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Glutathione peroxidase, thioredoxin, and membrane protein changes in erythrocytes predict ribavirin‐induced anemia
Author(s) -
Grattagliano Ignazio,
Russmann Stefan,
Palmieri Vincenzo O.,
Portincasa Piero,
Palasciano Giuseppe,
Lauterburg Bernhard H.
Publication year - 2005
Publication title -
clinical pharmacology and therapeutics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.941
H-Index - 188
eISSN - 1532-6535
pISSN - 0009-9236
DOI - 10.1016/j.clpt.2005.07.002
Subject(s) - ribavirin , hemoglobin , chemistry , thioredoxin , glutathione , anemia , biochemistry , glutathione peroxidase , medicine , oxidative stress , enzyme , genotype , gene
Objective Low erythrocyte membrane protein sulfhydril concentrations are a risk factor for ribavirin‐induced anemia. We further studied the role of oxidative stress and erythrocyte membrane alterations in ribavirin‐induced anemia. Methods The levels of thioredoxin, glutathione peroxidase, protein sulfhydrils, and protein‐mixed disulfides, as well as the electrophoretic membrane protein pattern, were determined in freshly isolated erythrocytes from healthy control subjects, patients without severe anemia during previous ribavirin treatment (still hepatitis C virus [HCV]–positive), and patients who had had severe anemia with ribavirin (still HCV‐positive or HCV‐negative), 6 months after full recovery. Erythrocytes were also incubated with buffer, ribavirin, phenylhydrazine, or dehydroepiandrosterone, and concentrations of protein sulfhydrils, protein‐mixed disulfides, thiobarbituric acid–reactive substances, and total and oxidized glutathione, as well as osmotic resistance, were determined. Results Patients with previous severe ribavirin‐induced anemia had lower levels of protein sulfhydrils (30.9 nmol/mg protein versus 43.2 nmol/mg protein, P < .001) and thioredoxin (0.6 nmol/g hemoglobin versus 1.2 nmol/g hemoglobin, P < .001), higher levels of protein‐mixed disulfides (1.5 nmol/g hemoglobin versus 0.5 nmol/g hemoglobin, P < .001) and glutathione peroxidase (618 mU/mg protein versus 393 mU/mg protein, P < .001), and a membrane protein pattern consistent with band 4 dimer disaggregation. These differences were independent of HCV seropositivity. There were negative correlations between levels of glutathione peroxidase and thioredoxin ( r = −0.87) and between levels of protein sulfhydrils and protein‐mixed disulfides ( r = −0.93). In vitro studies showed that erythrocytes of patients who had had hemolysis during treatment of HCV are more susceptible to oxidative stress. Conclusions Pronounced differences in markers of oxidative stress and membrane proteins exist between patients with and without a history of ribavirin‐induced anemia. Our findings suggest that there are erythrocyte‐related risk factors for ribavirin‐induced severe anemia. Clinical Pharmacology & Therapeutics (2005) 78 , 422–432; doi: 10.1016/j.clpt.2005.07.002