| Rheumatoid arthritis is the most common inflammatory | | | | acute inflammation to chronic inflammation. IL-6 seems |
| form of arthritis. It is a chronic, systemic autoimmune | | | | to do this by stimulating B-cells, T-cells, and attracting |
| disease that affects more than 2 million Americans. | | | | cells that aggravate inflammation into the synovium. |
| The aim of therapy for this disease has been to help | | | | IL-6 also transforms cells from a less aggressive state |
| with symptoms, slow down progression, and possibly | | | | into a more aggressive state. |
| effect remission. | | | | Even more interesting is the theory advanced by Dr. |
| Rheumatologists usually use non-steroidal anti | | | | Gary Firestein at the University of California, San |
| inflammatory drugs (NSAIDS) or low doses of | | | | Diego, who posits that "IL-6 plays a significant role in a |
| corticosteroids to help with symptoms. To slow down | | | | primitive broad-based immune response." |
| disease, they employ disease-modifying anti-rheumatic | | | | A substantial role for IL-6 involvement in the |
| drugs (DMARDS). Examples of DMARDS are drugs | | | | development of diabetes, obesity, cardiovascular |
| such as hydroxychloroquine (Plaquenil), sulfasalazine | | | | disease, infections, and even cancer has been |
| (Azulfidine), leflunomide (Arava), and methotrexate. By | | | | demonstrated. The presence of an IL-6 footprint in all |
| far, the "workhorse" DMARD is methotrexate. | | | | these disorders implicates immunity as a causative |
| In recent years, biologic drugs have been added to the | | | | factor and secondarily points out the key role that IL-6 |
| therapeutic armamentarium. Biologic drugs are laser-like | | | | plays in these diseases. |
| drugs that target the immune pathway abnormalities in | | | | Another interesting note is the effect IL-6 plays in |
| RA. Medicines that target tumor necrosis factor, a | | | | anemia. It apparently decreases the absorption of iron |
| particularly important instigator of chronic inflammation | | | | from the bowel and affects the storage of iron. This |
| include drugs such as etanercept (Enbrel), infliximab | | | | may explain why patients with severe inflammatory |
| (Remicade), and adalimumab (Humira). | | | | disorders such as rheumatoid arthritis often develop |
| Other biologic therapies target B-cells (Rituxan) or | | | | what is called the anemia of chronic disease. Unlike iron |
| T-cells (Orencia). | | | | deficiency anemia which is due to lack of iron and |
| What many of these biologic therapies have in | | | | which may be due to side effects of drugs, the |
| common is the ability to shut down the production of | | | | anemia of chronic disease is due to the inflammation |
| cytokines, the chemical messengers that promote | | | | stemming from RA. |
| inflammation. Tumor necrosis factor is a prime | | | | Attempts to target IL-6 have recently been successful |
| example of a cytokine that perpetuates inflammation. | | | | with the use of an antibody directed against receptors |
| There are many other cytokines that also play | | | | for IL-6. In other words, the linking sites for IL-6 on |
| important roles in inflammation. | | | | different cells are blocked by an antibody. This |
| Interleukin-6 (IL-6) is a cytokine that also appears to | | | | prevents the IL-6 from attaching to different cells and |
| play a pivotal role in the inflammation of rheumatoid | | | | causing damage. |
| arthritis. new potentially very effective treatment. IL-6 is | | | | The most prominent IL-6 receptor antibody that has |
| ubiquitous inside the joint and is expressed by almost | | | | been studied is a drug called tociluzumab (Actemra). |
| 20 per cent of cells inside the synovial capsule (lining of | | | | Clinical trials are ongoing at the time of this article (late |
| the joint). It appears to be pivotal in the transition from | | | | 2007). |