L-[1-¹³C]phenylalanine breath test in patients with chronic liver disease of different etiologies

Abstract

The aim of this study was to compare the oxidation of L-[1-(13)C]phenylalanine ((13)C-PheOx) in patients with chronic liver failure due to different etiologies using L-[1-(13)C]phenylalanine breath test. Breath samples were collected before the administration of 100 mg L-[1-(13)C]phenylalanine, and every 10 min thereafter until completion of 1 h. Control subjects (n=9) presented a larger cumulative percentage of (13)C dose recovery (CPDR) than patients (n=124) with chronic liver disease, regardless of the etiology (7.5+/-0.7 vs. 4.2+/-0.2, p=0.001). No differences in CPDR were found considering the Child-Pugh (CP) class or etiology: alcoholic (CP A=7.7+/-0.7, CP B=4.1+/-0.5, CP C=2.0+/-0.3), hepatitis C virus (CP A=5.4+/-0.5, CP B=4.0+/-0.2, CP C=2.2+/-0.3), hepatocellular carcinoma (CP A=5.5+/-1.6, CP B=3.6+/-1.8, CP C=2.2+/-1.0); or cryptogenic cirrhotic patients (CP A=7.4+/-1.5, CP B=4.4+/-0.4, CP C=2.1+/-0.7). Results confirm that (13)C-PheOx decreases in patients with cirrhosis with respect to controls, notwithstanding the etiology.

Minimally invasive 13C-breath test to examine phenylalanine metabolism in children with phenylketonuria

“…The use of stable isotope based breath tests in clinical conditions are well known, with the 13 C-urea breath test for the detection of H Pylori infection in the stomach being the most well established as a routine test [29]. 1-13 C-phenylalanine oxidation to 13 CO 2 is also used as a test for chronic liver disease [30] and gastric emptying [31]. While it is likely that measurement of blood phenylalanine levels will remain the key measure of clinical management, there is a need for a routine, simple test to help better manage PKU children.…”

Liver function assessment with three13C breath tests by two-point measurements

“…This is a potential barrier to routine clinical employment of 13 C-labelled compound breath tests for liver function assessment. The PBT is useful for evaluating alcohol-related liver dysfunction [8]. As a Downloaded by [University of Toronto Libraries] at 21:26 25 December 2014 specific dose of phenylalanine must be administered to treat hepatic coma, this agent is acceptable even for subjects with a very poor liver function.…”

“…With respect to 13 C breath tests for cytosol, the usefulness of the l-[1-13 C]phenylalanine breath test (PBT) [7][8][9][10][11][12][13][14][15][16][17][18][19][20][21][22][23][24][25] and [ 13 C]galactose breath test [26][27][28][29][30][31] has been reported. Several studies focusing on mitochondria indicated the usefulness of the α-ketoisocaproate breath test [32][33][34][35][36][37][38] and methionine breath test (MethioBT) [39][40][41][42][43][44][45][46][47][48][49][50].…”

13 CO 2 breath tests in non-invasive hepatological diagnosis

“…This test, however, confirmed its usefulness by discriminating between groups of patients with compensated and decompensated cirrhosis, as well as between patients with oesophageal varices of varying degrees of severity [ 35 , 36 ]. Another study showed that the Phe-BT result was an independent survival predictor in patients with hepatic impairment [ 37 ].…”