Abstract:
Primary immune thrombocytopenia (ITP) is an autoimmune disorder characterized by isolated thrombocytopenia due to accelerated platelet destruction and impaired platelet production. Diagnosis of ITP is still challenging because ITP has been diagnosed by exclusion. Exclusion of thrombocytopenia due to bone marrow failure is especially important in Japan because of high prevalence of aplastic anemia compared to Western countries. Hence, we propose a new diagnostic criteria involving the measurement of plasma thrombopoietin (TPO) levels and percentage of immature platelet fraction (RP% or IPF%); 1) isolated thrombocytopenia with no morphological evidence of dysplasia in any blood cell type in a blood smear, 2) normal or slightly increased plasma TPO level (< cutoff), 3) elevated RP% or IPF% (> upper limit of normal), and 4) absence of other conditions that potentially cause thrombocytopenia including secondary ITP. A diagnosis of ITP is made if conditions 1-4 are all met. Cases in which criterion 2 or 3 is not met or unavailable are defined as \"possible ITP,\" and diagnosis of ITP can be made mainly by typical clinical course. These new criteria enable us to clearly differentiate ITP from aplastic anemia and other forms of hypoplastic thrombocytopenia and can be highly useful in clinical practice for avoiding unnecessary bone marrow examination as well as for appropriate selection of treatments.
摘要:
原发性免疫性血小板减少症(ITP)是一种自身免疫性疾病,其特征是由于加速的血小板破坏和血小板产生受损而导致的孤立性血小板减少症。ITP的诊断仍然具有挑战性,因为ITP已被排除。排除骨髓衰竭导致的血小板减少在日本尤为重要,因为与西方国家相比,再生障碍性贫血的患病率很高。因此,我们提出了一个新的诊断标准,包括测量血浆血小板生成素(TPO)水平和未成熟血小板分数百分比(RP%或IPF%);1)孤立的血小板减少症,在血涂片中没有任何血细胞类型的形态学证据,2)血浆TPO水平正常或略有增加(正常上限),和4)不存在可能引起血小板减少症的其他病症,包括继发性ITP。如果条件1-4都满足,则进行ITP的诊断。标准2或3不满足或不可用的情况被定义为“可能的ITP,ITP的诊断主要通过典型的临床病程进行。这些新标准使我们能够明确区分ITP与再生障碍性贫血和其他形式的增生性血小板减少症,并且在临床实践中非常有用,可以避免不必要的骨髓检查以及适当选择治疗方法。