title: Evaluation of locally established reference intervals for hematology and biochemistry parameters in Western Kenya.
abstract: BACKGROUND
  Important differences have been demonstrated in laboratory parameters from healthy persons in different geographical regions and populations, mostly driven by a combination of genetic, demographic, nutritional, and environmental factors. Despite this, European and North American derived laboratory reference intervals are used in African countries for patient management, clinical trial eligibility, and toxicity determination; which can result in misclassification of healthy persons as having laboratory abnormalities.
  
  
  METHODS
  An observational prospective cohort study known as the Kisumu Incidence Cohort Study (KICoS) was conducted to estimate the incidence of HIV seroconversion and identify determinants of successful recruitment and retention in preparation for an HIV vaccine/prevention trial among young adults and adolescents in western Kenya. Laboratory values generated from the KICoS were compared to published region-specific reference intervals and the 2004 NIH DAIDS toxicity tables used for the trial.
  
  
  RESULTS
  About 1106 participants were screened for the KICoS between January 2007 and June 2010. Nine hundred and fifty-three participants aged 16 to 34 years, HIV-seronegative, clinically healthy, and non-pregnant were selected for this analysis. Median and 95% reference intervals were calculated for hematological and biochemistry parameters. When compared with both published region-specific reference values and the 2004 NIH DAIDS toxicity table, it was shown that the use of locally established reference intervals would have resulted in fewer participants classified as having abnormal hematological or biochemistry values compared to US derived reference intervals from DAIDS (10% classified as abnormal by local parameters vs. >40% by US DAIDS). Blood urea nitrogen was most often out of range if US based intervals were used: <10% abnormal by local intervals compared to >83% by US based reference intervals.
  
  
  CONCLUSIONS
  Differences in reference intervals for hematological and biochemical parameters between western and African populations highlight importance of developing local reference intervals for clinical care and trials in Africa.
authors: Kenya Medical Research Institute, Kisumu, Kenya.
authors: Collins
authors: C
authors: Odhiambo
authors: Kenya Medical Research Institute, Kisumu, Kenya.
authors: Boaz
authors: B
authors: Oyaro
authors: Kenya Medical Research Institute, Kisumu, Kenya.
authors: Richard
authors: R
authors: Odipo
authors: Kenya Medical Research Institute, Kisumu, Kenya.
authors: Fredrick
authors: F
authors: Otieno
authors: U.S. Centers for Disease Control and Prevention (CDC), Bridgetown, Barbados.
authors: George
authors: G
authors: Alemnji
authors: U.S. Centers for Disease Control and Prevention (CDC), Kisumu, Kenya.
authors: John
authors: J
authors: Williamson
authors: U.S. Centers for Disease Control and Prevention (CDC), Kisumu, Kenya.
authors: Clement
authors: C
authors: Zeh
mesh_terms: D015492:AIDS Serodiagnosis / Q000592:standards; D000293:Adolescent; D000328:Adult; D001671:Biochemistry / Q000592:standards*; D001772:Blood Cell Count / Q000592:standards; D004777:Environment; D005260:Female; D014644:Genetic Variation; D006304:Health Status; D006405:Hematology / Q000592:standards*; D006801:Humans; D007630:Kenya; D008297:Male; D011446:Prospective Studies; D011786:Quality Control; D012016:Reference Values; D055815:Young Adult