Defining optimal blood pressure control for pre-transplant end-stage renal disease patients: scoping review.

BACKGROUND: Strict blood pressure control is essential to prevent cardiovascular disease and is associated with decreased mortality. However, in patients with end-stage renal disease awaiting renal transplantation, the level of optimal blood pressure control is not yet defined. METHODS: Following the PRISMA Extension for Scoping Reviews, we searched MEDLINE and EMBASE for all peer-reviewed articles using keywords including 'end-stage renal disease', 'blood pressure', and 'pre-transplant' from their inception to 7 August 2022. RESULTS: Seven observational studies, including one population-based study, were included in the review. Most studies investigated factors associated with post-transplant graft failure or mortality. There was considerable heterogeneity in defining optimal pre-transplant blood pressure measurement frequency among studies (average of three measurements vs. single measurement). One study suggested that low pre-transplant diastolic blood pressure (<50 mmHg) was associated with lower odds of delayed graft failure and mortality. Two studies noted that pre-transplant hypertension, or clinical criteria of hypertension that were present prior to transplant, was associated with post-transplant adverse outcomes. In contrast, one study noted that pre-transplant sustained hypotension with mean blood pressure <80 mmHg, was associated with a higher frequency of delayed graft failure. CONCLUSION: This systematic review summarizes the current evidence regarding the relationship between pre-transplant blood pressure control and post-transplant outcomes in end-stage renal disease patients. While the results from the included studies are mixed, more stringent blood pressure control than currently practiced may be beneficial to decrease graft failure and mortality in this patient population.

Analysis of local versus imported expanded criteria donor kidneys: A single-center experience with 497 ECD kidney transplants.

BACKGROUND: The value of importing expanded criteria donor (ECD) kidneys is uncertain. METHODS: We retrospectively reviewed our single-center experience with ECD kidney transplants (KT). RESULTS: Over 12.8 years, we performed 497 ECD KTs including 247 local and 250 imported from other donor service areas. The import ECD group had more donors (16% vs 9%) ≥ age 70, more zero human leukocyte antigen mismatches (14% vs 2%), more KTs with a cold ischemia time >30 hours (46% vs 19%), and fewer kidneys managed with pump preservation (78% vs 92%, all P≤.05) compared to the local ECD group. Mean Kidney Donor Profile Index were 80% import vs 84% local. With a mean follow-up of 55 months, actual patient and graft survival rates were 71% and 58% in import vs 76% and 58% in local ECD KTs, respectively. Death-censored graft survival rates were 70% in import vs 69% in local ECD KTs. Delayed graft function occurred in 28% import vs 23% local ECD KTs (P=NS) whereas the incidence of primary nonfunction was slightly higher with import ECD kidneys (4.8% vs 2.4%, P=.23). CONCLUSIONS: Midterm outcomes are remarkably similar for import vs local ECD KTs, suggesting that broader sharing of ECD kidneys may improve utilization without compromising outcomes.

Single vs dual (en bloc) kidney transplants from donors ≤ 5 years of age: A single center experience.

AIM: To compare outcomes between single and dual en bloc (EB) kidney transplants (KT) from small pediatric donors. METHODS: Monocentric nonprospective review of KTs from pediatric donors ≤ 5 years of age. Dual EB KT was defined as keeping both donor kidneys attached to the inferior vena cava and aorta, which were then used as venous and arterial conduits for the subsequent transplant into a single recipient. Donor age was less useful than either donor weight or kidney size in decision-making for kidney utilization as kidneys from donors < 8 kg or kidneys < 6 cm in length were not transplanted. Post-transplant management strategies were standardized in all patients. RESULTS: From 2002-2015, 59 KTs were performed including 34 dual EB and 25 single KTs. Mean age of donors (17 mo vs 38 mo, P < 0.001), mean weight (11.0 kg vs 17.4 kg, P = 0.046) and male donors (50% vs 84%, P = 0.01) were lower in the dual EB compared to the single KT group, respectively. Mean cold ischemia time (21 h), kidney donor profile index (KDPI; 73% vs 62%) and levels of serum creatinine (SCr, 0.37 mg/dL vs 0.49 mg/dL, all P = NS) were comparable in the dual EB and single KT groups, respectively. Actuarial graft and patient survival rates at 5-years follow-up were comparable. There was one case of thrombosis resulting in graft loss in each group. Delayed graft function incidence (12% dual EB vs 20% single KT, P = NS) was slightly lower in dual EB KT recipients. Initial duration of hospital stay (mean 5.4 d vs 5.6 d) and the one-year incidences of acute rejection (6% vs 16%), operative complications (3% vs 4%), and major infection were comparable in the dual EB and single KT groups, respectively (all P = NS). Mean 12 mo SCr and abbreviated MDRD levels were 1.17 mg/dL vs 1.35 mg/dL and 72.5 mL/min per 1.73 m(2) vs 60.5 mL/min per 1.73 m(2) (both P = NS) in the dual EB and single KT groups, respectively. CONCLUSION: By transplanting kidneys from young pediatric donors into adult recipients, one can effectively expand the limited donor pool and achieve excellent medium-term outcomes.

Dual kidney transplants from adult marginal donors successfully expand the limited deceased donor organ pool.

BACKGROUND: The need to expand the organ donor pool remains a formidable challenge in kidney transplantation (KT). The use of expanded criteria donors (ECDs) represents one approach, but kidney discard rates are high because of concerns regarding overall quality. Dual KT (DKT) may reduce organ discard and optimize the use of kidneys from marginal donors. STUDY DESIGN: We conducted a single-center retrospective review of outcomes in adult recipients of DKTs from adult marginal deceased donors (DD) defined by limited renal functional capacity. If the calculated creatinine clearance in an adult DD was <65 mL/min, then the kidneys were transplanted as a DKT. RESULTS: Over 11.5 yr, 72 DKTS were performed including 45 from ECDs, 17 from donation after cardiac death (DCD) donors, and 10 from standard criteria donors (SCD). Mean adult DD and recipient ages were both 60 yr, including 29 DDs and 26 recipients ≥65 yr of age. Mean pre-DKT waiting and dialysis vintage times were 12 months and 25 months, respectively. Actual patient and graft survival rates were 84.7% and 70.8%, respectively, with a mean follow-up of 58 months. One yr and death-censored graft survival rates were 90% and 80%, respectively. Outcomes did not differ by DD category, recipient age, or presence of delayed graft function (DGF). Eleven patients died at a mean of 32 months post-DKT (eight with functioning grafts) and 13 other patients experienced graft losses at a mean of 33 months. The incidence of DGF was 25%; there were two cases (2.8%) of primary non-function. Mean length of initial hospital stay was 7.2 d. Mean serum creatinine and glomerular filtration rate levels at 12 and 24 months were 1.5 and 53 and 1.5 mg/dL and 51 mL/min/1.73 m(2) , respectively. DKT graft survival and function were superior to concurrent single ECD and similar to concurrent SCD KTs. Two patients underwent successful kidney retransplantation, so the dialysis-free rate in surviving patients was 87%. The proportion of total renal function transplanted from adult DD to DKT recipients was 77% compared to 56% for patients receiving single KTs. CONCLUSIONS: Dual kidney transplantation using kidneys from adult marginal DDs that otherwise might be discarded offer a viable option to counteract the growing shortage of acceptable single kidneys. Excellent medium-term outcomes can be achieved and waiting times can be reduced in a predominantly older recipient population.

APOL1 Genotype and Kidney Transplantation Outcomes From Deceased African American Donors.

BACKGROUND: Two apolipoprotein L1 gene (APOL1) renal-risk variants in donors and African American (AA) recipient race are associated with worse allograft survival in deceased-donor kidney transplantation (DDKT) from AA donors. To detect other factors impacting allograft survival from deceased AA kidney donors, APOL1 renal-risk variants were genotyped in additional AA kidney donors. METHODS: The APOL1 genotypes were linked to outcomes in 478 newly analyzed DDKTs in the Scientific Registry of Transplant Recipients. Multivariate analyses accounting for recipient age, sex, race, panel-reactive antibody level, HLA match, cold ischemia time, donor age, and expanded criteria donation were performed. These 478 transplantations and 675 DDKTs from a prior report were jointly analyzed. RESULTS: Fully adjusted analyses limited to the new 478 DDKTs replicated shorter renal allograft survival in recipients of APOL1 2-renal-risk-variant kidneys (hazard ratio [HR], 2.00; P = 0.03). Combined analysis of 1153 DDKTs from AA donors revealed donor APOL1 high-risk genotype (HR, 2.05; P = 3 × 10), older donor age (HR, 1.18; P = 0.05), and younger recipient age (HR, 0.70; P = 0.001) adversely impacted allograft survival. Although prolonged allograft survival was seen in many recipients of APOL1 2-renal-risk-variant kidneys, follow-up serum creatinine concentrations were higher than that in recipients of 0/1 APOL1 renal-risk-variant kidneys. A competing risk analysis revealed that APOL1 impacted renal allograft survival, but not recipient survival. Interactions between donor age and APOL1 genotype on renal allograft survival were nonsignificant. CONCLUSIONS: Shorter renal allograft survival is reproducibly observed after DDKT from APOL1 2-renal-risk-variant donors. Younger recipient age and older donor age have independent adverse effects on renal allograft survival.

Donor-derived myeloid sarcoma in two kidney transplant recipients from a single donor.

We report the rare occurrence of donor-derived myeloid sarcoma in two kidney transplant patients who received organs from a single deceased donor. There was no evidence of preexisting hematologic malignancy in the donor at the time of organ recovery. Both recipients developed leukemic involvement that appeared to be limited to the transplanted organ. Fluorescence in situ hybridization (FISH) and molecular genotyping analyses confirmed that the malignant cells were of donor origin in each patient. Allograft nephrectomy and immediate withdrawal of immunosuppression were performed in both cases; systemic chemotherapy was subsequently administered to one patient. Both recipients were in remission at least one year following the diagnosis of donor-derived myeloid sarcoma. These cases suggest that restoration of the immune system after withdrawal of immunosuppressive therapy and allograft nephrectomy may be sufficient to control HLA-mismatched donor-derived myeloid sarcoma without systemic involvement.

Deceased donor multidrug resistance protein 1 and caveolin 1 gene variants may influence allograft survival in kidney transplantation.

Variants in donor multidrug resistance protein 1 (ABCB1) and caveolin 1 (CAV1) genes are associated with renal allograft failure after transplantation in Europeans. Here we assessed transplantation outcomes of kidneys from 368 African American (AA) and 314 European American (EA) deceased donors based on 38 single-nucleotide polymorphisms (SNPs) spanning ABCB1 and 16 SNPs spanning CAV1, including previously associated index and haplotype-tagging SNPs. Tests for association with time to allograft failure were performed for the 1233 resultant kidney transplantations, adjusting for recipient age, sex, ethnicity, cold ischemia time, panel reactive antibody, human leukocyte antigen match, expanded-criteria donation, and APOL1-nephropathy variants in AA donors. Interaction analyses between APOL1 with ABCB1 and CAV1 were performed. In a meta-analysis of all transplantations, ABCB1 index SNP rs1045642 was associated with time to allograft failure and other ABCB1 SNPs were nominally associated, but not CAV1 SNPs. ABCB1 SNP rs1045642 showed consistent effects with the 558 transplantations from EA donors, but not with the 675 transplantations from AA donors. ABCB1 SNP rs956825 and CAV1 SNP rs6466583 interacted with APOL1 in transplants from AA donors. Thus, the T allele at ABCB1 rs1045642 is associated with shorter renal allograft survival for kidneys from American donors. Interactions between ABCB1 and CAV1 with APOL1 may influence allograft failure for transplanted kidneys from AA donors.

Pancreas transplantation in C-peptide positive patients: does "type" of diabetes really matter?

BACKGROUND: In the past, type 2 (C-peptide positive) diabetes mellitus (DM) was a contraindication for simultaneous pancreas-kidney transplantation (SPKT). STUDY DESIGN: We retrospectively analyzed outcomes in SPKT recipients according to pretransplantation C-peptide levels ≥ 2.0 ng/mL or < 2.0 ng/mL. RESULTS: From November 2001 to March 2013, we performed 162 SPKTs including 30 (18.5%) in patients with C-peptide levels ≥ 2.0 ng/mL pretransplantation (C-peptide positive group, range 2.1 to 12.4 ng/mL) and 132 in patients with absent or low C-peptide levels (<2.0 ng/mL, C-peptide "negative"). C-peptide positive patients were older at SPKT, had a later age of onset and shorter duration of pretransplantation DM, and more were African-American (all p < 0.05) compared with C-peptide negative patients. With a mean follow-up of 5.6 years, patient (80% vs 82.6%), kidney graft (63.3% vs 68.9%), and pancreas graft survivals (50% vs 62.1%, all p = NS) rates were comparable in C-peptide positive and negative patients, respectively. At latest follow-up, there were no differences in acute rejection episodes, surgical complications, major infections, readmissions, hemoglobin A1c levels, serum creatinine, and estimated glomerular filtration rate levels between the 2 groups. C-peptide levels were higher (mean 5.0 vs 2.6 ng/mL, p < 0.05) and post-transplant weight gain (≥ 5 kg) was more common (57% vs 33%, p = 0.004) in the C-peptide positive group. Survival outcomes in C-peptide positive (n = 14) vs C-peptide negative (n = 22) African-American patients were similar, as were outcomes in C-peptide positive patients with a body mass index < or ≥ 28 kg/m(2). CONCLUSIONS: Patients with higher pretransplantion C-peptide levels appear to have a type 2 DM phenotype compared to insulinopenic patients undergoing SPKT. However, survival and functional outcomes were similar, suggesting that pretransplantation C-peptide levels should not be used exclusively to determine candidacy for SPKT.

A Single Center 11 Year Experience with 202 Pancreas Transplants in the New Millennium: Evolving Trends.

Our single center experience with pancreas transplantation (PTx) over an 11+ year period is reviewed. METHODS: We retrospectively studied outcomes in 202 consecutive PTxs in 192 patients at our center. All patients received either rabbit anti-thymocyte globulin (rATG) or alemtuzumab (Alem) induction with tacrolimus/mycophenolate mofetil and tapered steroids or early withdrawal. 179 PTxs (89%) were performed with portal-enteric and 23 with systemic-enteric drainage. RESULTS: From 11/01 to 3/13, we performed 162 simultaneous kidney-PTxs (SKPT), 35 sequential PTxs after kidney, and 5 PTx alone (40 solitary PTxs, SPT). 186 PTxs (92%) were primary and 16 were pancreas retransplants. With a mean follow-up of 5.5 years, overall patient (86% SKPT versus 87% SPT), kidney (74% SKPT versus 80% SPT), and pancreas graft survival (both 65%) rates were comparable. Causes of PTx loss were also similar between SKPT and SPT; the rates of early thrombosis were 8.6% and 5%, respectively. Acute rejection rates were similar between groups (SKPT 29% versus SPT 28%, p= not significant). A randomized trial of Alem versus rATG induction in SKPT demonstrated lower rates of acute rejection and infection in the Alem group. Consequently, Alem induction has been used exclusively in all PTxs since 2009. Early steroid elimination has been feasible in most patients. Surveillance PTx biopsy-directed immunosuppression has contributed to equivalent long-term outcomes in SKPT and SPT. Good results have been achieved in African-American patients and in patients with a type 2 diabetes phenotype. CONCLUSIONS: Excellent 5-year outcomes following PTx can be achieved as >86% of patients are alive, >87% of surviving patients are dialysis-free, 80% of surviving patients remain insulin-free, and 88% of surviving patients have detectable C-peptide levels.

Pancreas transplantation: The Wake Forest experience in the new millennium.

AIM: To investigate the Wake Forest experience with pancreas transplantation in the new millennium with attention to surgical techniques and immunosuppression. METHODS: A monocentric, retrospective review of outcomes in simultaneous kidney-pancreas transplant (SKPT) and solitary pancreas transplant (SPT) recipients was performed. All patients underwent pancreas transplantation as intent-to-treat with portal venous and enteric exocrine drainage and received depleting antibody induction; maintenance therapy included tapered steroids or early steroid elimination with mycophenolate and tacrolimus. Recipient selection was based on clinical judgment whether or not the patient exhibited measureable levels of C-peptide. RESULTS: Over an 11.25 year period, 202 pancreas transplants were performed in 192 patients including 162 SKPTs and 40 SPTs. A total of 186 (92%) were primary and 16 (8%) pancreas retransplants; portal-enteric drainage was performed in 179 cases. A total of 39 pancreas transplants were performed in African American (AA) patients; of the 162 SKPTs, 30 were performed in patients with pretransplant C-peptide levels > 2.0 ng/mL. In addition, from 2005-2008, 46 SKPT patients were enrolled in a prospective study of single dose alemtuzumab vs 3-5 doses of rabbit anti-thymocyte globulin induction therapy. With a mean follow-up of 5.7 in SKPT vs 7.7 years in SPT recipients, overall patient (86% SKPT vs 87% SPT) and kidney (74% SKPT vs 80% SPT) graft survival rates as well as insulin-free rates (both 65%) were similar (P = NS). Although mortality rates were nearly identical in SKPT compared to SPT recipients, patterns and timing of death were different as no early mortality occurred in SPT recipients whereas the rates of mortality following SKPT were 4%, 9% and 12%, at 1-, 3- and 5-years follow-up, respectively (P < 0.05). The primary cause of graft loss in SKPT recipients was death with a functioning graft whereas the major cause of graft loss following SPT was acute and chronic rejection. The overall incidence of acute rejection was 29% in SKPT and 27.5% in SPT recipients (P = NS). Lower rates of acute rejection and major infection were evidenced in SKPT patients receiving alemtuzumab induction therapy. Comparable kidney and pancreas graft survival rates were observed in AA and non-AA recipients despite a higher prevalence of a "type 2 diabetes" phenotype in AA. Results comparable to those achieved in insulinopenic diabetics were found in the transplantation of type 2 diabetics with detectable C-peptide levels. CONCLUSION: In the new millennium, acceptable medium-term outcomes can be achieved in SKPT and SPTs as nearly 2/3rds of patients are insulin independent following pancreas transplantation.

Influence of recipient age on deceased donor kidney transplant outcomes in the expanded criteria donor era.

METHODS: We performed a retrospective single-center review of 884 deceased donor (DD) kidney transplants (KTs) in patients (pts) aged ≥40 yr. RESULTS: One hundred and four (11.8%) pts were ≥70 (mean 74), 286 (32.3%) were 60-69 (mean 64), and 494 (55.9%) were 40-59 (mean 51) yr of age; the proportion receiving expanded criteria donor (ECD) kidneys were 66%, 49%, and 30%, respectively (p < 0.001). Mean waiting time (15 months) was shorter for pts ≥70 yr compared to the other two groups combined (23 months, p = 0.002). With mean follow-up ranging from 54 to 70 months, actual pt (81% vs. 72%, p = 0.002) and graft (66% vs. 58.5%, p = 0.03) survival rates were higher in the younger compared to the two older groups, whereas death-censored graft survival was similar (76% vs. 73%, p = NS). The incidence of death with a functioning graft correlated with older recipient age group, increasing from 13% to 18% to 23% (p = 0.01). The incidence of delayed graft function was similar (31.8% overall), and renal function, morbidity, and resource utilization were similar among groups. CONCLUSIONS: By directing ECD kidneys to selected older pts, waiting times are reduced and censored survival outcomes are similar to middle-aged patients, suggesting that matching strategies for graft and patient lifespan are warranted.

The impact of APOL1, CAV1, and ABCB1 gene variants on outcomes in kidney transplantation: donor and recipient effects.

Dramatic improvements have been seen in short-term kidney allograft survival over recent decades with introduction of more potent immunosuppressant medications and regimens. Unfortunately, improvements in long-term graft survival have lagged behind. The genomics revolution is providing new insights regarding the potential impact of kidney donor genotypes on long-term graft survival. Variation in the donor apolipoprotein L1 (APOL1), caveolin 1 (CAV1), and multi-drug resistance 1 encoding P-glycoprotein genes (ABCB1) are all associated with graft survival after kidney transplantation. Although the precise mechanisms whereby these donor gene variants confer risk for graft loss have yet to be determined, these findings provide novel opportunities for modifying interactive environmental factors and optimizing kidney allocation with the ultimate goal of improving long-term graft survival rates.

Donor-specific antibodies adversely affect kidney allograft outcomes.

The effect of low titers of donor-specific antibodies (DSAs) detected only by sensitive solid-phase assays (SPAs) on renal transplant outcomes is unclear. We report the results of a systematic review and meta-analysis of rejection rates and graft outcomes for renal transplant recipients with such preformed DSAs, defined by positive results on SPA but negative complement-dependent cytotoxicity and flow cytometry crossmatch results. Our search identified seven retrospective cohort studies comprising a total of 1119 patients, including 145 with isolated DSA-SPA. Together, these studies suggest that the presence of DSA-SPA, despite a negative flow cytometry crossmatch result, nearly doubles the risk for antibody-mediated rejection (relative risk [RR], 1.98; 95% confidence interval [CI], 1.36-2.89; P<0.001) and increases the risk for graft failure by 76% (RR, 1.76; 95% CI, 1.13-2.74; P=0.01). These results suggest that donor selection should consider the presence of antibodies in the recipient, identified by the SPA, even in the presence of a negative flow cytometry crossmatch result.

Renal-limited 'lupus-like' nephritis.

In the setting of an IgG-dominant immune complex-mediated glomerulonephritis, there are multiple pathological findings that strongly suggest the diagnosis of lupus nephritis (LN) including (i) 'full-house' immunofluorescence staining for IgG, IgM, IgA, C3 and C1; (ii) extraglomerular immune deposits; (iii) combined mesangial, subendothelial and subepithelial immune deposits and (iv) the presence of endothelial tubuloreticular inclusions. We report four female adult patients with renal biopsy findings which are highly suggestive of LN but without extrarenal signs, symptoms or serologies of systemic lupus erythematosus at the time of biopsy or over a mean follow-up period of 3 years. Despite aggressive therapy, outcomes were poor in this small cohort. We refer to these cases as renal-limited 'lupus-like' nephritis.