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Although more and more clinical studies indicated that ImmuKnow assay could efficiently assess the immune status of recipients, it still has the challenge to predict the occurrence of clinical adverse events. This study aimed to establish a quantitative assessment model, which could more efficiently predict immune function of T lymphocytes after liver transplantation based on three indexes: CD4+ T lymphocyte count (C), CD4+/CD8+ ratio (R), and ImmuKnow adenosine triphosphate (ATP) value (A). We selected 194 recipients and measured the A, C, and R index every week, then obtained the Fisher linear discriminant functions by SPSS 16.0. Next, we divided the recipients into three groups: infection, stable, and rejection groups according to clinical status. After calculating, the discriminant function, 0.012A + 0.019C + 1.322R (simplified into T = 2A + 3C + 200R), was selected to represent the T-cell-mediated immune function. Based on the model, the optimal cutoff T values for infection and rejection were 1415 (sensitivity = 80%, specificity = 79.9%,AUC = 92.3%) and 1939.5 (sensitivity = 93.9%, specificity = 77.6%, AUC = 88.6%), relatively (p < 0.001). In conclusion, this model may be a more feasible way to evaluate the cellular immune function status in liver transplantation recipients., (© 2013 John Wiley & Sons A/S.)

Background: There have been increasing interests in the relationship between CD4(+) T lymphocytes and acute rejection (AR) in transplantation. In this study, we explore the role of CD4(+) T lymphocytes after liver transplantation., Methods:   From February to October 2009, 87 patients underwent liver transplantation. They were divided into the AR group and non-acute rejection (NAR) group, with 56 healthy individuals in the control group. Blood specimens were collected preoperatively and at one, two, and four wk postoperatively for all groups and also on the day when AR occurred and one wk after intravenous glucocorticoid therapy for the AR group. Adenosine triphosphate (ATP) levels were measured using the ImmuKnow™ test kits for immune cell functions., Results:   After transplantation, the ATP levels within CD4(+) T lymphocytes were significantly elevated in the two groups when compared with the preoperative levels. It peaked in the AR group and was significantly higher than that of the NAR group (p < 0.05). By ROC curve analysis, the obvious elevation of the ATP value one wk after transplantation had better sensitivity and specificity in diagnosing the AR. The ATP sensitivity rate for early AR was 85.7% and specificity rate 80.9% when the cutoff value was 407 μg/L. The ATP value collected on the day of AR occurrence has apparently positive correlation with the rejection acting index (RAI) (p < 0.01). After the intravenous glucocorticoid therapy, all the ARs were reversed and the ATP value declined significantly compared with the control group and that on the day when AR occurred (p < 0.01)., Conclusions:   During the early postoperative period (especially at first week after liver transplantation), the elevation of ATP levels within CD4(+) T lymphocytes has good sensitivity and specificity in diagnosing the AR at early stage. And the degree of AR has positive relationship with ATP value. After the intravenous glucocorticoid therapy, the obvious declination of AR might be used in evaluating the effectiveness of anti-rejection treatment., (© 2011 John Wiley & Sons A/S.)

Engagement of T-cell immunoglobulin mucin (Tim)-1 on T cells with its ligand, Tim-4, on antigen presenting cells delivers positive costimulatory signals to T cells. However, the molecular mechanisms for Tim-1-mediated regulation of T-cell activation and differentiation are relatively poorly understood. Here we investigated the role of Tim-1 in T-cell responses and allograft rejection using recombinant human Tim-1 extracellular domain and IgG1-Fc fusion proteins (Tim-1-Fc). In vitro assays confirmed that Tim-1-Fc selectively binds to CD4(+) effector T cells, but not dendritic cells or natural regulatory T cells (nTregs). Tim-1-Fc was able to inhibit the responses of purified CD4(+) T cells that do not express Tim-4 to stimulation by anti-CD3/CD28 mAbs, and this inhibition was associated with reduced AKT and ERK1/2 phosphorylation, but it had no influence on nTregs. Moreover, Tim-1-Fc inhibited the proliferation of CD4(+) T cells stimulated by allogeneic dendritic cells. Treatment of recipient mice with Tim-1-Fc significantly prolonged cardiac allograft survival in a fully MHC-mismatched strain combination, which was associated with impaired Th1 response and preserved Th2 and nTregs function. Importantly, the frequency of Foxp3(+) cells in splenic CD4(+) T cells was increased, thus shifting the balance toward regulators, even though Tim-1-Fc did not induce Foxp3 expression in CD4(+)CD25(-) T cells directly. These results indicate that Tim-1-Fc can inhibit T-cell responses through an unknown Tim-1 binding partner on T cells, and it is a promising immunosuppressive agent for preventing allograft rejection.