Study On Characteristics Of Immune Peripheral Blood Smear-positive Pulmonary Tuberculosis During Patient Treatment

Objective:In order to explore the immunological mechanisms associated withtuberculosis efficacy and to look for some effective prognosis related immunologicalbiomarkers, we observed and analyzed the clinical parameters and immunologicalfeatures of new smear-positive pulmonary tuberculosis patients before and during thetreatment.Methods:18healthy control cases and27cases of new smear positive pulmonarytuberculosis patients were included in the study.The patients were treated withstandard short-course chemotherapy and followed up monthly during thetreatment.Chest X-ray andsputum was inspected.The blood samples were obtainedmonthly to observe, by flow cytometry,the frequencies of naive T cells, effector Tcells (Teff), central memory T cells (TCM), CD4~+Foxp3~+regulatory T cells (Treg),natural regulatory T cells (nTreg) and induced regulatory T cells (CD25－iTreg).Tuberculosis antigen-specific secretion of IFN-gamma level was detected byELISPOT (Enzyme-linked Immunospot Assay, ELISPOT). Th1, Th2, inflammatoryand Treg ralative cytokines in plasma and supernatant of tuberculosis-specific antigenstimulate PBMC were deteced and analyzed by liquid assay.Result:1. Immunological characteristics of new smear positive pulmonary tuberculosispatients pretreatment:(1) The CD4~+and CD8~+lymphocyte frequencis ofpatients pretreatment were close to the healthy control group and no significantdifferences were found.(2) Compared with healthy controls, the CD4~+TCM cellfrequency of patients was significantly decreased, the frequencies of CD4~+CD45RA~+CD62L~+naive T cells and CD8~+CD45RO~+CCR7-Teff cell wassignificantly higher than the healthy controls.(3) PTB patients were groupedaccording to clinical data, the results of Naive, Teff and TCM phenotypingindicate that: CD4~+CD45RA-CD62L~+TCM cell of the cavity group (PTB-C)was significantly lower than the non-cavity group (PTB-I)(4) CD4~+Foxp3~+Treg and nTreg cell frequencies of patients pretreatmentwere the significantly higherthan the healthy controls.2. The dynamic changes of immunological characteristics during the treatment ofnew smear-positive pulmonary tuberculosis patients:(1) CD4~+TCM cellfrequence was gradually increased in the course of treatment.CD4~+TCM cellfrequence of patients at the end of1-6month during treatment significantlyhigherthan that pretreatment.(2) Compared with the non-cavity group and1month negtive-conversion group(PTB-S1), the CD4~+TCM frequenciesof cavitygroup and2-4month negtive-conversion group(PTB-S2) significantly increasedrespectively.(3) There was no significant change of CD4~+Teff frequancy duringtreatment.(4) The frequancies of CD4~+Foxp3~+Treg and nTreg increased firstand decreased afterwards during treatment. They are significantly higher at theend of1and2month than that pretreatment.(5) Compared with the non-cavitygroup (PTB-S1), nTreg frequency of cavity groupdid not increase significantly atthe end of1,2month treatment.Compared with the1month negtive-conversiongroup,2-4month negtive-conversion group did not decline obviously at the endof3-5month treatment.3. The results of dynamic cytokines assay showed that:(1)Tuberculosisantigen-specific IFN-gamma level (IFN-gamma release assay T-SPOT) wassignificantly decreased as the treatment progresses.(2) Plasma Th1, Th2andinflammatory cytokine concentration pretreatmentwere higher than healthycontrols,and they decreased significantly after treatment.(3) TB-specific antigencells secretedsignificantly higher levels of IL-2after treatment, and TNF-alphasignificantly reduced after treatment.Conclusion:1. CD4TCM cells of new smear positive pulmonary tuberculosis patients showed alower level before the treatment, and gradually increased in the course oftreatment. The elevated degree is relative to the cavity and the speed of sputumnegative conversion, suggesting that fruquency of CD4TCM cells is associatedwith prognosis. 2. The frequancies of CD4~+regulatory T cells increased first and decreasedafterwards during the treatment.The high level of Treg cell in the early treatmentperiod may correlated to the control of Pathologicalprocess, and decline duringthe late period of treatment is relative with smear-negative conversion speed.3. The tuberculosis antigen ESA-6-specific IFN-gamma level significantlyreducedwith the treatment progress. The extent of its decline is associated withsmear-negative conversion speed and cavity.4. TCM, nTreg cells, ESAT-6-specific IFN-gamma level is expected to be assess theefficacy of immune parameters, it is worth to further study expand the samplesize.