Erythrocyte rate and plasma viscosity in health and disease

Erythrocyte sedimentation rate(ESR) and plasma viscosity (PV) were assessed in patients with the following disorders: pulmonary tuberculosis (PTB); malignant lymphomas (ML) and sickle cell anaemia (SCA). Normal healthy individuals (controls) and pregnant women were also investigated. The degree of correlation between erythrocyte sedimentation rate and plasma viscosity was assessed in each case. The mean ESR values for the controls, pregnant subjects, sickle cell anaemia, pulmonary tuberculosis and malignant lymphomas patients were 14.02 +/- 16.15, 50.26 +/- 32.56, 9.12 +/- 8.84, 102.54 +/- 27.64 and 79.73 +/- 51.75 mm/hr, respectively. Similarly, their relative PV were found to be 1.69 +/- 0.13, 1.72 +/- 0.16, 1.86 +/- 0.18 2.01 +/- 0.52 and 0.24 +/- 2.18, respectively. The ESR was significantly higher in pulmonary tuberculosis, malignant lymphomas and in pregnancy but lower in SCA when compared with the control. With the exception of SCA patients, regression analysis showed that haematocrit and sex significantly influenced ESR values but not PV values. Erythrocyte sedimentation rate correlated positively with PV in patients with pulmonary tuberculosis and malignant lymphomas but not in pregnant women, SCA and normal controls. Therefore PV cannot reliably replace ESR as a routine laboratory test either in health or in disease conditions such as SCA.