RESUMO
To confirm and refine associations of human leukocyte antigen (HLA) genotypes with variable antibody (Ab) responses to hepatitis B vaccination, we have analyzed 255 HIV-1 seropositive (HIV(+)) youth and 80 HIV-1 seronegatives (HIV(-)) enrolled into prospective studies. In univariate analyses that focused on HLA-DRB1, -DQA1, and -DQB1 alleles and haplotypes, the DRB1*03 allele group and DRB1*0701 were negatively associated with the responder phenotype (serum Ab concentration > or = 10 mIU/mL) (P = 0.026 and 0.043, respectively). Collectively, DRB1*03 and DRB1*0701 were found in 42 (53.8%) out of 78 non-responders (serum Ab <10 mIU/mL), 65 (40.6%) out of 160 medium responders (serum Ab 10-1,000 mIU/mL), and 27 (27.8%) out of 97 high responders (serum Ab >1,000 mIU/mL) (P < 0.001 for trend). Meanwhile, DRB1*08 was positively associated with the responder phenotype (P = 0.010), mostly due to DRB1*0804 (P = 0.008). These immunogenetic relationships were all independent of non-genetic factors, including HIV-1 infection status and immunodeficiency. Alternative analyses confined to HIV(+) youth or Hispanic youth led to similar findings. In contrast, analyses of more than 80 non-coding, single nucleotide polymorphisms within and beyond the three HLA class II genes revealed no clear associations. Overall, several HLA-DRB1 alleles were major predictors of differential Ab responses to hepatitis B vaccination in youth, suggesting that T-helper cell-dependent pathways mediated through HLA class II antigen presentation are critical to effective immune response to recombinant vaccines.
Assuntos
Formação de Anticorpos/genética , Antígenos HLA-DR/genética , Vacinas contra Hepatite B/uso terapêutico , Adolescente , Análise de Variância , População Negra/genética , Brasil , Feminino , Variação Genética , Soronegatividade para HIV , Antígenos HLA-D/genética , Cadeias HLA-DRB1 , Haplótipos/genética , Vacinas contra Hepatite B/imunologia , Hispânico ou Latino/genética , Humanos , Masculino , Análise Multivariada , Polimorfismo de Nucleotídeo Único , África do Sul , Estados Unidos , População Branca/genética , Adulto JovemRESUMO
OBJECTIVE: To evaluate cord blood and predose nevirapine concentrations in infants exposed to the two-dose intrapartum neonatal nevirapine regimen. METHODS: The authors obtained plasma samples for nevirapine assay from cord blood and just prior to the 48-hours to 72-hours after birth neonatal nevirapine dose from a subset of infants participating in PACTG 316, a randomized, placebo-controlled trial of the two-dose intrapartum neonatal nevirapine regimen added to standard antiretroviral therapy. RESULTS: Nevirapine concentrations were measured in 109 cord blood samples and 149 predose samples. Cord blood nevirapine concentrations were below the target concentration of 100 ng/mL (10-times the in vitro IC(50) of nevirapine against wild-type HIV) in eight (7%) of 109 infants (95% confidence interval [CI], 3%-14%); the concentrations in six of these infants were below the assay limit of quantitation. Predose infant nevirapine concentrations were below 100 ng/mL in 23 (15%) of 149 infants (95% CI, 10%-22%); the concentrations in 13 of these infants were below the assay limit of quantitation. Lower predose nevirapine concentrations were associated with lower cord blood concentrations and a shorter interval between maternal dosing and delivery. All but one of the infants with predose nevirapine concentrations below the assay limit of quantitation were born less than 2 hours after maternal dosing. CONCLUSION: Infants born less than 2 hours after maternal nevirapine dosing during labor should receive a dose of nevirapine immediately after birth in addition to the standard infant dose at 48 to 72 hours.