Question

A 25-year-old female patient, Roseann Hough, went to emergency room complaining of abdominal pain and swollen legs and hands. She was vomiting severely. She said that she has had this symptoms on several previous occasions. The ER physician ruled out appendicitis, and ordered more testing including complement components. The following results were obtained: • RBC and WBC count - normal • Total serum protein - normal • CH50 - decreased • Alternate pathway function - normal • C3 level – normal • C4 level – decreased • C2 level – decreased

1. What symptoms led the physician to consider a possible complement abnormality?
2. What are possible reasons for decrease in both C4 and C2?
3. What other testing would you confirm your suspicion?

Answer 1

a.The symptoms experienced by the patient in several previous occasions led the physician to order for complement test.This test is done usually to assess for any signs of microbial or bacterial infection which can cause repeated infections

b. A decrease in C2 level can be because of Hereditary Angioedema in which the swelling can be seen in extremities and acute abdominal pain can occur. A C4 level decrease can be a sign of autoimmune disorder or collagen vascular disease.

c.The other test needed for confirmation of the suspicious are

• C4 level can be used to confirm Angioedema
• ANA to rule out autoimmune disorder
• RA to rule out rheumatoid arthritis