AAMA CMA Practice Question

Inflammation increases acute-phase plasma proteins such as fibrinogen that promote rouleaux formation, making red blood cells heavier and causing them to fall more rapidly in the ESR tube. Diseases characterized by systemic inflammation-such as rheumatoid arthritis-therefore raise the ESR. Conditions that increase red cell mass (polycythemia vera), alter cell shape (sickle cell disease), or hemoconcentrate blood (severe dehydration) usually decrease or have minimal effect on the ESR because aggregation is reduced or blood viscosity is increased.