Review Question - QID 102721

This patient is presenting with joint pain, a malar rash, and kidney disease suggesting a diagnosis of systemic lupus erythematosus (SLE). In patients with SLE, the level of anti-dsDNA antibody can be used to monitor disease activity.

SLE is characterized by the production of auto-antibodies that, along with immune complex formation, cause the multi-organ manifestations of the disease. One such auto-antibody is anti-dsDNA. Anti-dsDNA has high specificity for SLE and is rarely found in the presence of other autoimmune conditions. There is an especially strong correlation between IgG anti-dsDNA and glomerulonephritis in the context of SLE. Serum C3 and C4 levels are also used to track SLE disease activity. The diagnosis of SLE should be suspected when a patient presents with symptoms including serositis, oropharyngeal ulcers, anti-nuclear antibodies (ANA), photosensitivity (including a malar or discoid rash), hemolytic anemia, kidney disease among many other possible presenting symptoms.

Figure A is the butterfly/malar rash seen in SLE.

Incorrect Answers:
Answers 1 & 5: Anti-CCP is a more specific antibody found in rheumatoid arthritis when compared to rheumatoid factor. Rheumatoid arthritis would present with symmetric arthritis which is worse in the morning and improves throughout the day. Other findings could include malaise and anemia of chronic disease. This patient's arthralgias in the setting of kidney disease and a malar rash suggest a diagnosis of SLE.

Answer 3: Anti-nuclear antibody (ANA) is useful in the initial diagnosis of SLE but is not used to track disease progress. It may be the most appropriate initial step in management when considering a diagnosis of SLE but does not monitor disease progress.

Answer 4: Anti-topoisomerase could be elevated in scleroderma which presents with taut skin, sclerodactyly, interstitial lung disease, GERD, small bowel bacterial overgrowth, and kidney disease.

Bullet Summary:
Anti-dsDNA can be used to monitor flares in SLE.