Immunologic events and long term survival after combined heart and kidney transplantation : a twelve-year single-center experience

Current Treatment Options for the Failing Fontan Circulation

The Fontan operation was introduced in 1968. For congenital malformations, where biventricular repair is unsuitable, the Fontan procedure has provided a long-term palliation strategy with improved outcomes compared to the initially developed procedures. Despite these improvements, several complications merely due to a failing Fontan circulation, including myocardial dysfunction, arrhythmias, increased pulmonary vascular resistance, protein-losing enteropathy, hepatic dysfunction, plastic bronchitis, and thrombo-embolism, may occur, thereby limiting the life-expectancy in this patient cohort. This review provides an overview of the most common complications of Fontan circulation and the currently available treatment options.

The indirect alloresponse impairs the induction but not maintenance of tolerance to MHC class I-disparate allografts

We studied the effects of indirect allorecognition on the induction and maintenance phases of tolerance in miniature swine cotransplanted with heart and kidney allografts. MHC class I-mismatched heart and kidney grafts were cotransplanted in recipients receiving CyA for 12 days. Recipients were unimmunized or immunized with a set of donor-derived or control third-party MHC class I peptides either 21 days prior to transplantation or over 100 days after transplantation. T-cell proliferation, delayed type hypersensitivity reaction (DTH) and antibody production were assessed. All animals injected with donor MHC class I peptides developed potent indirect alloresponses specific to the immunizing peptides. While untreated recipients developed stable tolerance, all animals preimmunized with donor allopeptides rejected kidney-heart transplants acutely. In contrast, when peptide immunization was delayed until over 100 days after kidney-heart transplantation, no effects were observed on graft function or in vitro measures of alloimmunity. Donor peptide immunization prevented tolerance when administered to recipients pre transplantation but did not abrogate tolerance when administered to long-term survivors post transplantation. This suggests that the presence of T cells activated via indirect allorecognition represent a barrier to the induction but not the maintenance of tolerance.

Combined heart-kidney transplantation: the University of Wisconsin experience

BACKGROUND

Combined heart-kidney transplantation (HKTx) is increasing in frequency, but long-term outcomes are unknown and appropriately comparative analysis is lacking.

METHODS

This study was a retrospective review of prospectively collected data for 19 HKTx patients. Patient and graft survival, graft rejection and coronary allograft vasculopathy (CAV) were compared for HKTx vs recipients of a heart (n = 515) or kidney alone (n = 3,188) or both organs at separate time-points (n = 8).

RESULTS

Patient and graft survival did not differ for HKTx vs any group. HKTx time to first rejection episode was significantly prolonged for both organs vs single-organ recipients. The incidence of CAV was significantly lower for HKTx.

CONCLUSIONS

HKTx provides outcomes similar to those for solitary heart or kidney transplantation. There may be an immunologic advantage to receiving organs in a combined fashion. Such allocation of organs seems medically appropriate; however, more refined strategies are needed to identify optimal recipient populations.

Freedom From Graft Vessel Disease in Heart and Combined Heart- and Kidney-transplanted Patients Treated With Tacrolimus-based Immunosuppression

BACKGROUND

In end-stage cardiomyopathy where concomitant chronic renal failure is a contraindication for cardiac transplantation (HTx), simultaneous heart and kidney transplantation (HKTx) may be the only feasible therapeutic option. Due to the increased donor shortage, the clinical outcome of combined HKTx patients on tacrolimus-based immunosuppression was assessed and compared with a group of HTx patients.

METHODS

Three hundred forty-nine HTxs, including 13 (4%) combined HKTxs, were performed since 1995. Two hundred twenty-one HTx and all HKTx recipients received tacrolimus-based immunosuppression. Acute rejection episodes (AREs), infections, renal function and clinical outcome were evaluated. Pre-operative renal diagnoses for HKTx patients included cystic nephropathy (n = 4), glomerulonephritis (n = 4), cytostatica-induced nephropathy (n = 1), chronic rejection after renal transplant (n = 1), reflux nephropathy (n = 2) and chronic calcineurin-inhibitor -induced nephropathy after HTx (n = 1). Twelve patients (92%) were on hemodialysis pre-operatively, 1 underwent implantation of a left ventricular assist device (LVAD) before HKTx.

RESULTS

After 4.7 +/- 2 years, 92% of HKTx compared with 85% of HTx patients had survived (p = 0.42). Acute cardiac rejection episodes were more frequent in HTx than in HKTx patients (0.04 +/- 0.09 vs 0.02 +/- 0.04 ARE/100 patient-days; p = 0.07). Incidence of infection was comparable (0.3 +/- 0.2 vs 0.5 +/- 0.4 infection/100 patient-days). Freedom from transplant vasculopathy was 100% in the HKTx group compared with 71% in the HTx group after 4 years (p = 0.04).

CONCLUSIONS

Tacrolimus-based immunosuppression yields promising long-term results in HKTx and HTx. The incidence of transplant vasculopathy seems to be lower after HKTx than after HTx. If these results are secondary to a protective effect of tacrolimus-induced tolerance or of tolerance-associated co-transplantation they will need to be investigated in prospective multicenter trials.