Elevations of the ESR are typically associated with
increases in acute phase reactants (including fibrinogen), tumor necrosis
factor and immunoglobulins secondary to infectious, immune-mediated or
tumor-related conditions. However, the erythrocyte sedimentation rate may be
affected by many factors. While clinically useful in primary care, the general
lack of specificity can limit its usefulness.
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Hematologic Factors
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Increases ESR
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Decreases ESR
|
|
red blood cell count
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anemia
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polycythemia
|
|
red blood cell shape
|
macrocytosis, cold agglutinins, erythroid aggregates
|
sickling, microcytosis, spherocytosis
|
|
bile salts
|
|
high concentration (affects RBC membranes)
|
|
white blood cell count
|
|
extremely high WBC
|
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Protein Factors
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Increases ESR
|
Decreases ESR
|
|
fibrinogen
|
hyperfibrinogenemia
|
hypofibrinogenemia, dysfibrinogenemia
|
|
other serum proteins
|
increased gamma globulins, alpha globulins, beta
globulins, or monoclonal proteins
|
hypogammaglobulinemia
|
|
dextran
|
high molecular weight dextran
|
low molecular weight dextran
|
|
coagulation system
|
heparin
|
DIC (low fibrinogen)
|
|
Factor
|
Increases ESR
|
Decreases ESR
|
|
temperature
|
fever
|
hypothermia
|
|
nutritional status
|
extreme obesity
|
cachexia
|
|
serum cholesterol
|
high serum cholesterol
|
|
|
diet
|
|
recent feeding
|
|
organ failures
|
renal failure
|
congestive heart failure
|
|
drugs
|
|
valproic acid, steroids, anti-inflammatory agents
|
|
gender of the patient
|
females, especially during pregnancy (not early)
|
|
|
age of the patient
|
advanced age
|
|
• EDTA and
sodium citrate do not affect the ESR.
• Rouleaux
formation is the mechanism for several factors increasing the ESR.
• If there is
some suspicion that the ESR result is spurious, then other markers such as
C-reactive protein should be performed.