Cytotoxic lymphocytes: the role in inflammation in patients with chronic obstructive pulmonary disease exacerbation and remission
Background: Despite the number of publications related to the expression of surface antigens of periphery blood lymphocytes in chronic obstructive pulmonary disease (COPD), algorithm for interpreting of the results and implicating pathogenetic treatments still needs to be developed. Aim: To assess the role of cytotoxic lymphocytes in the maintaining of inflammation in COPD. Materials and methods: To examine immune status in 37 patients with COPD exacerbation or remission and 24 healthy donors (control group), blood cytotoxic T-lymphocytes and NK-cells contents were measured using indirect immunofluorescence method. Absolute and relative numbers of lymphocytes expressing CD3, CD4, CD8, CD16, CD20, CD23, CD25, CD54, CD71, CD72, HLA-DR, CD95 antigens, membrane immunoglobulins M (mIgM) and G (mIgG) were estimated. Results: In COPD., significantly increased numbers of blood cytotoxic lymphocytes were demonstrated independently from the disease stage (p < 0.001). During COPD exacerbation, significant elevations of CD4, CD8, CD20, CD72, NK-cells numbers, serum mIgM and mIgG were demonstrated. During remission, CD20 and CD72 content returned to normal, though, increased numbers of other cytotoxic cells persisted promoting inflammation and progressive damage of pulmonary and bronchial tissues. Conclusion: Observed changes may be due to excessive stimulation of T-cell component of immune system in COPD patients both in exacerbation and remission. Relative reduction of total T-lymphocyte numbers indicates non-specific (non-infectious) inflammation type. High cytotoxic potential of immune system results in pulmonary damage and promotes development of pneumosclerosis and emphysema.