To test or not to test? An updated evidence-based assessment of the value of screening and monitoring tests when using systemic biologic agents to treat psoriasis and psoriatic arthritis

Background Safety profiles of systemic biologic agents for the treatment of psoriasis and psoriatic arthritis (PsA) encompass a wide spectrum of adverse events. To date, no uniform evidence-based guidelines exist regarding screening and monitoring patients who are undergoing biologic therapy. Objective We sought to identify studies evaluating screening and monitoring tests in the treatment of psoriasis and PsA with systemic biologic agents, and to propose evidence-based practical guidelines. Methods The MEDLINE database was searched to identify data on risks associated with adalimumab, etanercept, infliximab, and ustekinumab. Articles were reviewed and graded according to methods developed by the US Preventative Services Task Force. Results Evidence was strongest (grade B) for tuberculosis screening. Interferon-gamma release assay was preferable to tuberculin skin testing. Among known hepatitis B virus carriers, the evidence grade was C for monitoring liver function tests and viral load. Limitations This study was limited by the lack of high-quality controlled trials evaluating screening and monitoring tests in patients treated with biologic agents. Conclusions Baseline tuberculosis testing remains the only screening test with strong evidence to support its practice. Other screening and monitoring tests commonly performed in patients who are taking biologic agents are supported only in certain clinical settings or lack evidence to support or recommend against their practice.