A 30 year old woman presents to a physician with rather non-specific complaints of fatigue, malaise, low-grade fever, and ahralgias. Screening serum chemistries demonstrate an elevated BUN. The urine shows proteinuria. Testing for which of the following will be most helpful for making the diagnosis?
High-Yield Explanation
Systemic lupus erythematosus is a orite on board examinations, and should be considered in any 15- to 45-year-old woman with chronic, poorly defined symptoms. Clues that help are malar rash, anti-double-stranded DNA antibodies, and renal involvement. Antinuclear antibody is a good screening test (it is also positive in some other autoimmune diseases) and should be used first in working this patient up. Renal involvement is unusual in most other autoimmune diseases. Anticentromeric antibody is a marker for the CREST form of scleroderma. Antimitochondrial antibody is a marker for primary biliary cirrhosis. Anti-TSH receptor antibody is a marker for Graves' disease. Ref: Hahn B.H. (2012). Chapter 319. Systemic Lupus Erythematosus. In D.L. Longo, A.S. Fauci, D.L. Kasper, S.L. Hauser, J.L. Jameson, J. Loscalzo (Eds),Harrison's Principles of Internal Medicine, 18e.