Abstract
Regulatory CD4+CD25 bright cells are a distinct population of T cells which modulate Th1 and Th2 mediated immune responses and have a preventive role in the development of autoimmune diseases including Crohn’s disease. Using flow cytometry we analyzed the percentage and absolute number of CD4+CD25bright cells in the peripheral blood of Crohn’s disease (CD) patients before and following non-myeloablative stem cell transplantation. All patients (N=14) survived the NST procedure and showed marked clinical and histological improvements in disease severity. Prior to NST, both the frequency and absolute number of CD4+CD25 bright cells in CD patients were reduced compared to healthy volunteers (p<0.01). Following NST, a robust increase in the absolute number of CD4+CD25+ cells was observed: pre-NST 10.3 ± 3.5 (N=14) vs. 6 mo post-NST 28.1 ± 13.4 (N=13) vs. 1 yr post-NST 24.7 ± 12.3 (N=12) versus 2 yr post-NST 20.2 ± 10.2 (N=9); p < 0.01. Two patients who relapsed after NST had less prominent increases in CD4+CD25 bright cell subset. When these patients were excluded from analysis, the difference between pre and post NST measurements increased (p < 0.0001). We conclude that autologous non-myeloablative stem cell transplantation induces the recovery of CD4+CD25 bright regulatory T cells which may contribute to the restoration of immunological homeostasis and remission of disease.
Absolute number of CD4+CD25+ cells in PB of CD patients pre and post NST
