Antiacetylcholine receptor antibody in neonatal myasthenia gravis
J. O. Donaldson, A. S. Penn, R. P. Lisak, O. Abramsky, T. Brenner and D. L. Schotland
Maternal titers to antiacetylcholine receptor antibody (anti-AChR Ab) were
higher in two mothers with myasthenia gravis (MG) who had infants with
neonatal MG than the nearly normal values in two mothers with MG who had
unaffected infants. In one unaffected infant, another IgG antibody crossed
the placenta, but an IgM antibody did not. In neonates there seems to be a
correlation between the concentration of anti-AChR Ab and the presence and
severity of the neonatal syndrome. The absence of fetal symptoms of MG and
the delayed onset or worsening of some cases of neonatal MG may be due to
high fetal levels of alpha-fetoprotein and its decline in concentration in
infants after birth.