Part of this response involves the release of interleukins, which are any of a class of lymphokines. Lymphokines are also known as cytokines or non-antibody proteins that the immune system uses as intercellular mediators. In the overstimulated immune system associated with psoriasis, cytokines send messages to skin cells to reproduce and mature at a much faster rate than normal. In the case of psoriatic arthritis, cytokines draw white blood cells into the joints, which results in a painful swelling of the joints and of the hands and feet. This process can also lead to inflammation in body tissues, such as the tendons and cartilage, and in the eyes, heart, lungs and kidneys. The cytokines also cause the recruiting and activation of additional T-cells, and the release of more cytokines, which continues the vicious cycle.
Since the role of the immune system was identified, treatments that suppress its destructive behavior have been used with success. Cyclosporine, normally given to prevent the rejection of a transplanted organ, and methotrexate, which is commonly indicated for cancer patients, are two immunosuppressive drugs that have been used to suppress some of the inflammatory reactions that are associated with psoriatic arthritis. However, these medicines also impact the immune system’s ability to fight infection, and they have other serious side effects.
As doctors have learned more about how the immune system functions, they have been able to target the actual mechanisms that cause specific immune responses, rather than targeting the entire immune system.
