University:
Mt. San Antonio College
Course:
MEDI 90 | Medical Terminology
Academic year:

2024
Views:

471

Pages:

1
Author:

Larbi M.

Cells in Leukocytes The different cells in the leukocyte formula are expressed as a percentage, which allows their absolute number to be calculated from the absolute number of leukocytes. Absolute values are a much more accurate reflection of normality than percentages. Only absolute values should be used to define the different quantitative anomalies of the formula, percentages are a source of confusion. These should no longer appear in the reports. Leukocytes Neutrophils (PNN) G/L G/L Adult (2 sexes) 4-10 1.7-7 Child New born Physiological changes 4-12 10-25 Smokers: >12 Black ethnicity: 0,8 Pregnancy Eosinophils (PNE) G/L Basophils (GNP) G/L Lymphocytes G/L Monocytes G/L 0.05-0.5 0-0.05 1.5-4 0.1-1.2 Child <10 years: >4 Infants and children have a high absolute number of lymphocytes. This results in an increase in the percentage, which explains the common and abusive expression "inverted formula" (compared to that of the adult). This is the consequence of the progressive development of the immune system. The transition to the adult formula is between 4 and 10 years old. Leukocyte values (especially neutrophils and monocytes) are slightly higher in men than in women. In black subjects, PNN values may be physiologically lower. In this case, the normal lower values are 0.8 G/L. Platelets Platelets are fragments of cytoplasm derived from marrow megakaryocytes that participate in coagulation and hemostasis. Normal platelet values are 150 to 400 G/L. The upper threshold for the normal platelet count is difficult to determine precisely due to the overlap between normal and pathological values. There are no physiological variations dependent on age and sex. Causes of errors These errors are normally "corrected" by the laboratory. However, they must be known to the clinician so that, on the one hand, he has an idea of the limits of validity of the results returned and, on the other hand, he understands why in certain cases, only part of the blood count can be returned.