Total and lipid-bound serum sialic acid in children with malignancy or infections.

Increased levels of sialic acid-containing glycoconjugates in serum have been observed in malignancies. In this study, significantly elevated serum concentrations of total sialic acid (TSA), TSA/total protein (TSA/TP) and lipid-bound sialic acid (LASA) were observed at diagnosis of children with various malignancies compared to healthy children. Serum TSA and TSA/TP were superior to LASA in differentiating solid tumors (p < 0.005) and leukemias (p < 0.05) from normal controls. In neuroblastoma and yolk sac tumors, a descending trend in TSA and TSA/TP was noted after successful treatment of the malignancy. Children with simultaneous malignancy and infection had significantly higher serum TSA (p < 0.05) and TSA/TP (p < 0.01) levels compared to patients with infectious diseases only, the corresponding areas under the curve were 0.83 and 0.88. The measurement of serum TSA and TSA/TP could be useful adjuncts in exclusion, diagnosis and follow-up of malignancies in children.