Relation of Serum and Salivary Total Sialic Acid and Total Sialic Acid/Total Protein Ratio with Clinical Parameters of Disease Progression in Preeclampsia

Sialic acid is a terminal component of carbohydrate chains of glycoproteins and glycolipids. The present study estimated total sialic acid (TSA) and its ratio with total proteins (TP), in serum and saliva of preeclampsia. The study further investigated the association of these parameters with clinical variables of disease progression. 50 preeclampsia patients (32 mild preclampsia and 18 severe preeclampsia cases) and 50 pregnant controls were included in the study. Serum and salivary free sialic acid, protein bound sialic acid and TP were measured spectrophotometrically. Serum and salivary TSA and its ratio with TP were calculated. There was a significant increase in serum TSA and its ratio with TP in preeclampsia compared to the controls. The increase reflected with the severity of the disease. Serum TSA and TSA/TP showed a significant positive correlation with blood pressure, proteinuria and a significant negative correlation with infant birth weight. In saliva, there was no statistical difference between TSA in preeclampsia and controls. Salivary TSA/TP increased significantly in preeclampsia. However the increase was not in accordance to the disease severity. Salivary TSA and TSA/TP were not significantly associated with any of the clinical parameters of disease progression. Significant increase in seum TSA reflects the disturbance in sialyation of serum proteins in preeclampsia, that could not be depicted in the saliva of these patients. Disturbance in serum protein sialyation is further exaggerated with the severity of the disease. Serum TSA and TSA/TP and not the respective salivary parameters, could serve as useful indicators in assessment of clinical progression of the disease.