Clinical Impacts of CD38+ B Cells on Acute Cellular Rejection With CD20+ B Cells in Renal Allograft

Background. There is an increasing evidence that the presence of CD20(+) B cells is associated with poor clinical outcomes in acute cellular rejection (ACR), but clinical significance of CD38(+) B cells is undetermined. We attempted to examine the clinical significance of the CD38(+) B cells alone or in combination with CD20(+) B cells in renal transplant recipients with ACR. Methods. Fifty-four patients with ACR were included. Biopsy specimens were stained for CD20 and CD38. The clinical outcomes of CD20 or CD38(+) B cells were evaluated with late-onset and repeated ACR, steroid resistance, incomplete recovery after rejection treatment, and allograft survival. Results. Twenty-three patients (42.6%) had CD20(+) and 25 (46.3%) patients had CD38(+) B cells. Of these, 15 patients (27.8%) were positive for both CD20 and CD38 (CD20(+)CD38(+)). CD38(+) patients had higher rates of late-onset or repeated ACR and incomplete recovery compared with CD38(-) patients (P<0.05). The patients with CD20(+)CD38(+) had a higher incomplete recovery rate than did patients with only CD20(+) or CD38(+) (P<0.05). The 5-year allograft survival was lower in CD20(+) and CD38(+) patients than in CD20(-) or CD38(-) patients (P<0.05 for each). CD20(+)CD38(+) patients had lower graft survival than did patients with CD20(+) or CD38(+) alone (P<0.05). Conclusion. Infiltration of CD38(+) B cells alone or in combination with CD20(+) B cells is a predictor for poor clinical outcomes of ACR in renal allograft.