Martin L. Mai

End-stage renal disease (ESRD) after orthotopic liver transplantation (OLTX) using calcineurin-based immunotherapy: risk of development and treatment.

BACKGROUND The calcineurin inhibitors cyclosporine and tacrolimus are both known to be nephrotoxic. Their use in orthotopic liver transplantation (OLTX) has dramatically improved success rates. Recently, however, we have had an increase of patients who are presenting after OLTX with end-stage renal disease (ESRD). This retrospective study examines the incidence and treatment of ESRD and chronic renal failure (CRF) in OLTX patients. METHODS Patients receiving an OLTX only from June 1985 through December of 1994 who survived 6 months postoperatively were studied (n=834). Our prospectively collected database was the source of information. Patients were divided into three groups: Controls, no CRF or ESRD, n=748; CRF, sustained serum creatinine >2.5 mg/dl, n=41; and ESRD, n=45. Groups were compared for preoperative laboratory variables, diagnosis, postoperative variables, survival, type of ESRD therapy, and survival from onset of ESRD. RESULTS At 13 years after OLTX, the incidence of severe renal dysfunction was 18.1% (CRF 8.6% and ESRD 9.5%). Compared with control patients, CRF and ESRD patients had higher preoperative serum creatinine levels, a greater percentage of patients with hepatorenal syndrome, higher percentage requirement for dialysis in the first 3 months postoperatively, and a higher 1-year serum creatinine. Multivariate stepwise logistic regression analysis using preoperative and postoperative variables identified that an increase of serum creatinine compared with average at 1 year, 3 months, and 4 weeks postoperatively were independent risk factors for the development of CRF or ESRD with odds ratios of 2.6, 2.2, and 1.6, respectively. Overall survival from the time of OLTX was not significantly different among groups, but by year 13, the survival of the patients who had ESRD was only 28.2% compared with 54.6% in the control group. Patients developing ESRD had a 6-year survival after onset of ESRD of 27% for the patients receiving hemodialysis versus 71.4% for the patients developing ESRD who subsequently received kidney transplants. CONCLUSIONS Patients who are more than 10 years post-OLTX have CRF and ESRD at a high rate. The development of ESRD decreases survival, particularly in those patients treated with dialysis only. Patients who develop ESRD have a higher preoperative and 1-year serum creatinine and are more likely to have hepatorenal syndrome. However, an increase of serum creatinine at various times postoperatively is more predictive of the development of CRF or ESRD. New strategies for long-term immunosuppression may be needed to decrease this complication.

Estimation of glomerular filtration rates before and after orthotopic liver transplantation: evaluation of current equations.

The ability to estimate rather than measure the glomerular filtration rate (GFR) in patients before and after liver transplantation would be helpful in estimating risk, dosing drugs, and assessing long‐term toxicity of calcineurin inhibitors. Currently available equations for estimating the GFR have not been validated in either the pre‐ or post‐liver transplant population. We have evaluated the performance of currently used formulas for the estimation of the GFR in this setting. Data were collected prospectively on patients who underwent liver transplantation between 1984 and 2001. GFR per 1.73 m2 was measured by I125 iothalamate in patients at the pretransplant evaluation and at 3 months, 1 year, and yearly posttransplant thereafter. GFR estimated by the Cockcroft‐Gault equation, the Nankivell equation, and the equations from the Modification of Diet in Renal Disease (MDRD) Study (6, 5, and 4 variables) was compared with the measured GFR. Pretransplant GFR was available in 1,447 patients. The mean GFR was 90.7 ± 40.5 mL/min. Values for r and r2 were highest for the MDRD Study 6‐variable equation (0.70 and 0.49, respectively). Only 66% of estimates were within 30% of the measured GFR. At 3 months, 1 year, and 5 years posttransplant, the mean GFR was 59.5 ± 27.1 mL/min, 62.7 ± 27.8 mL/min, and 55.3 ± 26.1 mL/min, respectively. Values for r and r2 for the MDRD Study 6‐variable equations at 1 and 5 years posttransplant were 0.74 (0.55) and 0.76 (0.58), respectively. At these time points, however, only 67% and 64% of the estimated GFR were within 30% of the measured GFR. MDRD Study equations had greater precision than other equations, but the precision was lower than reported for MDRD estimation of GFR in other populations. Better methods for estimating the GFR are required for evaluation of renal function before and after liver transplantation. (Liver Transpl 2004;10:301–309.)

Continued influence of preoperative renal function on outcome of orthotopic liver transplant (OLTX) in the US: where will MELD lead us?

Renal function is a component of the Model for End Stage Liver Disease (MELD), We queried the 1999–2004 OPTN/UNOS database to determine whether preoperative renal function remained an important determinant of survival in primary deceased donor liver transplant alone patients (DDLTA) or primary combined kidney liver transplant patients (KLTX). We examined preoperative creatinine, renal replacement therapy (RRT), incidence of KLTX, and patient survival in the 34 months before and after introduction of MELD and performed a multivariate Cox regression analysis of time to death.

Preoperative and perioperative predictors of the need for renal replacement therapy after orthotopic liver transplantation

Background. Acute renal failure developing after orthotopic liver transplantation (OLTx) requiring renal replacement heralds a poor prognosis. Our center has previously reported a 1-year survival of only 41.8%. We undertook this study to determine whether we could identify preoperative and perioperative factors that would predict which patients are at risk. Methods. OLTxs performed between January 1, 1996, and December 31, 2001, were included in our retrospective database review. Combined kidney-liver transplants or patients with preoperative renal replacement therapy (RRT) were excluded. A total of 724 OLTxs were studied, which were divided into group I: no RRT, n=637; group II: hemodialysis only post-OLTx, n=17; and group III: continuous RRT post-OLTx, n=70. Univariate and stepwise logistic multivariate analyses were performed. Results. Preoperative serum creatinine greater than 1.9 mg/dL (odds ratio [OR] 3.57), preoperative blood urea nitrogen greater than 27 mg/dL (OR 2.68), intensive care unit stay more than 3 days (OR 10.23), and Model for End-Stage Liver Disease score greater than 21 (OR 2.5) were significant. A clinical prediction model was constructed: probability of requiring dialysis posttransplant=(−2.4586+1.2726 [creatinine >1.9] + 0.9858 [blood urea nitrogen >27] + 0.4574 [Model for End-Stage Liver Disease score >21] + 1.1625 [intensive care unit days >3]). A clinical prediction rule for patients with a score greater than 0.12 was applied to OLTx recipients who underwent transplantation in 2002. A total of 15 of 20 patients who received RRT and 111 of 121 who did not were correctly classified with the model. Conclusions. This model allowed us to identify patients at high risk for developing the need for RRT postoperatively. Strategies for these patients to prevent or ameliorate acute renal failure and reduce the need for RRT postoperatively are needed.

Kidney allocation to liver transplant candidates with renal failure of undetermined etiology: Role of percutaneous renal biopsy

The feasibility, value and risk of percutaneous renal biopsy (PRB) in liver transplant candidates with renal failure are unknown. PRB was performed on 44 liver transplant candidates with renal failure of undetermined etiology and glomerular filtration rate (GFR) <40 mL/min/1.73 m2 (n = 37) or on renal replacement therapy (RRT) (n = 7). Patients with ≥30% interstitial fibrosis (IF), ≥40% global glomerulosclerosis (gGS) and/or diffuse glomerulonephritis were approved for simultaneous‐liver‐kidney (SLK) transplantation. Prebiopsy GFR, urinary sodium indices, dependency on RRT and kidney size were comparable between 27 liver‐transplant‐alone (LTA) and 17 SLK candidates and did not relate to the biopsy diagnosis. The interobserver agreement for the degree of IF or gGS was moderate‐to‐excellent. After a mean of 78 ± 67 days, 16 and 8 patients received LTA and SLK transplants. All five LTA recipients on RRT recovered kidney function after transplantation and serum creatinine was comparable between LTA and SLK recipients at last follow‐up. Biopsy complications developed in 13, of these, five required intervention. PRB is feasible in liver transplant candidates with renal failure and provides reproducible histological information that does not relate to the pretransplant clinical data. Randomized studies are needed to determine if PRB can direct kidney allocation in this challenging group of liver transplant candidates.

Excellent Renal Allograft Survival in Donor-Specific Antibody Positive Transplant Patients—Role of Intravenous Immunoglobulin and Rabbit Antithymocyte Globulin

Background. Timely transplantation of sensitized kidney recipients remains a challenge. Patients with a complement-dependent cytotoxicity negative and flow cytometry (FC) positive crossmatch carry increased risk of antibody-mediated rejection and thus graft loss. Solid phase assays are available to confirm donor specificity for antibody identified by FC crossmatch. Treatment using induction therapy with rabbit antithymocyte globulin (RATG) and intravenous immunoglobulin (IVIG) may allow successful transplant of these high-risk patients. Methods. A retrospective study of 264 consecutive patients after exclusions yielded 94 complement-dependent cytotoxicity anti-human globulin crossmatch-negative patients, including group 1: 58 primary transplants with panel-reactive antibody (PRA) less than 20%, group 2: 16 retransplants and PRA more than 20% who were FC crossmatch-negative, and group 3: 20 retransplants and PRA more than 20% who were FC crossmatch-positive. All were treated with RATG induction and maintenance therapy with tacrolimus, mycophenolate mofetil, and corticosteroids. Only group 3 received IVIG at 500 mg/kg daily in three doses. Results. Eighteen of 20 patients in group 3 had donor-specific antibody identified by solid phase assay. Cellular- and antibody-mediated rejections were statistically higher in group 3. Two-year serum creatinine and glomerular filtration rate along with 3-year patient and graft survival were comparable between the groups. Conclusions. Sensitized patients with positive FC crossmatch and donor-specific antibody identified by solid phase assays can be successfully transplanted using standard RATG induction, IVIG, and maintenance immunosuppression with equal renal function and graft survival to immunologically lower risk recipients. Given these results, this patient group should not be excluded from transplantation based on antibody specificities determined by virtual crossmatch techniques.

Comparison of kidney function between donation after cardiac death and donation after brain death kidney transplantation.

Backgroud Kidney graft survival is comparable between donation after cardiac death (DCD) and donation after brain death (DBD) kidney transplantation. However, data concerning kidney function after DCD kidney transplantation are lacking. Methods We retrospectively compared kidney function between 64 DCD and 248 DBD kidney transplant recipients. Graft function was assessed using iothalamate glomerular filtration rate at 1, 4, and 12 months, then annually. The primary endpoint was the composite of death-censored graft loss or two consecutive iothalamate glomerular filtration rates less than 50 mL/min/1.73 m2 occurring within 5 years from transplantation. Secondary endpoints included death and graft loss or death. Results Of the 312 patients, 102 (33%) experienced the primary endpoint, 78 (25%) experienced graft loss or death, and 44 (14%) died. In multivariable Cox regression analysis, there was no difference between DCD and DBD recipients regarding the primary endpoint (relative risk [RR], 1.16; P=0.59), death (RR, 0.97; P=0.94), or graft loss or death (RR, 1.09; P=0.79). In the subgroup of 64 DCD recipients, each 10-year increase in donor age was associated with increased risk of the primary endpoint (RR, 1.51; P=0.027) with the highest risk observed for donors older than 45 years (RR, 4.81; P=0.001). Delayed graft function affected 45% of the DCD recipients but had no impact on kidney function, graft survival, or patient survival. Conclusions Posttransplantation kidney function is comparable between DCD and DBD kidney transplantations. In the subgroup of DCD recipients, kidneys from donors older than 45 years may be associated with a higher risk of poor kidney function; however, this finding requires validation in a larger patient group.

Kidney Transplantation After Previous Liver Transplantation: Analysis of the Organ Procurement Transplant Network Database

Background. Patients after liver transplant have a high incidence of chronic kidney disease and end-stage renal disease (ESRD). We investigated kidney transplantation after liver transplantation using the Organ Procurement Transplant Network database. Methods. The Organ Procurement Transplant Network database was queried for patients who received kidney transplantation after previous liver transplantation. These patients were compared with patients who received primary kidney transplantation alone during the same time period. Results. Between 1997 and 2008, 157,086 primary kidney transplants were performed. Of these, 680 deceased donor kidney transplants and 410 living donor kidney transplants were performed in previous recipients of liver transplants. The number of kidney after liver transplants performed each year has increased from 37 per year to 124 per year in 2008. The time from liver transplant to kidney transplant increased from 8.2 to 9.0 years for living donor transplants and from 5.4 to 9.6 years for deceased donor. The 1, 3, and 5 year actuarial graft survival in both living donor kidney after liver transplant and deceased donor kidney after liver transplant are less than the kidney transplant alone patients. However, the death-censored graft survivals are equal. The patient survival is also less but is similar to what would be expected in liver transplant recipients who did not have ESRD. In 2008, kidney after liver transplantation represented 0.9% of the total kidney alone transplants performed in the United States. Conclusion. Kidney transplantation is an appropriate therapy for selected patients who develop ESRD after liver transplantation.

Results of a prospective randomized trial of sirolimus conversion in kidney transplant recipients on early corticosteroid withdrawal.

Background. The use of calcineurin inhibitors is associated with chronic nephrotoxicity and lower glomerular filtration rate (GFR). As a result, one strategy of transplant immunosuppression is calcineurin inhibitor elimination. Methods. The aim of this study was to determine the outcome of a prospective randomized trial of kidney transplant recipients receiving rapid corticosteroid withdrawal, tacrolimus and mycophenolate mofetil (MMF) for 1 month followed by randomization to switch to sirolimus-MMF or to stay on tacrolimus-MMF. The primary outcome was the difference in measured GFR at 1 year using intention-to-treat analysis. Results. Sixty patients were randomized to stay on tacrolimus-MMF and 62 to sirolimus-MMF. Actual graft survival (including death) at 2 years was 98.4% in the sirolimus group, 96.7% in the tacrolimus group. Sixty-three percentage of the patients in the sirolimus group withdrew during the 2-year period of the study compared with 18% of the tacrolimus group (P<0.0001), primarily related to rejection or medication side effects. Rejection during the first year occurred in 5% of the tacrolimus group and 13% of the sirolimus group (P=0.15). Measured GFR at 1 year (mean±SD) was 57.4±20.7 mL/min/1.73 m2 in the sirolimus group and 62.7±26.5 mL/min/1.73 m2 in the tacrolimus group (95% CI of difference −3.7–14.4). Conclusions. We conclude that conversion from tacrolimus-MMF to sirolimus-MMF at 1 month posttransplant in kidney recipients on rapid steroid withdrawal is poorly tolerated and does not improve GFR at 1 year.

The long-term management of pancreas transplantation.

Diabetes mellitus (DM) is a major health problem worldwide, which affects 18.2 million individuals (6.3% of the population) in the United States. Currently, the prevalence of Type 1 DM in the United States is estimated to be 1,000,000 individuals, and 30,000 new cases are diagnosed each year. In addition to end-stage renal disease (ESRD), DM is associated with blindness, accelerated atherosclerosis, dyslipidemia, cardio- and cerebrovascular disease, amputation, poor quality of life, and overall lifespan reduction. It accounts for more than 160,000 deaths per year in the United States alone. In 2002, the annual national direct and indirect costs of Types 1 and 2 DM exceeded