title: Establishment of haematological and immunological reference values for healthy Tanzanian children in Kilimanjaro Region.
abstract: OBJECTIVE
  To determine the normal haematological and immunological reference intervals for healthy Tanzanian children.
  
  
  METHODS
  We analysed data from 655 HIV-seronegative, healthy children from 1 month to 18 years of age from the Kilimanjaro Region of Tanzania for this cross-sectional study. Median and 95% reference ranges were determined for haematological and immunological parameters and analysed by age cohorts, and by gender for adolescents.
  
  
  RESULTS
  Median haemoglobin (Hb) and haematocrit (Hct) for all age groups were higher than established East African reference intervals. Compared to U.S. intervals, reference ranges encompassed lower values for Hb, Hct, mean corpuscular volume, and platelets. Applying the U.S. National Institute of Health Division of AIDS (DAIDS) adverse event grading criteria commonly used in clinical trials to the reference range participants, 128 (21%) of 619 children would be classified as having an adverse event related to Hb level. CD4-positive T-lymphocyte absolute counts declined significantly with increasing age (P < 0.0001). For those aged under five years, CD4-positive T-lymphocyte percentages are lower than established developed country medians.
  
  
  CONCLUSIONS
  Country-specific reference ranges are needed for defining normal laboratory parameters among children in Africa. Knowledge of appropriate reference intervals is critical not only for providing optimal clinical care, but also for enrolling children in medical research. Knowledge of normal CD4-positive T-lymphocyte parameters in this population is especially important for guiding the practice of HIV medicine in Tanzania.
authors.affiliation: Division of Pediatric Infectious Diseases, Department of Pediatrics, Duke University Medical Center, Durham, NC, USA. ann.buchanan@duke.edu
authors.forename: Ann M
authors.initials: AM
authors.lastname: Buchanan
authors.forename: Florida J
authors.initials: FJ
authors.lastname: Muro
authors.forename: Jean
authors.initials: J
authors.lastname: Gratz
authors.forename: John A
authors.initials: JA
authors.lastname: Crump
authors.forename: Augustine M
authors.initials: AM
authors.lastname: Musyoka
authors.forename: Moses W
authors.initials: MW
authors.lastname: Sichangi
authors.forename: Anne B
authors.initials: AB
authors.lastname: Morrissey
authors.forename: Jane K
authors.initials: JK
authors.lastname: M'rimberia
authors.forename: Boniface N
authors.initials: BN
authors.lastname: Njau
authors.forename: Levina J
authors.initials: LJ
authors.lastname: Msuya
authors.forename: John A
authors.initials: JA
authors.lastname: Bartlett
authors.forename: Coleen K
authors.initials: CK
authors.lastname: Cunningham
mesh_terms: D000293:Adolescent; D001774:Blood Chemical Analysis; D015496:CD4-Positive T-Lymphocytes / Q000276:immunology*; D002648:Child; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D006400:Hematocrit; D006403:Hematologic Tests / Q000592:standards*; D006454:Hemoglobins / Q000032:analysis*; D006801:Humans; D007159:Immunologic Tests / Q000592:standards*; D007223:Infant; D008297:Male; D012016:Reference Values; D013636:Tanzania
chemical_list: D006454:Hemoglobins