{kappa} and {lambda} Light Chain Composition of Antibody to the Capsular Polysaccharide of Haemophilus influenzae Type b

Concentrations of total immunoglobulins bearing κ and λ light chains were measured in the sera of 215 healthy white children aged 6 months to 10 years. Both κ and λ concentrations increased with age. However, the concentration of immunoglobulins bearing κ light chains increased at a greater rate than those bearing λ light chains (P</it> = .01). Thus, the κ:λ ratio of the youngest children (6–24 months) was significantly lower than that of the oldest (25–130 months) (P</it> = .0015). The relationship between the IgG antibody concentration and the light chain composition of the specific antibody directed to Haemophilus influenzae</it> type b (Hib) polysaccharide was also assessed in 62 of 215 serum samples with detectable Hib antibody. The IgG Hib antibody concentration was strongly correlated with the κ:λ Hib antibody ratio (r</it> = .60, P</it> = .001), and this correlation was independent of age. Thus, light chain selection and response to polysaccharides may be regulated by common mechanisms that mature late in ontogeny.