RESUMO
BACKGROUND: India has the highest prevalence of multidrug-resistant TB (MDR-TB) globally. Vitamin D deficiency is potentially an important risk factor for MDR-TB.METHODS: We conducted a case-control study of 90 newly diagnosed adult MDR-TB cases, 180 household controls and 82 non-household controls in Mumbai, India. Serum 25-hydroxyvitamin D (25(OH)D), anthropometry, clinical status and history, dietary data and sociodemographic data were collected from each participant. Interferon-gamma release assay (IGRA) was also performed in controls to assess latent TB. Multivariable regression was performed to estimate associations between 25(OH)D vs. case status and IGRA positivity.RESULTS: Mean participant age was 33.8 ± 12.0 years; 72.8% had 25(OH)D <20 ng/ml. Mean 25(OH)D was significantly (P < 0.05) lower in cases (12.5 ± 7.9) than both household (17.5 ± 11.2) and non-household controls (16.4 ± 9.1). In multivariable models, 25(OH)D concentration was inversely associated with MDR-TB case status among cases and household controls (OR 0.95 per 1 ng/ml, 95% CI 0.92-0.99; P = 0.015), and among cases and non-household controls (OR 0.94 per 1 ng/ml, 95% CI 0.89-1.00; P = 0.033); 53.6% of controls were IGRA-positive. 25(OH)D status was not associated with IGRA positivity.CONCLUSION: Vitamin D status was independently associated with MDR-TB case status. Research should evaluate the effectiveness of vitamin D supplementation in prevention and adjunctive treatment of MDR-TB.
Assuntos
Tuberculose Resistente a Múltiplos Medicamentos , Tuberculose Pulmonar , Deficiência de Vitamina D , Adulto , Estudos de Casos e Controles , Humanos , Pessoa de Meia-Idade , Fatores de Risco , Tuberculose Resistente a Múltiplos Medicamentos/complicações , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Tuberculose Resistente a Múltiplos Medicamentos/epidemiologia , Tuberculose Pulmonar/diagnóstico , Tuberculose Pulmonar/tratamento farmacológico , Tuberculose Pulmonar/epidemiologia , Vitamina D , Deficiência de Vitamina D/diagnóstico , Deficiência de Vitamina D/tratamento farmacológico , Deficiência de Vitamina D/epidemiologia , Adulto JovemRESUMO
The lipopolysaccharide (LPS) of S. typhimurium has been shown to be significantly detoxified after in vivo irradiation at 500 krad. Radiation is thus a useful method for converting endotoxin into toxoid. The structural alterations in the detoxified LPS are shown to be mainly in the lipid A molecule, resulting in the loss of beta-hydroxymyristic acid.
Assuntos
Endotoxinas/efeitos da radiação , Salmonella typhimurium , Animais , Relação Dose-Resposta à Radiação , Endotoxinas/toxicidade , Lipopolissacarídeos/efeitos da radiação , Lipopolissacarídeos/toxicidade , Camundongos , Polissacarídeos Bacterianos/efeitos da radiação , Polissacarídeos Bacterianos/toxicidade , Doses de RadiaçãoRESUMO
Gamma-irradiation of S. typhimurium cells up to a dose of 500 krad significantly reduces their toxicity. However, the antigenicity of these cells is not altered, which suggests that these cells could be used as a vaccine. The protection offered by the irradiated cells is comparable to that of formalin-treated cells. The radio-vaccine, however, offers an additional advantage of significant detoxification of the endotoxin, thereby minimizing side effects. The lipopolysaccharide extracted from the irradiated S. typhimurium cells offered cross-protection against other Salmonella species tested.
