Immune thrombocytopenia (ITP) is an autoimmune disease characterized by isolated thrombocytopenia. It is diagnosed in patients with a platelet count below 100,000 per cubic millimeter in whom other causes of thrombocytopenia have been ruled out, and its diagnosis is generally one of exclusion. Clinical manifestations of patients may vary from asymptomatic disease to mild mucocutaneous or life-threatening bleeding. Glucocorticoids are used as first-line treatment for ITP, while other second-line medications, mainly thrombopoietin-receptor agonists (TPO-RA) and rituximab, are given to patients in whom ITP does not remit, or relapses soon after glucocorticoid treatment. Refractoriness of ITP strongly questions its diagnosis and necessitates a thorough clinical and laboratory work-up to decide whether that is the case of refractory ITP or a misdiagnosis. The aim of this review is to summarize the conditions associated with isolated thrombocytopenia and highlight the characteristics of confusing cases. Even though the case of a myelodysplastic syndrome presented with isolated thrombocytopenia (MDS-IT) is relatively rare and not well-established in the literature, it constitutes one of the most predominant misdiagnoses of refractory ITP. MDS-IT patients are thought to present with multilineage dysplasia, normal karyotype and low risk prognostic score, based on IPSS-R. It has been shown that a significant proportion of MDS-IT patients are misdiagnosed as having the more common ITP. Therefore, it is crucial that in confusing cases of persistent thrombocytopenia a detailed diagnostic work-up is applied—including evaluation of peripheral-blood smear, bone marrow examination and cytogenetic testing—to avoid unnecessary therapy delay.
免疫性血小板减少症（ITP）是一种以孤立性血小板减少为特征的自身免疫性疾病。其诊断标准为患者血小板计数低于每立方毫米10万，且已排除其他导致血小板减少的原因，因此该诊断通常属于排除性诊断。患者的临床表现各异，可从无症状到轻微的皮肤黏膜出血，甚至危及生命的出血事件不等。糖皮质激素是ITP的一线治疗药物，而对于糖皮质激素治疗后病情未缓解或短期内复发的患者，则需使用二线药物，主要包括血小板生成素受体激动剂（TPO-RA）和利妥昔单抗。当ITP呈现难治性时，需对其诊断提出强烈质疑，并必须进行全面的临床和实验室检查，以明确是否为真正的难治性ITP或存在误诊。本综述旨在总结与孤立性血小板减少相关的疾病，并重点分析易混淆病例的特征。尽管以孤立性血小板减少为表现的骨髓增生异常综合征（MDS-IT）病例相对罕见且在文献中尚未充分确立，但它构成了难治性ITP最主要的误诊类型之一。根据修订版国际预后积分系统（IPSS-R），MDS-IT患者通常表现为多系发育异常、正常核型及低危预后评分。研究表明，相当比例的MDS-IT患者被误诊为更常见的ITP。因此，对于持续性血小板减少的疑难病例，必须进行详细的诊断评估——包括外周血涂片检查、骨髓检查和细胞遗传学检测——以避免不必要的治疗延误。
肿瘤(癌症)患者之家