Indocyanine green elimination test in orthotopic liver recipients.

OBJECTIVE: To determine its predictive capability on graft quality and resultant clinical outcome, the indocyanine green (ICG) elimination test was performed by a spectrophotometric method and a noninvasive finger-piece method with 50 orthotopic liver transplantations. BACKGROUND: Early detection of poor-functioning hepatic grafts is one of the most important issues in liver transplantation, but no reliable methods exist. METHODS: The ICG test was performed after 50 orthotopic liver transplantations on postoperative days 1, 3, and 7. Indocyanine green elimination constants (K(ICG)) were measured by both a standard spectrophotometric analysis (K(ICG)-B) and by a finger-piece method (K(ICG)-F). The patients were followed for a minimum of 3 months after transplantation. Results of ICG tests were correlated with various clinical determinations. RESULTS: Twelve of the 50 grafts were lost within three months, of which 7 were related to graft failure. Multivariate analysis using the Cox proportional hazard model revealed that K(ICG) on postoperative day 1 was a better predictor of liver-related graft outcome than any of the conventional liver function tests. Furthermore, K(ICG) values showed significant correlation with the severity of preservation injury, longer intensive care unit (ICU) and hospital stay, prolonged liver dysfunction, and septic complications. Correlation of K(ICG) values by the spectrophotometric method with those by the finger-piece method was highly satisfactory in the grafts that had K(ICG)-B <0.15 min-1 (y = 0.868x -0.011, r = .955). CONCLUSION: The ICG elimination test, conducted spectrophotometrically or optically on the day after liver transplantation, is a reliable indicator of graft quality and subsequent graft outcome early after liver transplantation

Tacrolimus analysis: A comparison of different methods and matrices

We determined the trough blood and plasma concentrations of tacrolimus from the day of transplantation through 30 days posttransplantation in four liver and four kidney transplant patients by three different methods. The first method involved a solid phase extraction of the blood or plasma using Sep-Pak columns (SPs) followed by quantitation of tacrolimus using an enzyme-linked immunosorbent assay (ELISA); the second method involved a liquid-liquid extraction using methylene chloride (MC) followed by quantitation of tacrolimus using the ELISA, and the third method involved a high-performance liquid chromatography (HPLC) fractionation of the extract obtained from the solid-phase extraction and quantitation of tacrolimus in the fractions by ELISA. The trough plasma tacrolimus concentrations ranged from 0.1 to 5.2 ng/ml. While the trough plasma concentrations of tacrolimus were similar and independent of the method of analysis in kidney transplant patients and in liver transplant patients with normal biochemical profile, in patients with liver dysfunction, tacrolimus plasma concentrations were higher when measured by SP-ELISA and MC-ELISA methods as compared to the HPLC-ELISA method. In plasma samples obtained from liver transplant patients with liver dysfunction, the presence of some metabolites that cross-reacted with the antibody used in the ELISA could be documented in the HPLC fraction corresponding to the metabolites. This indicates that while tacrolimus metabolites that cross-react significantly with the antibody used in the ELISA do not accumulate in kidney transplant patients, they can appear in the plasma of patients with liver dysfunction. The trough blood tacrolimus concentrations in patients were significantly higher than the corresponding plasma concentrations and ranged from 1.4 to 107 ng/ml. The trough blood tacrolimus concentrations were similar and independent of the method of analysis in kidney and liver transplant patients, suggesting unchanged tacrolimus to be the major component in the blood. The HPLC fractions corresponding to the metabolites of tacrolimus did not contain any components that cross-reacted with the antibody used. This study documents that the methods used in this study for the analysis of blood concentrations of tacrolimus appear to be specific for the parent tacrolimus and can be used in future pharmacokinetic and clinical studies. © 1995 Raven Press, Ltd., New York