Which component is most responsible for the increase in sedimentation rate?

The sedimentation rate, often measured by the erythrocyte sedimentation rate (ESR), is a test that determines how quickly red blood cells settle at the bottom of a test tube over a specified period. This rate can increase due to various factors in the presence of inflammation or disease.

Fibrinogen, a type of acute phase protein, plays a crucial role in this process. It enhances the aggregation of red blood cells. When inflammation occurs, the levels of fibrinogen rise, leading to an increased rate of sedimentation. The higher the fibrinogen concentration, the faster the red blood cells clump together and settle, which results in a higher sedimentation rate.

Albumin, while important in maintaining oncotic pressure in the blood, does not significantly influence sedimentation rates. Immunoglobulins can affect sedimentation but typically have a less pronounced effect compared to fibrinogen, which is more directly implicated in the aggregation of red cells during inflammatory processes. Platelets are involved in clotting but do not have a significant role in determining sedimentation rates.