Transplantation Reports最新文献

The introduction of assays for donor-derived cell-free DNA into clinical transplant medicine has provided an additional method to assess allograft health. We compared the performance of two of these assays, Prospera™ and AlloSure®. A series of 15 paired-samples from individual kidney transplant recipients were tested using both Prospera™ and AlloSure® assays simultaneously. Test performances were determined using the company cutoff of >1% to indicate active rejection. Additional analysis was also performed using a cutoff of 0.5%. Acute rejections were all confirmed by biopsy. There was one discordant result for 15 paired-samples when using a cutoff level of 1%, and results were concordant using a cutoff level of 0.5%. Seven biopsy were performed, six of which showed rejection. Using cutoff of 1%, Prospera™ identified 80% (4/5) of T cell-mediated rejections (TCMR) compared to 60% for AlloSure® (3/5). Both assays recognized the only case of antibody-mediated rejection. When using cutoff level of 0.5%, both assays correctly identified all cases of rejection. In this cohort, the two tests showed different sensitivities when using the validated cutoff of 1% dd-cfDNA, and the same sensitivity when using a lower cutoff of 0.5%. The result accuracy was confirmed by kidney biopsy.

Inflammatory myofibroblastic tumors (IMT) are rare, mesenchymal tumors that can occur in any anatomic location. IMTs have a variable clinical course but usually require wide surgical excision to prevent local recurrence. There have been limited case reports of IMT occurring in solid organ transplant recipients. Herein we report on a case of IMT presenting in a failed renal allograft. A 53-year-old male awaiting re-transplant presented with pain and a palpable mass in his allograft. Imaging demonstrated an infiltrative soft tissue mass encasing the renal hilum. Percutaneous biopsy demonstrated a myofibroblastic proliferation with myxoid background and no high-grade features. The tumor cells were diffusely positive for anaplastic lymphoma kinase-1 (ALK-1) and had a Ki-67 proliferation index of 10%. These findings were consistent with a diagnosis of IMT. A transplant nephrectomy was performed with wide margins to achieve an R0 resection. Pathology on the resection specimen confirmed an IMT that measured 6.5 cm x 6.3 cm. The patient has no evidence of local recurrence at 6-months follow-up and has been relisted for a second kidney transplant.

Background: Antibodies directed against donor mismatched Human Leucocyte Antigens (HLA) are known to cause antibody-mediated rejection and affect the graft survival of transplanted organs. The influence of donor-directed antibodies against the products of HLA class I and II genes in renal transplantation are well described for class I (HLA-A, B and C), but still not clear for class II notably HLA DP. The clinical effects of donor-specific antibodies (DSA) directed against HLA-DP are still controversial.

Methods: We report the outcome of kidney transplants in three highly sensitised individuals with significant sensitisation with donor-directed HLA-DP antibody. These recipients were on the waiting list for 6, 14 and 4 years, respectively and had kidney transplants from donors after brain death (DBD) with positive B cell flow cytometry crossmatch (FCXM). Two cases received induction therapy with a depleting antibody (Thymoglobulin®) while the third received Alemtuzumab followed by standard immunosuppression.

Results: The clinical course of these three patients were different. The first patient developed transplant glomerulopathy, but the graft is still functioning with eGFR 29 mL/min/1.73 m². The second patient did not have any adverse event with eGFR 26 mL/min/1.73 m², while the third patient had severe antibody-mediated rejection (AMR), which was treated successfully with eGFR 32 mL/min/1.73 m².

Conclusion: Patients waiting for a deceased allograft with HLA-DP DSA and a positive FCXM can be transplanted successfully with depleting antibody or Alemtuzumab induction without prior antibody removal followed by standard immunosuppression.

Background

Kidney transplantation is considered the best available treatment option for patients with end-stage renal disease (ESRD).In the last decade, organ transplantation has been actively developing in Kazakhstan. Several transplant centers have been opened in 3 regions of Kazakhstan. Here we present the first report of 10-year experience of kidney transplantation in our center.

Methods

Clinical data of the 416 cases of LDKT and DDKT from 2010 to 2020 were collected from electronic records. All data were retrospectively analyzed.

Results

Among 416 kidney transplantations, 56 DDKT and 360 LDKT have been performed in our center from 2010 to 2020. The mean age of the recipient was 37.±12.5; 35.8 % female; 53.7% male. Chronic glomerulonephritis was the most common cause of renal failure in recipients (319 cases; 77%). The overall patient survival rates for 1, 3,5 years were 98.31 %; 97.97 %; 97.52 % respectively for kidney transplantation from a living donor and 98.18 % for all years from a deceased donor. The 1, 3, 5 and 7-year graft survival was 96.26%, 89.47%, 86.58% and 51.95% for the group from a deceased donor, while for the living donor group it was 97.46%, 96.84%, 95.96% and 92.85% respectively.

Conclusions

Our clinical outcomes were comparable to other transplant centers in Kazakhstan. However, the proportion of deceased donor kidney transplants and highly sensitized recipients is very low. We believe that with a highly qualified multidimensional transplant team and improved protocols of donor and recipient selection, our center can improve our results and diminish the complications after transplantation.

Objective

We sought to assess the potential association between history of bariatric surgery and graft rejection among solid organ transplant (SOT) recipients.

Methods

We conducted a single-center retrospective study of adult (age ≥18 years) SOT recipients (2000-2015) at a large tertiary care transplant network with graft rejection and bariatric surgery history according to the international classification of diseases 9^th revision. Data were analyzed using ANOVA, Chi Square, Fisher Exact tests, and logistic regression.

Results

Of 4363 SOT recipients, 72.6% had a history of graft rejection and 55 (1.3%) had a history of bariatric surgery. On univariate analysis, patients with graft rejection were more likely to have a history of bariatric surgery than those without organ rejection (1.5% vs. 0.7%, p=0.015). In multivariable analysis adjusted for age, transplant organ type, and history of calcineurin-based immunosuppression, there was increased odds of rejection among those with a history of bariatric surgery (Odds Ratio (OR): 3.01, 95% Confidence Interval (CI):0.98-4.46, p=0.05). However, when adjusted for body mass index at transplant, the association was attenuated (OR:3.48, CI:0.81-14.9, p=0.10).

Conclusion

Our single-center data indicate that the relationship between a history of bariatric surgery and graft rejection after SOT may be explained by obesity.

Introduction

: Direct thrombin inhibitors are drugs of choice used to prevent thrombotic complications in hospitalized patients after heparin induced thrombocytopenia (HIT) diagnosis.

Material and method

: We present a case of bivalirudin resistance in patient undergoing heart transplantation due to dilated cardiomyopathy with confirmation of HIT. Bivalirudin was given intraoperatively as cardiopulmonary bypass circulation was applied. From initial infusion rate of 2.5 mg/kg/hour, up to 4 mg/kg/hour, due to low ACT results. The repeated ACT results were 422s, 452s and 468s on 5 minutes intervals.

Conclusion

: Resistance to bivalirudin, though rare, can be overbeared by high bivalirudin dosing under ACT control during surgical procedures including heart transplantation.

Introduction

Kidney transplantation (KT) demands that patients navigate a complex healthcare system and adhere to lifelong therapy and surveillance. Cultural and linguistic discordance between patients and providers has been identified as a barrier to successful KT. We studied KT outcomes and disparities among a native Somali population living in Minnesota.

Methods

Between 1995 and 2015, 2,385 patients underwent KT at our institution; 22 were self-designated Somali nationals. Patient and graft survival and time to first rejection were analyzed. Utilization of interpreter services was evaluated.

Results

Patient survival for the Somali cohort at 1 year was 100% and 95.5% at 5 years; compared to 97.2% at 1 year and 89.1% at 5 years for the Caucasian cohort (p = 0.40). Graft survival for the Somali cohort at 1 year was 100% and 95.5% at 5 years; for the Caucasian cohort 94.8% and 81.6% (p = 0.35). Rejection-free survival in the Somali cohort was 100% at 1 and 5 years, for the Caucasian cohort 86.2% and 82.1 (p = 0.41). Among 22 adult Somali KT recipients, 15 (68%) patients frequently utilized interpreter services in their KT-related clinical encounters.

Conclusion

Immigrant Somali KT recipients, appear to have comparable KT outcomes compared to a contemporaneous Caucasian cohort.

Budd Chiari syndrome (BCS) results from hepatic outflow obstruction. Endovascular management to restore venous patency, including inferior vena cava (IVC) angioplasty with stenting, and transjugular intrahepatic shunt (TIPS) placement to decompress liver congestion, have become standard of care. Herein, we describe a patient with BCS requiring liver transplantation and the surgical technique of suprahepatic IVC anastomosis including thoracic extension of an IVC stent with a review of the relevant literature. A 29-year-old female with BCS due to polycythemia vera, who had been previously managed with TIPS and IVC stent placement, was taken for liver transplantation. Preoperative imaging confirmed stent extension into the thoracic IVC and the stent was unable to be removed intraoperatively. The thoracic IVC was clamped through the diaphragm at the level of the right atrium and the stent was left in place and incorporated within the suprahepatic anastomosis with good vascular outcome at one year follow up. Diligent preoperative preparation is essential with adequate imaging and cardiac surgical consultation in patients with malpositioned stents. Review of the literature shows four cases in which performing the suprahepatic anastomosis including an embedded stent is a viable alternative that allows for avoidance of a thoracotomy.

Background

The presence of autoantibodies to angiotensin 2 type 1 receptor (anti-AT1R) have been implicated in allograft pathobiology following organ transplantation. While the significance of these antibodies has been described in renal transplantation, relatively few studies have examined their frequency and clinical implications in heart transplant patients.

Methods

We analyzed serum collected from 291 heart transplant recipients at the time of transplantation for the presence of anti-AT1R and repeated testing on serum collected from 176 of these patients following transplantation. Patients were followed for outcomes including overall survival, rejection episodes (acute cellular and antibody mediated), coronary allograft vasculopathy, and measures of allograft structure and cardiac function.

Results

Anti-AT1R was detected in the serum of 165/291 patients pre-transplant and in 86/176 patients post-transplant. The detection of anti-AT1R (either at risk or positive) compared with no detection in serum of patients pre- or post-transplantation had no influence on 10-year survival (Log rank 0.061 and 0.228, detection pre- or post-transplant, respectively). Similarly, the detection of anti-AT1R had no influence on important clinical outcomes of heart transplantation including acute cellular rejection (ACR), antibody-mediated rejection (AMR) or cardiac allograft vasculopathy (CAV), left ventricular ejection fraction (LVEF) or left ventricular mass (LV-mass).

Conclusions

The presence of anti-AT1R detected in patient serum samples by commercially available testing pre- or post- heart transplantation was not associated with clinically important outcomes including LV-mass, LVEF, ACR, AMR, CAV and overall survival. Our data brings into question the relevance of anti-AT1R testing as a risk factor or target for therapy among heart transplant recipients.

Background

The optimal management of calciphylaxis in kidney transplant recipients (KTRs) is uncertain.

Case presentation

We report 2 cases of refractory calciphylaxis in KTRs who suffered from persistent secondary hyperparathyroidism. They failed initial therapy with sodium thiosulphate but responded to treatment with bisphosphonates. No adverse events were noted with bisphosphonate therapy.

Conclusion

Bisphosphonates appear to be an effective therapy for KTRs with calciphylaxis who cannot tolerate or respond poorly to STS, particularly if they have persistent hyperparathyroidism post-transplantation.