LAUSR

BACKGROUND Post-transplantation pharmacotherapies typically employ combinations of immunosuppressive agents that have been designed for targeted inhibition of T-cells and T-cell subsets. Studies of acute and chronic effects of clinically employed immunosuppressive agents on B-cells and B-cell subsets are significantly fewer in number and warrant further investigation. Accordingly, the goal of the present cross-sectional study is to functionally evaluate differences of B-cell subsets in patients with end-stage renal disease (ESRD) and immunologically stable renal transplant patients. PATIENTS AND METHODS Of 103 patients who underwent renal transplantation, 73 patients were immunologically stable without rejection or infection. Among them, 34 patients were one-year post-transplantation, and 39 patients were five-year post-transplantation. The study also included 35 ESRD patients and 36 healthy volunteers. Flow cytometry identified B-cell subsets in the study groups. RESULTS Renal allograft recipients had reduced percentages of total B-cells (CD19+) and regulatory B-cells (Breg) (CD38highCD27 + CD24+) compared with healthy controls. The percentage of transitional B-cells (IgM + CD38highCD24high) and marginal zone (MZ) B-cells (IgD-CD27+) was reduced in transplant recipients compared with patients with ESRD and healthy volunteers. The highest percentage of plasma cells (PCs) (CD38highCD27 + CD24-) was in patients with ESRD. In five-year post-transplantation group, CD38lowCD21- B-cells increased when compared with the other groups. Healthy volunteers and patients with ESRD had fewer unswitched memory (UM) B-cells (IgM + IgD + CD38lowCD27+), and increased isotype switched memory (ISM) B-cells (IgM-IgD-CD38lowCD27+). There was no difference in the percentage of naïve B-cells (IgD + CD27-) among diverse groups. CONCLUSIONS The percentages of the total, transitional, Breg, PCs, MZ, and UM B-cell subsets in immunologically stable renal allograft recipients were significantly different from healthy controls. However, B-cell subsets in patients with ESRD were minimally different with immunologically stable renal allograft recipients.