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.

要检验的假设是自体输血 出生时的胎盘/脐带血对早产儿都有好处 术语，由于血容量扩张和红细胞 (RBC) 由于造血/免疫祖细胞而输注且长期 （重债穷国）注入。许多早产儿出生时红细胞量较低 这有时是不明显的，因为血液血细胞比容可能会被错误地表示 收缩时血浆容量升高。随之而来的 全身和肺血管系统损伤的填充不足 组织灌注和氧合并导致红细胞输注- 特别是在生命的最初几个小时和几天里。此刻 出生时，大约 67% 的胎儿胎盘血液位于婴儿体内 与延迟脐带结扎时的 80% 相比，脉管系统 直到分娩后 60 秒。目前产科的做法是钳夹 分娩后立即剪断脐带，以防止过度 足月新生儿的输血并允许及时复苏 苦恼的新生儿。立即钳夹脐带可阻止新生儿 自体输注红细胞和 HIPC 的潜在益处。三 将检验具体假设：1）自体输血 胎盘血和红细胞会增加新生儿循环血量 和红细胞体积，并将改善心血管血流动力学，以提供 临床效益； 3）输注自体HIPC将增强 血液学发育。这些假设将通过执行 早产儿的随机临床研究，其中结果 将比较相关实验室研究和临床结果 对照组婴儿之间采用标准立即夹紧（< 15 秒） 脐带与测试婴儿的对比——后者分为两部分 根据胎龄分组，延迟 60 秒 夹紧脐带（较大婴儿） 立即夹紧，然后 复苏（较小的婴儿）和随后的输血（24 天内） 延迟结扎脐带后自体移植（小时） 将收集并进行研究以评估其适用性 随后进行自体红细胞输注或 HIPC 银行 移植。这些目标将通过合作来实现 具有儿科血液学专业知识的研究人员的努力 输血医学、新生儿学、生物化学和生物统计学。