Lamech Tanuj Moses, Chellaraj Margaret, Penchalaiah Ratakonda, Dhanasekaran Damodaran
1Institute of Internal Medicine, Madras Medical College, Chennai, India.
2Department of Hematology, Madras Medical College, Chennai, India.
Indian J Hematol Blood Transfus. 2020 Jan;36(1):171-173. doi: 10.1007/s12288-019-01082-0. Epub 2019 Jan 25.
Pseudothrombocytopenia is an ex vivo EDTA-dependent artefactual thrombocytopenia, that has been described in association with several conditions. When EDTA-blood samples are drawn from patients with pseudothrombocytopenia and analysed by automated cell counters, low platelet counts are obtained (often below 50,000/mm). However, simultaneous heparinised samples show normal platelet counts, and peripheral smears show no reduction in numbers of platelets. We report a series of 12 patients with scrub typhus infections and pseudothrombocytopenia. An association between these two entities has only recently been appreciated. It appears that pseudothrombocytopenia may sometimes accompany acute scrub typhus infections. The distinction between pseudothrombocytopenia and true thrombocytopenia is of great clinical relevance, as the former is merely a laboratory artefact, and does not require blood product transfusions despite apparently severe reductions in platelet counts. It is therefore important to recognise that apparent thrombocytopenia, especially in patients with an acute febrile illness due to scrub typhus, is not always true thrombocytopenia.
假性血小板减少症是一种体外依赖乙二胺四乙酸（EDTA）的人为性血小板减少症，已被描述与多种病症相关。当从患有假性血小板减少症的患者采集EDTA血样并通过自动血细胞计数器分析时，会得到低血小板计数（通常低于50,000/mm³）。然而，同时采集的肝素化血样显示血小板计数正常，并且外周血涂片显示血小板数量没有减少。我们报告了一系列12例恙虫病感染合并假性血小板减少症的患者。这两种情况之间的关联直到最近才被认识到。似乎假性血小板减少症有时可能伴随急性恙虫病感染。假性血小板减少症与真性血小板减少症的区分具有重要的临床意义，因为前者仅仅是一种实验室人为现象，尽管血小板计数明显严重降低，但并不需要输注血液制品。因此，重要的是要认识到明显的血小板减少症，尤其是在因恙虫病导致急性发热性疾病的患者中，并不总是真性血小板减少症。
