Micronutrients show potential against TB recurrence
and selenium may reduce the recurrence of tuberculosis during
standard treatment, suggests a new study.
The risk of a recurrence of TB was cut by 45 per cent in the study subjects receiving the supplements, and by 63 per cent in HIV-subjects, according to results of the randomised trial published in the Journal of Infectious Diseases. "Our finding of a protective effect of micronutrients against TB recurrences is relevant considering that TB reactivation is very common among HIV-infected persons," wrote lead author Eduardo Villamor from the Harvard School of Public Health. "Should this finding be confirmed in other settings, routine micronutrient supplementation might be considered a part of standard anti-TB therapy." Tuberculosis (TB) is a contagious disease that is spread through the air via sneezing, coughing, talking or spitting. Infection with the bacteria that causes TB does not necessarily mean the person will become sick as the immune system can 'wall off' the bacilli, and it can lie dormant. According to the World Health Organisation (WHO), one-third of the global population is currently infected with the TB bacillus, thought not all are sick with TB. When the immune system is weakened, however, the probability of becoming sick greatly increases. In HIV-positive people, the combination of TB and HIV can be fatal due to the immune system suppression of HIV. The new study suggests that the micronutrient supplements could be an inexpensive and effective way of reducing the risks of recurrence of infection, regardless of HIV status. Study details The Harvard researchers recruited 887 patients in Tanzania receiving tuberculosis therapy and randomly assigned them to receive either the micronutrient supplement or placebo: 471 were HIV-positive and not receiving antiretroviral therapy and 416 were HIV-negative The subjects were followed for an average of 43 months. The supplement consisted of retinol (5000 IU), vitamin B1 (20 mg), vitamin B2 (20 mg), vitamin B6 (25 mg), niacin (100 mg), folic acid (0.8 mg), vitamin B12 (50 micrograms), vitamin C (500 mg), vitamin E (200 mg), and selenium (100 micrograms). At the end of the study, the recurrence of TB was significantly reduced by 45 per cent in the subjects receiving the micronutrient supplements. Moreover, supplementation was also associated with a 57 per cent reduction in the incidence of peripheral neuropathy regardless of HIV status. Peripheral neuropathy related to damage to the peripheral nervous system, which sends signals from the brain and spinal cord to other parts of the body. Additionally, in HIV-negative subjects an increase in levels of CD3+ and CD4+ T- cells, indicating a positive effect on the immune system. "Among HIV-negative adults, micronutrients appeared to increase T cell counts and reduced the incidence of complications. The impact of micronutrient supplementation on TB-related outcomes needs to be ascertained among HIV-infected patients receiving antiretroviral therapy," stated the researchers. "Should the potential benefits of micronutrient supplementation in HIV-uninfected patients with TB be confirmed in other settings, it could become a useful and relatively inexpensive element of TB treatment regimens," they concluded. Independent comment In an accompanying editorial, Christine Stabell Benn, Henrik Friis, and Christian Wejse from Copenhagen described the research as "promising". "An important task for the research community is to agree on the importance of different micronutrients. There may be sufficient evidence to suggest that some micronutrients should always be given," they wrote. "For each of these micronutrients, we need to establish the relevant doses to gain effect and to agree on testing fixed combinations of micronutrients. Some micronutrients may have conflicting evidence with respect to effect and interaction with other micronutrients and should, therefore, be tested individually for inclusion in the minimal package of micronutrients." "If [future studies] can help us identify an inexpensive and effective adjuvant therapy for patients with TB that can reduce the incidence of relapses and potentially increase survival, they would unquestionably be worth the cost and effort." Source: The Journal of Infectious Diseases Published online ahead of print, doi: 10.1086/587846 "A Trial of the Effect of Micronutrient Supplementation on Treatment Outcome, T Cell Counts, Morbidity, and Mortality in Adults with Pulmonary Tuberculosis" Authors: E. Villamor, F. Mugusi, W. Urassa, R.J. Bosch, E. Saathoff, K. Matsumoto, S.N. Meydani, W.W. Fawzi Editorial: The Journal of Infectious Diseases Published online ahead of print, doi: 10.1086/ 587847 "Should Micronutrient Supplementation Be Integrated into the Case Management of Tuberculosis?" Authors: C. Stabell Benn, H. Friis, C. Wejse
