Department of Hematology, The Second Affiliated Hospital, Chongqing Medical University, Chongqing, People's Republic of China.
Hematology. 2024 Dec;29(1):2335420. doi: 10.1080/16078454.2024.2335420. Epub 2024 Mar 28.
Thrombotic thrombocytopenic purpura (TTP) is a rare but life-threatening hematological disorder. Early differentiation between TTP and primary immune thrombocytopenia (ITP) accompanied by anemia is crucial to initiate an appropriate therapeutic strategy. The objective of this study was to evaluate the predictive value of red blood cell lifespan (RBCLS), determined using the carbon monoxide breath test, in the differential diagnosis of these two diseases.
We conducted a retrospective analysis of 23 patients with TTP and 32 patients with ITP accompanied by anemia. RBCLS measurements were compared and evaluated between these two patient groups.
TTP patients had a significantly shorter mean RBCLS (20 ± 8 days) than patients with ITP accompanied by anemia (77 ± 22 days, < 0.001) and healthy controls (114 ± 25 days, < 0.001). In TTP patients, RBCLS showed a significant negative correlation with reticulocyte percentage and lactic dehydrogenase levels ( < 0.001). When using a standard baseline of 75 days, RBCLS demonstrated a sensitivity of 100% and specificity of 53.1% in identifying TTP. The diagnostic accuracy could reach 93% by excluding the impact of gastrointestinal bleeding. By employing the Receiver Operator Characteristics (ROC) curve, the area under the curve for RBCLS was 0.985 (95% CI: 0-1, < 0.01) in predicting TTP, with an optimal cut-off value of 32 days, and sensitivity and specificity of 95.7% and 96.9%, respectively.
Our study proposes a simple and accessible method for evaluating RBCLS to differentiate between TTP and ITP accompanied by anemia.
血栓性血小板减少性紫癜（TTP）是一种罕见但危及生命的血液系统疾病。早期区分 TTP 和伴有贫血的原发性免疫性血小板减少症（ITP）对于启动适当的治疗策略至关重要。本研究旨在评估使用一氧化碳呼气试验测定的红细胞寿命（RBCLS）在这两种疾病鉴别诊断中的预测价值。
我们对 23 例 TTP 患者和 32 例伴有贫血的 ITP 患者进行了回顾性分析。比较并评估了这两组患者的 RBCLS 测量值。
TTP 患者的平均 RBCLS（20±8 天）明显短于伴有贫血的 ITP 患者（77±22 天， < 0.001）和健康对照组（114±25 天， < 0.001）。在 TTP 患者中，RBCLS 与网织红细胞百分比和乳酸脱氢酶水平呈显著负相关（ < 0.001）。当使用 75 天的标准基线时，RBCLS 对 TTP 的识别具有 100%的敏感性和 53.1%的特异性。通过排除胃肠道出血的影响，诊断准确性可达到 93%。采用受试者工作特征（ROC）曲线，RBCLS 的曲线下面积为 0.985（95%CI：0-1， < 0.01），最佳截断值为 32 天，敏感性和特异性分别为 95.7%和 96.9%。
本研究提出了一种简单易用的方法来评估 RBCLS，以区分 TTP 和伴有贫血的 ITP。
