CHEMOKINE RECEPTORS CCR1 AND CCR2 ON CIRCULATING LYMPHOCYTES IN UNTREATED CLL PATIENTS WITH ANEMIA AND IMMUNE THROMBOCYTOPENIA

Description

Background: Chronic lymphocytic leukemia (CLL) is frequently complicated due to immune deregulation. Autoimmune hemolytic anemia has an incidence of 5-10% and immune thrombocytopenia - of 1-2% of CLL patients (reviewed in De Back et al., 2018; Vitale et al., 2020). Chemokines and chemokine receptors constitute an important network of immune system that regulates migration of immune cells. CCR1 and CCR2 share protein sequences and responses to chemokines that are abundantly secreted in lymphoid organs.
Methods: We have examined by polychromatic flow cytometry the cell-surface expression of CCR1, CCR2, and the negative prognostic marker CD38 in the peripheral blood mononuclear cells (PBMC) of 60 untreated CLL patients, including 8 patients at Rai stage III-IV with anemia and/or thrombocytopenia (A/TC).
Results: The positive correlations have been determined between the presence of CD38 and CCR1 or CCR2 on leukemic cells. Moreover, these three indicators negatively correlated with the frequency of the leukemic cells within the PBMC as well as WBC sets. In the all 8 A/TC patients, CD38 was detected on leukemic cells; however, only 5 patients presented 30% of the CD38+ CLL cells. Notably, that CCR1 or CCR2 on CLL cells were determined in 7 A/TC patients.
Conclusions: Migration of the CCR1- and CCR2-expressing leukemic cells from circulation into the secondary lymphoid organs may contribute to aggressive pathogenesis of CLL. The association studies would verify whether the CCR1/CCR2 expression on circulating leukemic cells is a reliable negative predictor in CLL.
This research was funded by the Latvian Council of Science projects No. 651/2014 and No. lzp-2018/1-0156.

Period	29 May 2021
Event title	12th International Congress on Autoimmunity
Event type	Congress
Conference number	12
Location	GreeceShow on map
Degree of Recognition	International