Nathan F E, Herman J H, Keashen-Schnell M, McFarland J G, Besa E C, Hadley C, Catalano P M
Department of Medicine, Medical College of Pennsylvania, Philadelphia.
Pediatr Hematol Oncol. 1994 May-Jun;11(3):325-9. doi: 10.3109/08880019409141676.
Neonatal alloimmune thrombocytopenia (NAIT) most commonly involves antibodies directed against the PlA1 antigen, but other platelet specific alloantigens have been associated with it. We describe the case of a mother whose first three infants developed NAIT secondary to anti-Bak(a) antibodies, while her fourth infant did not. The three affected infants were treated postnatally with platelet transfusions. The fourth infant was treated antenatally with one dose of intravenous immunoglobulin (IVIg) given to the mother. Postpartum analysis revealed the infant's platelets to be Bak(a)-positive but negative for elevated IgG. Maternal serum reacted with neonatal platelets in vitro, but cord serum was negative for antiplatelet antibodies. These clinical observations do not prove the efficacy of IVIg; however, they raise several questions: Why wasn't this infant thrombocytopenic? Why didn't the umbilical cord contain maternal antibody? Was the single dose of IVIg responsible for preventing NAIT? IVIg is currently under investigation in a clinical trial evaluating its effectiveness in preventing NAIT in mothers with anti-PlA1 antibodies, where it has shown some success. There have been no reports of the use against anti-Bak(a) antibodies. We suggest that a weekly dose schedule may not be necessary for all affected pregnancies, and antibodies with specificity other than anti-PlA1 may require less vigorous therapy.
新生儿同种免疫性血小板减少症（NAIT）最常见的是涉及针对PlA1抗原的抗体，但其他血小板特异性同种抗原也与之相关。我们描述了这样一个病例：一位母亲的前三个婴儿因抗Bak(a)抗体继发NAIT，而她的第四个婴儿未患病。这三个患病婴儿出生后接受了血小板输注治疗。第四个婴儿在产前通过给母亲注射一剂静脉注射免疫球蛋白（IVIg）进行治疗。产后分析显示，婴儿的血小板为Bak(a)阳性，但IgG升高呈阴性。母亲的血清在体外与新生儿血小板发生反应，但脐带血清中抗血小板抗体呈阴性。这些临床观察结果并不能证明IVIg的疗效；然而，它们引发了几个问题：为什么这个婴儿没有血小板减少症？为什么脐带中没有母体抗体？是这一剂IVIg预防了NAIT吗？目前正在进行一项临床试验，研究IVIg在预防抗PlA1抗体母亲的NAIT方面的有效性，在该试验中它已显示出一定成效。尚无使用IVIg对抗抗Bak(a)抗体的报道。我们认为，对于所有受影响的妊娠，可能无需每周给药一次，而且除抗PlA1外具有特异性的抗体可能需要的治疗力度较小。
