B cell deficiency in thymoma tissues of Good’s syndrome patients

Good’s syndrome (GS) is a rare secondary immunodeficiency which is characterized by hypogammaglobulinemia and thymoma. This study aims to investigate the expression and distribution of B cells in thymoma tissue, given that B cells had been found to be reduced or absent in peripheral blood or bone marrow.

This study retrospectively analyzed thymoma tissues from 5 GS patients at the First Affiliated Hospital of Wenzhou Medical University and Zhejiang Provincial People’s Hospital. Tissues from 20 patients with simple thymoma were used as controls. Immunohistochemistry analyses were performed to detect the markers CD19, CD20, PAX5 and CD138 to evaluate the expression of B cells or plasma cells.

Compared to the control group, 4 GS patients exhibited a complete absence of B cells in their thymoma tissue, while 1 GS patient exhibited a notable reduction in B cells. The expression levels of CD19, CD20 and PAX5 in the thymoma tissues of GS patients were dramatically lower than those in the control group (0 vs. 85%, 20 vs. 85%, 20 vs. 85%, respectively; P < 0.05). However, no significant difference was observed in the expression frequency of CD138 between the thymoma tissues of the two groups (0 vs. 30%, P > 0.05).

This is the first report of B cell deficiency in 5 thymoma tissues of GS patients.