not clear if these actually lead to the development of SLE or just occur concomitantly.
Lupus may also develop as a result of exposure to various medications. Up to 10% of patients presenting or diagnosed with SLE may actually have DILE, and approximately 80 drugs have been implicated in causing DILE. The vast majority of these drugs, however, only have a handful of case reports.8–10 Table 1 lists common medications known to induce DILE. Some biologic medications have also been implicated in the development of DILE. Ramos-Casals and colleagues found 92 case reports of DILE between 1990 and 2006, in patients who had been treated with infliximab (n=40), etanercept (n=37), and adalimumab (n=15).19
Several mechanisms have been implicated in DILE, including genetics and auto-antibody production. Agents such as procainamide, hydralazine, and isoniazid generally cause DILE in patients with genetic abnormalities. These medications all undergo acetylation as part of their metabolism, so patients who are slow acetylators tend to have more problems with DILE compared with those who have normal or fast acetylation. Another potential cause of DILE involves hapten-like reactions where the drug or its metabolites bind to proteins rendering them foreign to the body. This in turn leads to an autoimmune response by the body. Other drugs, like the anti-TNF agents, are thought to produce auto-antibodies by causing direct damage to the immune system.8–10