Gm and Km phenotype frequencies in children with chronic active hepatitis (CAH) B virus infection

Epistatic effects of immunoglobulin GM and KM allotypes on outcome of infection with hepatitis C virus

Immunoglobulin GM and KM allotypes-genetic markers of gamma and kappa chains, respectively-are associated with immune responsiveness to several infectious pathogens and with survival in certain viral epidemics. We hypothesized that GM and KM allotypes affect the outcome of hepatitis C virus (HCV) infection. To test this hypothesis, we serologically allotyped 100 persons with well-documented clearance of HCV infection and 198 matched persistently infected persons. None of the GM or KM phenotypes by itself was associated with the clearance or persistence of HCV infection. Particular combinations of these phenotypes, however, were significantly associated with the outcome of HCV infection. Subjects with GM 1,17 5,13 and KM 1,3 phenotypes were over three times (odds ratio [OR], 3.57; 95% confidence interval [CI], 1.44 to 8.87) as likely to clear the infection as the subjects who lacked these phenotypes. This GM phenotype had a similar association with clearance in the absence of KM 3 (OR, 2.75; 95% CI, 1.21 to 6.23). The presence of GM 1,3,17 23 5,13 phenotype (in the absence of KM 3) was associated with persistence (OR, 0.21; 95% CI, 0.06 to 0.77), while its absence (in the presence of KM 1,3) was associated with the clearance of infection (OR, 2.03; 95% CI, 1.16 to 3.54). These results show epistatic interactions of genes on chromosomes 14 (GM) and 2 (KM) in influencing the outcome of an HCV infection. Further investigations involving candidate genes (GM, KM, HLA, and Fcgamma receptors) and cellular and humoral immune responses to HCV epitopes are needed to understand the mechanisms underlying these associations.

Frequency of Gm and Km phenotypes in children with mumps meningitis

Children with mumps meningitis, with mumps without meningitis and healthy subjects were examined for Gm 1, 2, 3, 5, 21 allotypes and for the Km 1 allotype. The comparison of the frequencies of Gm and Km phenotypes in three tested groups (each to the other) did not reveal significant differences. An association between mumps meningitis and the Gm or Km phenotypes was not found.

Genetic estimation of the humoral responses to several infectious agents

Heritabilities of antibody levels to measles, rubella, and mumps were estimated in 88 MZ and DZ twin pairs. The contribution of genetic factors in phenotypic antibody levels to measles was somewhat lower than environmental factors in both sexes (h² = 0.450 and 0.459). A significantly stronger genetic than environmental control of anti-mumps antibody levels was evident in both sexes, but more so in females (h² = 0.882) than in males (h² = 0.626). The genetic determination of anti-rubella antibodies was also significantly higher in girls (h² = 0.833), while environmental determination was greater in boys (h² = 0.350). © 1995 Wiley-Liss, Inc.