Review Question - QID 217769

This patient who presents with hand stiffness, knee pain, and enlarged metacarpophalangeal joints most likely has rheumatoid arthritis with an associated increase in her erythrocyte sedimentation rate (ESR). Interleukin-6 can cause an increased ESR through increased production of acute-phase proteins by the liver.

The ESR is a sensitive but not specific test of inflammatory activity in patients, especially those with rheumatological disease. The ESR will increase when increased expression of pro-inflammatory cytokines results in the production of reactive proteins such as fibrinogen by the liver. These proteins cause increased cross-linking between adjacent cells and result in precipitation at a faster rate in ESR testing than in patients without such inflammatory conditions. The most common causes of increased ESR include autoimmune diseases (e.g., rheumatoid arthritis, polymyalgia rheumatica, systemic lupus erythematosus), infection, vasculitis, and cancer. The most common signaling molecules that cause increased ESR are interleukin-1, interleukin-6, and tumor necrosis factor alpha.

Scapaticci et al. studied whether ESR and interleukin-6 could serve as useful markers for response to therapy in patients with rheumatoid arthritis. They found that ESR is more effective than interleukins as a marker of response. They recommend following the ESR during treatment and response.

Incorrect Answers:
Answer 1: Interleukin-2 stimulates the growth and survival of T-cells and natural killer (NK) cells. It is important in activating the adaptive cellular immune response to infection.

Answer 2: Interleukin-4 induces the differentiation of helper T-cells into Th2 subtype cells. It also promotes the growth of B-cells and enhances class switching to IgG and IgE. Together, these responses increase the ability of the immune system to produce a humoral immune response.

Answer 4: Interleukin-8 stimulates chemotaxis by neutrophils to sites of infection. This response recruits cellular components of the innate immune response but does not result in the production of acute-phase reactants.

Answer 5: Interleukin-10 decreases the inflammatory response by inhibiting macrophages and dendritic cells as well as the expression of major histocompatibility complex (MHC) molecules and Th1 cytokines. It would have the opposite effect on ESR by dampening the immune response.

Bullet Summary:
The most common signaling molecules that result in increased erythrocyte sedimentation rate are interleukin-1, interleukin-6, and tumor necrosis factor alpha.