Cairo M S
Division of Neonatalogy and Hematology/Oncology, Childrens Hospital of Orange County, CA 92668.
Am J Dis Child. 1989 Jan;143(1):40-6. doi: 10.1001/archpedi.1989.02150130050014.
Neonatal host defense simulates a clinical state of immunodeficiency that predisposes the preterm and term newborn to overwhelming bacterial sepsis. There are various immunologic components that are deficient in the newborn and new methods to enhance their function. Defects in both the quantitative and qualitative aspects of the neonatal phagocyte contribute substantially to the immaturity of neonates' immune systems. The neonate lacks an adequate number of granulocyte bone marrow progenitor cells, and has a decreased neutrophil storage pool and an increased tendency to peripheral neutropenia during neonatal sepsis. Additionally, the neonatal granulocyte demonstrates altered physiologic function compared with that found in the adult with respect to chemotaxis, phagocytosis, oxidative metabolism, and bacterial killing. Some recent clinical studies have suggested the benefit of using adult neutrophil transfusions as adjuvant treatment during neonatal bacterial sepsis, yet other studies have found the use of polymorphonuclear neutrophil leukocyte transfusions to be inconclusive. Reduced circulating immunoglobulins and impaired production of specific antibody have also led to recent trials in the use of prophylactic intravenous immunoglobulin in preterm infants predisposed to sepsis. Recently, hematopoietic colony-stimulating factors have been demonstrated to improve in vitro neonatal neutrophil physiologic activity. Future therapy of neonatal sepsis will depend on new nontoxic methods for enhancing neonatal host defense.
新生儿宿主防御模拟了一种免疫缺陷的临床状态，使早产和足月新生儿易患严重的细菌性败血症。新生儿存在多种免疫成分缺陷，并有增强其功能的新方法。新生儿吞噬细胞在数量和质量方面的缺陷在很大程度上导致了新生儿免疫系统的不成熟。新生儿缺乏足够数量的粒细胞骨髓祖细胞，在新生儿败血症期间中性粒细胞储存池减少，外周血中性粒细胞减少的倾向增加。此外，与成人相比，新生儿粒细胞在趋化性、吞噬作用、氧化代谢和细菌杀伤方面表现出生理功能改变。最近的一些临床研究表明，在新生儿细菌性败血症期间使用成人中性粒细胞输血作为辅助治疗有益，但其他研究发现使用多形核中性粒细胞输血的效果尚无定论。循环免疫球蛋白减少和特异性抗体产生受损也导致了最近在易患败血症的早产儿中使用预防性静脉注射免疫球蛋白的试验。最近，已证明造血集落刺激因子可改善体外新生儿中性粒细胞的生理活性。新生儿败血症的未来治疗将取决于增强新生儿宿主防御的新的无毒方法。
