Pretransplant CD28 Biomarker (Levels of Expression and Quantification of Molecules per Cell) in Peripheral CD4+ T Cells Predicts Acute Rejection Episodes in Liver and Kidney Recipients

Abstract Background Acute rejection (AR) remains a significant cause of graft loss. Better approaches to predict AR are being investigated. Surface CD28 protein is essential for T-cell proliferation and survival as well as cytokine production. Patients and Methods Pretransplant CD4 + CD28 + peripheral T cells were examined in 30 liver recipients (LRs) and 31 kidney recipients (KRs) by flow cytometry. Results Pretransplant CD4 + CD28 + T cells in LRs were significantly lower in rejectors than nonrejectors ( P  = .002). Furthermore, the total number of CD28 molecules per cell in LRs ( P  = .02) as well as KRs ( P  = .047) was significantly lower in rejectors than nonrejectors. The healthy group did not display differences when compared with patients with end-stage liver disease or renal failure; however, stratification analysis displayed higher levels of CD4 + CD28 + when compared with rejected LRs ( P  = .04) but not KRs. CD28 levels  P  = .003). Similarly, a total number of CD28 molecules ≤8359 ( P  = .031) in LRs and ≤7669 ( P  = .046) in KRs correlated with high risk of AR. Conclusion The preliminary results presented herein exhibit a fast and noninvasive method that assists clinicians to prevent AR by monitoring CD4 + CD28 + peripheral T cells.