The Use of Interferons in Respiratory Diseases

Interferons (IFNs) are a subclass of lymphocyte-released cytokines that interfere with intracellular viral replication. These drugs are classified into three groups: IFN type 1 (IFN-alpha, IFN-beta, and IFN-omega), IFN type 2 ( IFN-gamma), and IFN type 3 (IFN-lambda). Despite numerous trials, IFN therapy has yet to conclusively demonstrate superiority in the treatment of various pulmonary diseases. In addition to the FDA-approved and ongoing investigational uses for IFN therapy, there is a debate regarding the appropriate dosage of these agents. A retrospective literature review is moving experts towards low-dose therapies in nearly every application of IFN therapy. It is speculated that known and unknown toxicity may limit the beneficial effects of IFN therapy.