title: Iron status predicts treatment failure and mortality in tuberculosis patients: a prospective cohort study from Dar es Salaam, Tanzania.
abstract: BACKGROUND
  Experimental data suggest a role for iron in the course of tuberculosis (TB) infection, but there is limited evidence on the potential effects of iron deficiency or iron overload on the progression of TB disease in humans. The aim of the present analysis was to examine the association of iron status with the risk of TB progression and death.
  
  
  RESULTS
  We analyzed plasma samples and data collected as part a randomized micronutrient supplementation trial (not including iron) among HIV-infected and HIV-uninfected TB patients in Dar es Salaam, Tanzania. We prospectively related baseline plasma ferritin concentrations from 705 subjects (362 HIV-infected and 343 HIV-uninfected) to the risk of treatment failure at one month after initiation, TB recurrence and death using binomial and Cox regression analyses. Overall, low (plasma ferritin<30 µg/L) and high (plasma ferritin>150 µg/L for women and>200 µg/L for men) iron status were seen in 9% and 48% of patients, respectively. Compared with normal levels, low plasma ferritin predicted an independent increased risk of treatment failure overall (adjusted RR = 1.95, 95% CI: 1.07 to 3.52) and of TB recurrence among HIV-infected patients (adjusted RR = 4.21, 95% CI: 1.22 to 14.55). High plasma ferritin, independent of C-reactive protein concentrations, was associated with an increased risk of overall mortality (adjusted RR = 3.02, 95% CI: 1.95 to 4.67).
  
  
  CONCLUSIONS
  Both iron deficiency and overload exist in TB patients and may contribute to disease progression and poor clinical outcomes. Strategies to maintain normal iron status in TB patients could be helpful to reduce TB morbidity and mortality.
authors.affiliation: Department of Nutrition, Harvard School of Public Health, Boston, Massachusetts, United States of America. sisanaka@hsph.harvard.edu
authors.forename: Sheila
authors.initials: S
authors.lastname: Isanaka
authors.forename: Said
authors.initials: S
authors.lastname: Aboud
authors.forename: Ferdinand
authors.initials: F
authors.lastname: Mugusi
authors.forename: Ronald J
authors.initials: RJ
authors.lastname: Bosch
authors.forename: Walter C
authors.initials: WC
authors.lastname: Willett
authors.forename: Donna
authors.initials: D
authors.lastname: Spiegelman
authors.forename: Christopher
authors.initials: C
authors.lastname: Duggan
authors.forename: Wafaie W
authors.initials: WW
authors.lastname: Fawzi
mesh_terms: D000328:Adult; D015331:Cohort Studies; D005260:Female; D005293:Ferritins / Q000097:blood; D015658:HIV Infections / Q000150:complications; D006801:Humans; D007501:Iron / Q000378:metabolism*; D000090463:Iron Deficiencies; D019190:Iron Overload / Q000150:complications / Q000378:metabolism; D008297:Male; D018977:Micronutrients / Q000008:administration & dosage; D011446:Prospective Studies; D013636:Tanzania / Q000453:epidemiology; D017211:Treatment Failure; D014397:Tuberculosis, Pulmonary / Q000150:complications / Q000378:metabolism* / Q000401:mortality / Q000628:therapy; D055815:Young Adult
chemical_list: D018977:Micronutrients; D005293:Ferritins; D007501:Iron