Maternal antibody to fetal light chain (Inv) antigens

Abstract

We report a case of immunization by fetal light (L) chain (Inv) antigens in a primipara who had never received a transfusion. An Inv(l−a−) mother produced an immunoglobulin M anti-Inv(l) antibody in high titer to her Inv(l+a+) child. The child had an abnormal placenta and died of neonatal nephrosis at 6 months. A second child was born 3 years later. This infant's L chains were also Inv(l+a+), but the mother demonstrated no immunologic recognition of the incompatible Inv antigen as demonstrated by her anti-Inv(l) titer. The second child and his placenta were normal, and at 10 months of age he was found to have an anti-Gm(a) antibody in high titer to a maternal IgG H chain antigen. Anti-Gm antibodies in mothers and children are not uncommon and are usually not associated with noticeable disease, but the pathophysiology of maternal anti-lnv antibodies is not known.