Interferon-alpha (IFN alpha) ELISA

The interferons represent proteins with antiviral activity secreted from cells in response to a variety of stimuli. In mammals, class I interferon (IFN) genes form a superfamily consisting of three gene families, the alpha interferon (IFN alpha), the beta interferon (IFN beta) and the interferon omega (IFN omega) genes. The interferons exhibit a huge number of biological effects. The antiviral activity led to the name interferon and serves to define the unit of interferon activity. On purification of the natural human leukocyte interferons (IFN alpha), it was found that all fractions that exhibited antiviral activity also exhibited anti-growth activity. This observation was confirmed with purified recombinant interferons and extended to other activities like: stimulation of cytotoxic activities of lymphocytes and macrophages, natural killer cell activity as well as increase in expression of some tumor-associated antigens. The antiproliferative and antitumor activities of interferon have led to the application as an antitumor agent. The interferons also modulate cellular differentiation. The role of IFNa as a disease marker and marker for immunotherapeutic approaches has been demonstrated for a number of different indications and pathological situations:

• During the acute phase of a viral infection IFN alpha levels are significantly elevated in the majority of patients. IFN alpha levels fall significantly during the period of convalescence at the time viral infection is indicated by seroconversion tests.
• Increased levels of IFNa were found in the majority of patients suffering from inflammatory arthropathies like juvenile polyarthritis, rheumatoid arthritis, ancylosing spondylitis, polychondritis, psoriatic arthritis, polymyalgia rheumatica and sclerodermia. Elevated IFNa levels have also been shown for other autoimmune disorders like systemic lupus erythematosus and systemic vasculitis.
• Serum IFN alpha levels can help to distinguish between children with non-specific abdominal pain or mesenteric adenitis, and those with acute appendicitis.
• For resistant local recurrence in e.g. breast cancer and metastatic spread local infiltration of IFN alpha is a new interesting approach. Intrapleurally administered interferon causes measurable serum concentrations which correlated with the degeneration of malignant cells.