Department of Internal Medicine, Ochsner Health System, New Orleans, Louisiana, USA.
Center for Outcomes and Health Services Research, Ochsner Health System, New Orleans, Louisiana, USA.
J Clin Apher. 2020 Aug;35(4):264-270. doi: 10.1002/jca.21786. Epub 2020 May 14.
Thrombotic thrombocytopenic purpura (TTP) is a life-threatening disorder caused by inactivation of ADAMTS13. It is characterized by thrombocytopenia and microangiopathic hemolytic anemia. Previous studies have produced conflicting data regarding seasonal association of TTP diagnoses. This study evaluated the seasonal distribution of acute TTP in southern Louisiana. Additionally, this study timeline overlapped with the initiation of a new screening protocol for ADAMTS13 testing.
A retrospective analysis of patients receiving ADAMTS13 testing at Ochsner Medical Center from January 2010 to December 2017 was performed. TTP patient episodes were defined by ADAMTS13 activity <10%. Episodes were plotted according to season of presentation and a chi-square analysis was performed. Data of identified TTP patients was analyzed to evaluate for confounding variables. ADAMTS13 order volumes and results before and after screening protocol implementation were compared.
Two hundred and fifty-two ADAMTS13 tests were ordered on 245 unique patients. Twenty-five patients had ADAMTS13 activity <10%. No significant differences in seasonal TTP case distribution were identified. Patients with confirmed TTP were younger and more likely to be Black or African American. A screening protocol did not decrease the number of annual ADAMTS13 test orders in our time frame, but was associated with a nonsignificant increase in the percentage of positive results.
No significant seasonal distribution of TTP was identified in our population. This analysis provides previously unexamined regional information regarding this diagnosis. The number of tests ordered after the implementation of the screening protocol increased, corresponding with our facility's expanding reach.
血栓性血小板减少性紫癜（TTP）是一种由 ADAMTS13 失活引起的危及生命的疾病，其特征为血小板减少和微血管性溶血性贫血。先前的研究对于 TTP 诊断的季节性关联产生了相互矛盾的数据。本研究评估了路易斯安那州南部急性 TTP 的季节性分布。此外，本研究的时间线与 ADAMTS13 检测新筛选方案的启动相重叠。
对 2010 年 1 月至 2017 年 12 月在奥克斯纳医疗中心接受 ADAMTS13 检测的患者进行了回顾性分析。TTP 患者的发作定义为 ADAMTS13 活性＜10%。根据就诊季节绘制发作图，并进行卡方分析。对确定的 TTP 患者的数据进行分析，以评估混杂变量。比较筛选方案实施前后 ADAMTS13 订单量和结果。
共对 245 名患者进行了 252 次 ADAMTS13 检测。25 名患者的 ADAMTS13 活性＜10%。未发现季节性 TTP 病例分布存在显著差异。确诊为 TTP 的患者更年轻，且更可能为黑人或非裔美国人。在我们的时间范围内，筛选方案并未减少年度 ADAMTS13 检测订单数量，但与阳性结果的百分比增加无关。
在我们的人群中未发现 TTP 存在显著的季节性分布。本分析提供了关于这一诊断的以前未被检查过的区域性信息。筛选方案实施后，检测订单数量增加，与我们医疗机构的服务范围扩大相对应。
