Cyclosporine C2 monitoring is superior to C0 in predicting acute cellular rejection in heart transplant recipients in Taiwan

Abstract

The cyclosporine (CsA) blood concentration at 2 hours postdose (C2) has been shown to be better than trough level (C0) to predict acute cellular rejection (ACR) in solid organ transplantations. We tried to assess the superiority of C2 monitoring to C0 in heart transplantation (HTx). Prospective data were collected from the HTx recipients from November 1991 to April 2003. The 100 patients surviving longer than 3 months after HTx, provided 237 sample sets, with ACR graded by endomyocardial biopsy (EMB) and concurrent C0 and C2 levels. ACR was defined as International Society of Heart and Lung Transplantation (ISHLT) grade lb or higher. Nonparametric methods, logistic regression model, and receiver operating characteristic (ROC) analysis were used. There was no significant demographic heterogeneity between ACR and non-ACR groups. C2 was significantly lower in ACR than non-ACR groups (P = .0192) whereas C0 showed no significant difference. In the logistic regression model, C2 was a significant predictor against ACR (P = .026, odds ratio = 0.76 per 100 ng/mL), but C0 was not. ROC analysis showed that C2 of 600 ng/mL might provide the optimal cut-off point, with a sensitivity of 51.23% and a specificity of 71.43%, but C0 did not show this association. In conclusion, C2 monitoring is superior to C0 for predicting ACR in HTx. ACR should be suspected when the C2 value is below 600 ng/mL.