Biological therapies in the treatment of inflammatory disease and cancer: impact on pulmonary infection

Biological therapies are increasingly used for the treatment of inflammatory conditions in the realms of rheumatology, dermatology, and gastroenterology due to their ability to target specific cytokines in the inflammatory cascade. The impact of these biologic therapies is immunosuppression leading to an increased risk of infection. This review focuses on commonly used biologic agents in the treatment of inflammatory conditions and cancer and their impact on pulmonary infections. We have summarized potential pathogens in this group of patients. The hope being that this will increase awareness and therefore prevention timely diagnosis and successful treatment of patients receiving biologic therapies. It is also important to note that it is not solely the choice of an agent that predisposes to particular infections. Concomitant factors that might increase an individuals' risk of contracting an infection include the underlying disease, comorbid diseases, increased age, and other medical treatment as well as exposure to opportunistic pathogens. In the treatment of cancers many immunotherapies are being developed. The most notable adverse effects from immunotherapy are due to stimulation of the immune response, and these may mimic infection by causing flu-like symptoms and breathlessness due to pneumonitis. The treatment of this is immunosuppression, further leading to an increased risk of infection. Biologic therapies have been a revolution in the treatment of inflammatory conditions and cancers. They have improved outcomes and quality of life for patients. However, the use of these drugs needs to be balanced against the risk of infection and every patient needs to be assessed on an individual basis.