LSC - 2024 - Distinguishing B cell maturation subsets in lymph node aspirates and peripheral blood in patients with lung cancer and sarcoidosis

B cells may play a key role as more than just a passive immune cells in the lung cancer (LC) and sarcoidosis (SA). However, this role is likely context dependent, in which B cells comprise distinct subtypes with unique effector functions. Relative to T cells, knowledge of B cells in LC and SA remains less well developed. The aim of the study was to compare the B lymphocytes maturation profile and new hematological parameters: reactive lymphocytes (RE-LYMP) and antibody-synthesizing lymphocytes (AS-LYMP) between patients with LC, SA and healthy controls (HC). The cells were analyzed by hematological analyzer and flow cytometry in lymph nodes (LNs) obtained during EBUS/ TBNA procedure and in peripheral blood (PB). We found that LC patients had a significantly higher percentage of class switched memory B cells and a lower percentage of naive B cells than SA patients in LNs (68.5 vs. 23.8 and 19.7 vs 50.2%, p<0.05). We described also the predominance of class switched memory B cells in PB samples in LC. Next, we observed a significantly lower percentage of naive and transitional B cells in PB in LC than in SA and HC. SA patients had a significantly higher percentage of non-switched memory B cells than LC and HC. Finally, LC patients had significantly higher RE-LYMP and AS-LYMP parameters than SA and HC. Interestingly the AS-LYMP parameter positively correlated with the percentage of plasmablasts only in LC patients in PB. Our study presents a different B cell subpopulation profile in LC and SA patients, distinguishing the dominant subpopulations, and provides new evidence for the probable role of selected B subsets in different LC and SA microenvironment.