RESUMO
Background: Regulatory T-cells are CD4[+] cells involved in the regulation of suppression of immune response during infection. Many studies revealed that the number of these cells, increase in patients with active pulmonary TB [PTB. Few studies addressed this problem in MDR-PTB
Objective: This work aimed at studying some T reg - cell subsets in patients with MDR-PTB, compared to those with active pulmonary TB who responded to treatment as well as to healthy control subjects
Methods: Three groups were included in the study [20, in each group], group of healthy control and 2 groups as patients' groups [patients with MDR-PTB and patients' with PTB responding to treatment]. Routine blood work and CXR were done for all subjects in addition to microbiological evaluation of sputum in patients' groups. T reg - cell subsets in peripheral blood were studied by flow cytometry, using monoclonal antibodies against the following markers, CD4, CD25 and FoxP3 for identification
Results: Patients' groups, had higher frequency of T reg cell subsets, CD4[+] CD25[+] FoxP3[+] than the group of healthy subject, [P < 0.01] and treatment responders' group had non-significantly higher percentage of these cells than in patients with MDR-PTB [P > 0.05], but highly significant statistical difference for the percentage of total CD4[+] [P < 0.01]. Patients' with more radiologically extensive disease, had higher level of these cells than, in other patients [P < 0.05], with significant positive correlation
Conclusion: Although immune suppression characteristic of T reg - cells seems important in the pathogenesis of MDR-PTB, other mechanisms, immunologic, on non-immunologic are important as well