Abstract
In March 2009 was the beginning of an epidemic flue caused by avian influenza A virus H1N1. The disease varies from mild to serious and fatal cases. There are many hypotheses explaining why this virus infection would be fatal. One of these is the impaired immune response of the infected patient. The use of tumor necrosis factor-alpha inhibitors may cause decreased immune response and greater susceptibility to infections. We presented a case of a patient using adalimumab that have developed H1N1 without complications. This is the first case of H1N1 in a patient using adalimumab reported in Brazil. We discuss the possibility that anti-TNF may not predisposes to a serious form of the disease or fatal complications.