Monitoring treatment of acute kidney injury with damage biomarkers.

BACKGROUND: Damage biomarkers may identify mechanisms and sites of acute kidney injury (AKI). However, the utility of novel AKI biomarkers differs by context, and their utility for monitoring treatment of AKI is unknown. We hypothesized that selected AKI biomarkers would facilitate monitoring of mechanism-specific treatment. We examined this using a panel of biomarkers to monitor cisplatin-induced AKI treatment with alpha-lipoic acid (α-LA) that has previously been demonstrated to ameliorate cisplatin induced AKI. METHODS: AKI was induced in male Sprague Dawley rats using cisplatin (6mg/kg) in the presence or absence of a single dose of α-LA (100mg/kg). A panel of 12 urinary kidney damage biomarkers (CystatinC, NGAL albumin, alpha-1-acid glycoprotein, clusterin, KIM-1, osteopontin, total protein, cytochrome C, epidermal growth factor, interleukin-18 and malondialdehyde was examined as well as histological injury, serum creatinine and cystatin C, and clinical parameters. RESULTS: Cisplatin treatment modified all parameters, except interleukin-18 and malondialdehyde, with each parameter demonstrating a different temporal profile. α-LA treatment attenuated renal tubular injury scores (P <0.05), decreased peak serum creatinine (p=0.004) and cystatin C (p=0.04), and urinary damage biomarkers of proximal tubular injury (CystatinC, NGAL, albumin, and alpha-1-acid glycoprotein). Other urinary biomarkers were not modified. Neither α-LA alone, nor the cisplatin vehicle (DMSO) modified biomarker profiles. CONCLUSIONS: α-LA treatment ameliorated cisplatin-induced AKI. Protection was demonstrated by reduced structural damage, improved glomerular filtration and reduced excretion of urinary biomarkers of proximal tubular damage. Effective treatment of AKI can be monitored by site and perhaps by mechanism-specific kidney damage biomarkers.

Association between calcineurin inhibitor treatment and peripheral nerve dysfunction in renal transplant recipients.

Neurotoxicity is a significant clinical side effect of immunosuppressive treatment used in prophylaxis for rejection in solid organ transplants. This study aimed to provide insights into the mechanisms underlying neurotoxicity in patients receiving immunosuppressive treatment following renal transplantation. Clinical and neurophysiological assessments were undertaken in 38 patients receiving immunosuppression following renal transplantation, 19 receiving calcineurin inhibitor (CNI) therapy and 19 receiving a calcineurin-free (CNI-free) regimen. Groups were matched for age, gender, time since transplant and renal function and compared to normal controls (n = 20). The CNI group demonstrated marked differences in nerve excitability parameters, suggestive of nerve membrane depolarization (p < 0.05). Importantly, there were no differences between the two CNIs (cyclosporine A or tacrolimus). In contrast, CNI-free patients showed no differences to normal controls. The CNI-treated patients had a higher prevalence of clinical neuropathy and higher neuropathy severity scores. Longitudinal studies were undertaken in a cohort of subjects within 12 months of transplantation (n = 10). These studies demonstrated persistence of abnormalities in patients maintained on CNI-treatment and improvement noted in those who were switched to a CNI-free regimen. The results of this study have significant implications for selection, or continuation, of immunosuppressive therapy in renal transplant recipients, especially those with pre-existing neurological disability.

Nerve transfers.

Nerve transfers have been performed for many years, but the technique is further developing and gaining increased recognition as a time-tested procedure. The original operations are continually modified to treat a wide variety of peripheral nerve injuries, and yield reliable results. In addition, nerve transfers can be used in conjunction with tendon transfers or nerve grafts in order to best treat a specific patient's set of deficits. This review of nerve transfers briefly discusses the evolution of the technique, general principles, some specific transfers, post-operative rehabilitation, and their place on the reconstructive ladder.