Characterizing the risk of human leukocyte antigen-incompatible living donor kidney transplantation in older recipients

Older compatible living donor kidney transplant (CLDKT) recipients have higher mortality and death-censored graft failure (DCGF) compared to younger recipients. These risks may be amplified in older incompatible living donor kidney transplant (ILDKT) recipients who undergo desensitization and intense immunosuppression. In a 25-center cohort of ILDKT recipients transplanted between September 24, 1997, and December 15, 2016, we compared mortality, DCGF, delayed graft function (DGF), acute rejection (AR), and length of stay (LOS) between 234 older (age ≥60 years) and 1172 younger (age 18-59 years) recipients. To investigate whether the impact of age was different for ILDKT recipients compared to 17 542 CLDKT recipients, we used an interaction term to determine whether the relationship between posttransplant outcomes and transplant type (ILDKT vs CLDKT) was modified by age. Overall, older recipients had higher mortality (hazard ratio: 1.632.072.65, P < .001), lower DCGF (hazard ratio: 0.360.530.77, P = .001), and AR (odds ratio: 0.390.540.74, P < .001), and similar DGF (odds ratio: 0.461.032.33, P = .9) and LOS (incidence rate ratio: 0.880.981.10, P = 0.8) compared to younger recipients. The impact of age on mortality (interaction P = .052), DCGF (interaction P = .7), AR interaction P = .2), DGF (interaction P = .9), and LOS (interaction P = .5) were similar in ILDKT and CLDKT recipients. Age alone should not preclude eligibility for ILDKT.

Delayed graft function and acute rejection following HLA-incompatible living donor kidney transplantation

Incompatible living donor kidney transplant recipients (ILDKTr) have pre-existing donor-specific antibody (DSA) that, despite desensitization, may persist or reappear with resulting consequences, including delayed graft function (DGF) and acute rejection (AR). To quantify the risk of DGF and AR in ILDKT and downstream effects, we compared 1406 ILDKTr to 17 542 compatible LDKT recipients (CLDKTr) using a 25-center cohort with novel SRTR linkage. We characterized DSA strength as positive Luminex, negative flow crossmatch (PLNF); positive flow, negative cytotoxic crossmatch (PFNC); or positive cytotoxic crossmatch (PCC). DGF occurred in 3.1% of CLDKT, 3.5% of PLNF, 5.7% of PFNC, and 7.6% of PCC recipients, which translated to higher DGF for PCC recipients (aOR = _1.03 1.68_2.72 ). However, the impact of DGF on mortality and DCGF risk was no higher for ILDKT than CLDKT (p interaction > .1). AR developed in 8.4% of CLDKT, 18.2% of PLNF, 21.3% of PFNC, and 21.7% of PCC recipients, which translated to higher AR (aOR PLNF = _1.45 2.09_3.02 ; PFNC = _1.67 2.40_3.46 ; PCC = _1.48 2.24_3.37 ). Although the impact of AR on mortality was no higher for ILDKT than CLDKT (p interaction = .1), its impact on DCGF risk was less consequential for ILDKT (aHR = _1.34 1.62_1.95 ) than CLDKT (aHR = _1.96 2.29_2.67 ) (p interaction = .004). Providers should consider these risks during preoperative counseling, and strategies to mitigate them should be considered.

Center-level Variation in HLA-incompatible Living Donor Kidney Transplantation Outcomes

BACKGROUND

Desensitization protocols for HLA-incompatible living donor kidney transplantation (ILDKT) vary across centers. The impact of these, as well as other practice variations, on ILDKT outcomes remains unknown.

METHODS

We sought to quantify center-level variation in mortality and graft loss following ILDKT using a 25-center cohort of 1358 ILDKT recipients with linkage to Scientific Registry of Transplant Recipients for accurate outcome ascertainment. We used multilevel Cox regression with shared frailty to determine the variation in post-ILDKT outcomes attributable to between-center differences and to identify any center-level characteristics associated with improved post-ILDKT outcomes.

RESULTS

After adjusting for patient-level characteristics, only 6 centers (24%) had lower mortality and 1 (4%) had higher mortality than average. Similarly, only 5 centers (20%) had higher graft loss and 2 had lower graft loss than average. Only 4.7% of the differences in mortality (P < 0.01) and 4.4% of the differences in graft loss (P < 0.01) were attributable to between-center variation. These translated to a median hazard ratio of 1.36 for mortality and 1.34 of graft loss for similar candidates at different centers. Post-ILDKT outcomes were not associated with the following center-level characteristics: ILDKT volume and transplanting a higher proportion of highly sensitized, prior transplant, preemptive, or minority candidates.

CONCLUSIONS

Unlike most aspects of transplantation in which center-level variation and volume impact outcomes, we did not find substantial evidence for this in ILDKT. Our findings support the continued practice of ILDKT across these diverse centers.

Reversing donor-specific antibody responses and antibody-mediated rejection with bortezomib and belatacept in mice and kidney transplant recipients

Active antibody-mediated rejection (AMR) is a potentially devastating complication and consistently effective treatment remains elusive. We hypothesized that the reversal of acute AMR requires rapid elimination of antibody-secreting plasma cells (PC) with a proteasome inhibitor, bortezomib, followed by the sustained inhibition of PC generation with CTLA4-Ig or belatacept (B/B). We show in mice that B/B therapy selectively depleted mature PC producing donor-specific antibodies (DSA) and reduced DSA, when administered after primary and secondary DSA responses had been established. A pilot investigation was initiated to treat six consecutive patients with active AMR with B/B. Compassionate use of this regimen was initiated for the first patient who developed early, severe acute AMR that did not respond to steroids, plasmapheresis, and intravenous immunoglobulin after his third kidney transplant. B/B treatment resulted in a rapid reversal of AMR, leading us to treat five additional patients who also resolved their acute AMR episode and had sustained disappearance of circulating DSA for ≤30 months. This study provides a proof-of-principle demonstration that mouse models can identify mechanistically rational therapies for the clinic. Follow-up investigations with a more stringent clinical design are warranted to test whether B/B improves on the standard of care for the treatment of acute AMR.

"Early" and "Late" Hospital readmissions in the first year after kidney transplant at a single center

BACKGROUND

Hospital readmission (HR) after surgery is considered a quality metric.

METHODS

Data on 2371 first-time adult kidney transplant (KT) recipients were collected to analyze the "early" (≤30 days) and "late" (31-365 days) HR patterns after KT at a single center over a 12-year time span (2002-2013).

RESULTS

30-day, 90-day, and 1-year HR were 31%, 41%, and 53%, respectively. Risk factors for HR included age >50, female sex, black race, BMI >30, transplant LOS >5 days, and pre-transplant time on dialysis >765 days. Indications for early (n = 749) and late (n = 508) HR were similar. Early HR (OR: 3.80, P = .007) and black race (OR: 2.38, P = .009) were associated with higher odds of 1-year graft failure while frequency (1-2, 3-4, 5+) of HR (ORs: 4.68, 8.36, 9.44, P < .001) and age > 50 (OR: 2.11, P = .007) were associated with higher odds of 1-year mortality. Transplant LOS > 5 days increased both odds of 1-year graft failure (OR: 3.51, P = .001) and mortality (OR: 2.05, P = .006). One-year graft and recipient survival were 96.7% and 94.8%, respectively.

CONCLUSIONS

Hospital readmission was associated with reduced graft and patient survival; however, despite a relatively high and consistent HR rate after KT, overall 1-year graft and patient survival was high.

Hospital readmissions following HLA-incompatible live donor kidney transplantation: A multi-center study

Thirty percent of kidney transplant recipients are readmitted in the first month posttransplantation. Those with donor-specific antibody requiring desensitization and incompatible live donor kidney transplantation (ILDKT) constitute a unique subpopulation that might be at higher readmission risk. Drawing on a 22-center cohort, 379 ILDKTs with Medicare primary insurance were matched to compatible transplant-matched controls and to waitlist-only matched controls on panel reactive antibody, age, blood group, renal replacement time, prior kidney transplantation, race, gender, diabetes, and transplant date/waitlisting date. Readmission risk was determined using multilevel, mixed-effects Poisson regression. In the first month, ILDKTs had a 1.28-fold higher readmission risk than compatible controls (95% confidence interval [CI] 1.13-1.46; P < .001). Risk peaked at 6-12 months (relative risk [RR] 1.67, 95% CI 1.49-1.87; P < .001), attenuating by 24-36 months (RR 1.24, 95% CI 1.10-1.40; P < .001). ILDKTs had a 5.86-fold higher readmission risk (95% CI 4.96-6.92; P < .001) in the first month compared to waitlist-only controls. At 12-24 (RR 0.85, 95% CI 0.77-0.95; P = .002) and 24-36 months (RR 0.74, 95% CI 0.66-0.84; P < .001), ILDKTs had a lower risk than waitlist-only controls. These findings of ILDKTs having a higher readmission risk than compatible controls, but a lower readmission risk after the first year than waitlist-only controls should be considered in regulatory/payment schemas and planning clinical care.

The Incremental Cost of Incompatible Living Donor Kidney Transplantation: A National Cohort Analysis

Incompatible living donor kidney transplantation (ILDKT) has been established as an effective option for end-stage renal disease patients with willing but HLA-incompatible living donors, reducing mortality and improving quality of life. Depending on antibody titer, ILDKT can require highly resource-intensive procedures, including intravenous immunoglobulin, plasma exchange, and/or cell-depleting antibody treatment, as well as protocol biopsies and donor-specific antibody testing. This study sought to compare the cost and Medicare reimbursement, exclusive of organ acquisition payment, for ILDKT (n = 926) with varying antibody titers to matched compatible transplants (n = 2762) performed between 2002 and 2011. Data were assembled from a national cohort study of ILDKT and a unique data set linking hospital cost accounting data and Medicare claims. ILDKT was more expensive than matched compatible transplantation, ranging from 20% higher adjusted costs for positive on Luminex assay but negative flow cytometric crossmatch, 26% higher for positive flow cytometric crossmatch but negative cytotoxic crossmatch, and 39% higher for positive cytotoxic crossmatch (p < 0.0001 for all). ILDKT was associated with longer median length of stay (12.9 vs. 7.8 days), higher Medicare payments ($91 330 vs. $63 782 p < 0.0001), and greater outlier payments. In conclusion, ILDKT increases the cost of and payments for kidney transplantation.

High mortality in diabetic recipients of high KDPI deceased donor kidneys

BACKGROUND

Deceased donor (DD) kidney quality is determined by calculating the Kidney Donor Profile Index (KDPI). Optimizing high KDPI (≥85%) DD transplant outcome is challenging. This retrospective study was performed to review our high KDPI DD transplant results to identify clinical practices that can improve future outcomes.

METHODS

We retrospectively calculated the KDPI for 895 DD kidney recipients transplanted between 1/2002 and 11/2013. Age, race, body mass index (BMI), retransplantation, gender, diabetes (DM), dialysis time, and preexisting coronary artery disease (CAD) (previous myocardial infarction (MI), coronary artery bypass (CABG), or stenting) were determined for all recipients.

RESULTS

About 29.7% (266/895) of transplants were from donors with a KDPI ≥85%. By Cox regression older age, diabetes, female gender, and dialysis time >4 years correlated with shorter patient survival time. Diabetics with CAD who received a high KDPI donor kidney had a significantly increased risk of death (HR 4.33 (CI 1.82-10.30), P=.001) compared to low KDPI kidney recipients. The Kaplan-Meier survival curve for diabetic recipients of high KDPI kidneys was significantly worse if they had preexisting CAD (P<.001 by log-rank test).

CONCLUSION

Patient survival using high KDPI donor kidneys may be improved by avoiding diabetic candidates with preexisting CAD.

Survival Benefit with Kidney Transplants from HLA-Incompatible Live Donors

BACKGROUND

A report from a high-volume single center indicated a survival benefit of receiving a kidney transplant from an HLA-incompatible live donor as compared with remaining on the waiting list, whether or not a kidney from a deceased donor was received. The generalizability of that finding is unclear.

METHODS

In a 22-center study, we estimated the survival benefit for 1025 recipients of kidney transplants from HLA-incompatible live donors who were matched with controls who remained on the waiting list or received a transplant from a deceased donor (waiting-list-or-transplant control group) and controls who remained on the waiting list but did not receive a transplant (waiting-list-only control group). We analyzed the data with and without patients from the highest-volume center in the study.

RESULTS

Recipients of kidney transplants from incompatible live donors had a higher survival rate than either control group at 1 year (95.0%, vs. 94.0% for the waiting-list-or-transplant control group and 89.6% for the waiting-list-only control group), 3 years (91.7% vs. 83.6% and 72.7%, respectively), 5 years (86.0% vs. 74.4% and 59.2%), and 8 years (76.5% vs. 62.9% and 43.9%) (P<0.001 for all comparisons with the two control groups). The survival benefit was significant at 8 years across all levels of donor-specific antibody: 89.2% for recipients of kidney transplants from incompatible live donors who had a positive Luminex assay for anti-HLA antibody but a negative flow-cytometric cross-match versus 65.0% for the waiting-list-or-transplant control group and 47.1% for the waiting-list-only control group; 76.3% for recipients with a positive flow-cytometric cross-match but a negative cytotoxic cross-match versus 63.3% and 43.0% in the two control groups, respectively; and 71.0% for recipients with a positive cytotoxic cross-match versus 61.5% and 43.7%, respectively. The findings did not change when patients from the highest-volume center were excluded.

CONCLUSIONS

This multicenter study validated single-center evidence that patients who received kidney transplants from HLA-incompatible live donors had a substantial survival benefit as compared with patients who did not undergo transplantation and those who waited for transplants from deceased donors. (Funded by the National Institute of Diabetes and Digestive and Kidney Diseases.).

Quantifying the risk of incompatible kidney transplantation: a multicenter study

Incompatible live donor kidney transplantation (ILDKT) offers a survival advantage over dialysis to patients with anti-HLA donor-specific antibody (DSA). Program-specific reports (PSRs) fail to account for ILDKT, placing this practice at regulatory risk. We collected DSA data, categorized as positive Luminex, negative flow crossmatch (PLNF) (n = 185), positive flow, negative cytotoxic crossmatch (PFNC) (n = 536) or positive cytotoxic crossmatch (PCC) (n = 304), from 22 centers. We tested associations between DSA, graft loss and mortality after adjusting for PSR model factors, using 9669 compatible patients as a comparison. PLNF patients had similar graft loss; however, PFNC (adjusted hazard ratio [aHR] = 1.64, 95% confidence interval [CI]: 1.15-2.23, p = 0.007) and PCC (aHR = 5.01, 95% CI: 3.71-6.77, p < 0.001) were associated with increased graft loss in the first year. PLNF patients had similar mortality; however, PFNC (aHR = 2.04; 95% CI: 1.28-3.26; p = 0.003) and PCC (aHR = 4.59; 95% CI: 2.98-7.07; p < 0.001) were associated with increased mortality. We simulated Centers for Medicare & Medicaid Services flagging to examine ILDKT's effect on the risk of being flagged. Compared to equal-quality centers performing no ILDKT, centers performing 5%, 10% or 20% PFNC had a 1.19-, 1.33- and 1.73-fold higher odds of being flagged. Centers performing 5%, 10% or 20% PCC had a 2.22-, 4.09- and 10.72-fold higher odds. Failure to account for ILDKT's increased risk places centers providing this life-saving treatment in jeopardy of regulatory intervention.

The pathogenesis of acute allograft dysfunction in desensitized renal transplant recipients

BACKGROUND

Acute allograft rejection after HLA desensitization is common early post-transplant but the sequence of histopathologic changes leading to graft dysfunction has not been well defined.

METHODS

We evaluated the early pathogenesis and sequence of antibody-mediated graft damage of 35 desensitized living donor kidney recipients by studying the course of biopsies taken in the very early post-transplant period (<1 month).

RESULTS

A total of 14 of the 35 patients met criteria for acute antibody-mediated rejection (AMR). In these patients, the chronologic sequence of pathologic changes was C4d peritubular capillary deposition, acute tubular injury, and peritubular capillaritis, followed by glomerulitis and interstitial inflammation. Classic AMR lesions occurred early, followed by mononuclear cellular infiltration, which comprised CD4 and CD8 T cells and monocytes. Development of graft dysfunction in most patients occurred concurrently with the emergence of graft cellular infiltration, rather than at the earlier time of antibody deposition as detected via C4d deposition.

CONCLUSION

These data provide novel insight into the sequence of pathologic changes in patients with AMR post-transplant after HLA desensitization.

Change in bone mineral density at one year following glucocorticoid withdrawal in kidney transplant recipients

Glucocorticoid (GC) therapy induces deleterious effects on the skeleton in kidney transplantation but studies of GC discontinuation in this population are limited. This study evaluated changes in areal bone mineral density (BMD) with GC withdrawal. Subjects were enrolled one yr after renal transplantation and randomized to continue or stop prednisone; all subjects continued cyclosporine and mycophenolate mofetil. BMD measured by dual-energy X-ray absorptiometry was performed at enrollment and repeated at one yr and values were standardized. Mean ± standard deviation of annualized change in standardized BMD between GC withdrawal vs. continuation group at the lumbar spine was +4.7% ± 5.5 vs. +0.9% ± 5.3 (p = 0.0014); total hip +2.4% ± 4.2 vs. -0.4% ± 4.2 (p = 0.013), and femoral neck +2.1% ± 4.6 vs. +1.0% ± 6.0 (p = 0.37). There was no confounding by prednisone dose prior to enrollment, change in creatinine clearance, weight, or use of bone-active medications following study entry. Multivariate analysis determined that the change in BMD was positively associated with baseline alkaline phosphatase and creatinine clearance and negatively associated with baseline BMD. BMD improves with GC withdrawal after renal transplantation, and this gain in BMD is dependent on the baseline bone turnover, renal function, and BMD.

A nonsimultaneous, extended, altruistic-donor chain

We report a chain of 10 kidney transplantations, initiated in July 2007 by a single altruistic donor (i.e., a donor without a designated recipient) and coordinated over a period of 8 months by two large paired-donation registries. These transplantations involved six transplantation centers in five states. In the case of five of the transplantations, the donors and their coregistered recipients underwent surgery simultaneously. In the other five cases, "bridge donors" continued the chain as many as 5 months after the coregistered recipients in their own pairs had received transplants. This report of a chain of paired kidney donations, in which the transplantations were not necessarily performed simultaneously, illustrates the potential of this strategy.

Steroid-free maintenance immunosuppression with rapamune and low-dose neoral in pancreas transplant recipients

BACKGROUND

Steroid-free immunosuppression is an attractive option because it avoids the many side effects of chronic corticosteroid use. It is especially attractive in pancreas recipients because it avoids the diabetogenic effects of steroids.

METHODS

We evaluated the outcome of a steroid-free maintenance immunosuppressive protocol in pancreas transplant recipients. Between August 2003 and May 2006, a total of 97 pancreas transplant recipients received steroid-free maintenance immunosuppression, consisting of induction with thymoglobulin and prednisone for the first 5 days. Patients were maintained on sirolimus adjusted to a target rapamycin trough level and reduced-dose cyclosporine adjusted to target C2 levels. All pancreas transplants (n=124) performed in the previous 3 years and maintained on a steroid-based immunosuppressive protocol with cyclosporine and mycophenolate mofetil were used for comparison.

RESULTS

One-year patient and death censored pancreas graft survival were 93.8% and 94.8% for the steroid free group versus 95.2% and 87.9% for the comparator group, respectively. The incidence of acute rejection was 9.3% in the steroid-free group versus 28.3% in the comparator group (P<0.01). No pancreas loss in the steroid-free group was caused by acute rejection, whereas seven (5.6%) patients in the comparator group lost their pancreases because of acute rejection (P<0.05). At 1 year after transplant, the mean serum glucose and creatinine levels were not different between the two groups.

CONCLUSION

We conclude that excellent graft survival with a significantly lower incidence of acute rejection can be achieved using a steroid-free maintenance immunosuppressive protocol consisting of sirolimus and cyclosporine.

Clinical outcomes of renal transplant recipients treated with enteric-coated mycophenolic acid vs. mycophenolate mofetil as a switch agent using a primary steroid-free rapamune and microemulsion cyclosporine protocol

Since 2002 our transplant program has utilized a steroid free, cyclosporine (CSA)- and rapamycin (RAPA)-based maintenance immunosuppression regimen. In cases where it has been desirable to avoid the potential nephrotoxicity with this regimen we have used mycophenolic acid (MPA) as our "switch" drug of choice. Both mycophenolate mofetil (MMF) (Roche Inc., Nutley, NJ, USA) and enteric-coated MPA (ECM) (Novartis, East Hanover, NJ, USA) have been used. In this study, we retrospectively compared the tolerability of the two formulations of MPA. Thus we compared 103 recipients switched to RAPA/MMF (RMM group) to 114 switched to RAPA/ECM (REC group). There was a significantly higher incidence of patients requiring dose changes and drug discontinuation in the RMM group, as well as an increased frequency of dose changes. There were significantly more acute rejection episodes and kidney losses in the dose adjustment vs. no dose adjustment patients. However, when comparing the incidence of acute rejection and kidney loss between the RMM and REC groups, there was no significant difference. We conclude that in this cohort of recipients, the ECM formulation of MPA was better tolerated than the MMF formulation, resulting in fewer patients requiring dose adjustments or drug discontinuation.

Evaluation of immune regulation in transplant patients using the trans vivo delayed type hypersensitivity assay

Allograft recipient IL-10 and/or transforming growth factor-beta (TGF-beta) dependent anti-inflammatory T-cell delayed type hypersensitivity (DTH) responses to donor derived antigens, or regulatory T-cell responses, have been demonstrated in rodents and transplant patients using a previously described trans vivo DTH assay. We used this assay to determine the incidence of recipient anti-inflammatory T-cell responses to donor antigens in a large cohort (n = 420) of primary kidney and simultaneous kidney-pancreas transplant patients tested a mean of 4.8 years after transplantation. The results were compared with clinical outcomes and the presence of detectable circulating alloantibodies. We found an unexpectedly high incidence (21.9%) of this anti-inflammatory T-cell response to donor antigens in these recipients. There was a significant correlation between this T-cell phenotype and the presence of detectable circulating alloantibodies (p = 0.03). There was no correlation between this T-cell phenotype and the degree of HLA mismatch. In addition, the presence of an anti-inflammatory DTH response to donor antigens did not correlate with an improved clinical outcome at a median of nearly 5 years after transplantation. These findings suggest that detection of an anti-inflammatory T-cell response to donor antigens does not identify patients that have developed graft protective, regulatory T-cell responses.

Prospective, randomized trial of steroid withdrawal in kidney recipients treated with mycophenolate mofetil and cyclosporine

Our transplant centre began a prospective, randomized trial of steroid withdrawal in low risk renal transplant recipients on triple immunosuppression consisting of mycophenolate mofetil (MMF), microemulsion cyclosporine (CSA), and prednisone. One hundred and twenty patients were randomized either to discontinue or remain on steroids (60 patients per group). Study design consisted of analyses of 1-yr outcomes after study entry. This report includes the 1-yr results plus results at last follow-up (mean follow-up 3.7 yr). There were no significant differences in rates of patient and graft survival at 1 yr or at last follow-up. Additionally, the incidences of acute and chronic rejection as well as graft function were the same at 1 yr and at last follow-up. Significant improvement was noted in total serum cholesterol and bone density at 1 yr and last follow-up. Initial improvement in patient weight at 1 yr was not sustained at last follow-up. No significant impact of steroid withdrawal on serum triglycerides, blood pressure, or post-transplant diabetes mellitus was observed. To date, we have observed no immunologic risk, and some significant benefit in regards to side effects, of steroid withdrawal between 6 and 36 months after transplantation in low risk renal transplant recipients maintained on prednisone, MMF, and microemulsion CSA.

CONCLUSION

Steroid withdrawal in low risk kidney transplant recipients is safe and ameliorates many of the unwanted sides effects of steroid use.

Excellent clinical outcomes in primary kidney transplant recipients treated with steroid-free maintenance immunosuppression

Steroid-free maintenance immunosuppression is desirable to eliminate the side effects of chronic corticosteroid use. Complete steroid avoidance or rapid post-transplant steroid withdrawal has recently been used in renal transplant recipients with encouraging results. The present study evaluated the outcome of a steroid-free maintenance immunosuppressive protocol in kidney transplant recipients with at least one-yr follow up. Between April 2002 and October 2004, a total of 301 primary kidney transplant recipients received steroid-free maintenance immunosuppression. The regimen consisted of induction with thymogobulin and prednisone for the first five d. Patients were maintained on Sirolimus and Neoral. Neoral dose was adjusted to target C2 levels and the Sirolimus dose was adjusted to a target rapamycin trough level. All primary kidney transplants (n = 502) performed in the two yr (starting January 2000) prior to institution of the steroid-free regimen and thus maintained on a steroid-based immunosuppressive protocol were used for comparison. One-year patient and death censored graft survival were 93.1% and 98.1% for the steroid-free group vs. 95.2% and 95.2% for the comparator groups (p = ns). The incidence of biopsy-proven acute rejection was 4.9% in the steroid-free group vs. 9.4% in the comparator group (p < 0.01). Two (0.7%) of 301 patients in the steroid-free group lost their grafts because of acute rejection compared with nine (1.8%) patients in the comparator group (p < 0.05). At one-yr post-transplant the mean serum creatinine level was not different between the two groups. There were no significant differences in mean serum cholesterol and triglycerides levels as well as the percentage of patients on lipid lowering agents between the groups. White blood cell counts, daily doses of Neoral and weight gain were significantly lower in the steroid-free group vs. the comparator group. However, more patients in the steroid-free group required erythropoietin and iron therapy for anemia (p < 0.001). We conclude that excellent graft survival with a significantly lower incidence of acute rejection can be achieved using a steroid-free maintenance immunosuppressive protocol consisting of Neoral and Sirolimus.

Hand-assisted laparoscopic versus open nephrectomies in living donors

Shortages of cadaveric kidneys for transplant into rising numbers of patients with end-stage renal failure have increased the demand for kidneys from live donors. The morbidity associated with traditional open donor nephrectomies (ODN) may discourage many candidates. The newer laparoscopic technique has been promoted as having less morbidity.

OBJECTIVES

To evaluate outcomes of hand-assisted laparoscopic nephrectomies (HALN) and prospectively compare HALN and ODN.

METHODS

After retrospectively reviewing donor and recipient outcomes in 33 HALN (December through August, 2000), we prospectively compared another 47 with 30 ODN performed from September 2000 through April 2001.

RESULTS

All 80 HALN were successful, with no requirement to convert to an open procedure. Four donors experienced surgery-related complications: wound infection, retroperitoneal hematoma, prolonged ileus and early small-bowel obstruction, respectively. Two recipients had ureteral complications (1 stricture, 1 leak); 5 experienced delayed graft function, 2 requiring dialysis; and 2 kidneys were lost from infarction. The prospective comparison showed the operative time for HALN (mean 184 min, standard deviation [SD] 39 min) was significantly longer (143 [SD 27] min, p < 0.01), but resulted in less blood loss (p < 0.05). Lengths of time to warm ischemia/early graft function, resumption of oral intake/first bowel movement, and hospital discharge were similar. The abdominal-wall laxity and loss of cutaneous sensation from the flank incision experienced by many ODN patients after was uncommon in the HALN group. Three months after nephrectomy, donor complaints of incisional pain were less common after HALN (p < 0.01).

CONCLUSIONS

HALN had good outcomes for donors and recipients, with quicker, more complete recoveries 3 months afterward.

Evolution of immunosuppression in kidney transplantation: the Ohio State University experience

The goals and outcomes of immunosuppression in renal transplantation have changed significantly over the last 30 years. When graft survival rates were relatively low and acute rejection was a frequent occurrence in the early era of transplantation, the goal of immunosuppression was to improve survival and reduce the rate of acute rejection. Today, with excellent graft survival rates and a low incidence of acute rejection, the goal of immunosuppression has shifted toward not only eliminating acute rejection, but also toward reducing the side effects of medications, and maintaining long-term graft function by decreasing chronic nephropathy. Between September 1982-December 2004, 3,211 primary kidney transplant procedures were performed at The Ohio State University. We excluded from analysis all combined transplants as well as patients who were involved in clinical research protocols. Our immunosuppressive protocol changed substantially over this 24-year period, which can be divided into 5 eras in time. Each era is defined by a distinct immunosuppressive protocol that resulted in an incremental improvement in outcomes of patient and graft survival rates. In the present study, the outcomes of each era in patients with previous kidney transplant only are compared and future directions are discussed. The incidence of acute rejection episodes and graft survival from each era are compared and demonstrate the substantial improvement in results that have been achieved over the past 24 years.

IFN-gamma gene polymorphisms associate with development of EBV+ lymphoproliferative disease in hu PBL-SCID mice

Posttransplantation lymphoproliferative disorder (PTLD) is a devastating post-transplantation complication often associated with Epstein-Barr virus (EBV). Although the type and length of immunosuppression are risk factors, a patient's inherent immune capacity also likely contributes to this disorder. This report uses severe-combined immunodeficient mice given injections of human peripheral blood leukocytes (hu PBL-SCID [Severe Combined Immunodeficient] mice) to test the hypothesis that cytokine genotype associates with the development of EBV-associated lymphoproliferative disease (LPD). We observed that the A/A (adenosine/adenosine) genotype for base + 874 of the interferon gamma (IFN-gamma) gene was significantly more prevalent in PBLs producing rapid, high-penetrance LPD in hu PBL-SCID mice, compared to PBLs producing late, low-penetrance LPD or no LPD. In examining the relationship between genotype and cytolytic T-lymphocyte (CTL) function, transforming growth factor beta (TGF-beta) inhibited restimulation of CTLs in PBLs with adenosine at IFNG base + 874, but not in PBLs homozygous for thymidine. Importantly, neutralization of TGF-beta in hu PBL-SCID mice injected with A/A genotype PBLs resulted in reduced LPD development and expanded human CD8(+) cells. Thus, our data show that TGF-beta may promote tumor development by inhibiting CTL restimulation and expansion. Further, our data indicate that IFNG genotype may provide valuable information for both identifying transplant recipients at greater risk for PTLD and developing preventive and curative strategies.

Magnetic Resonance Cholangiography With Mangafodipir Trisodium (Teslascan) to Evaluate Bile Duct Leaks After T-Tube Removal in Liver Transplantation

Liver transplant patients who present with abdominal pain after removal of the T-tube can be initially evaluated by contrast-enhanced magnetic resonance cholangiography (CEMRC) instead of abdominal computed tomography and hepatobiliary scintigraphy. In this article, 3 liver transplant patients who were evaluated by CEMRC after removal of the T-tube. CEMRC successfully identified the presence, location and extent of bile duct leaks, and can be performed as a diagnostic study in patients with suspected bile duct leaks.

Magnetic resonance angiography for preoperative evaluation of potential kidney donors1

BACKGROUND

Careful evaluation of the renovascular anatomy for living kidney donors is essential to optimize donor and recipient outcomes. Arteriography has been the standard for delineating the renovascular anatomy. However, this procedure is invasive. Magnetic resonance angiography (MRA) is an attractive, noninvasive alternative. The aim of this study was to evaluate the accuracy of MRA in potential living kidney donors.

METHODS

A retrospective comparison of the preoperative MRA results with the intraoperative anatomy was performed in 189 living kidney donors.

RESULTS

MRA interpretations correctly identified the vascular anatomy of the donor kidneys in 173 donors (91.5%). In the remaining 16 patients (8.5%), the MRA interpretation was inaccurate. In 10 patients, the MRA reported fewer arteries than the number encountered during the donor operation, whereas in six patients MRA reported more arteries than what found during operation. In seven patients, MRA supplied additional important anatomical information, including kidney size disparity, the presence of nephrolithiasis, the presence of a renal cyst, and renal artery stenosis. All kidneys were successfully transplanted. The misinterpretation of the MRA did not adversely affect the recipient outcome.

CONCLUSION

The noninvasive MRA evaluation of donor renovascular anatomy is an acceptable substitute for traditional angiography.

EBV kidney allograft infection: possible relationship with a peri-graft localization of PTLD

Post-transplant lymphoproliferative disorder (PTLD) is a grave complication of transplantation and the result of uncontrolled proliferation of B lymphocytes infected with Epstein-Barr virus (EBV). Herein we assess whether EBV infects renal grafts and whether there is a relationship between EBV kidney infection and PTLD. Allograft biopsies from 23 patients with PTLD were studied for the presence of EBV DNA and RNA (EBER-1, -2) by in situ hybridization and for CD21 by immunohistochemistry. Results were compared to 43 transplants from people without PTLD. EBV DNA and RNA were detected in 11/43 patients without PTLD (26%), and in 15/23 (65%) patients with PTLD (p = 0.004). EBV DNA and RNA localized to proximal tubular cells and these cells showed up-regulation of the EBV receptor CD21. EBV-infected allografts were noted in 12/12 patients with PTLD located near the allograft and in 3/11 (27%) of patients with PTLD distant from the graft. Multiple biopsies in eight patients showed that graft EBV infection can precede the diagnosis of PTLD by as long as 42 months. It is concluded that EBV can infect kidney allografts, and there appears to be a relationship between this infection and the presence of PTLD near the graft.

Twenty years of renal transplantation at Ohio State University: the results of five eras of immunosuppression

Over the past 20 years, more than 4,000 patients have undergone an abdominal solid organ transplant at Ohio State University. The 20-year period can be divided into five eras, each defined by an immunosuppressive protocol used during that period. With each successful era came a new immunosuppressive protocol that produced an incremental improvement in outcomes of patients and graft survival resulting from the application of the newest and most sophisticated combination of immunosuppressive drugs. The incidence of acute rejection episodes and graft survival from each era are compared and demonstrate the substantial improvement in results that has been achieved over the past 20 years.

The impact of mycophenolate mofetil dosing patterns on clinical outcome after renal transplantation

BACKGROUND

Mycophenolate mofetil (MMF) has proven to be a very effective drug for the prevention of acute rejection following renal transplantation when dosed as prescribed at 2 or 3 g/d. However, circumstances arise in clinical transplantation where the dose must be lowered, either to avoid drug toxicity or because of concurrent infection. The impact on the incidence of acute rejection and graft survival when the MMF dose must be lowered has not previously been investigated.

METHODS

In this study, a cohort of 721 kidney transplant recipients who received immunosuppression using MMF in conjunction with cyclosporine and prednisone and OKT3 (n = 425) or Simulect (n = 296) induction were evaluated. Clinical outcomes were compared and contrasted between patients with and without MMF dose changes within the first year post-transplantation.

RESULTS

The majority of patients (70.3%, n = 507) had at least one dose change within the first post-transplant year. Compared with the 214 patients who did not have a dose change, these patients had a much higher incidence of acute rejection within the first post-transplant year (23.3% vs. 3.7%, p < 0.001). This resulted in a significantly decreased 3-yr death-censored graft survival (76.3% vs. 88.3%, p = 0.003). The incidence of acute rejection for patients who had a dose change was highest if the dose change occurred within the first post-transplant month (34.4%). The incidence of acute rejection for the dose change patients was influenced by recipient ethnicity (African-American vs. Caucasian) and the type of induction agent used (OKT3 vs. Simulect).

CONCLUSION

Altering the dose of MMF within the first post-transplant year correlated with a significantly worse clinical outcome in this cohort of renal transplant recipients. These data suggest that avoidance of MMF dose changes within the first year after renal transplantation would result in improved graft survival.

Simultaneous pancreas-kidney transplantation at a single center

Simultaneous pancreas-kidney transplantation (SPKT) is the procedure of choice in our program to treat type I diabetic patients with end-stage renal disease. Its value in type II diabetic patients remains to be carefully evaluated. With the improvements in the technical results and immunosuppression medications, the procedures have become safer than those performed in the previous decade. However, the diabetic host is a high-risk individual. Careful evaluation and selection is prudent to maintain excellent results with this scarce organ. As we have seen in this series, death is the number one cause of graft loss and improved pre-operative evaluation will continue to be of significant value to lower the mortality rate of SPKT. The success of SPKT has led to wider application of this procedure to less than ideal recipients. Due to the shortage of organs, there is a trend to use more marginal donors. The use of marginal donors and marginal recipients requires careful evaluation to maintain safety and cost effectiveness. At our center, long-term patient and graft survival rates have been acceptable. We will continue to use SPKT as the procedure of choice for acceptable candidates. There has been a trend to change our philosophy to use living donors for the kidney transplant followed by a sequential pancreas transplant in order to overcome the shortage of organs. The issue of primary enteric drainage has not been addressed in this report due to our success with bladder drainage, as we feel that it is a safer procedure and are comfortable that patient education and outpatient therapy has minimized the problems with its use. Despite the lower threshold for enteric conversion, fewer than 10% of our patients undergo conversion when they are at low risk for complications.

High incidence of donor-reactive delayed-type hypersensitivity reactivity in transplant patients

Evidence of transplant recipient cellular sensitization towards donor antigens has rarely been directly measured. Rather, sensitization has been generally inferred by the presence of detectable allo-reactive or donor-reactive antibodies. In this study a newly developed delayed-type hypersensitivity assay was used to directly determine the incidence of post-transplant donor-reactive T-cell sensitization in a large cohort of kidney and simultaneous kidney-pancreas recipients. These results were compared with the presence of detectable circulating alloantibodies and with patient clinical outcome. We found an unexpectedly high incidence (52%) of donor-reactive delayed-type hypersensitivity reactivity in our study patients. Donor-reactive delayed-type hypersensitivity reactivity occurred at a much higher frequency than detectable alloantibodies (20%). Further, we found no correlation between the presence of alloantibodies and donor-reactive delayed-type hypersensitivity reactivity. We also found no correlation between the development of donor-reactive delayed-type hypersensitivity reactivity and the degree of donor and recipient HLA matching. Finally, the presence of detectable donor-reactive delayed-type hypersensitivity reactivity did not correlate with a worse clinical outcome at the time of these analyses. We conclude that in transplant recipients, the presence of circulating alloantibodies is a poor indicator of previous T-cell sensitization to donor antigens. We also conclude that our current immunosuppression strategies are relatively ineffective at blocking T-cell allosensitization, but are very effective at blocking the biological consequences of that allosensitization.

Successful treatment of posttransplantation lymphoproliferative disorder (PTLD) following renal allografting is associated with sustained CD8(+) T-cell restoration

Posttransplantation lymphoproliferative disorder (PTLD) is a life-threatening Epstein-Barr virus (EBV)-associated B-cell malignancy occurring in 1% to 2% of renal transplantation patients. Host- and PTLD-related factors determining the likelihood of tumor response following reduction of immune suppression (IS) and antiviral therapy remain largely unknown. Standard therapy for PTLD is not well established. Eleven consecutive renal transplantation patients who developed EBV-positive PTLD 8 to 94 months after allografting were uniformly treated with acyclovir and IS reduction. All PTLDs were EBV-positive diffuse large B-cell lymphomas. Ten patients (91%) obtained a durable complete response (CR), and 9 (82%) have remained in continuous CR with a median follow-up of 29 months. Five patients (45%) lost their allograft. Of these, 4 patients had PTLD affecting the transplanted kidney. Peripheral blood CD8(+) T cells increased significantly (P =.0078) from baseline in 8 responders available for analysis. One of 2 patients whose absolute CD8(+) T-cell count subsequently dropped to baseline after IS reduction relapsed. The expanded CD8(+) T cells from 2 responders specifically recognized an immunodominant peptide from the EBV lytic gene BZLF-1. Another lytic EBV gene, thymidine kinase, was expressed in all 8 PTLDs tested. IS reduction and antiviral therapy for PTLD after renal transplantation is a highly successful therapeutic combination, but the risk of graft rejection is significant, particularly in patients with PTLD involving the renal allograft. A sustained expansion of CD8(+) T cells and a cellular immune response to EBV lytic antigens may be important for PTLD clearance in renal transplantation patients.

Patient survival after renal transplantation III: the effects of statins

BACKGROUND

Kidney transplant recipients have high cardiovascular risk and an unfavorable cardiovascular risk profile, which frequently includes hyperlipidemia. Although the use of HMG-CoA reductase inhibitors (statins) is associated with improved survival in the general population, the effects of these drugs on the survival of kidney transplant recipients have not been established.

METHODS

In this study, we determined which factors were associated with the use of statins in a population of 1,574 adult, kidney allograft recipients, transplanted in one institution. A risk factor analysis of patient survival was done with a primary focus on the possible relationship between statin use and survival.

RESULTS

The percent of patients treated with statins increased progressively from 1982 to 1996. Statins were used significantly more often in whites (30%) than in blacks (20%, P = 0.001) and in older individuals. These differences in statin use were not due to differences in lipid levels among the patient groups. As expected, the group of patients treated with statins had significantly higher serum lipid levels than untreated patients. Patient survival was significantly better in patients treated with statins than in untreated patients. That relationship became apparent, however, only after controlling for three additional factors: recipient age, transplant year, and serum cholesterol levels. In a multivariable Cox survival model, patient survival was associated significantly with statin use (hazard ratio [HR] = 0.76; confidence interval [CI], 0.6 to 0.96; P = 0.02), recipient age (HR = 1.05; CI, 1.04 to 1.06; P < 0.0001), and transplant year (HR = 1.05; CI, 1.01 to 1.08; P = 0.001). The serum cholesterol level was not associated significantly with patient survival in this model, but cholesterol significantly modified the relationship between statin use and patient survival.

CONCLUSIONS

Renal transplant recipients treated with statins have a 24% better survival than patients who do not receive these drugs.

Evidence that a similar range of alloimmune responses can develop in murine and human allograft recipients

Based on discrepancies between various laboratory and clinical observations, skepticism has developed regarding the pre-clinical value of rodent immunologic studies. In this article, we review the progression of our murine and human studies over the last several years, which have demonstrated that humans and mice can make very similar types of immune responses in vivo to allografts. Early studies by ourselves and others, demonstrated that mice can make either pro-inflammatory (rejection) or anti-inflammatory (acceptance) immune responses to graft alloantigens. We demonstrated that donor-reactive DTH assays could be used to monitor which type of alloimmune response had been selected by the allograft recipient. To help determine if similar immune response options are available to humans and detectable by DTH assays, we first developed the transvivo DTH assay. In this system, mice are used as a receptacle in which DTH responses made by human PBMC can be induced and measured. These transvivo DTH studies revealed that human allograft recipients, like mice, commonly make either pro-inflammatory or anti-inflammatory immune responses to graft alloantigens. In transplant patients, this rarely correlates with the development of donor-reactive alloantibodies during the post-transplant period.

The graft helps to define the character of the alloimmune response

INTRODUCTION

In mice, kidney and liver allografts may be spontaneously accepted, whereas cardiac and skin allografts in the same strain combinations are rapidly rejected. The reasons for this dichotomy in murine response outcomes remains to be determined.

METHODS AND RESULTS

When DBA/2 (H-2d) cardiac allografts were placed in C57BL/6 (H-2b) recipients, they were rejected within 10 days, unless the allograft recipients were transiently treated with gallium nitrate (GN), at which time the allografts were accepted for > 150 days. The cardiac allograft rejector mice displayed DBA/2-reactive DTH responses, whereas the cardiac allograft acceptor mice displayed both TGFbeta- and IL10-mediated inhibition of DTH responses. In contrast, DBA/2 kidney allografts placed at the same location in C57BL/6 mice were spontaneously accepted without immunosuppression. These kidney allograft acceptor mice displayed TGFbeta-mediated, but not IL10-mediated inhibition of donor-reactive DTH responses.

CONCLUSIONS

In the DBA/2-> C57B1/6 strain combination, cardiac allografts induce pro-inflammatory immunity and allograft rejection, while kidney allografts induce anti-inflammatory immunity and allograft acceptance despite the fact that both organs display the same strong MHC disparities and are implanted at the same location. Anti-inflammatory immunity and allograft acceptance are displayed by cardiac allograft recipients when they are transiently treated with select immunosuppressants. Thus, multiple immune response options are available to the organ allograft recipient, and the choice is determined, to some degree, by the allograft, itself.

Clinical significance of MHC-reactive alloantibodies that develop after kidney or kidney-pancreas transplantation

The purpose of this study was to determine the relationships between acute rejection, anti-major histocompatibility complex (MHC) class I and/or class II-reactive alloantibody production, and chronic rejection of renal allografts following kidney or simultaneous kidney-pancreas transplantation. Sera from 277 recipients were obtained pretransplant and between 1 month and 9.5 years post-transplant (mean 2.6years). The presence of anti-MHC class I and class II alloantibodies was determined by flow cytometry using beads coated with purified MHC molecules. Eighteen percent of recipients had MHC-reactive alloantibodies detected only after transplantation by this method. The majority of these patients produced alloantibodies directed at MHC class II only (68%). The incidence of anti-MHC class II, but not anti-MHC class I, alloantibodies detected post-transplant increased as the number of previous acute rejection episodes increased (p = 0.03). Multivariate analysis demonstrated that detection of MHC class II-reactive, but not MHC class I-reactive, alloantibodies post-transplant was a significant risk factor for chronic allograft rejection, independent of acute allograft rejection. We conclude that post-transplant detectable MHC class II-reactive alloantibodies and previous acute rejection episodes are independent risk factors for chronic allograft rejection. Implementing new therapeutic strategies to curtail post-transplant alloantibody production, and avoidance of acute rejection episodes, may improve long-term graft survival by reducing the incidence of chronic allograft rejection.

A randomized prospective trial of OKT3 induction in the current immunosuppression era

Recent improvements in immunosuppression and subsequent decreases in the incidence of acute rejection have brought into question the benefit of the use peri-transplant antibody therapy (i.e. induction therapy). In the current era of immunosuppression that includes mycophenolate mofetil (MMF) and cyclosporine emulsion (Neoral, Novartis, Basle, Switzerland), we designed and have completed a prospective, randomized trial to address this question. Cadaveric and living donor renal allograft recipients were randomized to receive either OKT3/MMF/delayed Neoral/prednisone or MMF/immediate Neoral/prednisone without OKT3. The incidence of rejection episodes was the primary end point. Patients with delayed graft function were excluded. All rejection episodes were biopsy proven and all patients have been followed for a minimum of 2 yr. Fifty-four patients received OKT3 induction, of which 6 patients suffered a rejection episode (11%), while 13 patients (27%) not receiving OKT3 (p=0.04) had a rejection episode. Four patients in the no OKT3 group suffered multiple rejections, while there were only 2 with more than one episode in the OKT3 group. There was no increased incidence of infectious complications in the group receiving OKT3. Hospital costs tended to be higher in the OKT3-treated group, but were not significantly different. The low incidence of rejection in the OKT3-treated group was intriguing and validates the use of antibody therapy in the early post-operative periods even in the era of improved baseline immunosuppression.