RESUMEN
OBJECTIVE: To determine reference values for full blood count parameters in a population of children 8 to 12 years old, living at an altitude of 2760 m above sea level. MATERIAL AND METHODS: Our sample consisted of 102 individuals on whom a full blood count was performed. The parameters included: total number of red blood cells, platelets, white cells, and a differential count (millions/µl and %) of neutrophils, lymphocytes, monocytes, eosinophils and basophils. Additionally, we obtained values for hemoglobin, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin, concentration of corpuscular hemoglobin and red blood cell distribution width. The results were statistically analyzed with a non-parametric test, to divide the sample in quartiles and obtain the lower and upper limits for our intervals. Moreover, the values for the intervals obtained from this analysis were compared to intervals obtained estimating+- 2 standard deviations above and below from our mean values. RESULTS: Our results showed significant differences compared to normal interval values reported for the adult Mexican population in most of the parameters studied. CONCLUSIONS: The full blood count is an important laboratory test used routinely for the initial assessment of a patient. Values of full blood counts in healthy individuals vary according to gender, age and geographic location; therefore, each population should have its own reference values.