Significance in neonatal myasthenia gravis of inhibitory effect of amniotic fluid on binding of antibodies to acetylcholine receptor.
The effect of amniotic fluid on the binding of anti-acetylcholine receptor (anti-AChR) antibodies from myasthenia gravis (MG) patients to AChR preparations was examined by radioimmunoassay using 125I-labelled alpha-bungarotoxin. Human amniotic fluid from healthy women in their second trimester inhibited the in-vitro interaction between antibody and antigen. This finding suggests that during pregnancy there is a similar inhibitory effect in MG on the in-vivo binding of maternal anti-AChR antibodies, transferred through the placenta, to AChR at the fetal neuromuscular junction. The presence of feto-placental inhibitory factors may explain the development of transitory muscular weakness only after birth and only in the minority of the babies born to myasthenic mothers.
D000109:Acetylcholine / Q000276:immunology*; D000653:Amniotic Fluid / Q000276:immunology*; D000818:Animals; D001666:Binding Sites, Antibody; D003429:Cross Reactions; D005260:Female; D005333:Fetus / Q000276:immunology; D005399:Fishes; D006801:Humans; D007166:Immunosuppressive Agents; D066298:In Vitro Techniques; D007231:Infant, Newborn; D007232:Infant, Newborn, Diseases / Q000276:immunology*; D008431:Maternal-Fetal Exchange; D009157:Myasthenia Gravis / Q000276:immunology*; D009469:Neuromuscular Junction / Q000276:immunology; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D011863:Radioimmunoassay / Q000379:methods; D051381:Rats; D011950:Receptors, Cholinergic / Q000276:immunology*
D007166:Immunosuppressive Agents; D011950:Receptors, Cholinergic; D000109:Acetylcholine