Expression Of Treg Cells Subtype In Patients With Acute Exacerbation Of Chronic Obstructive Pulmonary Disease And Its Correlation With Systemic Inflammatory Markers

[Objective] To investigate the expression of Treg cells in peripheral blood(PB) of patients involved in acute exacerbation of chronic obstructivepulmonary disease (AECOPD), stable chronic obstructive pulmonarydisease(SCOPD) and healthy controls and study its correlation with clinicalfeatures，especially systemic inflammatory markers.[Method] Outpatients and inpatients in the First Affiliated Hospital ofGuangxi Medical University from March1,2013to November3,2013weretaken as the research objects.25patients of AECOPD,25SCOPD patients and25healthy control persons were observed. The age, Sex, smoking history, bodymass index (BMI), lung function, C-reactive protein, fibrinogen, arterial bloodgas were collected, ELISA was used to detect the level of TNF-α, and flowcytometry was adopted to detect the proportion of CD4+CD25+CD127low,CD4+CD25+CD62L+, CD4+CD25+CD45RA+and CD4+CD25+CD45RO+Treg cells in peripheral blood.[Result] 1.Changes of clinical indicators of patients with AECOPD and theircorrelation：Sex ratio, age of the three groups were of no significant difference,BMI and smoking index was of no significant difference between AECOPDgroup and SCOPD group (P<0.05);PaCO2in AECOPD group was higher thanthat in SCOPD group, while FVC value, FEV1/FVC(%), and FEV1%predvalues of the former was lower than those of the latter (P<0.05); Fibrinogen,C-reactive protein and TNF-α of AECOPD group were higher than those ofSCOPD group with statistical significance (P <0.05); Fibrinogen of patientswith AECOPD was negatively correlated with their BMI and FEV1%pred(r=-0.670, r=-0.695, P＜0.05), but was positively correlated with their PaCO2RV/TLC（r=0.643，r=0.803，P＜0.05）.2.Treg cells subtypes of AECOPD: Compared with those in the normalcontrol group, the percentage of CD4+CD25+CD127lowandCD4+CD25+CD45RA+showed slightly lower in AECOPD group and SCOPDgroup (P<0.05), and those in AECOPD group showed the significant decreasethan those in group SCOPD (P<0.05). Compared with the normal control group,the percentage of CD4+CD25+CD45RO+were significant higher in AECOPDand SCOPD group (P<0.05), and those in AECOPD group showed much higherthan SCOPD group (P<0.05). Compared with those in the normal control group,the percentage of CD4+CD25+CD62L+showed slightly lower in AECOPDgroup and SCOPD group (P<0.05), and there were no significantly differentbetween AECOPD group and SCOPD group (P>0.05).3. Correlation of Treg cells subtypes of AECOPD with clinical indicators:The percentage of CD4+CD25+CD127low, CD4+CD25+CD62L+,CD4+CD25+CD45RA+and CD4+CD25+CD45RO+in patients with AECOPDwere not significantly correlated with the smoking index and BMI; The percentage of CD4+CD25+CD127low in patients with AECOPD was positivelycorrelated with PaO2、FEV1%pred (respectively r=0.641，r=0.737，P＜0.05)，was negatively correlated with PaCO2, RV/TLC （respectively r=-0.744,r=-0.564， P＜0.05), but had no significant correlation with systemicinflammation markers; The percentage of CD4+CD25+CD45RO+in patientswith AECOPD was positively correlated with PaCO2, fibrinogen（respectivelyr=0.463, r=0.641, P＜0.05）, was negatively correlated with PaO2（r=-0.652，P＜0.05),but had no significant correlation with lung function; The percentageof CD4+CD25+CD45RA+and CD4+CD25+CD62L+in patients with AECOPDshowed no correlation with their systemic inflammation markers, lung functionand arterial blood gas.4.COPD patients were conducted phenotype study according to theemphysema, BMI and the frequency of acute exacerbations. The percentages ofCD4+CD25+CD127lowand CD4+CD25+CD45RA+in emphysema group werelower than those in no emphysema group, and the percentage ofCD4+CD25+CD45RO+in emphysema group was significantly higher than thatin no emphysema group. There were no significant differences ofCD4+CD25+CD62L+between the two groups. These four indicators werefound no significant difference between BMI=1group and BMI>1group.There were no significant differences of these four indicators between the groupwith frequent reoccurrence and the group without frequent reoccurrence.[Conclusion]1. For AECOPD patients, not only the number of Treg cells reduces, butalso the number of Treg cells subtypes that have a strong immunosuppressiveactivity reduce, while the number of Treg cells subtypes that have a weakreduced immunosuppressive activity increase. which may be one of reasons of peripheral immune tolerance disorder and acute exacerbation.2. Cell population of CD4+CD25+CD127lowhas shown a certaincorrelation with PaCO2, PaCO2, FEV1%pred and RV/TLC in AECOPD andSCOPD patients, so it might play a certain role in the severe degree of COPDpatients.3. Enhanced proportion of CD4+CD25+CD45RO+cells shows no obviouscorrelation with FEV1%pred, but it is positively correlated with bloodfibrinogen to a certain degree. CD4+CD25+CD45RO+cells may be used topredict the occurrence and prognosis of acute exacerbation.4. Treg cell subtypes of COPD emphysema phenotype might exist itscharacteristics, which is worthy of further research for verification.