Department of Population Medicine and Diagnostic Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA.
Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, New York, USA.
J Vet Intern Med. 2024 Sep-Oct;38(5):2507-2517. doi: 10.1111/jvim.17152. Epub 2024 Aug 14.
Immune thrombocytopenia (ITP) is a common cause of severe thrombocytopenia in dogs. The pathogenesis of nonassociative, primary ITP (pITP) appears complex, with ill-defined thrombopoietic response.
Develop an immunoassay to measure plasma canine thrombopoietin (TPO) concentration and characterize TPO concentrations in dogs with pITP.
Forty-one healthy dogs, 8 dogs in an induced ITP model (3 control, 5 ITP), and 58 pITP dogs.
Recombinant canine TPO (rcTPO) was purchased and its identity confirmed by mass spectrometry. Monoclonal antibodies were raised to rcTPO and used to configure a sandwich ELISA using streptavidin-biotin detection. Assay performance, coefficients of variability, and healthy dog plasma TPO reference interval (RI) were determined, followed by assay of ITP samples.
Assay dynamic range was 15 pg/mL (lower limit of detection) to 1000 pg/mL TPO, with limit of quantitation of 62 pg/mL. Plasma TPO RI was 0 to 158 pg/mL, with plasma TPO <62 pg/mL for 35/41 healthy dogs. All dogs with induced ITP developed marked increases in plasma TPO concentration. Peak values ranged from 515 to >6000 pg/mL. In contrast, only 2/58 pITP dogs had TPO values above RI.
Plasma TPO concentration is paradoxically low at diagnosis for most dogs with pITP. This finding suggests that ineffective thrombopoiesis contributes to thrombocytopenia in pITP dogs and supports evaluating TPO receptor agonist treatment as used for pITP in humans. The TPO assay provides a new tool to study thrombopoiesis in pITP and other thrombocytopenic syndromes in dogs.
免疫性血小板减少症（ITP）是犬严重血小板减少症的常见原因。非关联性原发性 ITP（pITP）的发病机制似乎很复杂，其促血小板生成反应不明确。
开发一种免疫测定法来测量犬血浆中血小板生成素（TPO）的浓度，并描述患有 pITP 的犬的 TPO 浓度特征。
41 只健康犬、8 只诱导 ITP 模型犬（3 只对照，5 只 ITP）和 58 只 pITP 犬。
购买重组犬 TPO（rcTPO），并通过质谱法确认其身份。制备单克隆抗体，用于配置使用链霉亲和素-生物素检测的夹心 ELISA。确定了测定性能、变异系数和健康犬血浆 TPO 参考区间（RI），随后检测了 ITP 样本。
测定的动态范围为 15pg/mL（检测下限）至 1000pg/mL TPO，定量下限为 62pg/mL。血浆 TPO RI 为 0 至 158pg/mL，35/41 只健康犬的血浆 TPO <62pg/mL。所有诱导 ITP 的犬均出现血浆 TPO 浓度显著升高。峰值范围为 515 至 >6000pg/mL。相比之下，仅 2/58 只 pITP 犬的 TPO 值高于 RI。
大多数患有 pITP 的犬在诊断时血浆 TPO 浓度异常低。这一发现表明，无效的血小板生成导致 pITP 犬的血小板减少，并支持评估 TPO 受体激动剂治疗，如用于人类的 pITP。TPO 测定为研究 pITP 和其他犬血小板减少症综合征中的血小板生成提供了新的工具。
