Study of some T regulatory cell subsets in patients with multi-drug resistant pulmonary tuberculosis

BackgroundRegulatory 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.ObjectiveThis 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.MethodsThree 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.ResultsPatients’ 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.ConclusionAlthough 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.