Patients After Kidney Allograft Failure: Immunologic and Nonimmunologic Considerations

Impact of Calcineurin Inhibitor-Based Immunosuppression Maintenance During the Dialysis Period After Kidney Transplant Failure on the Next Kidney Graft Outcome: A Retrospective Multicenter Study With Propensity Score Analysis

The impact of immunosuppressive therapy (IS) strategies after kidney transplant failure (KTF) on potential future new grafts is poorly established. We assessed the potential benefit of calcineurin inhibitor (CNI)-based IS maintenance throughout the dialysis period on the outcome of the second kidney transplant (KT). We identified 407 patients who underwent a second KT between January 2008 and December 2018 at four French KT centers. Inverse probability of treatment weighting was used to control for potential confounding. We included 205 patients with similar baseline characteristics at KTF: a total of 53 received at least CNIs on the retransplant day (G-CNI), and 152 did not receive any IS (G-STOP). On the retransplant date, G-STOP patients experienced a longer pretransplant dialysis time, were more often hyperimmunized, and underwent more expanded-criteria donor KTs than G-CNI patients. During the second KT follow-up period, rejection episodes were similar in both groups. The 10-year survival rates without death and dialysis were 98.7% and 59.5% in G-CNI and G-STOP patients, respectively. In the multivariable analysis, CNI-based IS maintenance was associated with better survival (hazard ratio: 0.08; 95% confidence interval: 0.01-0.58, p = 0.01). CNI-based IS maintenance throughout the dialysis period after KTF may improve retransplantation outcomes.

Revisiting maintenance immunosuppression in patients with renal transplant failure: early weaning of immunosuppression versus prolonged maintenance-systematic review and meta-analysis

INTRODUCTION

Prolonged immunosuppression after dialysis start has been assumed to reduce sensitization, need for graft nephrectomy, and to favor re-transplantation. In contrast, immunosuppression is considered to increase the risk of mortality, infection, and malignancy. We aimed to assess the evidence regarding superiority of early or late withdrawal of maintenance immunosuppression post renal transplant failure.

METHODS

A literature search of the PubMed, WOS, Ovid, and Scopus databases was conducted. Combined relative risks, (RRs), mean differences, and 95% confidence intervals (CIs) were calculated by using a random-effect model.

RESULTS

Ten studies involving 1187 patients with kidney transplant failure were included. No difference could be detected between patients with early withdrawal of  immunosuppressive drugs (≤ 3 months) or prolonged immunosuppressive treatment (> 3 months) regarding mortality (95% CI 0.91-2.28), panel reactive antibodies (PRAs) (95% CI - 0.75-30.10), re-transplantation rate (95% CI 0.55-1.35), infectious episodes (95% CI 0.67, 1.17), cancer (95% CI 0.26-1.54), and graft nephrectomy (95% CI 0.82-1.63). Similarly, no difference was found between immunosuppressive drug withdrawal over < 6 or ≥ 6 months regarding mortality (95% CI 0.16, 2.89), re-transplantation rate (95% CI 0.85-1.55), cancer (95% CI 0.37-1.63), and allograft nephrectomy (95% CI 0.87-4.33).

CONCLUSION

Prolonged maintenance immunosuppression post kidney transplant failure is not associated with increased risk of mortality, infection, or malignancy, or reduced risk of sensitization or allograft nephrectomy compared with early withdrawal.

Orthotopic Kidney Transplant as a Fifth Intra-Abdominal Organ after Two Previous Kidney and Two Previous Pancreas Transplants

Background

Patients with more than two prior kidney transplant procedures pose unique surgical challenges. Once both the right and left retroperitoneal spaces have been dissected, intra-abdominal implantation is usually necessary. If the external iliac arteries have been used previously, it is sometimes necessary to use the aorta and vena cava for implantation. Gaining safe exposure in these cases can be complicated by history of prior laparotomy, adhesive disease, and other surgical histories. Case Presentation. A 58-year-old female with type 1 diabetes and end-stage renal disease presented for surgical evaluation for kidney transplant. Surgical history was notable for prior simultaneous kidney-pancreas transplant followed by both a living donor kidney transplant and a pancreas after kidney transplant. She had undergone both an allograft nephrectomy and an allograft pancreatectomy and currently had a nonfunctioning kidney in the left retroperitoneal position and a nonfunctioning pancreatic allograft on the right common iliac artery. The entire distal aortoiliac system was surgically inaccessible. She was listed for transplantation, and a cadaveric graft was allocated. Intraoperatively, severe lower abdominal and pelvic adhesions prevented any use of the iliac system. A left native nephrectomy was performed, and the allograft was implanted in the left orthotopic position. The native left renal vein was used for outflow, the donor renal artery was joined end-to-side to the infrarenal aorta, and a uretero-ureterostomy was created. The operation was uneventful. The allograft functioned without delay, and almost one year later, the GFR is approximately 50 mg/dL.

Conclusion

The left orthotopic position can be a good choice for kidney transplant candidates with histories of prior complex lower abdominal surgery.

Management of Immunosuppression After Kidney Transplant Failure: Effect on Patient Sensitization

BACKGROUND

Immunosuppressive treatment is often interrupted in the first months following kidney transplant failure (KTF) to limit side effects. The aim of this study was to assess the effect of prolonged treatment (PT) of more than 3 months' duration after KTF on HLA sensitization and treatment tolerance.

METHODS

We performed a retrospective observational study involving 119 patients with KTF in 3 French kidney transplant centers between June 2007 and June 2017. Sensitization was defined as the development of HLA donor-specific antibodies (DSA).

RESULTS

In the PT group receiving calcineurin inhibitor (CNI) treatment, 30 of 52 patients (57.7%) were sensitized vs 52 of 67 patients (77.6%) who had early cessation of treatment (P = .02). The results were confirmed by multivariate analysis (odds ratio [OR] = 0.39, 95% confidence interval [CI] [0.16; 0.98], P = .04). The development of de novo DSAs after CNI treatment (n = 63/90 [70.0%]) was significantly more frequent than during CNI treatment, (n = 18/52 [34.6%], P = .01). Panel-reactive antibody ≥85% was lower in the PT group in multivariate analysis (OR = 0.28, 95% CI [0.10; 0.78], P = .02). No differences in the rates of infection, cardiovascular complications, neoplasia, and deaths were observed between the 2 groups. In multivariate analysis, continuation of corticosteroid treatment had no influence on sensitization but was associated with a higher rate of infection (OR = 2.66, 95% CI [1.09; 6.46], P = .03).

CONCLUSION

Maintenance of CNI treatment after return to dialysis in patients requesting a repeat transplant could avoid the development of anti-HLA sensitization with a good tolerance.

CYC1, SDHA, UQCRC1, UQCRQ, and SDHB might be important biomarkers in kidney transplant rejection

BACKGROUND

Kidney transplant rejection is considered as a vital factor of kidney transplant failure. Therefore, it's necessary to search for effective biomarkers for kidney transplant surveillance.

METHODS

In this study, we conducted time-series gene expression profiles analysis of samples from kidney transplant patients with different post-transplant days through weighted gene co-expression network analysis (WGCNA). Associations between gene co-expression modules and days post-transplant were determined through spearman rank correlation analysis. Potential kidney transplant rejection-related modules were subjected to gene functional enrichment analysis through clusterProfiler and protein-protein interaction analysis via STRING database.

RESULTS

A total of 11 gene co-expression modules were identified, and the pink module which was mainly involved in "energy derivation by oxidation of organic compounds" and "Huntington disease" showed significant correlation with the phenotypic trait "days post-transplant". CYC1, SDHA, UQCRC1, UQCRQ, and SDHB in the pink module exhibited high scores in the protein-protein interaction network analysis.

CONCLUSIONS

We reported several potential genes may be associated with the kidney transplant rejection, which should provide novel biomarkers for kidney transplant surveillance.

Clinical Prognosis of Renal Retransplant Patients: A Single-Center Experience

BACKGROUND

Retransplantation is a treatment option in patients with end-stage renal failure due to graft loss. Outcomes of these patients due to high immunologic risk remain unclear. The aim of this study was to evaluate outcomes of renal retransplantation patients retrospectively.

METHODS

Renal retransplant patients in our unit were evaluated retrospectively between 2010 and 2018. Patients' demographic characteristics, primary diseases, the causes of prior graft loss, immunologic status, desensitization protocols, the induction and maintenance treatments, the complications during the follow-up period, numbers of acute rejections, and the clinical prognosis were all detected from the patients' files.

RESULTS

We retrospectively evaluated 17 patients who underwent a second or third renal allograft. Of these, 16 received a second and the remaining 1 patient received a third renal allograft. Immunologically, all of the 17 patients had negative flow cytometry crossmatch, 1 patient had a positive complement-dependent cytotoxicity crossmatch (Auto 12%), 16 patients had positive panel reactive antibody, the median HLA-mismatch was 3.5, and the score of donor-specific antibody relative intensity score (RIS) was 6.4 ± 6.3. Ten pretransplant patients had desensitization treatment. While scores for HLA-MM and HLA-RIS in the patients who had a desensitization therapy were determined higher, no statistical difference was observed (respectively, P = .28 and .55). No acute rejection episode developed. BK virus DNA viremia was detected in 4 patients during the posttransplant 6th month. We observed no patient death or no graft loss during the follow-up period.

CONCLUSION

Although the retransplant patients who had a graft loss previously have high immunologic risks, retransplantation is reliable in these patients, but they should be followed up carefully in terms of BKV nephropathy.

Influence of Pretransplant Dialysis Vintage on Repeated Kidney Transplantation Outcomes

Dialysis has a dose-dependent effect on first kidney transplantation outcomes, and a shorter waiting time on dialysis is associated with superior graft function. There are not enough data to support this statement in the case of a repeated transplantation. As such, we aimed to evaluate the influence of the dialysis vintage before the last transplantation on graft function as well as patient and graft survival in repeated transplantation situations. Patients who underwent repeated kidney transplantations were included in the retrospective study. Specifically, 79 patients were included who were divided into 4 groups according to the dialysis vintage before the last transplantation. We assessed graft function and patient and graft survival rates after 1- and 3-year follow-up. One-year graft function was worse for patients with a dialysis vintage of more than 31 months (P = .005), but there was no difference after 3 years. One- and 3-year graft survival was better for patients with a dialysis vintage of less than 12 months (P = .017). We concluded that a longer waiting time on dialysis was associated with worse graft function and diminished long-term graft survival after repeated kidney transplantation.

Donor-Specific Antibodies After Starting Hemodialysis in Nonrenal Solid Organ Transplant Recipients: Role of TH17

BACKGROUND

Nonrenal transplantation could cause a progressive deterioration in renal function until need dialysis. It is important to know if these patients increased their risk to develop de novo donor-specific anti-HLA antibody (DSA) after starting hemodialysis (HD) and if so, try to find the mechanism.

MATERIAL AND METHODS

In this double-phase study, we first analyzed the incidence of development DSA in nonrenal transplant recipients after starting HD by a retrospective study. Secondly, a prospective study was designed to analyze the pharmacokinetics of immunosuppressive drugs and the cytokine profile of these patients.

RESULTS

Of 179 pancreas transplant recipients, 16 needed to start HD, and 62.5% of these patients developed de novo DSA after starting HD, with 80% of them class I DSA. In the second phase of the study, the plasma levels of the immunosuppressive drugs as measured by a limited sampling strategy of 3 sample time points (C0, C2, and C4) were stable. The cytokine profile showed that there was an increase in Th1 cytokine (interferon gamma of 0.045 ng/mL) and also in Th17 cytokines (transforming growth factor β >10 ng/mL).

CONCLUSION

Our data suggest that the development of DSA after starting HD in nonrenal transplant recipients could be mediated by Th17 immune response mechanisms.

Patterns of Early Rejection in Renal Retransplantation: A Single-Center Experience

It has been reported that kidney retransplant patients had high rates of early acute rejection due to previous sensitization. In addition to the acute antibody-mediated rejection (ABMR) that has received widespread attention, the early acute T-cell-mediated rejection (TCMR) may be another important issue in renal retransplantation. In the current single-center retrospective study, we included 33 retransplant patients and 90 first transplant patients with similar protocols of induction and maintenance therapy. Analysis focused particularly on the incidence and patterns of early acute rejection episodes, as well as one-year graft and patient survival. Excellent short-term clinical outcomes were obtained in both groups, with one-year graft and patient survival rates of 93.9%/100% in the retransplant group and 92.2%/95.6% in the first transplant group. Impressively, with our strict immunological selection and desensitization criteria, the retransplant patients had a very low incidence of early acute ABMR (6.1%), which was similar to that in the first transplant patients (4.4%). However, a much higher rate of early acute TCMR was observed in the retransplant group than in the first transplant group (30.3% versus 5.6%, P < 0.001). Acute TCMR that develops early after retransplantation should be monitored in order to obtain better transplant outcomes.