Conversion from cyclosporin A to tacrolimus in pediatric liver transplantation

The dosing regimen for conversion from cyclosporin A (CsA) to tacrolimus immunosuppression was studied in 12 pediatric liver allograft recipients. Patients were stratified according to their age. Tacrolimus was started orally at a dosage of 0.05 mg/kg b.i.d., 12 h after stopping CsA administration and increased thereafter if needed. Tacrolimus and CsA concentrations were assayed by immunoassay using, respectively, an IMx and a TDx autoanalyzer (Abbott-France). Mean CsA concentration was in the therapeutic range 12 h prior to and at the time of introduction of tacrolimus. After 72 h of tacrolimus therapy, CsA concentrations were undetectable whereas mean tacrolimus concentration was 10.4 ng/mL with a mean dose of 0.09 mg/ kg b.i.d. The decline of CsA concentration was clearly biphasic. A slower decline in CsA concentration was detected after initiation of tacrolimus therapy, suggesting an inhibition of CsA metabolism by tacrolimus. No nephrotoxicity was observed. This dosage regimen allowed effective immunosuppression while avoiding additive nephrotoxicity.

Antibodies against p53 protein in serum of patients with benign or malignant pancreatic and biliary diseases

Specific markers for pancreatic or biliary cancer have been developed in the past few years. Ca 19-9 has a good sensitivity but it is also increased in benign cholestasis. Mutations in the p53 gene are commonly reported in pancreatic cancer and can be detected by a serological analysis. The aim of this work was to find out the sensitivity and specificity of this new assay in diagnosing cancer of the pancreas or of the bile ducts. The presence of antibodies against p53 was determined by an enzyme linked immunosorbent assay (ELISA) in 29 patients with pancreatic cancer, 33 with biliary tract cancer, and 33 with benign biliary or pancreatic diseases as controls. p53 Antibodies were detected in eight of 29 patients with pancreatic cancer (28%), in five of 33 patients with biliary tract (15%), and in one patient (3%) with stones of the common bile duct. The sensitivity and the specificity for the diagnosis of malignant biliary or pancreatic diseases were 21% and 96% respectively. It is concluded that the presence of p53 antibodies in the serum of patients with pancreatic and biliary diseases is specific for malignancy and independent from the presence of cholestatic disease.