Association between Gc genotype and susceptibility to TB is dependent on vitamin D status.
Eur Respir J
; 35(5): 1106-12, 2010 May.
Article
em En
| MEDLINE
| ID: mdl-19797128
ABSTRACT
Group-specific component (Gc) variants of vitamin D binding protein differ in their affinity for vitamin D metabolites that modulate antimycobacterial immunity. We conducted studies to determine whether Gc genotype associates with susceptibility to tuberculosis (TB). The following subjects were recruited into case-control studies in the UK, 123 adult TB patients and 140 controls, all of Gujarati Asian ethnic origin; in Brazil, 130 adult TB patients and 78 controls; and in South Africa, 281 children with TB and 182 controls. Gc genotypes were determined and their frequency was compared between cases versus controls. Serum 25-hydroxyvitamin D (25(OH)D) concentrations were obtained retrospectively for 139 Gujarati Asians, and case-control analysis was stratified by vitamin D status. Interferon (IFN)-gamma release assays were also performed on 36 Gujarati Asian TB contacts. The Gc2/2 genotype was strongly associated with susceptibility to active TB in Gujarati Asians, compared with Gc1/1 genotype (OR 2.81, 95% CI 1.19-6.66; p = 0.009). This association was preserved if serum 25(OH)D was <20 nmol.L(-1) (p = 0.01) but not if serum 25(OH)D was > or =20 nmol.L(-1) (p = 0.36). Carriage of the Gc2 allele was associated with increased PPD of tuberculin-stimulated IFN-gamma release in Gujarati Asian TB contacts (p = 0.02). No association between Gc genotype and susceptibility to TB was observed in other ethnic groups studied.
Texto completo:
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Base de dados:
MEDLINE
Assunto principal:
Tuberculose
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Vitamina D
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Proteína de Ligação a Vitamina D
Tipo de estudo:
Clinical_trials
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Observational_studies
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Risk_factors_studies
Limite:
Adult
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Child, preschool
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Female
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Humans
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Male
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Middle aged
País como assunto:
Africa
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America do sul
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Asia
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Brasil
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Europa
Idioma:
En
Ano de publicação:
2010
Tipo de documento:
Article