Metabonomic analysis of rats with acute heart rejection.

ABSTRACT

BACKGROUND: Organs transplantation is an effective treatment for end-stage organ failure. Despite the use of modern immunosuppressants to decrease its incidence, acute rejection episodes (ARE), still present a problem for diagnosis, resolution, and prediction of long-term outcomes due to the absence of sufficiently robust biomarkers. METHODS: Using an heterotopic heart transplantation model using Dark Agouti to Lewis rats, and sirolimus (rapamycin, Rapa) treatment by gavage, we divided recipients into four groups controls, ARE, Rapa-14, and Rapa-7. We evaluated recipients by hematoxylin and eosin staining of grafts and reverse transcription polymerase chain reactions. Levels of plasma metabolites were quantified using gas chromatography/time-of-flight mass spectrometry. Data were evaluated employing partial least-squares discriminant analysis (PLS-DA), the area under the receiver operating characteristic curves with negative predictive values (NPV) and positive predictive values (PPV). RESULTS: The graft survival was prolonged by Rapa. Plasma levels of 10 metabolites differed significantly between the ARE and the Rapa-14 groups as illustrated by the total ion current. According to PLS-DA, proline, glycine, serine, phenylalanine, and isocitrate showed the greatest effects with areas under the curve of 0.944, 0.917, 1.0, 0.861, and 0.944 respectively. The NPV values were 85.7%, 85.7%, 100%, 83.3%, and 85.7% and PPV values, 100%, 100%, 100%, 83.3%, and 100% respectively. Therefore, these metabolites may be used to predict the occurrence and progression of ARE. CONCLUSION: The trend of changes suggested that plasma metabolites correlated with the immune state of recipients. Therefore, metabonomics may provide new biomarkers for graft injury in the early phases of ARE.