Plasma bile acid concentrations in patients with human immunodeficiency virus infection receiving protease inhibitor therapy: possible implications for hepatotoxicity

Abstract

Study objectives: To evaluate whether patients with human immunodeficiency virus (HIV) infection who were receiving protease inhibitor therapy had altered bile acid concentrations compared with noninfected control subjects, and whether bile acid concentrations could predict the onset of hepatotoxicity caused by protease inhibitors.

Design: Retrospective sample analysis from a prospectively conducted clinical trial.

Setting: Academic research center.

Patients: Eleven adults with advanced HIV disease who were taking protease inhibitor-based antiretroviral therapy, one of whom had developed protease inhibitor-induced hepatotoxicity.

Measurements and main results: Plasma concentrations of cholic acid (CA), chenodeoxycholic acid (CDCA), deoxycholic acid (DCA), lithocholic acid (LCA), ursodeoxycholic acid (UDCA), and taurocholic acid (TC) were analyzed by using a novel high-performance liquid chromatography with tandem mass spectrometry detection method. Comparisons of the relative contribution of each bile acid to the total bile acid pool were made with previously published values and with bile acid concentrations contained in two pooled plasma samples from healthy, non-HIV-infected volunteers analyzed in our laboratory. Each pooled plasma sample used for this analysis contained contributions from three non-HIV-infected volunteers. The LCA and TC concentrations in HIV-infected patients were 3-4-fold higher than those previously reported for non-HIV-infected subjects; concentrations of other bile acids were similar to those of previous reports. The relative contribution of CDCA to the total bile acid pool was 9% in HIV-infected patients compared with 30-50% in noninfected subjects. Total and individual bile acid concentrations in the HIV-infected patient who developed hepatotoxicity were similar to the bile acid concentrations from the other study patients who did not develop hepatotoxicity.

Conclusion: These data suggest that bile acid concentrations may be altered by HIV infection and/or protease inhibitor therapy. However, further investigations should be performed to assess whether antiretroviral-associated hepatotoxicity can be predicted by alterations in individual bile acid concentrations.

Figure 1

Concentration versus time data for the six bile acids: cholic acid (CA), chenodeoxycholic acid (CDCA), deoxycholic acid (DCA), lithocholic acid (LCA), taurocholic acid (TC), and ursodeoxycholic acid (UDCA). Data are mean ± SD from the first pharmacokinetic analysis (PK1) after dual–protease inhibitor therapy (open circles) and from PK2 after triple–protease inhibitor therapy (closed triangles). Dotted lines (PK1) and dashed lines (PK2) represent data from the patient who developed hepatotoxicity. Horizontal solid lines represent the normal range of the bile acid concentration in healthy control subjects.

Figure 2

Composite total bile acid exposure in all patients at pharmacokinetic visits 2 and 3. Closed circles represent the patient who developed hepatotoxicity between PK2 and PK3. Composite exposure was calculated as the combination of the 12-hour area under the concentration-time curve for the six major bile acids (cholic acid, chenodeoxycholic acid, deoxycholic acid, lithocholic acid, taurocholic acid, and ursodeoxycholic acid).

Figure 3

Aspartate aminotransferase (AST) and alanine aminotransferase (ALT) concentrations and composite bile acid exposure (area under the concentration-time curve [AUC]) for the one patient who developed drug-induced hepatotoxicity. The composite bile acid exposure was calculated as the combination of the 12-hour AUC values for the six major bile acids (cholic acid, chenodeoxycholic acid, deoxycholic acid, lithocholic acid, taurocholic acid, and ursodeoxycholic acid).

Figure 4

Cholic acid (CA):chenodeoxycholic acid (CDCA) area under the concentration-time curve ratios for individual patients at pharmacokinetic (PK) visits 1–3. Closed triangles represent the patient who developed hepatotoxicity between PK2 and PK3.