Introduction Individuals with end stage renal disease (ESRD) undergoing renal replacement therapy (RRT) are at increased risk of tuberculosis (TB). Timely identification and treatment of latent TB infection (LTBI) reduces the risk of progression to active disease. Diagnosing LTBI is challenging in ESRD as standard tests, such as the tuberculin skin test (TST) and Interferon Gamma Release Assay (IGRA) are less reliable. Although TB guidelines exist for ESRD they acknowledge a lack of evidence base and are limited in their scope.
This study aimed to establish the current LTBI screening and treatment practice in patients of RRT in a central London teaching hospital with the hypothesis that there would be a varied approach with overall low levels of screening.
Methods New starters on haemodialysis (HD) in the year 2010 were identified from computerised renal databases and information collected on; demographics, renal diagnosis, co-morbidities, dialysis attributes, TB risk factors, screening methods and LTBI treatment. All patients were followed for a period of 5 years to establish the rate of active TB after commencing RRT. Screening was considered to have taken place if any of the following were performed irrespective of symptoms of active disease; TST, IGRA, radiography specifically to investigate for TB or documented risk stratification.
Results Of the 331 eligible patients only 77 (23.2%) received screening. In those who were screened, 13 (16.9%) were diagnosed with active TB equating to an incidence of 3927/100,000, 37 (48.1%) with latent TB and 27 (35.1%) with neither. Risk factor stratification was the commonest modality of LTBI identification although there were a wide variety of approaches. Chemoprophylactic treatment regimes were non-standardised and often based on clinical experience rather than guidelines. Of those with active infection, disease developed most commonly within the first year of starting HD.
Conclusion High rates of active TB occur mainly within the first year of RRT. There is a lack of a uniform approach to detecting and treating LTBI in this population currently. Risk stratification and the use of immunological tests may offer the most sensitive approach to screening ESRD and within the first year of RRT.