Question

1. A 27-year-old male comes to the clinic complaining of rash and puffiness around the eyes. On examination he is well built, blood pressure 146/96 mm Hg (normally 120/80 mm Hg), pulse 82 beats per minute. There is an erythematous malar (red) rash present on the face. Further investigation of his renal function shows serum creatinine 5 mg/mL (normal 0.7 -1.3 mg/mL) and blood urea nitrogen BUN 40 mg/mL (normal 5 - 20 mg/mL). Both creatinine and BUN are waste products in the blood that are indicators of kidney function in which elevated values suggest impaired kidney function. Urine analysis shows evidence of few casts (cellular debris), no white blood cells, no pus or bacteria. His serum is positive for ANA (anti-nuclear antibody complexes). The presence of ANA suggests that antibody complexes are not being cleared from the blood. 101) Which complement defect in this patient is most likely leading to this presentation? Circle the correct answer. (2 points extra for multiple choice) A. C2/C4 deficiency B. Properdin factor D deficiency C. C5-C9 complex deficiency D. Decay accelerating factor (DAF) deficiency E. Complement receptor deficiency 1 (ii) Justify your selection using complete sentences (4 points extra): 1 (ii) One function of the kidney is to filter the blood. What might explain why the kidney function is compromised? Use complete sentences (4 points extra).

Answer 1

i)C2/c4 deficiency is most likely as clinical presentation in the case resembles to systemic lupus erythromatosus.

ii) Complement proteins are an important part of our immune system but deficiency of c3 and c4 complement protein is associated with sle, an autoimmune disorder in which body takes its own orgzns as antigen and fight against them.

whereas properdin deficiency is linked to neisseria infections, DAF deficiency with CHAPLE syndrome.