High Kynurenine:Tryptophan Ratio Is Associated with Liver Fibrosis in HIV-Monoinfected and HIV/Hepatitis C Virus-Coinfected Women

Abstract

Background: Tryptophan catabolism, measured by the kynurenine:tryptophan (kyn/trp) ratio, is associated with gut microbiota alterations in people with HIV (PWH). We examined the association of the kyn/trp ratio with liver fibrosis in women with/without HIV infection. Methods: The plasma kyn/trp ratio was measured in 137 HIV-monoinfected, HIV/hepatitis C virus (HCV)-coinfected, and uninfected women in the Women's Interagency HIV Study. Fibrosis was estimated using FIB-4 in all participants and vibration-controlled transient elastography liver stiffness measurement (LSM) in a subset (n = 83). We used multivariable linear regression to evaluate the associations of infection status and kyn/trp ratio with relative differences in fibrosis estimates. Results: The median kyn/trp ratio (interquartile range) was 0.056 (0.045-0.066) in HIV/HCV-coinfected, 0.038 (0.032-0.046) in HIV-monoinfected, and 0.031 (0.025-0.034) in uninfected women (P