INTRODUCTION

Human peripheral blood monocytes are the part of the leukemia microenvironment. We examined three monocyte subgroups: classical (CD14++CD16-), intermediate (CD14++CD16+) and non-classical (CD14+CD16++) monocytes. As these subpopulations can be also characterized by different levels of HLA-DR and CD163, we evaluated their expression on monocyte subpopulations of patients with chronic lymphocytic leukemia (CLL) and healthy individuals.

MATERIAL AND METHODS

The monocyte subsets in peripheral blood of CLL patients (n = 40) and healthy controls (n = 10) were evaluated by flow cytometry. The monoclonal antibodies: anti-CD14 FITC, anti-CD16 PE-Cy5, anti-CD163 PE, anti-HLA-DR PE were used.

RESULTS

The percentage of CD16-positive monocytes was significantly higher in CLL patients than in healthy donors. The highest percentage of CD163+ monocytes is in the 'classical' (CD14++CD16-) population. In turn, the non-classical monocytes constituted the majority of cells lacking HLA-DR expression. In CLL patients, there was no statistically significant relationship between the percentage of each monocyte subpopulation and the stage according to Rai Staging of CLL.

CONCLUSIONS

The presence of CD163 on classical monocytes suggests that these cells have anti-inflammatory properties. Besides, the low expression of HLA-DR on non-classical monocytes may result in impaired ability to stimulate the immune system.