title: Determination of normal ranges for serum C3 and C4 levels in an adult Zimbabwean population.
abstract: OBJECTIVE
  To determine reference levels of serum complement proteins (C3 and C4) by analyzing the concentrations of this serum component in blood samples drawn from otherwise healthy adult Zimbabweans.
  
  
  METHODS
  This was a cross sectional study carried out at the University of Zimbabwe College of Medicine and National Blood Transfusion Services, Harare, Zimbabwe.
  
  
  METHODS
  Ninety five ethnically heterogenous apparently healthy blood donors aged between 18 and 60 years were enrolled in the study. These included 50 males and 45 females.
  
  
  METHODS
  Serum C3 and C4 levels were determined using an immuno-turbidimetric method.
  
  
  RESULTS
  Serum levels of complement (C3) ranged from 66 to 185 mg/dl. The respective levels of C4 were 15 to 52 mg/dl. These values varied significantly with age. Serum levels of C3 in patients aged 18 to 50 years were 63 to 192 mg/dl; they were lower (80 to 124 mg/dl) in patients in the 51 to 60 year old age bracket. C4 levels were lower (12 to 49 mg/dl) in the younger adults (18 to 40 years) than in those aged 41 to 60 years (24 to 53 mg/dl). The levels of both C3 and C4 did not vary with gender.
  
  
  CONCLUSIONS
  This study is probably the first to establish local reference ranges for C3 and C4 in Zimbabwe. These results should find useful clinical and research application.
authors.affiliation: Department of Medical Laboratory Sciences, University of Zimbabwe, College of Medicine, PO Box A178, Avondale, Harare, Zimbabwe.
authors.forename: R
authors.initials: R
authors.lastname: Gomo
authors.forename: E N
authors.initials: EN
authors.lastname: Sibanda
mesh_terms: D000293:Adolescent; D000328:Adult; D001782:Blood Donors; D003176:Complement C3 / Q000032:analysis*; D003181:Complement C4 / Q000032:analysis*; D003430:Cross-Sectional Studies; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D012016:Reference Values; D018709:Statistics, Nonparametric; D015030:Zimbabwe
chemical_list: D003176:Complement C3; D003181:Complement C4