Dean of the College of Medicine, University of Sharjah
Cytokines are immune-mediators that are secreted mostly by inflammatory cells and play an important role in mediating cross talk between various inflammatory and structural cells. Cytokines have been implicated in the pathophysiology of a number of chronic inflammatory diseases including rheumatoid arthritis, Diabetes and asthma. Asthma is a very common inflammatory disease of the airways that affect pediatric and adult population. The incidence of asthma is increasing all over the world including the Gulf Countries. Two cells play a vital role in the inflammatory response to antigens in asthma including T cells and eosinophils. Both are increased in asthmatic lungs and were shown to be highly activated. IL-5 is one of the early cytokines that was described by our group to be increased in asthma. This cytokine is mainly produced by Th-2 cells and was shown in vitro to be essential for the differentiation, activation and survival of eosinophils. Animal studies using antigen challenge models have demonstrated that over expression of this cytokine is associated with increased number of eosinophils and enhanced responses to allergen challenge. On the other hand IL-5 knockout mice failed to respond to allergen challenge and have decrease number of eosinophils in the lung. A number of groups including our group have confirmed the role of eosinophils in asthma and suggested that, elimination and deactivation of eosinophils from the lung of asthmatics might be a new therapeutic approach for this disease especially for patients who do not respond to steroids. In the last 15 years many clinical trials were performed using antibodies to IL-5 were conducted. The early studies failed to show positive response. However with the introduction of biomarkers and personalised medicine, it was shown recently that selecting patents on the basis of high eosinophil count is associated with positive clinical response particularly in severe eosinophilic asthmatic subjects. Initial studies was followed by large number of placebo controlled trials that confirmed the effectiveness of the anti IL-5 antibodies. recently anti IL-5 antibody therapeutic approach was approved by the FDA and is currently in clinical practice. In this talk I will discuss our experience in the last 20 years of IL-5 discovery, and translational studies that resulted in putting IL-5 on the guidelines for asthma management.