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.