Application of TruGraf v1: A Novel Molecular Biomarker for Managing Kidney Transplant Recipients With Stable Renal Function

TruGraf v1 is a laboratory-developed DNA microarray-based gene expression blood test to enable proactive noninvasive serial assessment of kidney transplant recipients with stable renal function. It has been previously validated in patients identified as Transplant eXcellence (TX: stable serum creatinine, normal biopsy results, indicative of immune quiescence), and not-TX (renal dysfunction and/or rejection on biopsy results). TruGraf v1 is intended for use in subjects with stable renal function to measure the immune status as an alternative to invasive, expensive, and risky surveillance biopsies.

MATERIALS AND METHODS

In this study, simultaneous blood tests and clinical assessments were performed in 192 patients from 7 transplant centers to evaluate TruGraf v1. The molecular testing laboratory was blinded to renal function and biopsy results.

RESULTS

Overall, TruGraf v1 accuracy (concordance between TruGraf v1 result and clinical and/or histologic assessment) was 74% (142/192), and a result of TX was accurate in 116 of 125 (93%). The negative predictive value for TruGraf v1 was 90%, with a sensitivity 74% and specificity of 73%. Results did not significantly differ in patients with a biopsy-confirmed diagnosis vs those without a biopsy.

CONCLUSIONS

TruGraf v1 can potentially support a clinical decision enabling unnecessary surveillance biopsies with high confidence, making it an invaluable addition to the transplant physician's tool kit for managing patients. TruGraf v1 testing can potentially avoid painful and risky invasive biopsies, reduce health care costs, and enable frequent assessment of patients with stable renal function to confirm the presence of immune quiescence in the peripheral blood.

Investigator Assessment of the Utility of the TruGraf Molecular Diagnostic Test in Clinical Practice

BACKGROUND

TruGraf v1 is a well-validated DNA microarray-based test that analyzes blood gene expression profiles as an indicator of immune status in kidney transplant recipients with stable renal function.

METHODS

In this study, investigators assessed clinical utility of the TruGraf test in patient management. In a retrospective study, simultaneous blood tests and clinical assessments were performed in 192 patients at 7 transplant centers, and in a prospective observational study they were performed in 45 subjects at 5 transplant centers.

RESULTS

When queried regarding whether or not the TruGraf test result impacted their decision regarding patient management, in 168 of 192 (87.5%) cases the investigator responded affirmatively. The prospective study indicated that TruGraf results supported physicians' decisions on patient management 87% (39/45) of the time, and in 93% of cases physicians indicated that they would use serial TruGraf testing in future patient management. A total of 21 of 39 (54%) reported results confirmed their decision that no intervention was needed, and 17 of 39 (44%) reported that results specifically informed them that a decision not to perform a surveillance biopsy was correct.

CONCLUSIONS

TruGraf is the first and only noninvasive test to be evaluated for clinical utility in determining rejection status of patients with stable renal function and shows promise of providing support for clinical decisions to avoid unnecessary surveillance biopsies with a high degree of confidence. TruGraf is an invaluable addition to the transplant physician's tool kit for managing patient health by avoiding painful and invasive biopsies, reducing health care costs, and enabling frequent assessment of patients with stable renal function to confirm immune quiescence.

Salvage Procedure for Unexpected Portal Vein Thrombosis in Living Donor Liver Transplantation

Portal vein thrombosis (PVT) is considered a relative contraindication to living donor liver transplantation (LDLTx) due to technical difficulty and ethical considerations. So far, there have been a few reported cases of LDLTx with PVT, most of which were treated by thrombectomy with or without a venous conduit. We report a case of LDLTx in an unexpected recipient with grade 4 diffuse PVT, which was successfully managed using a variceal left gastric vein and a deceased donor iliac vein conduit to create a "de novo portal vein" for splanchnic inflow to the right lobe. The patient experienced an uneventful postoperative course with normal blood flow in the de novo portal vein at 1-year follow up. This report demonstrated that a variceal collateral vein can be used as appropriate alternative inflow for the right lobe in LDLTx cases in which an unexpected PVT is encountered.

Hepatic angiosarcoma and liver transplantation: case report and literature review

Hepatic angiosarcoma is a rare malignant vascular tumor that accounts for up to 2% of all primary liver tumors. Accurate diagnosis of this tumor is difficult, especially if the patient has no history of exposure to specific carcinogens including thorotrast, arsenicals, and vinyl chloride monomer. Diagnosis of diffuse angiosarcoma by means of liver biopsy has been reported as treacherous and nondiagnostic. Herein, we present a case of a 61-year-old Caucasian male with history of cryptogenic cirrhosis, normal alpha-fetoprotein, and pretransplant abnormal liver MRI who underwent nondiagnostic liver biopsies followed by liver transplantation. High grade diffuse angiosarcoma was diagnosed in the explanted liver. The patient developed bone metastases at 8 months and is alive 1 year posttransplantation. Diffuse liver tissue infiltration seen pretransplant on CT scan or MRI, suggesting the possibility of diffuse liver lesions (HCC, angiosarcoma, etc) must be fully investigated with all techniques available including multiple open liver biopsies to avoid the sacrifice of a liver allograft in these patients.

Non-resective ablation therapy for hepatocellular carcinoma: effectiveness measured by intention-to-treat and dropout from liver transplant waiting list

BACKGROUND

Orthotopic liver transplantation (OLT) for patients with small hepatocellular carcinoma (HCC) is widely accepted, and the usefulness of local ablation techniques as a bridge for liver transplantation is still under investigation.

METHODS

From December 1997 to February 2003, patients with cirrhosis and T0-T1-T2-T3 stage HCC received multi-modality ablative therapy (MMT) for the treatment of their HCC and were evaluated for OLT; listed, and transplanted when an allograft became available. MMT included radiofrequency ablation (RFA), and/or Trans-Arterial Chemo-Embolization (TACE), and alcohol (EtOH) ablation, followed by Trans-Arterial Chemo-Infusion (TACI), with repeated treatments based on follow up hepatic magnetic resonance imaging (MRI) during the waiting period for OLT.

RESULTS

A total of 135 HCC patients were seen at our center within this time frame. The intention-to-treat group included 33 (24.4%) patients with T0, T1, T2, T3 HCC and cirrhosis. There were 31 men and two women. The mean age was 53.6 +/- 7.2 yr. All patients received MMT with a mean of 2.90 +/- 1.5 procedures per patient. Tumor-node-metastasis (TNM) stages at time of listing were: T0 in one patient, T1 in nine patients, T2 in 17 patients, and T3 in six patients. Twenty-eight (85%) patients have received OLT. Five (12.19%) patients were listed and removed (dropout) from the transplant waiting list after waiting 5, 5, 5, 8, and 14 months respectively. The waiting time of the HCC listed group was 9.1 +/- 14.8 months with a mean follow up of 32 months. OLT patient survival and cancer-free survival are 92.9% and 95.24%, respectively; the overall survival of intention-to-treat group was 79% at 32 months follow up. Predictors of dropout included an alpha-fetoprotein (AFP, >400 ng/mL) and T3 HCC stage.

CONCLUSION

Aggressive ablation therapy with a short transplant waiting time optimizes the use of OLT for curative intent in selective cirrhotic HCC patients.

Massive hepatic artery atherosclerosis of an otherwise suitable donor liver: a case report

Most of the few reports about hepatic artery disease found in the literature describe hepatic artery aneurysms or hepatic artery calcifications. Atherosclerosis of the hepatic artery is not commonly evaluated during deceased donor liver procurement. Herein we present a case of a stable 47-year-old Caucasian female donor whose liver function tests were within normal limits and a liver biopsy showed less than 5% steatosis. The liver when received at our center appeared grossly unremarkable. Back-table evaluation showed a complete occlusion of the trunk of the proper hepatic artery. The pathology report revealed hepatic occlusion due to arterial atherosclerosis. Transplantation was canceled, and the liver was used for isolated hepatocyte perfusion, revealing < 25% hepatocyte viability. Hepatic artery atherosclerosis and patency need to be evaluated at the time of procurement to prevent recipient morbidity due to anesthetic induction, or initiation of a recipient abdominal incision prior to declining the liver graft for this rare finding.

Non-resective ablation and liver transplantation in patients with cirrhosis and hepatocellular carcinoma (HCC): safety and efficacy

We investigated the efficacy of nonresective ablation techniques and the tumor-free survival of cirrhotic patients undergoing liver transplantation for hepatocellular carcinoma (HCC). In group 1, 11 HCC patients were treated with these techniques and transplanted. On the waiting list, patients were treated to complete ablation, judged by gadolinium-enhanced MRI and alpha-fetoprotein (AFP) levels. Group 1 was compared with a concurrent group of 10 liver transplant patients (group 2) with incidental HCC (stages T1 three patients, T2 seven patients). The group 1 patients received 36 procedures (4 alcohol ablations, 14 trans -hepatic artery chemo-embolizations, 15 trans -hepatic chemo-infusions, and 3 radio frequency ablations) for treatment of 13 liver masses. Tumor-node-metastasis (TNM) stage was reduced in eight patients (72.7%), unchanged in two patients and increased in one patient before transplantation. The mean waiting time for transplantation was 12.9 7.6 months. Both groups had a tumor-free survival of 100%, at 30 12 months post transplant. On pathology, 54.5% of explanted livers had residual viable HCC after tumor treatment, and 36.4% (4/11) explants had synchronous lesions. Non-resective ablation therapy is safe and effective in reducing the HCC progression in cirrhotic patients awaiting liver transplantation. The cancer-free survival rate in this treatment group is equal to that for incidental T1-T2 HCCs.