Anti-TNF-alpha Trough Level Measurements in Inflammatory Bowel Disease

Crohn´s disease and ulcerative colitis are diseases where the proinflammatory cytokine Tumor Necrosis Factor-alpha (TNF) plays an important role. Anti-TNF agents are used in the treatment. However, some patients do not respond and response rates declines over time. The cause may be immunogenicity against the agent itself, the agent´s failure to neutralize TNF or another biological pathway leading to inflammation. Anti-TNF agents have been administrated as fixed doses at certain frequencies and this may not be optimal for all patients, but recent studies have indicated a correlation between efficacy and serum drug concentration levels (trough levels). Our preliminary data suggest that trough levels early in the treatment course may be predictive of later trough levels. By multiple measurements, this will be assessed. The study will also investigate biological markers in serum and blood cells which may be predictable for trough levels. Finally, we will compare different methods to measure serum drug concentrations.