title: Low plasma selenium concentrations, high plasma human immunodeficiency virus load and high interleukin-6 concentrations are risk factors associated with anemia in adults presenting with pulmonary tuberculosis in Zomba district, Malawi.
abstract: BACKGROUND
  Although anemia is common among adults with pulmonary tuberculosis and human immunodeficiency virus (HIV) infection in sub-Saharan Africa, the factors contributing to its pathogenesis have not been well characterized.
  
  
  OBJECTIVE
  To characterize the antioxidant micronutrient status, interleukin-6 (IL-6) concentrations, and HIV load in relationship with anemia in adults with pulmonary tuberculosis.
  
  
  METHODS
  Zomba district, Malawi.
  
  
  METHODS
  Erythropoietin, IL-6, plasma HIV load, and markers of micronutrient status (hemoglobin (Hb), plasma concentrations of retinol, alpha-tocopherol, carotenoids, ferritin, zinc, and selenium) were measured in 500 adults who presented with pulmonary tuberculosis in Zomba Central Hospital, Malawi.
  
  
  RESULTS
  Among 370 HIV-positive and 130 HIV-negative adults, the prevalence of anemia was 88 and 77%, respectively (P = 0.002), and moderate to severe anemia (Hb < 80 g/l) occurred in 30 and 15%, respectively (P = 0.001). Geometric mean IL-6 concentration was 21.1 pg/ml, with no difference between HIV-positive and -negative adults. The erythropoietin response to anemia was not different between adults with elevated IL-6 and those with lower IL-6 concentrations. In a multivariate logistic regression model, HIV load, and lower plasma selenium concentrations were associated with moderate to severe anemia. In a final multivariate linear regression model, IL-6, plasma HIV load, and plasma selenium concentrations were associated with Hb concentrations.
  
  
  CONCLUSIONS
  This study suggests that low selenium concentrations, high HIV load, and high IL-6 concentrations are associated with anemia in adults with pulmonary tuberculosis in sub-Saharan Africa.
authors.affiliation: Johns Hopkins University School of Medicine, Baltimore, USA. mvlettow@imailbox.com
authors.forename: M
authors.initials: M
authors.lastname: van Lettow
authors.forename: C E
authors.initials: CE
authors.lastname: West
authors.forename: J W M
authors.initials: JW
authors.lastname: van der Meer
authors.forename: F T
authors.initials: FT
authors.lastname: Wieringa
authors.forename: R D
authors.initials: RD
authors.lastname: Semba
mesh_terms: D000328:Adult; D000740:Anemia / Q000097:blood / Q000453:epidemiology*; D015415:Biomarkers / Q000097:blood; D015897:Comorbidity; D005260:Female; D006678:HIV / Q000302:isolation & purification*; D006801:Humans; D015850:Interleukin-6 / Q000097:blood*; D016015:Logistic Models; D008295:Malawi / Q000453:epidemiology; D008297:Male; D018977:Micronutrients / Q000097:blood; D015995:Prevalence; D012307:Risk Factors; D012643:Selenium / Q000097:blood*; D012720:Severity of Illness Index; D014397:Tuberculosis, Pulmonary / Q000097:blood*
chemical_list: D015415:Biomarkers; D015850:Interleukin-6; D018977:Micronutrients; D012643:Selenium