title: Seasonal variation in haematological and biochemical reference values for healthy young children in The Gambia.
abstract: BACKGROUND
  Haematological and biochemistry reference values for children are important for interpreting clinical and research results however, differences in demography and environment poses a challenge when comparing results. The study defines reference intervals for haematological and biochemistry parameters and examines the effect of seasonality in malaria transmission.
  
  
  METHODS
  Blood samples collected from clinically healthy children, aged 12-59 months, in two surveys during the dry and wet season in the Upper River region of The Gambia were processed and the data analysed to generate reference intervals based on the 2.5(th) and 97.5(th) percentiles of the data.
  
  
  RESULTS
  Analysis was based on data from 1141 children with median age of 32 months. The mean values for the total white cell count and differentials; lymphocyte, monocyte and neutrophil decreased with increasing age, were lower in males and higher in the wet season survey. However, platelet values declined with age (p < 0.0001). There was no evidence of effect of gender on mean values of AST, ALT, lymphocytes, monocytes, platelets and haemoglobin.
  
  
  CONCLUSIONS
  Mean estimates for haematological and biochemistry reference intervals are affected by age and seasonality in the first five years of life. This consistency is important for harmonisation of reference values for clinical care and interpretation of trial results.
authors.affiliation: Medical Research Council Unit, Fajara, Gambia. jokebe@mrc.gm.
authors.forename: Joseph
authors.initials: J
authors.lastname: Okebe
authors.affiliation: Medical Research Council Unit, Fajara, Gambia.
authors.forename: Julia
authors.initials: J
authors.lastname: Mwesigwa
authors.affiliation: Medical Research Council Unit, Fajara, Gambia.
authors.forename: Schadrac C
authors.initials: SC
authors.lastname: Agbla
authors.affiliation: Medical Research Council Unit, Fajara, Gambia.
authors.forename: Frank
authors.initials: F
authors.lastname: Sanya-Isijola
authors.affiliation: Medical Research Council Unit, Fajara, Gambia.
authors.forename: Ismaela
authors.initials: I
authors.lastname: Abubakar
authors.affiliation: Medical Research Council Unit, Fajara, Gambia.|Institute of Tropical Medicine, Antwerp, Belgium.|London school of Hygiene and Tropical Medicine, London, UK.
authors.forename: Umberto
authors.initials: U
authors.lastname: D'Alessandro
authors.affiliation: Medical Research Council Unit, Fajara, Gambia.
authors.forename: Assan
authors.initials: A
authors.lastname: Jaye
authors.affiliation: Medical Research Council Unit, Fajara, Gambia.
authors.forename: Kalifa
authors.initials: K
authors.lastname: Bojang
mesh_terms: D000367:Age Factors; D015415:Biomarkers / Q000097:blood*; D001772:Blood Cell Count; D002675:Child, Preschool; D003430:Cross-Sectional Studies; D005260:Female; D005714:Gambia; D064368:Healthy Volunteers; D006454:Hemoglobins / Q000378:metabolism*; D006801:Humans; D007223:Infant; D008297:Male; D011446:Prospective Studies; D012016:Reference Values; D012621:Seasons; D012737:Sex Factors
chemical_list: D015415:Biomarkers; D006454:Hemoglobins