Kroll H, Kiefel V, Giers G, Kaplan C, Murphy M, Waters A, Mueller-Eckhardt C
Institut für Klinische Immunologie und Transfusionsmedizin, Justus-Liebig-Universität Giessen, Deutschland.
Beitr Infusionsther Transfusionsmed. 1996;33:150-5.
Fetal alloimmune thrombocytopenia is caused by maternal immunization against a fetal platelet alloantigen and transplacental transfer of the antibody into the fetal circulation. Since 10-20% of the fetuses or newborns are threatened by intracranial hemorrhages (ICH) early management is required. Intensive prenatal monitoring should be performed if a maternal HPA-1a antibody is known and a previous infant suffered from thrombocytopenia and/or ICH. Fetal blood sampling (FBS) should be started at 20th to 22nd weeks of gestation to assess fetal phenotype and platelet count. Different concepts to elevate the fetal platelet count have been discussed: corticosteroids, maternal intravenous immunoglobulins (ivIgG), fetal ivIgG and repeated fetal platelet transfusions. In a European survey with data from five centres maternal corticoid treatment and ivIgG infusion were accompanied by increasing fetal platelet counts in only 20 and 24% of the cases, respectively. In fetuses with very low platelet counts only transfusions of compatible platelets in short intervals are able to sustain a safe platelet count. Fetuses with mild thrombocytopenia should be monitored by subsequent FBS since it could be shown that platelet counts tend to decline during gestation. To avoid bleeding complications during and after FBS which was observed in about 5% of the cases every cord vessel puncture should be covered by a platelet transfusion. As no safe and non-invasive therapy exists for fetal alloimmune thrombocytopenia the value of prenatal screening programs in unaffected pregnancies is questionable.
胎儿同种免疫性血小板减少症是由母体针对胎儿血小板同种抗原的免疫反应以及抗体经胎盘转移至胎儿循环系统所致。由于10%-20%的胎儿或新生儿受到颅内出血（ICH）的威胁，因此需要早期处理。如果已知母体存在HPA-1a抗体，且之前的婴儿患有血小板减少症和/或颅内出血，则应进行强化产前监测。应在妊娠第20至22周开始进行胎儿血样采集（FBS），以评估胎儿的表型和血小板计数。已经讨论了提高胎儿血小板计数的不同方法：皮质类固醇、母体静脉注射免疫球蛋白（ivIgG）、胎儿静脉注射免疫球蛋白和反复进行胎儿血小板输血。在一项来自五个中心数据的欧洲调查中，母体使用皮质类固醇治疗和静脉注射免疫球蛋白分别仅在20%和24%的病例中使胎儿血小板计数增加。对于血小板计数极低的胎儿，只有短时间间隔输注相容的血小板才能维持安全的血小板计数。轻度血小板减少症的胎儿应通过后续的胎儿血样采集进行监测，因为已经表明血小板计数在妊娠期间往往会下降。为避免在胎儿血样采集期间及之后出现出血并发症（约5%的病例中观察到），每次脐带血管穿刺都应输注血小板。由于目前尚无针对胎儿同种免疫性血小板减少症的安全且无创的治疗方法，因此在未受影响的妊娠中进行产前筛查项目的价值值得怀疑。
