Correlation between G2m(n) immunoglobulin allotype and human antibody response and susceptibility to polysaccharide encapsulated bacteria.

Abstract

To determine whether genetic factors influence the human antibody response to polysaccharides, we correlated Ig allotypes with the concentrations of antibody to 14 bacterial capsular antigens in 130 actively immunized Caucasian adults. The 88 individuals possessing G2m(n), an allotype antigen of IgG2 subclass heavy chains, had significantly higher postimmunization antibody levels to Haemophilus influenzae type b (Hib) and 8 of 11 pneumococcal types (P < 0.05) than the 42 lacking this antigen. For Hib, pneumococcus type 14, and meningococcus group C, an increased response was observed in IgG class but not in IgM or IgA classes of antibody. The G2m(n) positive individuals also had higher preimmunization antibody levels to most polysaccharide antigens. Total IgG2 concentrations were correlated with the mean postimmunization antibody concentrations to pneumococci (P = 0.005), but this correlation was independent of G2m(n) by multiple regression analysis.To determine if the lack of G2m(n) was associated with increased susceptibility to infection, we compared the frequencies of various Ig allotypes in 98 children infected with Hib and 98 matched controls. Caucasian children with Hib infections other than epiglottitis were significantly more likely to lack the G2m(n) allotype than controls (P < 0.05). G2m(n) negative Caucasian children . 18 mo old have a 5

Coexistence of (Partial) Immune Defects and Risk of Recurrent Respiratory Infections

“…The IgG2 subclass is the main antipolysaccharide antibody and patients with IgG2 subclass deficiency are more prone to develop pneumonia, sinusitis, and invasive pneumococcal disease (4 ). The G2m(n) allotype of IgG2 has been associated with increased susceptibility to infections with encapsulated bacteria (5 ). The link between IgG2 and phagocytosis of encapsulated bacteria is constituted by Fc␥ receptor (R) IIa, the only Fc␥ receptors that bind IgG2 (6 ).…”

Correlation of the Km(1) immunoglobulin allotype with anti-polysaccharide antibodies in Caucasian adults.

“…constant regions of heavy or light chains of immunoglobulins. We have recently reported that the allotype of IgG-2 heavy chains, G2m(n), is correlated with the human IgG antibody response and susceptibility to polysaccharide encapsulated bacteria in Caucasians (11). Here we examine the relationship of Km allotypes, antigenic markers on kappa light chains, to the light chain distribution of the antibody response.…”

Immunoglobulin constant heavy G chain genes as risk factors in childhood allergies

“…In infectious diseases, patients with the IGHG*bfn/*bfn diplotype(=B1/B1-cells) have a better outcome of bacterial infections as a consequence of a high production of specific bacterial antibodies especially to polysaccharide antigens (20,21) and a more favourable outcome in autoimmune juvenile chronic arthritis (22). Furthermore the IGHG*bf-n/*bf-n diplotype (=B2/B2-cells), which was infrequent in children with a family history of allergy and atopy, is common in IgG2 deficiency and in common variable immunodeficiency (23,24).…”