High Intrapatient Tacrolimus Variability Is Associated With Worse Outcomes in Renal Transplantation Using a Low-Dose Tacrolimus Immunosuppressive Regime.

BACKGROUND: High intrapatient tacrolimus variability has been associated with worse clinical outcomes postrenal transplantation. Theoretically, tacrolimus levels consistently outside the target therapeutic window may result in allograft dysfunction as subtherapeutic tacrolimus levels predispose to episodes of acute rejection, whereas supratherapeutic levels may cause nephrotoxicity. METHODS: We investigated the effect of tacrolimus variability in a "Symphony" style low-dose tacrolimus based regime, by collecting data from 432 patients over a 4-year period.Three hundred seventy-six patients were included, with a mean follow-up of 1495 days. Tacrolimus variability 6 to 12 months after renal transplantation was calculated, and outcomes were compared in low (n = 186) and high variability (n = 190) groups. RESULTS: High variability patients were found to be at increased risk of rejection during the first posttransplant year (P = 0.0054) and to have reduced rejection-free survival (hazard ratio, 1.953; 95% confidence interval, 1.234-3.093; P = 0.0054). High variability patients had significantly worse (P < 0.0001) glomerular filtration rates at 1, 2, 3, and 4 years posttransplant. High variability patients were at increased risk of allograft loss (hazard ratio, 4.928; 95% confidence interval, 2.050-11.85; P = 0.0004). CONCLUSIONS: This suggests that highly variable tacrolimus levels predict worse outcomes postrenal transplantation, although the causal nature of this relationship remains unclear. High tacrolimus variability may identify a subset of patients who warrant increased surveillance and patient education regarding dietary and medication compliance.

Impaired gluconeogenesis in a porcine model of paracetamol induced acute liver failure.

AIM: To investigate glucose homeostasis and in particular gluconeogenesis in a large animal model of acute liver failure (ALF). METHODS: Six pigs with paracetamol induced ALF under general anaesthesia were studied over 25 h. Plasma samples were withdrawn every five hours from a central vein. Three animals were used as controls and were maintained under anaesthesia only. Using (1)H NMR spectroscopy we identified most gluconeogenic amino acids along with lactate and pyruvate in the animal plasma samples. RESULTS: No significant changes were observed in the concentrations of the amino acids studied in the animals maintained under anaesthesia only. If we look at the ALF animals, we observed a statistically significant rise of lactate (P < 0.003) and pyruvate (P < 0.018) at the end of the experiments. We also observed statistically significant rises in the concentrations of alanine (P < 0.002), glycine (P < 0.005), threonine (P < 0.048), tyrosine (P < 0.000), phenylalanine (P < 0.000) and isoleucine (P < 0.01). Valine levels decreased significantly (P < 0.05). CONCLUSION: Our pig model of ALF is characterized by an altered gluconeogenetic capacity, an impaired tricarboxylic acid (TCA) cycle and a glycolytic state.

Endo-biliary stents for benign disease: not always benign after all!

This case report describes the presentation, management and treatment of a patient who suffered small bowel perforation due to the migration of his biliary stent which had been inserted for benign disease.