With the Anti-TNF alpha Inhibitor ELISA, antibodies against drugs in the rheumatism therapy (e.g. Enbrel®) can be detected. Drugs in the rheumatism therapy (e.g. Enbrel®) are used to suppress inflammation in rheumatic patients. During the therapy with drugs (e.g. Enbrel®), some patients can develop antibodies against the drug itself. This might lead to severe complications, even a systemic anaphylaxis with possibly lethal outcome.