Introduction:
The whole blood count is one of the most frequent biological tests in medical practice. As with any other biological parameter, its interpretation is based on comparison with predefined reference values (RV) adapted to the patient's native population. However, most of low-income countries uses reference values from western countries which populations may differ. RVs are usually established using direct methods that are described as time and resources consuming. Alternatively, indirect methods based on cumulative hospital data are suggested by authors. The aim of our study is to use these indirect methods to define RVs for haematological parameters.
Methods
We collected 44,350 whole blood count data from adult patients aged 18 to 100 performed on sysmex® Xn 550 and Xn1000 machines deployed in two university hospitals and one clinic in of Ouagadougou. Subjects under the age of 18 and pregnant women and patient from critic’s care were excluded. Data were analysed using the Reference Limit Estimator (RLE) that is a software developed and made available for free by the German Society for Clinical Chemistry and Medical Biology (DGKL. Reference values for each parameter calculated using this method correspond to values between the 2.5 and 97.5 percentiles of the distribution data for non-pathological subjects.
Results:
The derived RVs for women and men were respectively: [101.4 - 143.7] versus [120.7 - 167.7] g/L for haemoglobin concentration; [23 - 36.1] pg versus [24.4 - 36.1] pg for MCH, [313.2 - 383.2] versus [325.1 - 385.7] g/L for MCCH, with lower limits than in the literature. RVs for leukocytes ([3.22 -12.27] Giga/L) and platelets ([100 - 357] Giga/L) showed no differences between women and men.
Conclusion:
There preliminary data shows that indirect methods are credible alternative to direct methods for RVs establishment in low-income countries.
Key words: Blood count parameters, Reference values, Normal values, Indirect methods, Africa
Blood count parameters, Reference values, Normal values, Indirect methods, Africa