Critical reviews of clinical data: Focus on T cell agents for the treatment of psoriasis

Background: Psoriasis is a common, chronic, inflammatory, multisystem disease with predominantly skin and joint manifestations. Patients with psoriasis also have an elevated risk of developing cardiovascular disease and recent evidence suggests an increased risk of mortality in patients with severe psoriasis. Discussion: Psoriasis is now recognized as the most prevalent T cell mediated disease in humans. This relatively recent understanding of the pathophysiology of psoriasis has led to the development of agents that address the underlying immunologic disease process and not just the external symptoms. Because psoriasis has no definitive cure to date, its treatment must be viewed much as the treatment for any life-long chronic disease, with the paramount goal being the maintenance of the patient's overall health and function for the long term. The likely need for long-term treatment of psoriasis makes it incumbent upon the clinician to be on the alert for evidence of adverse effects. Similarly, the need for chronic treatment means that the data of most value may be data regarding long-term benefits rather than merely short-term resolution of symptoms. Objective: Therefore, this review critically examines the available studies of T cell agents focusing on long-term data and evaluating study parameters to fairly assess their relevance to clinical practice. Conclusion: There are no current data elucidating whether therapies that target the underlying immunologic process that leads to psoriatic skin lesions will also provide some clinical benefit in terms of prevention of the other systemic diseases linked to psoriasis, such as rheumatoid arthritis, Crohn's disease, inflammatory bowel disease and also cardiovascular disease, which is a promising area for future investigation.