Different reconstitution of peripheral blood lymphocytes and dendritic cells in liver and kidney transplant patients

Pre-Transplantation Immune Cell Distribution and Early Post-Transplant Fungal Infection Are the Main Risk Factors of Liver Transplantation Recipients in Lower Model of End-Stage Liver Disease

BACKGROUND

The prognosis of patients after liver transplantation (LTx) with high Model of End-Stage Liver Disease (MELD) score (>30) is predicted, but patients with lower MELD scores (<30) have no conclusive studies of pre- and post-transplant risk factors that influence the long-term outcome.

METHODS

This retrospective study reviewed 268 recipients with MELD score <30, from 2008 to 2013 in our institution, for evaluation of pre-transplant risk factors including patients' clinical background data, pre-transplant lymphocyte subpopulation, and early post-transplant infection complication as predictors for long-term survival after LTx.

RESULTS

The post-transplant patients' survival estimates were 90.7%, 85.1%, and 83.6% at 1, 3, and 5 years, respectively. In multivariate analysis, age >55years, presence of ascites, cluster of differentiation (CD)3 < 93.2 (count/μL), CD4/CD8 <2.4, fungal infection, and more than one site of fungal colonization significantly influenced survival (P = .0003, P = .002, P = .04, P = .004, P < .0001, and P > .0001, respectively). We also noticed that these five factors accumulatively influence the long-term survival rate; this means that in the presence of any two risk factors, the 5-year survival can still be 88.4%, whereas in the presence of any three risk factors, the survival rate dropped to only 57.1%.

CONCLUSIONS

Older patients in the presence of pre-transplant low immune cell number and ascites in association with post-transplant fungal infection are the independent risk factors in MELD scores <30 LTx groups for long-term survival. Patients in these groups with any of the three factors had inferior long-term survival results.

Comprehensive immune monitoring reveals profound immunological changes in pancreas after kidney (PAK) transplant recipients

Pancreas transplantation is a therapeutic option for the management of complicated Type 1 diabetes mellitus. While standard protocols include use of induction therapy followed by maintenance immunosuppression, the amount, frequency and duration of induction treatment has not been clearly defined. While the effect of various induction regimens on lymphocytes has been demonstrated, a prospective immune monitoring approach is not widely used to determine "immunological titration" of immunosuppression. In this study, we analyzed a patient cohort with pancreas after kidney transplantation and measured a wide range of quantitative and functional T and B cell parameters to identify those that would provide greatest value in personalized prospective immune assessment and design of immunosuppression. While there were significant quantitative differences observed in the 2 groups of PAK patients for various lymphocyte subsets, the notable observation was that lymphocyte subset quantitation was uninformative with regard to T cell function. Patients with normal lymphocyte counts had impaired T cell functional responses and vice versa. The use of immune monitoring to determine optimal IS regimens needs to be studied further to facilitate personalized management of immunosuppression with reduced risk of allograft rejection in PAK, and limited morbidity and mortality related to infection and malignancy.

Dendritic cells and regulation of alloimmune responses: relevance to outcome and therapy of organ transplantation

Dendritic cells are uniquely well-equipped for antigen capture, processing and presentation. They are highly-efficient antigen-presenting cells that induce and regulate T-cell reactivity. Due to their inherent tolerogenicity, immature dendritic cells offer considerable potential as candidate cellular vaccines for negative regulation of immune reactivity/promotion of tolerance. Both classic myeloid and, more recently, characterized plasmacytoid dendritic cells, exhibit tolerogenic properties. Manipulation of dendritic cells differentiation/ maturation in the laboratory using cytokines, pharmacologic agents or genetic engineering approaches can render stably immature dendritic cells that promote organ transplant tolerance in rodents. There are also indications from human studies of the ability of dendritic cells to promote T-cell tolerance and induce T-regulatory cells, with potential for therapeutic application in organ transplantation. In addition, recent clinical observations suggest that modulation of dendritic cell function (e.g., by immunosuppressive drugs) affects the outcome of transplantation. The challenge confronting applied dendritic cell biology is the identification of optimal strategies and therapeutic regimens to allow the potential of these powerful immune regulatory cells to be realized in the clinic.