Study to Assess the Safety, Tolerability, and Pharmacodynamics of RTA 402 in Patients With Hepatic Dysfunction

Inclusion Criteria: * Chronic liver disease. * An estimated creatinine clearance of ≥ 60 mL/min. * Serum alanine transaminase (ALT) or aspartate transaminase (AST) elevation must be above the upper limit of normal and below 5 times the upper limit of normal for patients with underlying liver disease; Child-Pugh score 5 to 9 (mild to moderate impairment). * Patient must agree to practice effective contraception during the entire study period. * Patient is willing to avoid strenuous physical activity from 24 hours prior to the study start, throughout the study, and for 2 weeks after the administration of the dose of study drug * Patient is willing to avoid any alcohol consumption for the 24 hours prior to, and the 48 hours after administration of study drug; and avoid excessive alcohol consumption for the duration of the follow-up period. * Patient must be able and willing to sign informed consent form. Exclusion Criteria: * Patient with clinically significant illnesses or recent hospitalization (within 60 days) which could compromise participation in the study in the judgment of the investigator, including: uncontrolled diabetes; active or uncontrolled infection; Confirmed diagnosis of HIV infection; uncontrolled hypertension, symptomatic congestive heart failure, unstable angina pectoris, myocardial infarction within the past 6 months, or uncontrolled cardiac arrhythmia. * Patient with any other auto immune disease, major chronic inflammatory disease or syndrome requiring significant treatment within the past year. * Patients who are pregnant or breast feeding * Patient receiving or has received any investigational drug within 30 days prior (or is currently using an investigational device) * Patients with prior (within 4 weeks) or concurrent treatment with oral steroids, or protein-based therapy (i.e. TNFa) * Patients with positive urine screen for drugs of abuse except when receiving a prescribed medication for a known indication * Patients with Grade 2 or above hepatic encephalopathy. * Patients who donated blood or experienced a significant blood loss (\>450 mL) within 8 weeks of screening * Patients with a history of bleeding varices within 12 weeks of screening. * Patients with psychiatric illness or other condition that would limit compliance with study requirements.