Evaluation of the 13C-aminopyrine breath test using nondispersive infraredspectrometry

Objective: the aim of the study was to assess the value of the 13C Aminopyr ine Breath Test (ABT) when performed using the NonDispersive InfraRed Spect rometry (NDIRS), which is a simple and cheap alternative to the mass spectr ometry. Methods: The results obtained by using the NDIRS method for performing the ABT were compared to the results obtained by a reference method, the 14C Am inopyrine Breath Test. For this purpose, in 32 patients admitted for variou s liver problems, an ABT was performed by using the 2 methods simultaneousl y. The repeatability of the results obtained at 120 minutes by the NIDRS me thod as compared to the 14C test was assessed by the method of Bland and Al tman. Results : The mean of difference between the results obtained by both metho ds at 120 minutes was 0.06 +/- 0.46. The coefficient of repeatability betwe en the two tests was 0.92 for a confidence interval of 95%. A good correlat ion (r = 0.93) was found between all individual results obtained in breath samples at different times of collection (30, 60, 90, 120 minutes), and bet ween the results obtained at 120 minutes for both 13C and 14C tests (r = 0. 94). Conclusion : The 13C ABT performed using NDIRS is a valid alternative to th e 14C technique in routine clinical practice.