Informed consent and biological agents in rheumatology and internal medicine.

The reported association between biological agents and serious infections or malignancies, including reactivation of latent tuberculosis, needs specific disclosure in informed consent acquisition, together with information about the possible efficacy in clinical contexts often characterized by resistance to previous treatments. Ethical and clinical issues bound to the need for experimenting with new agents with potentially serious adverse effects deserve specific attention. Studies aimed at evaluating mental capacity to consent in subjects receiving biological agents are required.