Antibody responses to three pneumococcal polysaccharides (types 3, 14, and 18C) were analysed after vaccination with a 23-valent polysaccharide vaccine. Antibodies to all three polysaccharides could be detected before immunization. Clear cut IgG, IgA, and/or IgM antibody responses to the polysaccharides were seen in three-quarters of the vaccinees. IgG2 was the predominant and IgG1 the second most abundant subclass of anti-pneumococcal IgG antibodies both before and after the vaccination. The relative proportions of IgG2 and IgG1 antibodies exhibited a continuous variation from 1:0 to approximately 0:2. After vaccination, G2m(n)-positive homozygotes had about four times more IgG2 antibodies (anti-14 and anti-18C) than G2m(n)-negative vaccinees. Heterozygotes occupied an intermediate position. The same pattern was seen less clearly in type 3 antibodies after vaccination, and in all three antibodies before vaccination. The G2m(n) allotypes had no detectable effect on the levels of IgG1, IgG4, or IgM antibodies, and possibly a weak effect on IgG3 and IgA antibodies (G2m(n)-positive homozygotes responded strongly).
A study was carried out to search for underlying immunoglobulin deficiencies in 25 patients with recurrent or chronic sinusitis. The mean duration of the patient histories of recurrent or chronic sinusitis was 7.2 years. Concentrations of serum immunoglobulins and specific pneumococcal antibodies were measured in the patients and in 25 age- and sex-matched control individuals. The mean serum IgA concentration (1.6 g/L) was lower in the patients than in the control individuals (2.1 g/L, p = .024). On the other hand, the mean serum concentration of IgG antibodies to pneumococcal type 14 polysaccharide was higher in the patients (2.54 microg/mL) than in the control individuals (0.92 microg/mL, p = .008). However, elevated concentrations of IgG antibodies to pneumococcal type 14 polysaccharide were detected mainly in patients with the highest serum IgA concentrations. The results suggest that in a subpopulation of patients with a long-lasting history of sinusitis, a low serum IgA concentration may be associated with a susceptibility to sinusitis.
The concentrations of seven immunoglobulin isotypes (IgA, IgE, IgM, IgG1, IgG2, IgG3, and IgG4) were measured in the sera of 207 Finnish blood donors, and they were allotyped with anti-Gm antibodies: anti-f, anti-a, anti-x, and anti-n. The above population could be divided into 12 phenotypes, and significant differences in isotype concentrations between different phenotypes were observed. They are best explained by postulating that the following alleles of different loci are associated with a high concentration of the product of the locus: a(x)-IgG1, n-IgG2, b-IgG3, and perhaps 4b-IgG4. The following concentration differences between the low and the high homozygotes were found: IgG1, 1.2-fold; IgG2, 1.5-fold; and IgG3, 2.6-fold. No significant allotype-associated differences in the concentrations of IgA, IgM, or IgE could be detected.
Antigenicity of two Haemophilus influenzae type b (Hib) conjugate vaccines was studied by immunizing adults and 2-year-old children. Both vaccines induced strong anti-Hib responses and strong antibody responses to diphtheria toxin (DT), the protein part of the conjugate. The adults' responses were stronger than the children's. A conjugate of Hib oligosaccharide and mutant diphtheria toxin (HbOC) emerged as slightly superior to a conjugate of Hib polysaccharide and diphtheria toxoid (PRP-D). HbOC induced somewhat higher total anti-Hib responses and significantly higher IgG1 anti-Hib responses than PRP-D. IgG1 and IgG2 were the main IgG subclasses of the anti-Hib antibodies, whereas IgG1 and IgG4 were the main subclasses of the anti-DT antibodies. Within this main rule, the ratio IgG1/IgG2 of anti-Hib antibodies varied between individuals. The average ratio was higher than five in children but approximately one in adults. It was lower in adult recipients of the polysaccharide conjugate (0.69) than in adult recipients of the oligosaccharide conjugate (1.55). A large interindividual variation was observed in concentrations of IgG2 of Hib specificity, perhaps reflecting a small number of IgG2-committed B-cell clones participating in the response.
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