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Protein energy malnutrition and risk of tuberculosis infection

2002; Elsevier BV; Volume: 360; Issue: 9339 Linguagem: Inglês

10.1016/s0140-6736(02)11169-x

1474-547X

Johan R. Boelaert, Victor R. Gordeuk,

Child Nutrition and Water Access

In your June 15 Editorial,1Editorial Foie gras, fine words, and failure-just another UN summit.Lancet. 2002; 360: 2047Summary Full Text Full Text PDF PubMed Scopus (249) Google Scholar you discuss the UN World Food Summit. In June, 2002, the UN Food and Agriculture Organization (FAO) and the World Food Programme (WFP) warned at the World Food Summit of a severe, mainly drought-induced, food crisis affecting about 13 million people in six southern African countries—Lesotho, Malawi, Mozambique, Swaziland, Zambia, and Zimbabwe—which are also struck by highly prevalent HIV-1 infection (around 15–36% in adults)2Joint United Nations Programme on HIV/AIDS (UNAIDS). Report on the global HIV/AIDS epidemic, June 2000. Geneva UNAIDS, 2000.Google Scholar and tuberculosis (co-infection in a third of HIV-1–infected people). We stress the potential impact of protein energy malnutrition on the incidence of tuberculosis.There is strong evidence that primary malnutrition raises the incidence and exacerbates clinical manifestations of tuberculosis.3Macallan DC Malnutrition and tuberculosis.Diagn Microbiol Infect Dis. 1999; 34: 153-157Summary Full Text Full Text PDF PubMed Scopus (125) Google Scholar In a World War II study, Leyton4Leyton GB Effects of slow starvation.Lancet. 1946; 2: 73-79Abstract PubMed Scopus (68) Google Scholar studied hard-working prisoners of war in a German camp. Soviet prisoners had a daily caloric intake of about 1350 kcal, whereas UK prisoners received additional Red-Cross food supplies, which doubled their daily caloric intake. The rate of radiologically and microscopically confirmed pulmonary tuberculosis was 15·8-fold higher in the Soviet prisoners than in the UK prisoners (19·0 vs 1·2%). Leyton concluded that the lack of food, not poor natural immunity, was the main cause of this difference in rate.Experimental data have since corroborated this observation. Mice with protein calorie malnutrition infected intravenously with Mycobac-terium tuberculosis expressed less interferon-gamma, tumour necrosis factor α, and inducible nitric oxide in their lungs than did control mice. Malnourished mice also had decreased granulomatous reaction, higher lung bacillary load, and a more fatal tuberculosis course than did well nourished mice, which could be reversed by restoring a diet with normal protein content.5Chan J Tian Y Tanaka KE et al.Effects of protein calorie malnutrition on tuberculosis in mice.Proc Natl Acad Sci USA. 1996; 93: 14857-14861Crossref PubMed Scopus (111) Google Scholar In other studies, protein malnutrition has impaired T-cell function, particularly the production of T-helper-1 cytokines and macrophage antimycobacterial effector functions.The relation between malnutrition and tuberculosis should be highlighted in the context of the highly prevalent southern African HIV-1 and tuberculosis co-infection. HIV-1 infection devastates CD4 lymphocyte numbers but has similar immunological consequences to malnutrition, by suppressing T-helper-1 and macrophage functions, which may have an additive effect in raising tuberculosis incidence, morbidity, and mortality. Malnutrition will also increase the incidence of tuberculosis in HIV-1-negative individuals. Finally, HIV-1 infection and tuberculosis impair the nutritional state, which can lead to slim disease and consumption, respectively.Thus, a merciless vicious circle exists between these two major infections and nutritional deficiency. Therefore, an effective approach to control HIV-1 and tuberculosis infection in sub-Saharan Africa, and particularly southern Africa, needs to include food security. World leaders at the G8 summit in July, 2000, decided to tackle the three priority diseases of poverty-HIV-1 infection, tuberculosis, and malaria-and to reduce prevalence of and death from tuberculosis by 50% by 2010. The way to achieve this ambitious task is paved by medical difficulties and by societal issues, including provision of an adequate food supply. In your June 15 Editorial,1Editorial Foie gras, fine words, and failure-just another UN summit.Lancet. 2002; 360: 2047Summary Full Text Full Text PDF PubMed Scopus (249) Google Scholar you discuss the UN World Food Summit. In June, 2002, the UN Food and Agriculture Organization (FAO) and the World Food Programme (WFP) warned at the World Food Summit of a severe, mainly drought-induced, food crisis affecting about 13 million people in six southern African countries—Lesotho, Malawi, Mozambique, Swaziland, Zambia, and Zimbabwe—which are also struck by highly prevalent HIV-1 infection (around 15–36% in adults)2Joint United Nations Programme on HIV/AIDS (UNAIDS). Report on the global HIV/AIDS epidemic, June 2000. Geneva UNAIDS, 2000.Google Scholar and tuberculosis (co-infection in a third of HIV-1–infected people). We stress the potential impact of protein energy malnutrition on the incidence of tuberculosis. There is strong evidence that primary malnutrition raises the incidence and exacerbates clinical manifestations of tuberculosis.3Macallan DC Malnutrition and tuberculosis.Diagn Microbiol Infect Dis. 1999; 34: 153-157Summary Full Text Full Text PDF PubMed Scopus (125) Google Scholar In a World War II study, Leyton4Leyton GB Effects of slow starvation.Lancet. 1946; 2: 73-79Abstract PubMed Scopus (68) Google Scholar studied hard-working prisoners of war in a German camp. Soviet prisoners had a daily caloric intake of about 1350 kcal, whereas UK prisoners received additional Red-Cross food supplies, which doubled their daily caloric intake. The rate of radiologically and microscopically confirmed pulmonary tuberculosis was 15·8-fold higher in the Soviet prisoners than in the UK prisoners (19·0 vs 1·2%). Leyton concluded that the lack of food, not poor natural immunity, was the main cause of this difference in rate. Experimental data have since corroborated this observation. Mice with protein calorie malnutrition infected intravenously with Mycobac-terium tuberculosis expressed less interferon-gamma, tumour necrosis factor α, and inducible nitric oxide in their lungs than did control mice. Malnourished mice also had decreased granulomatous reaction, higher lung bacillary load, and a more fatal tuberculosis course than did well nourished mice, which could be reversed by restoring a diet with normal protein content.5Chan J Tian Y Tanaka KE et al.Effects of protein calorie malnutrition on tuberculosis in mice.Proc Natl Acad Sci USA. 1996; 93: 14857-14861Crossref PubMed Scopus (111) Google Scholar In other studies, protein malnutrition has impaired T-cell function, particularly the production of T-helper-1 cytokines and macrophage antimycobacterial effector functions. The relation between malnutrition and tuberculosis should be highlighted in the context of the highly prevalent southern African HIV-1 and tuberculosis co-infection. HIV-1 infection devastates CD4 lymphocyte numbers but has similar immunological consequences to malnutrition, by suppressing T-helper-1 and macrophage functions, which may have an additive effect in raising tuberculosis incidence, morbidity, and mortality. Malnutrition will also increase the incidence of tuberculosis in HIV-1-negative individuals. Finally, HIV-1 infection and tuberculosis impair the nutritional state, which can lead to slim disease and consumption, respectively. Thus, a merciless vicious circle exists between these two major infections and nutritional deficiency. Therefore, an effective approach to control HIV-1 and tuberculosis infection in sub-Saharan Africa, and particularly southern Africa, needs to include food security. World leaders at the G8 summit in July, 2000, decided to tackle the three priority diseases of poverty-HIV-1 infection, tuberculosis, and malaria-and to reduce prevalence of and death from tuberculosis by 50% by 2010. The way to achieve this ambitious task is paved by medical difficulties and by societal issues, including provision of an adequate food supply.