Free and bound forms of sialic acid in blood plasma of patients with chronic lymphocytic leukemia

Abstract

The level of free and bound forms of sialic acids (SА) was investigated in chronic lymphocytic leukemia (CLL) and at different stages of receiving chemotherapy. Determination of sialic acid in blood plasma of patients with CLL before treatment were carried out on the first day and 2 months after taking chemotherapy drugs for combination schemes. Hematologically healthy donors represented the control group. Determination of SA was conducted by thiobarbituric method using trichloroacetic acid for distribution of total sialic acids onto free, protein bound sialic acid, and oligo bound sialic acid. Levelof free sialic acid in serum in chronic lymphocytic leukemia was equal to 43.2% compared to the total number of plasma. On the first day of chemotherapy on background of the general level of oligo bound sialic acids we observed increase in free sialic acid by 24.2% compared to patients not receiving treatment. The level of sialic acids increased 2.6 times compared to norm and featured no significant changes at different stages of treatment. The concentration of sialic acids bound to proteins at 73.4% was lower compared to the control group. After receiving chemotherapy on the first day there was a decline of this indicator to 56.2% compared to groups of patients before treatment. Two months after the treatment the level of all parameters under study returned back to the values obtained at the start of treatment. This data can serve as an additional efficiency criterion of the chemotherapy.

Keywords

• glycoconjugate
• polychemotherapy
• N-acetylneuraminic acid
• neuraminidase
• sialyltransferase