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

SummaryObjectivesImmune 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 (Treg) in patients with cavity multidrug-resistant tuberculosis (MDR-TB) before and after surgery.MethodsWe compared the proportion of Treg 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.ResultsThe proportion of CD4+CD25high and CD4+CD25+FoxP3+ Treg 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+CD25high and CD4+CD25+FoxP3+ Treg cells showed a positive correlation (r = 0.878, p < 0.001).ConclusionCirculating Treg cells are increased in proportion in patients with cavity MDR-TB and decreased after surgery. Infection with M. tuberculosis may induce Treg cell-surface molecular changes with increased numbers of cells.