Hydroxycarbamide and white matter integrity in pediatric sickle cell disease: Commentary to accompany: Hydroxycarbamide treatment in children with sickle cell anaemia is associated with more intact white matter integrity: a quantitative MRI study.
Hydroxycarbamide and white matter integrity in pediatric sickle cell disease: Commentary to accompany: Hydroxycarbamide treatment in children with sickle cell anaemia is associated with more intact white matter integrity: a quantitative MRI study.
复制标题
儿童镰状细胞病中的羟基脲和白质完整性：附带评论：镰状细胞性贫血儿童的羟基脲治疗与更完整的白质完整性相关：一项定量 MRI 研究。
DOI：
10.1111/bjh.16252
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发表时间：
2019
影响因子：
6.5
通讯作者：
Jordan,LoriC
中科院分区：
文献类型：
--
作者：
Lance,EboniI;Jordan,LoriC
羟基脲是目前少数几种获批的镰状细胞病（SCD）疾病缓解疗法之一，与SCD幼儿的疼痛发作、趾炎、急性胸部综合征和住院率显著降低相关（Thornburg et al. 2012）。现行指南建议从9月龄开始为患有最常见和最严重形式SCD（血红蛋白SS（HbSS））的儿童提供羟基脲治疗（Yawn et al. 2014）。然而，在这一人群中，羟基脲在神经保护方面的疗效尚无定论。目前的研究支持使用羟基脲维持接受1年定期输血治疗的SCD儿童经颅多普勒（TCD）速度，但不支持使用羟基脲预防SCD儿童卒中（Ware & Helms 2012; Ware et al. 2016）。最近对7项研究进行的荟萃分析记录了HbSS或HbSβ0地中海贫血儿童在羟基脲治疗前后的TCD测量结果，为神经保护作用提供了额外的支持（DeBaun和Kirkham 2016）。在开始羟基脲治疗后，TCD流速平均降低25 cm/s;在开始羟基脲治疗后3个月即可观察到TCD流速降低，并持续至少36个月（DeBaun and Kirkham 2016; DeBaun et al. 2016）。此外，与未治疗的SCD患者相比，羟基脲可通过降低脑氧提取分数水平来降低治疗的SCD患者的脑代谢应激（Fields et al. 2019）。（2019）显示，与未治疗的SCD儿童相比，接受羟基脲治疗的SCD儿童的白色微结构完整性存在显著差异。采用专门的磁共振成像（MRI）序列（扩散张量成像（DTI））对10至18岁HbSS儿童和年龄匹配的健康对照组的白色微结构进行了评估，该序列表征了水分子的扩散特性。脑血管反应性（CVR），即脑动脉扩张和增加脑血流量的能力，通过二氧化碳激发和血氧水平来评估
Hydroxycarbamide, one of the few currently approved disease-modifying therapies for sickle cell disease (SCD), is associated with significantly lower rates of pain episodes, dactylitis, acute chest syndrome and hospitalization in young children with SCD (Thornburg et al. 2012). Current guidelines recommend offering hydroxycarbamide therapy to children with the most common and severe form of SCD, haemoglobin SS (HbSS), starting at 9 months of age (Yawn et al. 2014). However, the efficacy of hydroxycarbamide with regards to neuroprotection in this population is inconclusive. Current studies support the use of hydroxycarbamide to maintain transcranial Doppler (TCD) velocities in children with SCD and a history of abnormal TCD velocities who have received one year of regular blood transfusion therapy, but do not support use for secondary stroke prevention in children with SCD and a history of stroke (Ware & Helms 2012; Ware et al. 2016). A recent meta-analysis of 7 studies documenting TCD measurements before and after hydroxycarbamide therapy in children with HbSS or HbSβ0 thalassaemia offers additional support for a neuroprotective effect (DeBaun and Kirkham 2016). An average decrease in TCD velocity of 25 cm/s was demonstrated after starting hydroxycarbamide therapy; TCD velocity decreases can be seen as soon as 3 months after initiating hydroxycarbamide therapy and are sustained for at least 36 months (DeBaun and Kirkham 2016; DeBaun et al. 2016). Furthermore, hydroxycarbamide may reduce cerebral metabolic stress in treated patients with SCD in comparison to untreated patients with SCD by reducing cerebral oxygen extraction fraction levels (Fields et al. 2019).In this issue of the British Journal of Haematology, Kapustin et al.(2019) showed significant differences in the white matter microstructural integrity of children with SCD treated with hydroxycarbamide in comparison to untreated children with SCD. White matter microstructure was assessed in children with HbSS aged 10 to 18 years and age-matched healthy controls with a specialized magnetic resonance imaging (MRI) sequence, diffusion tensor imaging (DTI), that characterizes the diffusion properties of water molecules. Cerebrovascular reactivity (CVR), the ability of cerebral arteries to dilate and increase cerebral blood flow, was assessed with a carbon dioxide challenge and blood-oxygen-level