Assesments of toll like receptor 2 expression, Mannose Binding Lectin Gene Polymorphisms, Serum Mannose Binding Lectin Concentrations, CD4, CD8 ratio in chronic obstructive pulmonary disease patients and cigarete smokers

Aim: The aim of the present study is to assess monocyte (CD14+) Toll-like receptor 2 expression (TLR-2), mannose-binding lectin (MBL) gene polymorphisms, serum MBL concentrations, CD4+, CD8+ and CD4/CD8 ratio as possible biomarkers in chronic obstructive pulmonary disease (COPD) patients and in cigarette smokers and to search for possible correlations between the clinical pulmonary function tests.Materials and methods: In this prospective study, 20 COPD patients were enrolled as Group 1, 20 COPD patients who were cigarette smokers were enrolled as Group 2, 20 cigarette smokers with normal pulmonary function tests were enrolled as Group 3 and 20 healthy volunteers were enrolled as the control group for Group 4. Circulating MBL concentrations were assessed by ELISA method and MBL gene polymorphisms were assessed by real time RT-PCR method. Flow cytometry method with monoclonal antibodies was used for the evaluation of lymphocyte subsets: CD4+ and CD8+ T lymphocytes and TLR-2 expression on CD14+ monocytes. Pulmonary function tests were performed to all cases except group 4 controls.Results: In all cases MBL gene frequencies were found A/B allele 82,5% (66/80), homozigot D allele 15 % (12/80) and homozygote B allele 2,5% (2/80) and we found no statistical differences between the study groups.Circulating MBL concentrations were found as 2103±1311 ng/ml, 2324±1001 ng/ml, 1746±1142 ng/ml and 2040±879 ng/ml respectively in Groups 1, 2, 3 and 4. No statistical difference was found between the study groups. TLR-2 expression on CD14+ monocytes 56.41±24.49%, 64.47±22.93%, 64.18±23.47% and 51.82±24.79% respectively in groups 1, 2 , 3 and 4. No statistical difference was found between the study groups for TLR-2, CD4+, CD8+ and CD4/CD8 ratio. We found significant positive correlations between CD4+ T subsets and FEV1 and FEV1/FVC ratio, and between CD4/CD8 ratio and FEV1/FVC. We found negative correlations between serum MBL concentrations and CD4/CD8 ratio. Serum MBL concentration correlated positively with cigarette smoking and negatively with pulmonary function tests (FEV1 and FEV1/FVC).Conclusion: Our results revealed that CD4/CD8 ratio and serum MBL concentration could correlate well with pulmonary function tests and could be used as one of the clinical biomarkers of COPD. However we believe these results still needs further investigation which includes larger series of COPD patients. Previously no study was performed in Turkish population about the MBL gene polymorphism and our study is the first article presenting this data.Key Words: COPD, cigarette smoking, TLR-2, CD4, CD8, MBL, MBL variant, FEV1/FVC.