Normally red blood cells in a blood sample sediment slowly due to their negative surface, which causes cells adjacent to reject each other when intercellular distance falls below a minimum. In some conditions that cause increased acute phase proteins (α-globulins, fibrinogen) or immunoglobulin, plasma proteins attach to the surface of red blood cells and reduce potential surface and increased erythrocyte sedimentation causing their aggregation. ESR is the rate at which red blood cells from a blood sample anticoagulated in an hour sediment. The faster red blood cells sediment, the higher ESR is, being an indicator of acute phase response. An increase in ESR occurs in at least 24 hours after initiation of the inflammatory response and acute phase response, and after completion decreases with a half-life of 96-144 hours.
Compared with CRP and serum amyloid A, ESR is increased in situations that produce increased concentration of immunoglobulins, immune complexes and other proteins.
Screening test is recommended in suspected inflammatory reactions, infections, autoimmune disorders, plasma cell dyscrasias.
Monitoring the evolution and treatment of certain diseases: arteritis, rheumatoid polymyalgia, rheumatoid arthritis, rheumatic fever, systemic lupus erythematosus, Hodgkin’s disease, tuberculosis, bacterial endocarditis.
The diagnosis of temporal arteritis, rheumatoid polymyalgia.
ESR is not a diagnostic test for a disease and should not be used for screening asymptomatic patients.
Manual Westergren method: Place the tube upright in a holder and graduated millimeter read the erythrocyte sedimentation in mm after 1 hour; in some tests is read result after an interval of 2 hours, but it does not provide additional information.
Reference values :
<50 years of age: <15 mm / h <50 years of age: <25 mm / hr
> 50 years <20 mm / h > 50 years <30 mm / hr
1. Increased ESR
Collagen diseases; is the most useful test for the diagnosis and monitoring of temporal arteritis, rheumatoid arthritis and polymyalgia rheumatica.
Infections, pneumonia, syphilis, tuberculosis, subacute bacterial endocarditis.
Inflammatory diseases: acute pelvic inflammatory disease, gout, arthritis, nephritis, nephrosis.
Increased serum immunoglobulins, multiple myeloma, Waldenstrom’s macroglobulinemia.
Acute heavy metal poisoning.
Destruction of tissue / cell acute myocardial infarction, postoperative (elevated can keep up to 1 month).
Toxemia, hypothyroidism, hyperthyroidism.
Anemia acute or chronic diseases.
A moderately elevated ESR should always be investigated.
ESR increases during menstrual cycle, reaching a maximum in the premenstrual phase in pregnancy. In older women (70-89 years), apparently healthy women can have high ESR (up to 60 mm / h).
2. Factors determining increased ESR:
Medications: Oral contraceptives, dextrans (due to absorption on the surface of red blood cells), anticonvulsants, aspirin, carbamazepine, cephalothin, cyclosporine, dexamethasone, etretinate, fluvastatin, hydralazine, indomethacin, isotretinoin, lomefloxacin, methysergide, misoprostol, ofloxacin, procainamide, propafenone, quinine , sulfamethoxazole, zolpidem.
3. Factors that lower ESR:
Temperatures> 20 to 24 ° C.
Hyperlipoproteinemia (particularly Chylomicrons).
Abnormal erythrocytes: microcytes, drepanocytes, echinocytes, poichilocytes, stomatocytes, acantocytes, sferocytes (by lowering the surface necessary for erythrocyte aggregation).
Medicines: aspirin, gold, corticotropin, cyclophosphamide, corticosteroids, hydroxychloroquine, methotrexate, NSAIDs, penicillamine, sulfasalzine, tamoxifen, trimethoprim.