Analysis of tryptophan catabolism in HBV patients by HPLC with programmed wavelength ultraviolet detection.
BACKGROUND
In order to understand the tryptophan catabolism in acute and chronic hepatitis B patients, we quantitatively analyzed plasma kynurenine and tryptophan simultaneously by high performance liquid chromatography with programmed wavelength ultraviolet detection.


METHODS
A new and specific high performance liquid chromatography method to simultaneously measure plasma kynurenine and tryptophan with programmed wavelength ultraviolet detection using 3-nitro-tyrosine as internal standard was elaborated. Thirty patients were recruited (10 patients with acute HBV, 10 with chronic HBV and 10 healthy subjects).


RESULTS
The retention times of kynurenine and tryptophan were 2.9 min and 4.4 min, respectively. For kynurenine, the assay was linear from 0.442 micromol/l to 18.3 micromol/l. For tryptophan, the linearity was from 3.67 to 470 micromol/l. The detection limits were 0.014 micromol/l for Kyn and 0.122 micromol/l for Trp, respectively. Its precision and recovery are satisfactory. In this study we found that the kynurenine per tryptophan ratio of acute group is higher than control group and chronic group.


CONCLUSIONS
The method is simple, fast, accurate, and suitable for applicability to clinical measurement.
Key Laboratory of Clinical Laboratory Diagnostics, Ministry of Education, The Faculty of Laboratory Medicine, Chongqing Medical University, Chongqing, 400016, China.
Li
L
Ma
Biao
B
Xu
Wenjuan
W
Wang
Wenping
W
Deng
Min
M
Ding
D002138:Calibration; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D006262:Health; D006509:Hepatitis B / Q000097:blood*; D006801:Humans; D007736:Kynurenic Acid / Q000097:blood; D013056:Spectrophotometry, Ultraviolet / Q000379:methods*; D014364:Tryptophan / Q000097:blood*
D014364:Tryptophan; D007736:Kynurenic Acid