Pilkington C, Lefvert A K, Rook G A
Department of Medical Microbiology, UCL Medical School, London.
Autoimmunity. 1995;21(2):131-5. doi: 10.3109/08916939508993361.
Neonatal autoimmune diseases are thought to be due to the transfer of maternal autoantibodies. However, there is a puzzling lack of correlation between maternal autoantibody titres and disease in the neonate. So far, no factor reliably predictive of neonatal disease has been found. Agalactosyl IgG is a variable feature of normal IgG. Preliminary studies indicated that the percentage of agalactosyl IgG is lower in the serum of normal neonates, than in the serum of the mother at delivery. Since raised % agalactosyl IgG is often associated with autoimmune disease we sought to determine whether this relationship holds true in a neonatal autoimmune disease. We measured the % agalactosyl IgG in paired maternal-cord sera from patients with myasthenia gravis, some of whom had offspring with neonatal myasthenia gravis. We found that the percentage of agalactosyl IgG was significantly higher in affected than in unaffected neonates. Moreover % agalactosyl IgG was higher in sera of affected neonates than in serum from their mothers, while unaffected infants of mothers with myasthenia had %Gal(0) lower than their mothers, mimicking the normal situation. This suggests that in affected neonates a high proportion of the IgG is synthesised by the baby itself rather than derived from the mother. This agrees with previous evidence based on the presence of idiotypes not found in the mother which implied that the neonates with neonatal myasthenia gravis produce their own autoantibodies.
新生儿自身免疫性疾病被认为是由于母体自身抗体的转移所致。然而，母体自身抗体滴度与新生儿疾病之间令人困惑地缺乏相关性。到目前为止，尚未发现可靠预测新生儿疾病的因素。无半乳糖基IgG是正常IgG的一个可变特征。初步研究表明，正常新生儿血清中无半乳糖基IgG的百分比低于分娩时母亲血清中的百分比。由于升高的无半乳糖基IgG百分比常与自身免疫性疾病相关，我们试图确定这种关系在新生儿自身免疫性疾病中是否成立。我们测量了重症肌无力患者母婴配对血清中的无半乳糖基IgG百分比，其中一些患者的后代患有新生儿重症肌无力。我们发现，患病新生儿中无半乳糖基IgG的百分比显著高于未患病新生儿。此外，患病新生儿血清中的无半乳糖基IgG百分比高于其母亲的血清，而重症肌无力母亲的未患病婴儿的无半乳糖基IgG百分比低于其母亲，这与正常情况相似。这表明，在患病新生儿中，很大一部分IgG是由婴儿自身合成的，而非来自母亲。这与之前基于母亲体内未发现的独特型的存在而得出的证据一致，该证据表明患有新生儿重症肌无力的新生儿会产生自己的自身抗体。
