Significant decreased CXCR3

Background: Good's syndrome (GS) is a rare acquired immunodeficiency defined by the co-occurrence of thymoma and hypogammaglobulinemia. Follicular helper T (Tfh) cells, a specialized CD4+ T cell subset, play a critical role in supporting B-cell antibody production. The status and characteristics of Tfh cells in GS, however, remain largely unexplored. Methods: This study utilized flow cytometry to analyze CD4+CXCR5+ T cells, along with Tfh1 (CXCR3+CCR6-), Tfh2 (CXCR3-CCR6-), and Tfh17 (CXCR3-CCR6+) subsets, in three GS patients compared to twenty healthy controls (HCs). Serum levels of Th1/Th2/Th17 cytokines were also assessed. Results: The cohort included a 45-year-old female and a 70-year-old female, both with type AB thymoma, and a 47-year-old male with type A thymoma. All patients exhibited markedly reduced serum IgG levels (0.87 g/L, 1.44 g/L, 3.0 g/L) and a profound reduction or absence of peripheral B cells (0%, 0%, 3.7%). The proportions of CD4+CXCR5+ T cells and total Tfh cells in two patients (Cases 1 & 2) were comparable to HCs, while a significant increase was noted in the third patient (Case 3). A key finding was a consistent and drastic reduction in CXCR3+CCR6- Tfh1 cells across all patients, whereas Tfh2 cell frequencies were significantly elevated. Tfh17 cell percentages and Th1/Th2/Th17 cytokine profiles showed no significant alterations. Conclusion: Our findings reveal, for the first time, a pronounced decrease in circulating CXCR3+ Tfh1 cells in GS patients, suggesting a potential role for this specific immune imbalance in the disease's immunopathogenesis.