Department of Haematology, Institute of Clinical Pathology and Medical Research (ICPMR), Sydney Centres for Thrombosis and Haemostasis, Westmead Hospital, Westmead, NSW, Australia; NSW Health Pathology, NSW, Australia; School of Biomedical Sciences, Charles Sturt University, Wagga Wagga, NSW, Australia.
Department of Haematology, Institute of Clinical Pathology and Medical Research (ICPMR), Sydney Centres for Thrombosis and Haemostasis, Westmead Hospital, Westmead, NSW, Australia; NSW Health Pathology, NSW, Australia.
Pathology. 2021 Feb;53(2):247-256. doi: 10.1016/j.pathol.2020.07.012. Epub 2020 Oct 5.
Heparin induced thrombocytopenia (HIT) is a rare but potentially fatal complication of heparin therapy. In some patients, HIT causes platelet activation and thrombosis (sometimes abbreviated HITT), which leads to adverse clinical sequalae ('pathological HIT'). The likelihood of HIT is initially assessed clinically, typically using a scoring system, of which the 4T score is that most utilised. Subsequent laboratory testing to confirm or exclude HIT facilitates exclusion or diagnosis and management. The current investigation comprises a multicentre (n=9) assessment of contemporary laboratory testing for HIT, as performed over the past 1-3 years in each site and comprising testing of over 1200 samples. The primary laboratory test used by study participants (n=8) comprised a chemiluminescence procedure (HIT-IgG) performed on an AcuStar instrument. Additional immunological testing performed by study sites included lateral flow (STiC, Stago), enzyme linked immunosorbent assay (ELISA), Asserachrom (HPIA IgG), PaGIA (BioRad), plus functional assays, primarily serotonin release assay (SRA) or platelet aggregation methods. The chemiluminescence procedure yielded a highly sensitive screening method for identifying functional HIT, given high area under the curve (AUC, generally ≥0.9) in a receiver operator characteristic (ROC) analysis against SRA as gold standard. ELISA testing resulted in lower ROC AUC scores (<0.8) and higher levels of false positives. Although there is clear association with the likelihood of HIT, the 4T score had less utility than literature suggests, and was comparable to a previous study reported by some of the authors.
肝素诱导的血小板减少症（HIT）是肝素治疗的一种罕见但潜在致命的并发症。在某些患者中，HIT 会导致血小板激活和血栓形成（有时缩写为 HITT），从而导致不良的临床后果（“病理性 HIT”）。HIT 的可能性最初通过临床评估来评估，通常使用评分系统，其中 4T 评分是最常用的。随后进行实验室检测以确认或排除 HIT，有助于排除或诊断和管理。目前的研究包括对过去 1-3 年内每个地点进行的当代 HIT 实验室检测的多中心（n=9）评估，共检测了超过 1200 个样本。研究参与者（n=8）使用的主要实验室检测方法包括在 AcuStar 仪器上进行的化学发光检测（HIT-IgG）。研究地点进行的其他免疫检测包括侧向流动（STiC，Stago）、酶联免疫吸附测定（ELISA）、Asserachrom（HPIA IgG）、PaGIA（BioRad），以及功能检测，主要是血清素释放检测（SRA）或血小板聚集方法。化学发光检测对识别功能性 HIT 具有高度灵敏的筛选方法，在与 SRA 作为金标准的接收器操作特性（ROC）分析中，曲线下面积（AUC，通常≥0.9）较高。ELISA 检测导致 ROC AUC 评分较低（<0.8）和假阳性水平较高。尽管与 HIT 的可能性有明确的关联，但 4T 评分的实用性不如文献所述，并且与一些作者之前报道的先前研究相当。
