Systemic lupus erythematosus: Is it one disease?

Systemic lupus erythematosus (SLE) is a multisystemic disease with a variety of clinical presentations. Monogenic predisposing conditions to the development of this disease have been described. As examples, an impaired expression of interferon-α regulated genes or complement deficiencies have been reported in patients with SLE, with particular clinical presentations. Those defects present particular presentations and a different severity, making an argument that lupus is not a single disease but many. Treatment could be individualized depending on the underlying defect generating the subtype of the disease.