Clinical significance of slow recovery of graft function in living donor kidney transplantation

Intraoperative central venous pressures related to early graft function in deceased donor kidney transplant recipients with low immunological risks

This study aims to analyze data from patients who received kidney transplantation from deceased donors to investigate the anesthetic factors influencing early and late graft outcomes, including the incidence of slow graft function (SGF), delayed graft function (DGF), and 3-year graft outcomes. We retrospectively analyzed 202 recipients who underwent deceased donor kidney transplantation from March 2010 to December 2020. Anesthetic monitoring data during the intraoperative period was analyzed at 5-minute intervals, and basic clinical parameters were evaluated. The mean recipient age was 46.6 ± 10.3 years, and the mean donor age was 41.7 ± 12.7 years. Anesthetic time averaged 285.8 ± 70.2 min, and operation time averaged 223.1 ± 44.0 min. The incidence of SGF was 11.8%, and the incidence of DGF was 3.9%. Mean central venous pressures (CVPs) were higher in recipients with SGF or DGF (11.7 mmHg) compared to those with immediate graft function (9.7 mmHg). Higher CVP was identified as an independent risk factor for SGF or DGF (odds ratio 1.219, p = 0.006). This study suggests that intraoperative monitoring of CVP is crucial for predicting short-term graft function in deceased donor kidney transplantation and should be managed to prevent excessive fluid intake.

An analysis of the relationship between donor and recipient biomarkers and kidney graft function, dysfunction, and rejection

BACKGROUND

The study aimed to find predictive biomarkers to evaluate donor kidney function to predict graft dysfunction as well as to assess an early signs of acute graft rejection.

METHOD

Twenty-seven deceased donors and 54 recipients who underwent a successful kidney transplantation were enrolled in the study. An assessment was made in serum and urine from donors and recipients to measure the following biomarkers: neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), tissue inhibitor of metalloproteinase 2 (TIMP-2) and urinary N-acetyl-b-D-glucosaminidase (uNAG). These biomarkers were used to establish a model for predicting a reduced graft function (RGF) classified as either a delayed or slow graft function.

RESULT

Our analysis suggest that out of four tested biomarkers, the serum TIMP-2 and uNAG levels of the donors had a predictive value for RGF; the area under the receiver operating characteristic curves (AUROC) of serum TIMP-2 and uNAG were 0.714 and 0.779, respectively. The combined best fitting prediction model of serum TIMP-2, uNAG, and creatinine levels was better in predicting RGF than the serum creatinine level alone. In addition, the recipient serum TIMP-2 level on the third day post-transplantation (D3) was associated with the estimated glomerular filtration rate (eGFR) on the seventh day post-transplantation (D7; OR 1.119, 95% CI 1.016-1.233, p = 0.022). Furthermore, the ROC curve value revealed that the AUROC of TIMP-2 on D3 was 0.99 (95% CI 0.97-1, p < 0.001), and this was the best predictive value of the renal function on D7.

CONCLUSIONS

Donor serum TIMP-2 and uNAG levels are useful predictive biomarkers because they can provide the donor-based prediction for RGF.

ABO Blood Incompatibility Positively Affects Early Graft Function: Single-Center Retrospective Cohort Study

BACKGROUND

We investigated the association between ABO-incompatible (ABO-I) kidney transplantation and early graft function.

METHODS

We retrospectively analyzed 95 patients who underwent living donor kidney transplantation between May 2009 and July 2019. It included 61 ABO-compatible (ABO-C) and 34 ABO-I transplantations. We extracted data on immunologic profile, sex, age, cold ischemic time, type of immunosuppression, and graft function. Two definitions were used for slow graft function (SGF) as follows: postoperative day (POD) 3 serum creatinine level >3 mg/dL and estimated glomerular filtration rate (eGFR) <20 mL/min/1.73 m². Logistic regression analysis was performed to analyze the effect of ABO-I on the incidence of SGF.

RESULTS

The characteristics between the ABO-C and ABO-I were not different. ABO-I received rituximab and plasma exchange. Patients also received tacrolimus and mycophenolate mofetil for 2 weeks and prednisolone for 1 week before transplantation as preconditioning. Of the 95 study patients, 19 (20%) and 21 (22%) were identified with SGF according to POD 3 serum creatinine level or eGFR, respectively. Multivariable analysis revealed that ABO-I significantly reduced the incidence of SGF (odds ratio, 0.15; 95% confidence interval, 0.03-0.7; P = .02), and cold ischemic time >150 min increased the incidence of SGF (odds ratio, 6.5; 95% confidence interval, 1.7-25; P = .006). Similar results were identified in POD 3 eGFR. Inferior graft function in patients with SGF was identified up to 6 months after transplantation.

CONCLUSION

ABO-I reduces the incidence of SGF, which is associated with an inferior graft function up to 6 months.

Evaluation of Renal Anionic Secretion Following Living-donor and Deceased-donor Renal Transplantation: A Clinical Pharmacokinetic Study of Cefoxitin Microdosing

Renal transplantation is the treatment of choice for patients with end-stage renal disease. Because kidneys are the primary excretory organs for various drugs/drug metabolites, changes in renal graft function would significantly alter the clearance and exposure of renally secreted drugs. Renal allografts from living and deceased donors normally undergo numerous insults, including injuries associated with prolonged cold ischemic time, reperfusion, and nephrotoxicity due to calcineurin inhibitors. These physiologic and pharmacologic stresses can alter the expression and functional capacity of renal organic anionic transporters (OATs).

Methods

The objectives of this study were to assess the longitudinal changes in renal anionic secretion in kidney transplant patients, to study the effect of prolonged cold ischemic time on OAT secretion in kidney transplant patients (living- versus deceased-donor recipients), and to compare OAT secretory capacity of renal transplant recipients with healthy volunteers. Cefoxitin was used as a probe drug to assess OAT secretion. Cefoxitin pharmacokinetics was studied in 15 de novo renal transplant recipients following intravenous administration of 200 mg cefoxitin within 14 d and beyond 90 d posttransplantation.

Results

No longitudinal changes in real OAT secretion in early posttransplant period were observed, and there were no differences in renal OAT secretion between living- and deceased-donor renal transplant recipients. Overall, cefoxitin exposure was 2.6-fold higher and half-life increased by 2.2-fold in renal transplant recipients when compared with historical healthy controls.

Conclusions

These results suggest that OAT system is functioning well, but renal transplant recipients would need significantly lower dosage of drugs that are primarily secreted via the OAT system compared with normal subjects.

Clinical relevance of cell-free mitochondrial DNA during the early postoperative period in kidney transplant recipients

Recent studies indicate that urinary mitochondrial DNA (mtDNA) is predictive of ischemic AKI and is related to delayed graft function (DGF) in renal transplantation. Nevertheless, the clinical implications and prognostic value of urinary mtDNA in kidney transplantation remain undetermined. Here, we aimed to evaluate the associations between cell-free mtDNA and clinical parameters, including pathological findings in allograft biopsy and post-transplant renal function. A total of 85 renal transplant recipients were enrolled, and blood and urine samples were collected at a median of 17 days after transplantation. Cell-free nuclear and mtDNA levels were measured by quantitative polymerase chain reaction for LPL and ND1 genes. Urinary cell-free mtDNA levels were significantly higher in patients with DGF (P < 0.001) and cases of deceased donor transplantation (P < 0.001). The subjects with acute rejection showed higher urinary mtDNA levels than those without abnormalities (P = 0.043). In addition, allograft functions at 9- and 12-month post-transplantation were significantly different between tertile groups of mtDNA independent of the presence of DGF or acute rejection, showing significantly better graft outcome in the lowest tertile group. Urinary cell-free mtDNA levels during the early post-transplant period are significantly associated with DGF, acute rejection in graft biopsy, and short-term post-transplant renal function.

Exposure to Hyperchloremia Is Associated with Poor Early Recovery of Kidney Graft Function after Living-Donor Kidney Transplantation: A Propensity Score-Matching Analysis

The effects of hyperchloremia on kidney grafts have not been investigated in patients undergoing living-donor kidney transplantation (LDKT). In this study, data from 200 adult patients undergoing elective LDKT between January 2016 and December 2017 were analyzed after propensity score (PS) matching. The patients were allocated to hyperchloremia and non-hyperchloremia groups according to the occurrence of hyperchloremia (i.e., ≥110 mEq/L) immediately after surgery. Poor early graft recovery was defined as estimated glomerular filtration rate (eGFR) < 60 mL/min/1.73 m² during the first 48 hours after surgery. After PS matching, no significant differences in perioperative recipient or donor graft parameters were observed between groups. Although the total amount of crystalloid fluid infused during surgery did not differ between groups, the proportions of main crystalloid fluid type used (i.e., 0.9% normal saline vs. Plasma Solution-A) did. The eGFR increased gradually during postoperative day (POD) 2 in both groups. However, the proportion of patients with eGFR > 60 mL/min/1.73 m² on POD 2 was higher in the non-hyperchloremia group than in the hyperchloremia group. In this PS-adjusted analysis, hyperchloremia was significantly associated with poor graft recovery on POD 2. In conclusion, exposure to hyperchloremia may have a negative impact on early graft recovery in LDKT.

Pure versus hand-assisted retroperitoneoscopic live donor nephrectomy: a retrospective cohort study of 1508 transplants from two centers

BACKGROUND

Although minimally invasive procedures have been established as the standard for a donor nephrectomy, there are many different surgical techniques described in the literature. The aim of this study is to compare the outcomes of kidney transplant procedures using the pure retroperitoneoscopic donor nephrectomy (PRDN) and hand-assisted retroperitoneoscopic donor nephrectomy (HARDN) techniques.

METHODS

A retrospective study involving 1508 transplant procedures was conducted; 874 were PRDN procedures; and 634 were HARDN. We reviewed the outcomes of the PRDN and HARDN groups, which were performed at two different centers over an identical time period.

RESULTS

Donors in the PRDN group had a longer operation time (P < 0.0001), reduced estimated blood loss (P < 0.0001), less open conversion (P = 0.0002), lower postoperative serum C-reactive protein levels (P < 0.0001), and a shorter postoperative hospital stay (P < 0.0001) than the HARDN group. Recipients in the PRDN group had lower serum creatinine levels at postoperative day 1-6 and the decreased incidence of slow graft function (P = 0.0017) than the HARDN group. The HARDN procedure was an independent risk factor for the incidence of acute rejection (P = 0.0211) and graft loss (P = 0.0193).

CONCLUSIONS

Our study suggests that the PRDN procedure is less invasive for donors as it results in reduced blood loss, lower postoperative serum CRP levels, and a shorter postoperative stay than the HARDN procedure. Additionally, PRDN provides a better outcome for recipients as it lowers the incidence of acute rejection and improves graft survival compared to HARDN.

Ischemia-Reperfusion Injury Reduces Long Term Renal Graft Survival: Mechanism and Beyond

Ischemia-reperfusion injury (IRI) during renal transplantation often initiates non-specific inflammatory responses that can result in the loss of kidney graft viability. However, the long-term consequence of IRI on renal grafts survival is uncertain. Here we review clinical evidence and laboratory studies, and elucidate the association between early IRI and later graft loss. Our critical analysis of previous publications indicates that early IRI does contribute to later graft loss through reduction of renal functional mass, graft vascular injury, and chronic hypoxia, as well as subsequent fibrosis. IRI is also known to induce kidney allograft dysfunction and acute rejection, reducing graft survival. Therefore, attempts have been made to substitute traditional preserving solutions with novel agents, yielding promising results.

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Ischaemia reperfusion injury (IRI) potentiates delayed renal graft function and causes reduction in renal graft survival

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IRI causes innate immune system activation, hypoxic injury, inflammation and graft vascular disease

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Reducing prolonged cold ischaemic time improves graft survival

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Novel protective strategies include mesenchymal stem cells, machine perfusion, and ex vivo preservation solution saturated with gas.

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Further studies are needed to investigate the long-term effects of novel ex vivo preservation agents

Pre-transplant Evaluation of Donor Urinary Biomarkers can Predict Reduced Graft Function After Deceased Donor Kidney Transplantation

Several recipient biomarkers are reported to predict graft dysfunction, but these are not useful in decision making for the acceptance or allocation of deceased donor kidneys; thus, it is necessary to develop donor biomarkers predictive of graft dysfunction. To address this issue, we prospectively enrolled 94 deceased donors and their 109 recipients who underwent transplantation between 2010 and 2013 at 4 Korean transplantation centers. We investigated the predictive values of donor urinary neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1 (KIM-1), and L-type fatty acid binding protein (L-FABP) for reduced graft function (RGF). We also developed a prediction model of RGF using these donor biomarkers. RGF was defined as delayed or slow graft function. Multiple logistic regression analysis was used to generate a prediction model, which was internally validated using a bootstrapping method. Multiple linear regression analysis was used to assess the association of biomarkers with 1-year graft function. Notably, donor urinary NGAL levels were associated with donor AKI (P = 0.014), and donor urinary NGAL and L-FABP were predictive for RGF, with area under the receiver-operating characteristic curves (AUROC) of 0.758 and 0.704 for NGAL and L-FABP, respectively. The best-fit model including donor urinary NGAL, L-FABP, and serum creatinine conveyed a better predictive value for RGF than donor serum creatinine alone (P = 0.02). In addition, we generated a scoring method to predict RGF based on donor urinary NGAL, L-FABP, and serum creatinine levels. Diagnostic performance of the RGF prediction score (AUROC 0.808) was significantly better than that of the DGF calculator (AUROC 0.627) and the kidney donor profile index (AUROC 0.606). Donor urinary L-FABP levels were also predictive of 1-year graft function (P = 0.005). Collectively, these findings suggest donor urinary NGAL and L-FABP to be useful biomarkers for RGF, and support the use of a new scoring system based on donor biomarkers to facilitate decision-making in acceptance and allocation of deceased donor kidneys and contribute to maximal organ utilization.

Impact of donor kidney function and donor age on poor outcome of living-unrelated kidney transplantation (KT) in comparison with living-related KT

Living-unrelated donors (LURD) have been widely used for kidney transplantation (KT). We retrospectively reviewed 779 patients who underwent living-donor KT from 2000 to 2012, to compare outcomes of 264 KT from LURD and 515 from living-related donors (LRD), and to identify risk factors for living KT. Median follow-up was 67 months. Mean donor age, total human leukocyte antigen (HLA) mismatches, and HLA-DR mismatches were higher, and mean estimated glomerular filtration rate (eGFR) was lower in LURD. Acute rejection (AR)-free survival (p = 0.018) and graft survival (p = 0.025) were lower for LURD than LRD, whereas patient survival rate was comparable. Cox regression analysis showed HLA-DR mismatches (OR 1.75 for one mismatch; OR 2.19 for two mismatches), recipient age ≤ 42 yr, and donor age > 50 yr were significant risk factors for acute rejection. For graft survival, AR and donor eGFR (OR 1.90, p = 0.035) were significant. We also identified significant impact of recipient age > 50 yr and diabetes for patient survival. However, KT from LURD was not a significant risk factor for AR (p = 0.368), graft survival (p = 0.205), and patient survival (p = 0.836). Our data suggest that donor eGFR and donor age are independent risk factors for clinical outcomes of living KT, which can be related with poor outcome of KT from LURD.

Impact of right-sided nephrectomy on long-term outcomes in retroperitoneoscopic live donor nephrectomy at single center

Objective. To assess the long-term graft survival of right-sided retroperitoneoscopic live donor nephrectomy (RPLDN), we compared the outcomes of right- and left-sided RPLDN. Methods. Five hundred and thirty-three patients underwent live donor renal transplantation with allografts procured by RPLDN from July 2001 to August 2010 at our institute. Of these, 24 (4.5%) cases were selected for right-sided RPLDN (R-RPLDN) according to our criteria for donor kidney selection. Study variables included peri- and postoperative clinical data. Results. No significant differences were found in the recipients' postoperative graft function and incidence of slow graft function. Despite significant increased warm ischemic time (WIT: mean 5.9 min versus 4.7 min, P < 0.001) in R-RPLDN compared to that in L-RPLDN, there was no significant difference between the two groups regarding long-term patient and graft survival. The complication rate in R-RPLDN was not significantly different compared to that in L-RPLDN (17% versus 6.5%, P = 0.132). No renal vein thrombosis was experienced in either groups. Conclusions. Although our study was retrospective and there was only a small number of R-RPLDN patients, R-RPLDN could be an option for laparoscopic live donor nephrectomy because of similar results, with the sole exception of WIT, in L-RPLDN, and its excellent long-term graft outcomes.

Clinical significance of the ratio between FOXP3 positive regulatory T cell and interleukin-17 secreting cell in renal allograft biopsies with acute T-cell-mediated rejection

The aim of this study is to investigate the clinical significance of the ratio between interleukin-17 (IL-17) secreting cell and FOXP3-positive regulatory T cell (FOXP3(+) Treg) infiltration in renal allograft tissues with acute T-cell-mediated rejection (ATCMR). Fifty-six patients with biopsy-proven ATCMR were included. Infiltration of FOXP3(+) Treg and IL-17-secreting cells was evaluated with immunostaining for FOXP3 or IL-17 on the biopsy specimens, and the patients were divided into the FOXP3 high group (Log FOXP3/IL-17 > 0·45) or the IL-17 high group (Log FOXP3/IL-17 < 0·45). We compared the allograft function, severity of tissue injury, and clinical outcome between the two groups. In the IL-17 high group, allograft function was significantly decreased compared with the FOXP3 high group (P < 0·05). The severity of interstitial and tubular injury in the IL-17 high group was higher than the FOXP3 high group (P < 0·05). The proportions of steroid-resistant rejection, incomplete recovery and recurrent ATCMR were higher in the IL-17 high group than in the FOXP3 high group (all indicators, P < 0·05). The IL-17 high group showed lower 1-year (54% versus 90%, P < 0·05) and 5-year (38% versus 85%, P < 0·05) allograft survival rates compared with the FOXP3 high group. Multivariate analysis revealed that the FOXP3/IL-17 ratio was a significant predictor for allograft outcome. The FOXP3/IL-17 ratio is a useful indicator for representing the severity of tissue injury, allograft dysfunction and for predicting the clinical outcome of ATCMR.

Poor early graft function impairs long-term outcome in living donor kidney transplantation

Background

Poor early graft function (EGF) after living donor kidney transplantation (LDKT) has been found to decrease rejection-free graft survival rates. However, its influence on long-term graft survival remains inconclusive.

Methods

Data were collected on 472 adult LDKTs performed between July 1996 and February 2010. Poor EGF was defined as the occurrence of delayed or slow graft function. Slow function was defined as serum creatinine above 3.0 mg/dL at postoperative day 5 without dialysis.

Results

The incidence of slow and delayed graft function was 9.3 and 4.4%, respectively. Recipient overweight, pretransplant dialysis and warm ischemia were identified as risk factors for the occurrence of poor EGF. The rejection-free survival was worse for poor EGF as compared to immediate graft function with an adjusted hazard ratio (HR) of 6.189 (95% CI 4.075–9.399; p < 0.001). Long-term graft survival was impaired in the poor EGF group with an adjusted HR of 4.206 (95% CI 1.839–9.621; p = 0.001).

Conclusions

Poor EGF occurs in 13.7% of living donor kidney allograft recipients. Both, rejection-free and long-term graft survivals are significantly lower in patients with poor EGF as compared to patients with immediate graft function. These results underline the clinical relevance of poor EGF as phenomenon after LDKT.

Consideration of donor age and human leukocyte antigen matching in the setting of multiple potential living kidney donors

BACKGROUND

Defining living donor (LD)-related risk factors affecting kidney transplant outcome will allow better donor selection and more educated informed consent when there is more than one potential donor. We studied risk factors in a large cohort at a single institution.

METHODS

We reviewed 1632 recipients who underwent LD kidney transplantation at the University of Minnesota between January 1, 1990, and October 1, 2009. Using Cox regression, we studied the effect of donor and recipient risk factors on patient and graft survival. We specifically examined the effect of donor age and human leukocyte antigen (HLA) matching because these are variables that may help clinical decision making when multiple potential donors exist.

RESULTS

Mean donor age was 40.6 years for all transplants; 180 (11%) donors were 55 years or older, and 24 (1.5%) donors were older than 65 years. Mean number of HLA mismatches (per transplant) was 2.9 (29.2% of recipients had one to two HLA mismatches, 39.8% had three to four HLA mismatches, and 25% had five to six HLA mismatches). Donor age more than 65 years, five to six HLA mismatches, delayed graft function, and acute rejection were independent predictors of decreased patient and graft survival. When controlling for recipient age, donor age more than 65 years remained a risk factor for worse outcome.

CONCLUSIONS

Our data suggest that advanced donor age (>65 years) and degree of HLA mismatch (≥5) are independent donor-related risk factors associated with worse outcome. When multiple potential LDs exist, it may be ideal to attempt to use a donor younger than 65 years and with less than five HLA mismatches.