Summary
Background. Immunity ensures the body’s homeostasis, i.e. protects from everything that is genetically foreign to it – antigens. Phagocytes (monocytes and granulocytes) play a central role in innate immunity and have also confirmed immune functions. In the case of primary or secondary disorders of phagocytic functions, the failure of the immune response is manifested, therefore, effective assessment of phagocytic function, which can be performed by laboratory tests, is important in clinical practice.
Methods. The results of activity of phagocytosis of monocytes and granulocytes of 85 patients (45 men and 40 women, aged 8 months – 61 years), obtained by quantitative flow cytometry (PHAGOTESTTM, Celonic Group, Germany) and semi-quantitative fluorescence microscopy (number of fluorescein isothiocyanate (FITC)-labeled E. coli per 100 phagocytosed granulocytes) were analyzed. The principle of calculating the phagocytosis activity factor: one phagocytosed bacterium found by the microscopy method corresponds to the X fluorescence intensity (RLU) determined by the flow cytometry method.
Results. The mean phagocytic activity of 85 subjects’ monocytes and granulocytes obtained by flow cytometry is 5609.64 ± 185.10 RLU (relative light units) and 7.05 ± 0.20 phagocyted bacteria by fluorescence microscopy. Men, according to age, had a higher proportion of phagocally active monocytes than women (p = 0.008). The results of phagocytic activity, obtained by two methods (flow cytometry and fluorescence microscopy) significantly correlated (r > 0.7, p < 0.05). One phagocyted bacterium found by microscopy corresponds to 797.92 ± 14,31 RLU measured by a flow cytometer.
Conclusion. Flow cytometry and fluorescence microscopy methods are informative for assessment of phagocytic activity. When assessing phagocytic activity by flow cytometry, the differences of the functional activity of monocytes related to the sex and age of the subjects were identified.
