Systemic lupus erythematosus

Systemic lupus erythematosis (SLE) is an autoimmune connective tissue disorder. While there is no cure, there have been major advances in its treatment in recent years. There are variants such as drug-induced lupus and discoid lupus.

Initial presentation

Symptoms can be diffuse, but one classical sign, not always present, is a "butterfly-shaped" rash centered on the nose.

Diagnosis

(CC) Image: Robert Badgett
Alternate criteria

Laboratory tests

A number of immunologic tests are useful in diagnosis, and some in following disease progress. While the "LE prep" microscopic examination of the 1940s is obsolete, the first screening test is the antinuclear antibody titer. When these are elevated, more specific but less sensitive tests come into play, such as anti-double-stranded DNA antibodies (dsDNA) and anti-Smith antibodies (Sm). Antihistone antibodies are elevated in drug-induced lupus.

Alternative criteria

Recursive partitioning has been used to identify more parsimonious criteria. This analysis presented two diagnostic classification trees:

1. Simplest classification tree: LSE is diagnosed if the patient has an immunologic disorder (anti-DNA antibodies, anti-Smith antibodies, false positive syphilis test, or LE cells) or malar rash.

• sensitivity = 92%
• specificity = 92%

2. Full classification tree: Uses 6 criteria.

• sensitivity = 97%
• specificity = 95%

Other alternative criteria have been suggested.

Treatment

The beginnings of treatment, in the 1950s, used crude antiinflammatory and immunosuppressants such as ACTH. The core of today's treatment, however, are specific monoclonal antibodies.