The aim of research: The aim of this research was comparison of inflammatory response between differently treated patients with ulcerative colitis. Materials and methods: Blood samples of all participants were taken for analysis. The sample was treated with Fc receptor blocking solution, then incubated for 20 minutes without a light source at room temperature with the addition of anti-human CD14s PerCP-Cy5.5-conjugated antibodies and phycoerythrin-conjugated antibodies reactive to human CD16 and with murine antibodies reactive to human CD44, conjugated with fluorescein isothiocyanate. After cell lysis, cells were analyzed by flow cytometry. Data were processed using FlowLogic Software. The results: Ulcerative colitis patients treated with biological therapy had a significant decrease in the median fluorescence intensity of the CD44 marker on the CD14+CD16++ subpopulation of monocytes. The median fluorescence intensity of the CD44 marker on CD44+CD14+ lymphocytes is almost twice as high in patients treated with biological therapy compared to patients treated with non-biological therapy. The percentages of CD44+CD14+ lymphocytes did not differ between the mentioned groups. Conclusions: Different expression of the CD44 marker on non-classical monocytes of patients was described, with regard to the therapy the patient received. In addition to non-classical monocytes, CD44+CD14+ lymphocytes are also affected – different expression of the CD44 marker was observed depending on the therapy.