Abstract:Objective To investigate the relationship between total serum IgG concentration and tumor progression in patients with gastric cancer. Methods From January 2010 to May 2017, a total of 90 patients with gastric cancer in Sun Simiao Hospital of Beijing University of Chinese Medicine were enrolled as study subjects and 90 ageandsex-matched adults from normal physical examination were enrolled as control subjects. The serum IgG subgroup and total IgG concentrations were measured by enzymelinked immunosorbent assay. The relationships between serum IgG concentration in patients with gastric cancer and clinicopathologic features were analyzed. The numbers of plasma cells with CD138 antibody in both tumor and non-cancerous tissues were evaluated by immunohistochemistry. Results The total serum IgG concentration in patients with gastric cancer was significantly lower than that in healthy control group ［(923.6±290.5) mg/dl vs. (1072.5±298.6) mg/dl］, with a significant difference (t=3.391, P=0.001). The total serum IgG and IgG1 concentrations were correlated with lymphatic metastasis (t=3.585, P<0.001; t=3.545, P<0.001) and gastric cancer stages (t=3.669, P<0.001; t=3.401, P<0.001). Furthermore, the CD138+ plasma cells in tumor tissues were significantly fewer than those in noncancerous gastric mucosa (88.7±31.9 vs. 108.5±33.4), with significant differences (t=2.778, P=0.007). Multivariate analysis suggested that total serum IgG concentration (HR=0.411, 95%CI: 0.0940.989, P=0.011) and lymph node metastasis (HR=3.148, 95%CI: 1.9885.297, P<0.001) were independent predictors for poor prognosis. Conclusion Decreased total serum IgG concentration is closely related to tumor progression and poor prognosis in patients with gastric cancer, which indicates that the impaired humoral immunity is associated with tumor progression.

Key words:Stomach neoplasms,Immunoglobulin G,Plasma cells,Immunity,Prognosis