Assessing Antibiotic Induced Liver Injury for Stratification of Tuberculosis Patients

Overview

A panel of highly sensitive circulating biomarkers for acute liver injury have been identified and demonstrated to identify liver injury on first presentation to hospital before standard tests are elevated in patients with paracetamol overdose. The investigators wish to test these biomarkers in patients with active and latent tuberculosis to see if they can be used to stratify patients undertaking anti-tuberculosis drug therapy. Anti-tuberculosis drug induced liver injury is the most frequent side-effect of anti-tuberculosis therapy, affecting 2-5% of tuberculosis patients seen at the Royal Infirmary Edinburgh and hindering their effective treatment. Patients will be recruited from the TB out-patient clinic at the Royal Infirmary Edinburgh. Blood samples will be taken every time the patient visits the clinic and also retrieved from the biochemistry lab. The biomarkers in the blood samples will be analysed to determine if they rise in patients who develop liver injury.

To improve patient stratification, the investigators have developed a panel of novel circulating liver specific and mechanistic biomarkers that report early acute liver injury. Such biomarkers are needed as current early biomarkers of liver injury lack sensitivity and specificity. The panel of biomarkers either have enhanced liver specificity or provide mechanistic insights. Currently, antituberculosis drug-induced liver injury (ATDILI) is the most frequent side-effect of anti-tuberculosis therapy and this hinders the effective treatment of TB, as it means that treatment regimens are not completed. At present, the risk of ATDILI means that monitoring of liver function is required, with levels of ALT measured monthly. If levels of ALT rise to 2-5x the upper limit of normal levels (ULN) and the patient is unwell the frequency of monitoring is increased to biweekly monitoring. Antibiotic therapy is only changed if levels of ALT remain greater than 3xULN, the patient continues to display symptoms and there is a positive causality assessment that the anti-tuberculosis drugs are causing ATDILI. This project will recruit patients taking antituberculosis drugs and determine the diagnostic and prognostic value of the biomarker panel, in relation to liver injury as a result of anti-tuberculosis therapy.