Pushing the envelope in renal preservation; improved results with novel perfusate modifications for pulsatile machine perfusion of cadaver kidneys.

INTRODUCTION: Novel preservation techniques may diminish ischemia/reperfusion (I/R) injury. Our preservation laboratory has modified Belzer MPS for machine perfusion (MP) with prostaglandin E1 (PGE 1), nitroglycerin (NTG), and polyethylene glycol-superoxide dismutase (PEG-SOD) to attenuate I/R injury. We reviewed our recent experience using this novel formulation (NF) compared with standard perfusates. RESULTS: Between January 1998 and March 2000, 1060 consecutive kidneys were preserved in our laboratory. One hundred forty-eight kidneys (14%) were discarded. Fifty-eight percent of kidneys during this time period underwent MP (n = 532). En bloc kidney pairs were randomly assigned to pulsatile MP using Waters RM3 or MOX-100 perfusion systems using 1 of 3 perfusates; NF (NF; n = 119), Belzer MPS (MPS; n = 201), or Belzer II albumin gluconate (ALB; n = 212) Significant improvements in delayed graft function (DGF) rate were seen with NF versus other perfusates (8% vs 14% vs 19%, respectively; P =.03). At 6 months, graft survival was significantly improved with NF compared with MPS and ALB (96% vs 90% vs 87%, respectively; P =.03). NF also produced a significantly higher percentage of recipients with a serum creatinine level < or = 1.5 mg/dL. CONCLUSIONS: Novel modifications of standard MP perfusate improved outcomes after renal transplantation. Preservation-based interventions targeted to ameliorate I/R injury can improve outcomes and may allow expansion of the donor pool.

Renin system activation and delayed function of the renal transplant.

Delayed graft function (DGF), defined as persistent renal failure that requires dialysis within the first week after kidney transplantation, occurs commonly after cadaveric renal transplantation (CRT). This has important implications for long-term outcome because the 1-year allograft survival rate is significantly reduced when DGF occurs. The mechanisms contributing to the development of DGF are not well established. However, several lines of evidence indicate that excess renin system activity, in both the cadaver kidney donor and recipient, contributes importantly to the pathogenesis of DGF. If this hypothesis can be verified in clinical studies, then pharmacologic agents that interrupt the renin-angiotensin system (eg, type 1 angiotensin II receptor blockade, angiotensin converting enzyme inhibition, and beta-adrenergic blockade) in the donor and recipient might significantly improve the outcome of cadaveric renal transplants.

Glutathione supplementation during cold ischemia does not confer early functional advantage in renal transplantation.

BACKGROUND: Reduced glutathione (GSH), a component of University of Wisconsin (UW) solution, is reported to oxidize during storage. Consequently the commercial manufacturer of UW recommends the supplemental addition of GSH to UW before utilization. We investigated the influence of supplemental GSH during cold ischemia on early renal allograft function. METHODS: One hundred kidneys were locally procured from heart-beating donors, preserved in our laboratory, and transplanted during an 18-month period. Selected donor, preservation, and outcome characteristics were collected and compared by presence of supplemental GSH and method of preservation. All kidneys were randomized to receive 3.0 mM supplemental GSH to perfusate or no supplementation (control) and were preserved by either cold storage (CS) in UW or machine perfused (MP) in UW-machine perfusate solution (MPS). During MP, perfusion characteristics (flow, resistance, perfusate electrolytes, and pH) were serially measured. RESULTS: There were no significant differences among the groups when the donor characteristics of age, serum creatinine, and intra-operative urine output were compared. Preservation characteristics were similar among the groups with the exception of cold ischemia time, which was longer in the MP group compared to CS (26.1 h vs. 21.9 h, P=0.03). When compared with CS, kidneys preserved by MP exhibited a 33.4% increase in immediate function (93% vs. 62%, P=0.01), a corresponding 29.4% decrease in the incidence of delayed graft function (10% vs. 34%, P=0.02), and a 10% improvement in short-term (6-month) graft survival (98% vs. 88%, P=0.02). The addition of GSH supplementation to perfusate resulted in no significant differences in graft outcomes. CONCLUSIONS: Despite recommendations by the manufacturer that UW solution be routinely supplemented with GSH, supplemental GSH does not influence early renal allograft function. Our data suggest that a far greater beneficial impact on early graft function is achieved by machine perfusion. We conclude that GSH supplementation of commercially available UW is not necessary.

The influence of pulsatile preservation on renal transplantation in the 1990s.

BACKGROUND: Unlike simple cold storage (CS), pulsatile machine preservation (MP) of kidneys for transplantation permits pharmacologic manipulation of the perfusate and aids in the pretransplant assessment of the kidney graft. These characteristics of MP may have importance in the era of increasing use of extended criteria donor kidneys. The overall aim of this article is to critically assess practices at our preservation unit with respect to graft function. Specific aims are to (1) compare the influence of MP versus CS on graft function, (2) determine which pretransplant variables have significance in pretransplant assessment, and (3) determine whether pharmacologic manipulation during MP is advantageous. METHODS: There were 650 consecutive kidneys preserved in our laboratory between January 1, 1993 and March 1, 999, by either MP or CS. All MP kidneys were preserved by continuous hypothermic pulsatile perfusion using Belzer-MPS or Belzer II solution. Perfusion parameters and electrolytes were measured serially during pulsatile perfusion. All CS kidneys were stored in University of Wisconsin solution. All kidneys obtained from donors exhibiting extended criteria features underwent pretransplant frozen section biopsies. Transmission electron microscopy (EM) was performed on a subset of kidneys undergoing pharmacologic manipulation. Four agents were assessed prospectively for their ability to influence MP characteristics when added to perfusate: PGE1, trifluoperazine, verapamil, and papaverine. RESULTS: MP was associated with improved immediate, 1-, and 2-year graft function and reduced length of initial hospital stay when compared with CS grafts. Changes in the machine perfusion variables flow and resistance, and the [Ca++] in perfusate, were significantly associated with delayed graft function (DGF) after the transplant. Biopsy information was not predictive of DGF. The addition of PGE1 to perfusate improved MP characteristics, reduced the release of [Ca++] into perfusate, and ameliorated mitochondrial ischemic injury in transmission EM images. Early graft function was improved in the presence of PGE1+MP, compared with function in the presence of other pharmacologic agents or CS alone. CONCLUSIONS: MP is associated with improved early and long term renal function. Moreover, PGE1 augments MP in improving graft function. The combination of MP+PGE1 may be important in optimizing the ability to use extended donor criteria kidneys and, thereby, improve the overall efficiency of cadaveric renal transplantation.

Donor treatment with phentolamine mesylate improves machine preservation dynamics and early renal allograft function.

BACKGROUND: It has been suggested that pharmacologic conditioning of the donor before organ procurement may protect the renal allograft from injuries associated with the cold ischemic period. We compared the administration of two vasoactive agents before organ procurement to: (1) determine their influence on machine perfusion characteristics and (2) determine their impact on delayed graft function (DGF) in transplanted renal allografts. METHODS: Between January 1997 and December 1998, 150 kidneys were procured from heart-beating donors and preserved in our laboratory by machine perfusion (MP) or cold storage (CS). The following vasoactive agents were randomly administered to the donor 5 min before aortic cross clamp: phentolamine mesylate (PM) or hydralazine (H). The control groups received no donor conditioning. Kidneys were grouped as follows: (1) MP+PM, (2) MP+H, (3) MP, (4) CS+PM, (5) CS+H, (6) CS. 10 mg PM/50 kg donor weight was administered to the PM groups and 20 mg H/50 kg donor weight was administered to the H groups. DGF was defined as the need for dialysis within the first 7 days after the transplant. RESULTS: MP+PM increased renal flow by 12% and decreased renal resistance by 18% compared with the MP+H group, and increased renal flow by 23% and decreased renal resistance by 30% compared with the MP group. Moreover, the MP+PM group was associated with improved early allograft function. CONCLUSIONS: Donor treatment with PM immediately before aortic cross-clamp is associated with improved machine perfusion dynamics (renal flow and renal resistance) and lower incidence of DGF compared with donor treatment with H or no treatment. Moreover, MP of renal allografts was associated with improved early function compared with CS grafts.

Calcium ion concentration of machine perfusate predicts early graft function in expanded criteria donor kidneys.

Pulsatile preservation offers the advantage of pretransplant assessment of donor kidneys. Selected electrolyte concentrations of machine perfusate were measured over time in order to: (1) describe electrolyte changes in perfusate during the pulsatile preservation of expanded-criteria donor (ECD) kidneys, and (2) to assess the prognostic significance of these characteristics to early graft function. One hundred and fifty ECD kidneys were preserved in our laboratory between 1 January 1995 and 11 January 1997. ECD kidneys were defined as those requiring pretransplant biopsy. Kidneys were grouped by the presence or absence of delayed graft function (DGF), and perfusion parameters were measured every hour during pulsatile perfusion. All kidneys were preserved by continuous hypothermic pulsatile perfusion using Belzer II solution. Renal flow is decreased and renal resistance is increased in the presence of DGF in machine-preserved ECD kidneys. In addition, ionized calcium concentration of the machine perfusate is significantly elevated in the DGF group compared with the No DGF group (0.091 vs 0.054, P = 0.0016). The incidence of DGF is significantly lower in the ECD kidney. Among the pretransplant variables of donor characteristics, perfusion parameters and histology, perfusion parameters are highly predictive of early graft function. In addition, we found that ionized calcium concentration in the perfusate is significantly elevated in kidneys exhibiting DGF, which may have implications for assessing the suitability of donor kidneys for transplantation.

Prostaglandin E1 influences pulsatile preservation characteristics and early graft function in expanded criteria donor kidneys.

INTRODUCTION: Unlike simple cold storage, machine preservation allows dynamic assessment and manipulation of the donor organ prior to transplantation. We prospectively compared the effects of five pharmacological agents added to the perfusate during machine preservation of expanded criteria donor (ECD) kidneys in order to (1) describe their influence on perfusion parameters and (2) determine their influence on early graft outcome. METHODS: Two hundred seventy-five consecutive ECD kidneys were preserved in our laboratory between 1/1/94 and 12/31/97 by either machine perfusion (MP) or cold storage (CS). ECD kidneys were defined as those requiring pretransplant biopsy. ECD kidneys were divided by method of preservation and MP kidneys were randomized to receive prostaglandin E1 (MP+PGE1), trifluoperazine (TFP), verapamil (VER), papaverine (PAP), mannitol (MAN), or no intervention during the period of machine perfusion. CS kidneys were randomized to receive PGE1 (CS+PGE1), TFP, VER, PAP, or no intervention. All MP kidneys were preserved by continuous hypothermic pulsatile perfusion using Belzer II solution and perfusion parameters were measured every hour during pulsatile perfusion. All CS kidneys were stored in 1.0 L of University of Wisconsin (UW) solution. RESULTS: The addition of PGE1 to machine perfusate increased renal flow and decreased renal resistance. Moreover, the MP+PGE1-treated group was associated with improved early graft function compared to all other groups. The addition of VER, TFP, PAP, or MAN influenced neither the perfusion characteristics nor the incidence of early graft function in MP kidneys. Similarly, the addition of VER, TFP, or PAP did not influence early graft function in the CS kidneys. The CS+PGE1 group exhibited a significantly lower incidence of early graft function than did the MP+PGE1 group. CONCLUSIONS: PGE1 treatment during machine preservation improves hydrostatic perfusion parameters and reduces the incidence of delayed graft function in ECD kidneys. Moreover, the addition of PGE1, TFP, VER, or PAP to UW does not influence early graft function in the CS kidney.

Prostaglandin E1 improves pulsatile preservation characteristics and early graft function in expanded criteria donor kidneys.

Unlike simple cold storage, machine preservation allows dynamic assessment and manipulation of the donor organ before transplantation. The effects of four pharmacologic agents added to the perfusate during machine preservation of expanded criteria donor (ECD) kidneys were prospectively compared to 1) describe their influence on perfusion parameters and 2) determine their influence on early graft outcome. Between 1 January 1995 and 1 October 1997, 125 consecutive ECD kidneys were preserved in the authors' laboratory. A definition of ECD was assigned to kidneys requiring pretransplant biopsy. The ECD kidneys were randomized to receive prostaglandin E1 (PGE1), trifluoperazine (TFP), verapamil (VER), mannitol (MAN), or no intervention (control) during machine preservation. All kidneys were preserved by continuous hypothermic pulsatile perfusion (CHPP) using Belzer II solution, and perfusion parameters were measured every 2 hours during pulsatile perfusion. The addition of PGE1 to the perfusate increased renal flow and decreased renal resistance. Moreover, the PGE1 treated group was associated with improved early graft function when compared with all other groups. The addition of VER, TFP, and MAN influenced neither the perfusion characteristics nor the incidence of early graft function. Treatment with PGE1 during machine preservation enhances hydrostatic perfusion parameters (renal flow and renal resistance) and reduces the incidence of delayed graft function in ECD kidneys.

Mycobacterium tuberculosis infection of a native polycystic kidney following renal transplantation.

BACKGROUND: Tuberculosis is a recognized complication following renal transplantation. Patients with autosomal dominant polycystic kidney disease are increasingly being offered renal transplantation as an alternative to chronic hemodialysis. These patients are uniquely susceptible to serious upper urinary tract infections that are associated with significant morbidity and mortality. While involvement with gram-negative organisms is well described, mycobacterial infection of native polycystic kidneys after transplantation has not been addressed. METHODS: A case report of a renal transplant recipient who suffered an isolated Mycobacterium tuberculosis infection of a native polycystic kidney and a literature review. RESULTS: Despite appropriate drug therapy, the infection proved refractory, and the patient required nephrectomy. CONCLUSIONS: Mycobacterial tuberculosis, though not common, must be recognized as a potential source of infection of native polycystic kidneys in immunocompromised transplant recipients. Similar to the pattern observed with more common pathogens, these infections may be difficult to eradicate with standard antimicrobial drug regimens.

Effect of nifedipine on renal allograft function and survival beyond one year.

We previously reported that a calcium channel blocker supplemented immunosuppression produced excellent patient and graft survival rates in cadaveric kidney transplantation. We report here the long term outcome of patients treated with nifedipine-supplemented triple immunosuppression as compared with those of historical controls who were treated similarly without nifedipine. Study subjects included 111 patients transplanted in 1990-1994, treated with nifedipine and triple immunosuppression and with functioning grafts for more than one year (Nifedipine group). The results of cyclosporine (CyA) dose, blood pressure (BP), serum creatinine (Cr), and actuarial graft survival rate (GSR) up to 5 years posttransplant in these patients were compared with those of 52 patients transplanted in 1985-1990, treated similarly without calcium channel blockers (Control group). Donor sources, gender ratio, age distribution, causes of end stage renal disease, incidence of hypertension prior to transplantation and incidence of rejection in the first year between the groups were comparable. Throughout the study period the Nifedipine group had significantly lower serum Cr (1.5 +/- 0.7 vs. 1.8 +/- 0.7 mg/dl) and higher GSR (93.8% vs. 88% at 5 years) than the Control group. BP was comparable despite higher CyA doses in the Nifedipine group (4.3 +/- 1.1 vs. 3.3 +/- 1.1 mg/kg/day). We conclude that nifedipine is beneficial in improving long-term graft function and survival in kidney transplant recipients by mitigating CyA associated renal injury.

Excellent outcome with a calcium channel blocker-supplemented immunosuppressive regimen in cadaveric renal transplantation. A potential strategy to avoid antibody induction protocols.

Many transplant centers routinely utilize monoclonal antibody or polyclonal antibody based induction protocols in recipients of cadaver renal allografts. Given the potential complications associated with antibody-based immunosuppression regimens (e.g., CMV disease), we tested the hypothesis that a combination of a calcium antagonist and a triple drug protocol (cyclosporine + prednisone + azathioprine) would be an effective substitute for antibody-based induction protocols in ensuring excellent patient and graft survival rates. Our postulate was tested in a prospective study of 52 consecutive recipients of cadaver renal allografts (44 first, 5 second, and 3 third grafts) utilizing nifedipine as the first line calcium antagonist. Nifedipine was selected over verapamil or diltiazem due to its lack of interference with the metabolism of CsA. Some of the significant outcomes of our prospective trial were (A) a cumulative patient survival rate of 98.1% for the 52 recipients at 18 months posttransplantation; (B) a cumulative allograft survival rate of 92.1% for the 52 consecutive cadaver renal allografts at 18 months; (C) a cumulative allograft survival rate of 100% at 18 months for the 24 of 52 renal allografts without delayed graft function following transplantation; and (D) a cumulative allograft survival rate of 86% at 18 months for the 28 of 52 renal allografts with delayed graft function. Of the 4 of 52 who lost their grafts, 2 grafts were removed following discontinuation of immunosuppressive therapy while the remaining 2 had primary nonfunction; and (E) the lack of a requirement for monoclonal or polyclonal antibodies for the treatment of acute rejection episodes in this patient population. These gratifying results compare very favorably with (A) recent reports of the effects of long-term diltiazem therapy and of verapamil used in conjunction with an induction protocol that included Minnesota antilymphocyte globulin in recipients of cadaver renal allografts, and (B) the clinical outcome in many institutions with OKT3/ATG/ALG induction protocols. Whereas the mechanisms involved in the excellent clinical outcome found with the calcium antagonist remain undefined, our results strongly argue for a prospective, randomized and controlled study in which a calcium antagonist-supplemented immunosuppressive regimen is compared with antibody-based induction protocols.

Minimal sensitization and excellent renal allograft outcome following donor-specific blood transfusion with a short course of cyclosporine.

UNLABELLED: A new protocol of donor-specific blood transfusion under cyclosporine coverage was developed and examined for immunologic consequences and clinical efficacy in recipients of one- or zero-HLA-haplotype-matched renal allografts. Between 1985 and 1989, 75 recipients were transfused with 100 ml of stored whole blood at 1, 8, and 15 days of its storage from either one-HLA-haplotype-matched related donors (n = 65, 33 from their parents, 30 from siblings, and 2 from offspring) or from zero-HLA-haplotype-matched donors (n = 10, 7 from spouses and 3 from siblings). During DST, all recipients received cyclosporine, 6 mg/kg/day, starting a day before and finishing a week after DST (23 days). Recipients were monitored by donor-specific mixed lymphocyte culture responses before and after DST, and serially for antibodies by fluorescence activated cell sorter analysis and by standard complement-dependent lymphocytotoxicity assay. Following DST with CsA, only 3 of 75 patients (4%) were sensitized against the blood donor. This rate is considerably lower, albeit statistically not significantly, compared with the 10% rate found in 30 recipients who had received DST without CsA in our previous study. Repeat MLC studied one to two months after DST (the day before transplant) were significantly increased compared with pre-DST (stimulation index: mean +/- SEM; 10.3 +/- 1.4 to 15.8 +/- 2.8, P = 0.004, and relative response: 40.9 +/- 5.1% to 49.8 +/- 5.5%, P = 0.003). Since the stimulation index with controls did not change after DST (23.4 +/- 2.9 to 26.2 +/- 3.3), enhanced MLC responses appear to be donor-specific. The changes in MLC responses did not correlate with the number of blood transfusion received prior to DST, the number of rejection episodes, or graft outcome. Fifty-seven recipients underwent a kidney transplant from their one-HLA-haplotype-matched blood donors within two to three months after DST. All 10 recipients of zero-haplotype-matched donors were also successfully transplanted from their respective blood donors. The graft survival rates were at least 90% at two years in both groups. IN CONCLUSION: (1) 100 ml of stored whole-blood DST, three times at weekly intervals with a short course of CsA is minimally sensitizing but effective in enhancing graft survival; (2) this protocol could be used in donor-recipient pairs who do not share a haplotype; and (3) DST with CsA elicits augmentation of donor-specific MLC responses.

Kidney transplantation in insulin dependent diabetic patients: improved survival and rehabilitation.

Between 1977 and 1986, 50 insulin-dependent diabetic patients received a kidney transplant, 19 from living related donors and 31 from cadaveric donors. Cumulative patient survival was 81% and graft survival was 64% and 33% for living related and cadaveric donor kidneys, respectively, at five years. These results are comparable to that of nondiabetic patients. While physical performance and visual acuity significantly improved after a successful kidney transplantation, neuropathies and angiopathies might not improve. Physical performance improved even in those patients whose nerve conduction time had deteriorated. These findings suggest that kidney transplantation is an effective means of improving survival and rehabilitation of diabetic patients with end-stage renal disease.

Urinary calculi in renal transplant recipients.

UNLABELLED: Urinary calculi are an uncommon complication in renal transplant recipients. During a 15-year period, in 544 cases of kidney transplantation with a functioning allograft for more than 3 months, and a long-term follow-up, we have observed 9 cases (1.7%) of urinary calculi. Calculi occurred in 6 male and 3 female patients, 6 patients were recipients of living related and 3 of cadaveric kidneys. Calculi were diagnosed as early as 3 months and as late as 3.5 years after transplantation, but most were detected within the first year. The location of the calculi was the bladder in 4 cases, the transplant in 3, and indeterminant in 2. Crystallographic analysis of retrieved stones revealed calcium oxalate and/or phosphate in 4 cases, triple phosphate in 2, and uric acid in 1. All patients had one or more stone-predisposing factors, such as obstructive uropathy and recurrent urinary tract infection (4 cases), hyperoxaluria (3), or hypercalciuria (2). During long-term follow-up (mean 60 months), only one patient lost the renal graft, 14.5 years after transplantation, primarily from causes unrelated to urinary calculi. One instance of stone recurrence was noted. IN CONCLUSION: (1) urinary calculi after renal transplantation are relatively uncommon; (2) predisposing factors and crystallographic composition of the calculi are identical in type, but not frequency, to those of nontransplant patients; and (3) with proper medical and surgical management, post-transplant urolithiasis does not appear to affect graft prognosis.