Usefulness of acoustic radiation force impulse and fibrotest in liver fibrosis assessment after liver transplant.

UNLABELLED:  Background and rationale. Acoustic radiation force impulse (ARFI) is a non-invasive tool used in the evaluation of liver fibrosis in HCV positive immune-competent patients. This study aimed to assess the accuracy of ARFI in discriminating liver transplanted patients with different graft fibrosis severity and to verify whether ARFI, eventually combined with non-invasive biochemical tests, could spare liver biopsies. This prospective study included 51 HCV positive liver transplanted patients who consecutively underwent to annual liver biopsy concomitantly with ARFI and blood chemistry tests measurements needed to calculate several non-invasive liver fibrosis tests. RESULTS: Overall ARFI showed an AUC of 0.885 in discriminating between patients without or with significant fibrosis (Ishak score 0-2vs. 3-6). Using a cut-off of 1.365 m/s, ARFI possesses a negative predictive value of 100% in identifying patients without significant fibrosis. AUC for Fibrotest was 0.848 in discriminating patients with Ishak fibrosis score 0-2 vs. 3-6. The combined assessment of ARFI and Fibro-test did not improve the results obtained by ARFI alone. CONCLUSION: ARFI measurement in HCV positive liver transplanted patients can be considered an easy and accurate non-invasive tool in identify patients with a benign course of HCV recurrence.

Multi-detector row CT scanner angiography in the evaluation of living kidney donors.

Renal vascular anomalies are frequent and are not usually problematic, especially when they have been identified and localised with preoperative imaging; computed tomography angiography is a fast and minimally invasive procedure that may afford accurate visualisation of arterial and venous anatomy. We report on our experience with the utilisation of multi-detector row angiography in the preoperative evaluation of living kidney donors. Nineteen living kidney donors underwent multidetector row scan angiography with 3D post-processing. The subjects were 12 male and 7 female donors with a mean age of 60 years. Renal vascular anomalies were identified in 52.6% of donors. A total of 10 supernumerary arteries were identified. Surgical correlation was available for 19 kidneys (17 left and 2 right). The donated kidneys were selected on the basis of CT scan and renal function. CT scan identified all 29 arteries including 10 double right or left arteries (100% specificity and sensitivity). Dual multi-phase multi-detector row CT angiography is a minimally invasive and highly accurate method for preoperative evaluation of renal donors. It affords comprehensive depiction of the arterial and venous anatomy of the kidney, which is particularly critical for planning and performing the donor nephrectomy, especially via a laparoscopic approach.

Renal allograft rupture caused by acute tubular necrosis.

Renal allograft rupture is a rare but potentially lethal complication of kidney transplantation. A renal allograft recipient receiving quadruple immunosuppressive therapy developed a spontaneous allograft rupture 13 days after kidney transplantation. Warm ischaemia time during the transplant was 80 minutes. The ruptured kidney graft could not be salvaged because of the patient's haemodynamic instability. The histopathological examination showed interstitial oedema with severe acute tubular necrosis with no signs of acute rejection. The most common causes of renal graft rupture are acute rejection and vein thrombosis, while acute tubular necrosis may only rarely be responsible for this complication. Renal graft rupture may be the result of interstitial damage attributed both to the prolonged warm ischaemia time during the transplant and to post-transplant acute tubular necrosis in the absence of graft rejection. In those patients whose haemodynamic status cannot be stabilized by appropriate aggressive haemodynamic support therapy, graft nephrectomy should be considered the only definitive treatment.

Oxidative stress is activated by free fatty acids in cultured human hepatocytes.

BACKGROUND: Nonalcoholic fatty liver disease (NAFLD) is strongly associated to oxidative stress, metabolic syndrome, and cardiovascular risk. Hepatocytes overloaded with fatty acids (FA) could generate substances that interfere with endothelial function, providing a potential explanation for this association. We have investigated the response of cultured human hepatoblastoma cells (Hep-G2) that were exposed to FA by measuring markers of oxidative stress and thrombosis and expression of the insulin receptor. METHODS: Hep-G2 cells were conditioned with a mixture of FA with or without N-acetyl-L-cysteine (NAC), glutathione (GSH), or adiponectin (ADN). After 7 days, we measured intracellular GSH (iGSH), nitric oxide (NO), malondialdehyde (MDA), and tissue plasminogen inhibitor-1 (PAI-1). Real-time polymerase chain reaction (PCR) was used to determine gene expression of inducible nitric oxide synthase (iNOS) and insulin receptor (INS-R). RESULTS: Exposure to FA decreased iGSH and NO levels in Hep-G2 cells and increased MDA and PAI-1 production. Gene expression of iNOS and INS-R in Hep-G2 cells was decreased by exposure to FA. Co-incubation with NAC and GSH prevented the change of iNOS mRNA levels, but not of INS-R; co-incubation with ADN restored the gene expression of INS-R, but not of i-NOS. ADN prevented also the FA-induced increase in MDA in cultured human endothelial cells. CONCLUSION: Exposure to FA activates oxidative stress and production of prothrombotic markers and decreases expression of insulin receptors in cultured human hepatocytes. These effects of FA are partially prevented by ADN and might contribute to the increased cardiovascular risk in patients with NAFLD and metabolic syndrome.

Severe neurotoxicity in tacrolimus-treated living kidney transplantation in two cases.

Two living kidney-transplant recipients under tacrolimus-based immunosuppressive therapy experienced severe neurotoxicity, with tonic-clonic seizures. In both cases the dosage reduction did not result in improvement of symptoms, which completely disappeared after modification of the immunosuppressive regimen from tacrolimus to cyclosporine. Severe neurotoxicity, with seizures or uncommon clinical features, such as serious myalgias, is not foreseeable. We recommend the conversion to cyclosporine-based immunosuppression in such cases.