Decrease in CD4⁺CD25⁺FoxP3⁺ T_reg cells after pulmonary resection in the treatment of cavity multidrug-resistant tuberculosis

Summary 

Objectives

Immune regulatory mechanisms may limit the immunopathologic condition of infection with Mycobacterium tuberculosis and suppress cellular immune responses in the host. We investigated the CD4⁺CD25⁺FoxP3⁺ circulating regulatory T cells (T_reg) in patients with cavity multidrug-resistant tuberculosis (MDR-TB) before and after surgery.

Methods

We compared the proportion of T_reg cells in 13 patients with cavity MDR-TB pre- and postoperatively and in 10 healthy control subjects by flow cytometry using three specific markers in peripheral blood lymphocytes: cell-surface CD4 and CD25 expression and intracellular FoxP3 expression.

Results

The proportion of CD4⁺CD25^high and CD4⁺CD25⁺FoxP3⁺ T_reg was significantly higher in patients with cavity MDR-TB and at 1-month postoperatively than in healthy controls (p<0.001). The proportion of CD4⁺ and CD4⁺CD25⁻ cells was significantly lower in patients with cavity MDR-TB than in controls (p<0.001). Pre- and postoperative proportions of CD4⁺CD25^high and CD4⁺CD25⁺FoxP3⁺ T_reg cells showed a positive correlation (r=0.878, p<0.001).

Conclusion

Circulating T_reg cells are increased in proportion in patients with cavity MDR-TB and decreased after surgery. Infection with M. tuberculosis may induce T_reg cell-surface molecular changes with increased numbers of cells.

Keywords: Multidrug-resistant tuberculosis, CD4⁺CD25⁺FoxP3⁺ T_reg, Surgery