Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA.
Maulana Azad Medical College, University of Delhi, New Delhi, India.
Transfusion. 2021 Jan;61(1):266-273. doi: 10.1111/trf.16188. Epub 2020 Nov 12.
Thrombotic thrombocytopenic purpura (TTP) is a life-threatening disorder characterized by thrombocytopenia, microangiopathic hemolysis, and ischemic organ failure. The PLASMIC and French TTP scores can help guide clinical decisions when ADAMTS13 testing is not immediately available. Older individuals often present atypically, but the impact of age on these tools is not known.
We calculated the sensitivity and specificity of the PLASMIC and French TTP scores in patients enrolled in the Johns Hopkins thrombotic microangiopathy (TMA) registry.
Of 257 patients with TMA enrolled in the registry, we excluded patients less than 18 years of age (n = 19), with prior TMA (n = 81) or who initially presented at another hospital (n = 25). The remaining 132 patients (75 with TTP and 57 with other TMA) were analyzed. Sensitivity of a French score of 2 decreased with age and was 72.2%, 61.5%, and 46.2% for ages 18 to 39, 40 to 59, and ≥ 60 years old, respectively. A PLASMIC score ≥ 5 had higher sensitivity than the French score but this also decreased with age; sensitivity was 91.4% (95% confidence interval [CI], 76.9-98.2), 78.3% (95% CI, 56.3-92.5), and 76.9% (95% CI, 46.2-95.0) for patients 18 to 39, 40 to 59, and ≥ 60 years old, respectively. Older patients had higher platelet counts and serum creatinine than the youngest group, contributing to the loss in sensitivity.
The PLASMIC and French TTP scores have reduced sensitivity at age ≥ 60 years and are less reliable in identifying TTP in older patients. A high index of suspicion and availability of rapid ADAMTS13 assays is required to correctly diagnose all patients with TTP.
血栓性血小板减少性紫癜（TTP）是一种危及生命的疾病，其特征为血小板减少、微血管病性溶血性贫血和缺血性器官衰竭。PLASMIC 和 French TTP 评分可在 ADAMTS13 检测不可用时帮助指导临床决策。老年人的表现常常不典型，但这些工具的年龄影响尚不清楚。
我们计算了 Johns Hopkins 血栓性微血管病（TMA）登记处纳入的 TMA 患者中 PLASMIC 和 French TTP 评分的敏感性和特异性。
在登记处纳入的 257 例 TMA 患者中，我们排除了年龄小于 18 岁的患者（n = 19）、有既往 TMA 病史的患者（n = 81）或最初在其他医院就诊的患者（n = 25）。分析了剩余的 132 例患者（75 例 TTP 和 57 例其他 TMA）。French 评分 2 的敏感性随年龄增加而降低，分别为 18 至 39 岁、40 至 59 岁和≥60 岁的 72.2%、61.5%和 46.2%。PLASMIC 评分≥5 的敏感性高于 French 评分，但也随年龄降低；敏感性分别为 91.4%（95%置信区间 [CI]，76.9-98.2）、78.3%（95% CI，56.3-92.5）和 76.9%（95% CI，46.2-95.0）。年龄较大的患者血小板计数和血清肌酐高于最年轻组，导致敏感性降低。
PLASMIC 和 French TTP 评分在年龄≥60 岁时敏感性降低，在识别老年患者 TTP 时不太可靠。需要高度怀疑并提供快速 ADAMTS13 检测，以正确诊断所有 TTP 患者。
