CLINICAL AND IMMUNOHEMATOLOGIC EFFECTS OF PLACENTAL BLOOD

胎盘血的临床和免疫血液学影响

• 批准号: 6302242
• 负责人: RONALD G STRAUSE
• 金额: $ 36.97万
• 依托单位: UNIVERSITY OF IOWA
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-04-01 至 2001-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6302242
• 关键词: anemia; autotransfusion; blood preservation; blood volume; clinical research; hematopoietic stem cells; hemodynamics; human subject; human therapy evaluation; newborn human (0-6 weeks); placenta; premature infant human; umbilical cord

The hypothesis to be tested is that transfusion of autologous placental/cord blood at birth will benefit preterm infants both sort- term, due to blood volume expansion and to the red blood cells (RBCs) infused, and long-term due to hematopoietic/immunologic progenitor cells (HIPC) infused. Many premature infants are born with a low RBC volume that is sometimes inapparent because the blood hematocrit can be falsely elevated by plasma volume under constriction. The consequent insufficient filing of the systemic and pulmonary vasculature impairs tissue perfusion and oxygenation and leads to RBC transfusions- particularly during the first hours and days of life. At the moment of birth, about 67% of fetal-placental blood is located within the infant's vasculature, compared to 80% when umbilical cord clamping is delayed until 60 seconds post-delivery. Current obstetrical practice is to clamp the umbilical cord immediately following delivery to prevent over- transfusion of term neonates and to permit prompt resuscitation of distressed neonates. Immediate cord clamping denies neonates the potential benefits of an autologous transfusion of RBCs and HIPC. Three specific hypotheses will be tested: 1) transfusion of autologous placental blood and RBCs will increase neonatal circulating blood volume and RBC volume and will improve cardiovascular hemodynamics to provide clinical benefit; and 3) transfusion of autologous HIPC will enhance hematologic development. These hypothesis will be tested by performing a randomized clinical study of preterm neonates, in which the results of relevant laboratory studies and clinical outcomes will be compared between control infants with standard immediate clamping (< 15 seconds) of the umbilical cord versus test infants--the latter divided into two groups depending on gestational age, with either 60 seconds delayed clamping of the cord (larger infants) of immediate clamping followed by resuscitation (smaller infants) and subsequent transfusion (within 24 hours) of autologous following delayed clamping of the umbilical cord will be collected and studies performed to assess its suitability for either later autologous RBC transfusion or HIPC banking and transplantation. These goals will be achieved by the collaborative efforts of investigators with expertise in pediatric hematology and transfusion medicine, neonatology, biochemistry and biostatistics.

要测试的假设是自体的输血 出生时胎盘/脐带血将使早产儿都受益 - 术语，由于血液体积的膨胀和红细胞（RBC） 注入，长期由于造血/免疫祖细胞而引起的 （HIPC）注入。许多早产婴儿天生有较低的RBC量 有时那是不可能的，因为血液细胞比容是错误的 在收缩的血浆体积上升高。结果 系统性和肺脉管系统的备案不足 组织灌注和氧合，导致RBC输血 - 特别是在生命的头几个小时和几天。瞬间 出生，大约67％的胎儿血液位于婴儿中 脉管系统，脐带夹紧延迟时为80％ 直到退货后60秒。目前的产科实践是夹紧 分娩后立即的脐带，以防止过度 术语新生儿的输血并允许及时复苏 苦恼的新生儿。立即的绳子夹具否认新生儿 RBC和HIPC自体输血的潜在好处。三 将测试特定的假设：1）自体的输血 胎盘血和RBC会增加新生儿循环血容量 和RBC量，将改善心血管血流动力学以提供 临床益处； 3）自体HIPC的输血将增强 血液学发育。这些假设将通过执行 早产的随机临床研究，其中的结果 将比较相关的实验室研究和临床结果 在具有标准立即夹紧的对照婴儿之间（<15秒） 脐带与测试婴儿的 - 后者分为两个 组取决于胎龄，任一60秒延迟 立即夹紧的绳索（较大的婴儿），然后 复苏（较小的婴儿）和随后的输血（在24之内 小时）自体内脐带延迟夹紧 将收集并进行研究以评估其适用性 后来的自体RBC输血或HIPC银行业务和 移植。这些目标将由协作实现 研究人员在小儿血液学和 输血医学，新生儿学，生物化学和生物统计学。