[Interpretation of tuberculosis and hepatitis screening before immunosuppressive treatment]

An unrecognized latent tuberculosis infection (LTBI) may be reactivated under immunosuppressive therapy and become life threatening. Diagnosing LTBI requires the combination of targeted patient history and physical examination with the results of an interferon-gamma release assay (IGRA) and in addition, a chest X‑ray is needed to rule out active tuberculosis. Established therapies for LTBI reduce the reactivation risk by approximately 80%. For the initial screening of an HBV infection HBsAg and anti-HBc are determined. Hereby, HBsAg carriers (high HBV reactivation risk, indications for antiviral prophylaxis) and serologically resolved HBV infections (low HBV reactivation risk, use of prophylaxis only in high-risk immunosuppression) can be reliably detected. A previously unrecognized HCV infection, with an increased risk of developing liver cirrhosis during immunosuppression, can be detected in screening by anti-HCV antibodies and be successfully treated with antivirals without interferon.