Why esr increase in rheumatoid arthritis?

In rheumatoid arthritis (RA), the increased ESR (erythrocyte sedimentation rate) is primarily a result of the inflammatory response associated with the disease. Here are some factors that contribute to the elevation of ESR in RA:

Increased Fibrinogen: Inflammation in RA leads to an increase in the production of acute phase proteins, including fibrinogen. Fibrinogen is a protein involved in blood clotting and can cause red blood cells to aggregate and settle more rapidly, resulting in a higher ESR.

Altered Plasma Viscosity: The inflammatory process in RA can cause changes in the composition and viscosity of the plasma. Increased levels of inflammatory proteins and other substances can make the plasma thicker and more viscous. This increased viscosity hinders the sedimentation of red blood cells, contributing to a higher ESR.

Immunoglobulin Production: RA is characterized by the overproduction of immunoglobulins, particularly rheumatoid factor (RF) and anti-cyclic citrullinated peptide (anti-CCP) antibodies. These immunoglobulins can bind to red blood cells, forming immune complexes. The presence of these immune complexes promotes red blood cell aggregation and enhances sedimentation, leading to an elevated ESR.

C-reactive Protein (CRP) Levels: CRP is another acute phase protein that is elevated in response to inflammation. While ESR and CRP are both indicators of inflammation, ESR is influenced by several factors, including fibrinogen levels and plasma viscosity, whereas CRP is more specific to the inflammatory response. High levels of CRP, along with an elevated ESR, can suggest the presence of active inflammation in RA.

It's important to note that while an elevated ESR is commonly observed in RA, it is not specific to the disease and can be influenced by various other factors, medical conditions, and medications. Therefore, ESR is usually considered in conjunction with other clinical findings, laboratory tests, and diagnostic criteria to assess disease activity and monitor treatment response in individuals with rheumatoid arthritis.