Red Blood Cell Indices Sources of Error

Red Blood Cell Indices #2

Sources of Error in Red Blood Cell Indices

Mean Corpuscular Volume (MCV)

  • Definition: MCV is a measure of the average volume of a red blood cell.

  • Factors Causing False Elevation of MCV:

    • Autoagglutination: Occurs in conditions such as cold agglutinin disease or paraproteinemia, leading to clustering of RBCs that may produce misleadingly higher MCV values.
    • Hyperglycemia: Results in osmotic swelling of red blood cells, which in turn causes a falsely elevated MCV. This enlargement can skew results during analysis.
    • Leukocytosis: An increase in white blood cells can also contribute to an artificially high MCV measurement by influencing the population of red blood cells in a given volume of blood.

Mean Corpuscular Hemoglobin (MCH)

  • Definition: MCH is the average amount of hemoglobin per red blood cell. It is calculated from the total hemoglobin divided by the number of red blood cells.

  • Factor Causing False Elevation of MCH:

    • Hyperlipidemia: Elevated levels of lipids in the blood can falsely raise MCH values as the lipid content can interfere with hemoglobin concentration measurements.

Mean Corpuscular Hemoglobin Concentration (MCHC)

  • Definition: MCHC is a measure of the average concentration of hemoglobin in a given volume of packed red blood cells.

  • Factors Causing False Elevation of MCHC:

    • Hyperlipidemia: Similar to its effect on MCH, elevated lipids can lead to inflated MCHC values.
    • Autoagglutination: As with MCV, autoagglutination can result in spurious increases in MCHC.
    • Leukocytosis: Increased white blood cell counts can also skew MCHC results upwards.
    • Hereditary Spherocytosis: A genetic condition leading to spherically shaped red blood cells can result in falsely elevated MCHC values due to the nature of the cells’ shape and distribution.
    • Hemolysis: The destruction of red blood cells can elevate MCHC by altering the concentration of hemoglobin in the remaining RBCs.
    • Ictericia (Jaundice): Increased bilirubin levels associated with jaundice can also lead to elevated MCHC values due to the interaction between hemoglobin and bilirubin.