Why is my wife's ESR so high?
Q: My wife is 7 months pregnant. She has been suffering from tuberculosis (in the lymph node) for the past nine months. She was on rifampicin 600mg and INH 300mg per day and it was last week that her TB course finished. Her gynaecologist suggested to get the ESR tested. Her ESR came as 130mm/hr, haemoglobin 10.1 and the WBCs increased to 13000. At the time she was diagnosed for lymph node TB, her ESR was 72mm/hr but even after the complete course, her ESR is 130mm/hr. Why is this? Does she need further treatment?
A:Erythrocyte sedimentation rate (ESR) is a nonspecific screening test for various diseases. It is a simple and inexpensive test that measures the distance that red blood cells have fallen after one hour in a vertical column of anticoagulated blood under the influence of gravity. The amount of fibrinogen (a blood protein) in the blood directly correlates with the ESR. Although many studies have been done, an increased ESR remains a nonspecific finding. The use of the ESR as a screening test in asymptomatic persons is limited by its low sensitivity and specificity as it is affected by many variables. Women tend to have higher ESR values, as do the elderly. Obese people too tend to have raised ESR for some unknown reason though this is not thought to have any clinical significance. Any condition that increases fibrinogen levels (e.g., pregnancy, infections (including TB), diabetes mellitus, end-stage renal failure, heart disease, collagen vascular diseases, malignancy) may elevate the ESR. In anaemia the ESR rises as the speed of the upward flow of plasma is altered so that red blood cell aggregates fall faster. Macrocytic (larger) red cells with a smaller surface-to-volume ratio also settle more rapidly. Earlier, this test was commonly used as an index of disease activity in patients who had certain disorders. With the development of more specific methods of evaluation, the ESR has remained an appropriate measure of disease activity or response to therapy for only a few diseases like temporal arteritis, polymyalgia rheumatica, rheumatoid arthritis and, possibly, Hodgkin's disease. The ESR remains an important diagnostic criterion for only two diseases: polymyalgia rheumatica and temporal arteritis. No obvious cause is apparent in fewer than 2 percent of patients with a markedly elevated ESR. An elevated ESR in the absence of other findings should not prompt an extensive laboratory or radiographic evaluation but a mild to moderately raised one without any obvious cause should be repeated after a few months rather than an expensive search for occult disease. If the disease is cured, the ESR value should gradually return to normal over a period of 4 to 6 weeks.