Immunoglobulin D (IgD) and IgD receptor expression in diffuse large B-cell lymphoma.

Immunoglobulin D (IgD) levels are often elevated in patients with autoimmune diseases. However, the oncogenic activities of IgD and IgD receptor (IgDR) in diffuse large B-cell lymphoma (DLBCL) have not been reported in detail. Therefore, we aimed to investigate the expression of IgD and IgDR in patients with DLBCL. Membrane IgD (mIgD) and IgDR expression in tissue samples was analyzed using IHC, mIgD and IgDR expression on peripheral blood mononuclear cells (PBMCs) was analyzed by FCM, and secreted IgD (sIgD) level was analyzed by ELISA. Fisher's exact test and Spearman correlation analysis were used to evaluate the relationship between IgD, IgDR, and clinical parameters. The pathological lymph nodes of 34 patients with DLBCL were studied, and mIgD and IgDR expression was found in 16 and 19 patients. mIgD and IgDR expression was upregulated in patients with DLBCL and mIgD expression was significantly associated with IgDR expression. Further correlation analysis showed that mIgD expression was correlated with serum β-MG level and Hans algorithm as germinal center B (GCB), whereas IgDR expression correlated with serum LDH level, IPI score and GCB. ELISA showed that sIgD level was significantly increased in DLBCL patients and it correlated with serum β-MG and LDH levels. FCM showed that mIgD and IgDR expression in PBMCs of patients with DLBCL was significantly higher than that in healthy controls. Our findings suggest that overexpression of IgD and IgDR is an abnormal activation state in DLBCL.