Reference no: EM133572332

Case Study #4: Lee is a 49-year-old woman who had been feeling weak and easily fatigued for several months, during which time her appetite had diminished and she had lost weight. She also experienced vague limb pain and felt stiff in the morning for an hour or more. Although this brought her concern, she didn't report her symptoms until she noticed that some of the joints in her hands and her wrists were swollen and reddish, and that her joints started to hurt when she moved them after inactivity. The physician noticed that the affected joints were the same on both sides of the body and noted subcutaneous nodules associated with some of the affected joints. She further observed swelling around the knee and ankle joints and mentioned that Lee's skeletal muscles appeared somewhat atrophied. The physician ordered X-rays, a blood test for rheumatoid factors, a complete blood cell count, and an erythrocyte sedimentation rate test.

Lee displayed synovitis of several joints in the wrists, hands, knees, and ankles that was present on both the right and left sides of her body. She had weakness, muscle atrophy, and other systemic symptoms that could be related to proinflammatory cytokines-particularly tumor necrosis factor (TNF), interleukin-1, and interleukin-6-released from the inflamed synovial joints. Her X-rays confirmed the involvement of the same joints on both sides of her body. Her erythrocyte sedimentation rate, a nonspecific measure of inflammation, was abnormally fast; she also had a mild anemia (low red blood cell count) known as normochromic normocytic anemia, which is often seen in people with joint inflammations. Her test for rheumatoid factors, which are IgM antibodies that target the Fc portion of IgG antibodies, was abnormally elevated. The physician told Lee that she was prescribing rest and physical therapy and recommend aspirin until Lee mentioned that she had a history of gastritis. The physician said that she would instead prescribe an NSAID that was a selective COX-2 inhibitor. She stated that glucocorticoid drugs may be needed later.

Questions

1. What is the Fc portion and the Fab portion of an antibody?

2. What is normochromic normocytic anemia? Given this form of anemia, what is the potential cause of anemia in Lee's case?

3. Briefly describe the type II and type II isoforms of the cyclooxygenase enzyme.

4. What is an NSAID and why did the physician prescribe a selective COX-2 inhibitor when learning of Lee's history with gastritis?

5. What are glucocorticoids, and why might they be of value in treating inflammatory diseases?

6. Following the rheumatoid factor blood test, Lee's physician decides to run a cyclic citrullinated peptide (CCP) assay. Why is this a good choice and what is the CCP assay measuring?