What is ESR?

• ESR represents the rate at which red cells in plasma settle when placed in a tube.
• It not only tells you if there is inflammation, but also its magnitude
• It can rise in both infection and inflammation
• It can change with Anemia where there are fewer red cells, as well as with Sickle cell where the shape of red cells has changed.
• Numbers over 100 are often due to infection
• It is affected by age, sex, weight, and temperature
• Severe renal failure raises the ESR

Points to Remember about ESR:

• ESR is not diagnostic by itself as it is nonspecific.
• It can be seen in different conditions including Infections, Rheumatic diseases, Vasculitis, Spondyloarthropathy (low levels), and Malignancy
• History and physical exam are needed as to decide the significance of the ESR.
• It is not always elevated in polymyalgia rheumatica (PMR).
• Levels greater than 50 are suspicious for temporal arteritis in patients over the age of fifty who present with headaches, jaw pain, or scalp tenderness.
• It has prognostic value for rheumatic diseases such as rheumatoid arthritis.
• It does not change as quickly as CRP.
• It may be useful for monitoring improvement in conditions such as temporal arteritis.

Causes of High ESR:

• Infection
• Inflammation
• Obesity
• Age
• Sex (Higher in Women)
• Pregnancy
• Kidney failure

Causes of Low ESR: 

• Anemia
• Abnormal shape of red cells (Sickle Cell)
• Elevated Hematocrit
• Chronic Illness
• CHF
• High WBC Count
• Hypofibrinogenemia

Work up of Elevated ESR: 

• CBC with diff (looking for High WBC count in case of infection, etc.)
• Rheumatoid Factor, Anti-CCP (Rheumatoid Arthritis)
• HLA-B27 (Spondyloarthropathy)
• ANA (Lupus and other Connective Tissue Diseases)
• Quantitative Immunoglobulins and Serum Immune fixation or SPEP (Monoclonal Gammopathy)
• CRP (another sign that will increase with inflammation)
• Fibrinogen (another sign that also will increase with inflammation)
• Chemistry Panel (to look at kidney function)
• Urinalysis (to look at kidney function, proteinuria)
• C-ANCA, P-ANCA (to look for vasculitis)
• Anti -GBM antibodies (to look for Goodpasture’s disease)
• Hepatitis B Surface Antigen, Hepatitis C Antibody (to look for vasculitis caused by these)
• Angiotensin Converting Enzyme inhibitor (to look for Sarcoidosis)
• Ferritin (Adult-onset Still’s Disease)

Summary

• ESR is Non-specific
• Clinical Exam often is needed to determine the significance of ESR
• ESR is not always elevated in Polymyalgia Rheumatica
• ESR over 100 often means infection
• Elevated ESR + Age 50 or higher: Need to look for Polymyalgia Rheumatica and Temporal Arteritis
• Serial ESR testing is not always reliable
• Temporal Arteritis is a clinical diagnosis. This means if you suspect it, then treat it as you do the work up