Plasma and urine beta-thromboglobulin in severe preeclampsia

Beta-thromboglobulin (BTG) has been shown to be a specific platelet protein and can be used as a marker of platelet activation in preeclampsia. Concomitant studies of BTG levels in plasma and urine were performed with eight primiparous severe preeclamptic patients and eight normal primiparous women matched for age. The mean plasma BTG in the severe preeclamptic patients was 186.62 +/- 29.93 ng/ml, and in the control group 45.38 +/- 31.84 ng/ml. The P-value for the difference was highly significant (P = 0.000). In contrast, the mean urine BTG in the study group was 8.42 +/- 4.61 ng/ml, while the mean value for the control group was similar, 5.00 +/- 3.20 ng/ml. The P-value for the difference was not significant (0.05 less than P less than 0.10). These results show that urinary BTG cannot be considered an indicator of platelet activation in severe preeclampsia. A low urinary BTG concentration in the presence of high plasma BTG levels may rather express renal impairment. Failure of BTG renal clearance would contribute to further raising the level of plasma BTG.