ASSOCIATION BETWEEN MATERNAL Gm ALLOTYPE AND NEONATAL SEPTICAEMIA WITH GROUP B STREPTOCOCCI

Abstract

SUMMARY Thirty‐four mothers to infants seriously infected with group B streptococci (GBS) were investigated for Glm(1) and G3m(5) allotype markers. The frequency of Gm(1, ‐5) was 14.7%, of Gm(1, 5) 20.6% and Gm(‐1, 5) 64.7%. There was a marked deficit of Gm(1) individuals and the distribution significantly differed from that in the normal Swedish population.

Correlation between Low Levels of Maternal IgG Antibodies to R Protein and Neonatal Septicemia with Group B Streptococci Carrying R Protein

“…The finding was later confirmed and extended to types la, lb and II by several authors [4,8,19], It has also been shown that the protective ma ternal antibodies are of the IgG class [4,8,19]. Previ ous studies indicated that mothers of GBS-infected infants have low levels of IgG antibodies against a number of bacterial carbohydrate antigens [5] and that this deficiency is probably genetically based [7], In contrast to carbohydrate antigens, little is known about the role of bacterial protein antigens in neonatal GBS infections. However, in vitro studies indicate that GBS protein antigens might exert an an tiphagocytic effect [18].…”

Deficiency of IgG Subclasses in Mothers of Infants with Group B Streptococcal Septicemia

“…An abnorm al Gm allotype distribution with an increased num ber o f G3m(5) phenotype individuals and G3m(5,5) homocygotes has previously been described in these mothers [12]. The Gm phenotype G3m(5,5) is known to be associat ed with G2m (-23, -23) and low IgG2 levels [18] and with IgG2 deficiency [23].…”

“…In previous studies, we have shown that such mothers in general are low IgG responders to a wide spectrum of bacterial carbohydrate antigens [5]. Furthermore, they differ significantly from the popu lation with respect to Gm -allotypes, indicating that their relative deficiency in production of such IgG an tibodies might be genetically determined [ 12].…”

Low Levels of Antibodies to Surface Antigens of Group B Streptococci in Commercial IgG Preparations

“…On this background, it has been suggested to vaccinate women with GBS anti gens, i.e., with the type-specific carbohydrate antigens [4], However, recent reports indicate that individuals with low prevaccination levels of antibodies against bacterial carbohydrate antigens respond poorly to immunization with such antigens [14], Our studies in dicate that mothers to GBS-infected infants may be poor responders to bacterial carbohydrate antigens on a genetical basis (6,8]. Another possibility might be to protect the infant at risk by passive immuniza tion of the mother with IgG antibodies against GBS antigens.…”