Quantitative Analysis of Serum IgG Galactosylation Assists Differential Diagnosis of Ovarian Cancer

CA-125, the most frequently used biomarker for ovarian cancer detection, cannot provide accurate diagnosis due to its poor specificity as it may also increase in many benign gynecological conditions. Thus, reducing the false-positive outcomes is urgently needed. Decrease in terminal galactosylated N-glycans of serum IgG has been found in various malignancies compared to healthy controls. Here, this alteration of IgG galactosylation was extended to be investigated between ovarian cancer and benign conditions with similar elevated CA-125 levels, in an attempt to effectively distinguish between false-positive subjects and ovarian cancer patients. In the study of 58 patients with elevated CA-125 levels (>35 U/mL), the degree of IgG galactosylation was measured from the relative intensities of IgG digalactosyl (G2), monogalactosyl (G1), and agalactosylated (G0) N-glycans according to the formula G0/(G1 + G2·2). This ratio was found significantly higher in the malignant group than in the benign group (0.74 vs 0...