Gm allotypes influence the production of IgG3 but the effect is age-dependent.
Serum concentrations of IgG3 were found to be higher in Gm-f-positive (= b-positive) than in f-negative individuals except in young children. Young children aged 3-4 months had a mean concentration of 0.24 g/l of IgG3 regardless of allotype. The concentration gradually rose with age in f-positive individuals to a geometric mean of 0.56 g/l in adults but it remained essentially unchanged in f-negative people. A corresponding allotype effect was seen in influenza-specific antibody responses. While the total IgG response (mainly IgG1) was equally strong in f-positive and in f-negative patients, f-positive (= b-positive) patients produced more IgG3 antibodies than f-negative patients. The difference between geometric mean values of opposite homozygotes (f/f versus f-negative) was 2.3-fold (p = 0.0113). This finding indicates that the b-positive gamma-3 allele is more productive than the g-positive allele.
Rautonen
N
N
Department of Bacteriology and Immunology, University of Helsinki, Finland.
Sarvas
H
H
Julkunen
I
I
Pyhälä
R
R
Mäkelä
O
O
D000328:Adult; D000367:Age Factors; D000911:Antibodies, Monoclonal; D000914:Antibodies, Viral / Q000276:immunology; D002675:Child, Preschool; D006801:Humans; D007126:Immunoglobulin Allotypes / Q000276:immunology*; D007074:Immunoglobulin G / Q000096:biosynthesis*; D007223:Infant; D009980:Influenza A virus / Q000276:immunology; D007251:Influenza, Human / Q000276:immunology; D011863:Radioimmunoassay
D000911:Antibodies, Monoclonal; D000914:Antibodies, Viral; D007126:Immunoglobulin Allotypes; D007074:Immunoglobulin G