coagulation, microangiopathic hemolytic anemia and acute kidney injury. Greatly diminished levels of ADAMTS13 (< 5%) activity and neurological impairment suggested an initial diagnosis of thrombotic thrombocytopenic purpura (TTP). Therapeutic plasma exchange (TPE) was initiated and complete renal, neurological, hematological and hepatic recovery was observed. Secondary TTP induced by ALF due to HELLP syndrome was the final diagnosis. Our case addresses the overlapping nature of postpartum TMAs and raises the possibility that HELLP-induced ALF may constitute an additional mechanism resulting in TTP, thereby opening a possible indication for TPE.

中文翻译：

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伪装成血小板减少性血栓性紫癜的严重 HELLP 综合征：病例报告。

产后发生的血栓性微血管病 (TMA) 可能难以控制。它们表现为机械性溶血性贫血和内皮功能障碍引起的消耗性血小板减少症的组合。这种内皮攻击的原因可能有多种：血小板减少性血栓性紫癜 (TTP)、HELLP 综合征、抗磷脂综合征、非典型溶血和尿毒症综合征或妊娠急性脂肪肝。TTP 是由于 ADAMTS13 的严重缺乏导致的，ADAMTS13 是一种蛋白酶，专门切割主要由肝细胞产生的 von Willebrand 因子。有两个主要原因，抗 ADAMTS13 自身抗体的产生，以及 ADAMTS13 中的遗传缺陷，在少数情况下。一线治疗基于血浆置换。HELLP 综合征发生在妊娠晚期，通常与先兆子痫有关，是一种以肝窦毛细血管损伤为特征的 TMA 形式。及时分娩是主要的治疗方法。我们提出了一个案例，说明区分不同产后 TMA 的挑战，重点是 TTP 和 HELLP 综合征之间的区别。具体而言，我们强调了源自 HELLP 的急性肝衰竭 (ALF) 如何导致 TTP，并对血浆交换产生惊人的反应。一名 28 岁、33 + 4 周的孕妇在部分肝坏死、弥散性血管内凝血、微血管病性溶血性贫血和急性肾损伤的情况下出现严重子痫前期并发 ALF。ADAMTS13 的水平大大降低（< 5%) 活动和神经功能障碍提示血栓性血小板减少性紫癜 (TTP) 的初步诊断。开始治疗性血浆置换 (TPE)，观察到肾脏、神经、血液和肝脏完全恢复。HELLP 综合征引起的 ALF 继发性 TTP 是最终诊断。我们的案例解决了产后 TMA 的重叠性质，并提出了 HELLP 诱导的 ALF 可能构成导致 TTP 的额外机制的可能性，从而为 TPE 开辟了可能的适应症。