Breath pentane is a marker of acute cardiac allograft rejection

Breath pentane, a product of lipid peroxidation that serves as a noninvasive marker of tissue inflammation and injury, was measured as a potential marker of acute cardiac allograft rejection. We prospectively studied 37 consecutive outpatients with stable cardiac allograft function. Breath pentane levels were measured with gas chromatography, and the results were compared the findings from routine surveillance endomyocardial biopsy. Data analysis was performed with the receiver operating characteristic curve and negative and positive predictive values. Statistical methods include analysis of variance and two-sample t-tests. Histopathologic findings consistent with rejection were present on endomyocardial biopsy in 52% of the subjects. Pentane levels in healthy control subjects did not differ from those of patients undergoing transplantation without rejection. Average pentane excretion for subjects with mild rejection (4.2 +/- 2.8 nmol/L) or moderate rejection (5.4 +/- 2.6 nmol/L) exceeded that seen in subjects who did not have rejection (1.7 +/- 0.9 nmol/L) (p < 0.02). A pentane cutoff value of 2.43 nmol/L, chosen to give the highest negative predictive value, had a sensitivity of 0.80. We concluded that breath pentane excretion is a sensitive noninvasive screening test for the detection of cardiac allograft rejection.