Abstract：
OBJECTIVE: To delineate the natural history of splenic complications other than loss of splenic function in children with sickle cell disease (SCD), we performed a retrospective chart review of patients with SCD treated at the Texas Children\'s Hospital.
METHODS: We determined the dates of diagnoses of splenic complications, the number of acute splenic sequestration crises (ASSC), and hydroxyurea treatment in pediatric patients with SCD. We also examined the association of hydroxyurea therapy with the onset and severity of ASSC.
RESULTS: The cumulative prevalence of splenic complications was 24.7% for splenomegaly, 24.2% for ASSC, 9.6% for hypersplenism, and 5.6% for splenectomy. The cumulative prevalence of splenic complications was highest in patients with hemoglobin Sβ0 (69.2%), intermediate in hemoglobin SS (33.3%), low in hemoglobin SC (9.0%), and non-existent in hemoglobin Sβ+. The overall event rate of ASSC was 8.3 per 100 patient-years. The event-rate was 28.4 for hemoglobin Sβ0, 10.9 for hemoglobin SS, and 3.5 for hemoglobin SC. Patients with hemoglobin SS and hemoglobin Sβ0 on hydroxyurea therapy had a significantly higher occurrence of ASSC than those who were not, with event rates of 14.2 and 3.1, respectively. The event rate was also higher for children who started hydroxyurea before age 2 years than for those who started after this age (19.8 and 9.2, respectively).
CONCLUSIONS: The prevalence and severity of splenic problems vary widely between different sickle cell genotypes, with hemoglobin Sβ0 having the most severe complications. Hydroxyurea therapy is associated with increased incidence of ASSC, particularly when initiated before 2 years of age.
METHODS: We determined the dates of diagnoses of splenic complications, the number of acute splenic sequestration crises (ASSC), and hydroxyurea treatment in pediatric patients with SCD. We also examined the association of hydroxyurea therapy with the onset and severity of ASSC.
RESULTS: The cumulative prevalence of splenic complications was 24.7% for splenomegaly, 24.2% for ASSC, 9.6% for hypersplenism, and 5.6% for splenectomy. The cumulative prevalence of splenic complications was highest in patients with hemoglobin Sβ0 (69.2%), intermediate in hemoglobin SS (33.3%), low in hemoglobin SC (9.0%), and non-existent in hemoglobin Sβ+. The overall event rate of ASSC was 8.3 per 100 patient-years. The event-rate was 28.4 for hemoglobin Sβ0, 10.9 for hemoglobin SS, and 3.5 for hemoglobin SC. Patients with hemoglobin SS and hemoglobin Sβ0 on hydroxyurea therapy had a significantly higher occurrence of ASSC than those who were not, with event rates of 14.2 and 3.1, respectively. The event rate was also higher for children who started hydroxyurea before age 2 years than for those who started after this age (19.8 and 9.2, respectively).
CONCLUSIONS: The prevalence and severity of splenic problems vary widely between different sickle cell genotypes, with hemoglobin Sβ0 having the most severe complications. Hydroxyurea therapy is associated with increased incidence of ASSC, particularly when initiated before 2 years of age.
摘要：
目的：描述镰状细胞病（SCD）患儿除脾功能丧失以外的脾并发症的自然史，我们对在得克萨斯儿童医院接受治疗的SCD患者进行了回顾性图表回顾.
方法：我们确定了脾并发症的诊断日期，急性脾隔离危象（ASSC）的数量，和羟基脲治疗小儿SCD。我们还检查了羟基脲治疗与ASSC发作和严重程度的关系。
结果：脾肿大的脾并发症的累积患病率为24.7%，ASSC为24.2%，脾功能亢进为9.6%，脾切除术占5.6%。血红蛋白Sβ0患者脾并发症的累积患病率最高(69.2%),中间血红蛋白SS（33.3%），低血红蛋白SC（9.0％），并且在血红蛋白Sβ+中不存在。ASSC的总事件发生率为8.3/100患者-年。事件发生率为血红蛋白Sβ028.4，血红蛋白SS10.9，和3.5为血红蛋白SC。血红蛋白SS和血红蛋白Sβ0接受羟基脲治疗的患者ASSC发生率明显高于未接受羟基脲治疗的患者,事件发生率分别为14.2和3.1。在2岁之前开始使用羟基脲的儿童的事件发生率也高于在该年龄之后开始使用羟基脲的儿童（分别为19.8和9.2）。
结论：不同镰状细胞基因型的脾问题的患病率和严重程度差异很大，血红蛋白Sβ0的并发症最严重。羟基脲治疗与ASSC的发病率增加有关，特别是在2岁之前开始。
方法：我们确定了脾并发症的诊断日期，急性脾隔离危象（ASSC）的数量，和羟基脲治疗小儿SCD。我们还检查了羟基脲治疗与ASSC发作和严重程度的关系。
结果：脾肿大的脾并发症的累积患病率为24.7%，ASSC为24.2%，脾功能亢进为9.6%，脾切除术占5.6%。血红蛋白Sβ0患者脾并发症的累积患病率最高(69.2%),中间血红蛋白SS（33.3%），低血红蛋白SC（9.0％），并且在血红蛋白Sβ+中不存在。ASSC的总事件发生率为8.3/100患者-年。事件发生率为血红蛋白Sβ028.4，血红蛋白SS10.9，和3.5为血红蛋白SC。血红蛋白SS和血红蛋白Sβ0接受羟基脲治疗的患者ASSC发生率明显高于未接受羟基脲治疗的患者,事件发生率分别为14.2和3.1。在2岁之前开始使用羟基脲的儿童的事件发生率也高于在该年龄之后开始使用羟基脲的儿童（分别为19.8和9.2）。
结论：不同镰状细胞基因型的脾问题的患病率和严重程度差异很大，血红蛋白Sβ0的并发症最严重。羟基脲治疗与ASSC的发病率增加有关，特别是在2岁之前开始。
