Gilbert's syndrome and hyperbilirubinemia in protease inhibitor therapy--an extended haplotype of genetic variants increases risk in indinavir treatment

BACKGROUND/AIMS

Gilbert's syndrome is a frequent genetic conjugation abnormality associated with adverse drug effects. Genetic UDP glucuronosyltransferase (UGT)1A gene variants can influence gene transcription, inducibility and glucuronidation activity. Protease inhibitors used in human immunodeficiency virus (HIV) infection and chronic viral hepatitis can inhibit UGTs. Indinavir (IDV) can lead to hyperbilirubinemia in Gilbert's syndrome (UGT1A1*28), which does not explain interindividual severity differences and may thus involve additional UGT1A variants.

METHODS

One hundred and twenty-five HIV patients receiving IDV and 427 healthy blood donors were genotyped for the presence of UGT1A1*28, UGT1A3 -66T/C, UGT1A7 -57T/G, UGT1A7(N129K/R131K) using Taqman 5' nuclease assays.

RESULTS

Hyperbilirubinemia was observed in 42%. UGT1A1*28 frequencies did not differ between HIV patients and controls but were significantly higher in hyperbilirubinemic patients. The frequency of homozygous carriers of the 4 UGT1A marker haplotype increased with hyperbilirubinemia affecting all patients with bilirubin levels >85 micromol/l.

CONCLUSIONS

In IDV treatment the risk of severe hyperbilirubinemia is associated with genetic variants of the UGT1A3 and UGT1A7 genes in addition to Gilbert's syndrome (UGT1A1*28). This haplotype is a useful predictor of protease inhibitor-induced side effects.

Switching to atazanavir improves metabolic disorders in antiretroviral-experienced patients with severe hyperlipidemia

OBJECTIVE

To describe the efficacy and change in lipid profile in patients with severe hyperlipidemia after switch to an atazanavir-containing highly active antiretroviral therapy regimen.

DESIGN AND METHODS

Open-field, 24-week, prospective observational cohort study including 33 HIV-infected, antiretroviral-experienced patients with hyperlipidemia. Changes in lipid profiles were evaluated by analyses of triglycerides, total cholesterol, high- and low-density lipoprotein (HDL and LDL) cholesterol, and efficacy by HIV RNA and CD4 cell changes, both from baseline to week 24.

RESULTS

A rapid and significant decrease of 46% (5.81 +/- 4 mmol/L vs. 3.16 +/- 2.6 mmol/L, P = 0.002) in triglyceride levels was shown. Similarly, a sustained improvement of 18% was observed in total cholesterol levels during the first 24 weeks after switching to atazanavir (6.45 +/- 1.9 mmol/L vs. 5.3 +/- 1.3 mmol/L, P = 0.001). After 24 weeks of treatment there was a significant decrease of 22% in non-HDL cholesterol (5.76 +/- 1.9 mmol/L at baseline vs. 4.5 +/- 1.3 mmol/L at 24 weeks; P = 0.003). HDL and LDL cholesterol profiles did not change significantly as did the viral load or CD4 cell count.

CONCLUSIONS

Switching to atazanavir results in a significant improvement in HIV therapy-induced hyperlipidemia. A switch to atazanavir is proposed as a valuable option to improve atherogenic lipid profiles while maintaining virologic control.

Tissue distribution of the T cell activation antigen Ta1. Serological, immunohistochemical and biochemical investigations

The recently described Ta1 antigen is expressed by activated T cells in vitro and in vivo, as observed in patients with certain immune-mediated diseases, such as multiple sclerosis. In this paper we report on the tissue distribution of the Ta1 antigen. Serological testing of human tumour cell lines and immunohistochemical analysis of human tissue sections revealed a reactivity of the anti-Ta1 antibody with normal and malignant tissues of the upper gastro-intestinal tract, the biliary tract, exocrine pancreas and kidney. SDS-PAGE analysis of immunoprecipitates from 125I-labelled cells, employing the anti-Ta1 antibody, yielded a 113-115 kD band from three serologically Ta1 positive tumour cell lines, from a serologically Ta1 negative human EBV-transformed B lymphoblastoid cell line, from peripheral blood mononuclear cells (PBMC) and, as previously described, a 105 kD band from PHA activated T cells (Fox et al., 1984). After endoglycosidase F treatment similar bands of 85 kD were precipitated from activated T cells and from tumour cell lines. It is therefore likely that very similar glycoproteins, which differ only modestly in the size of carbohydrate chains, bear the Ta1 epitope on Ta1 positive tissues.