The curiously suspicious: infectious disease may ameliorate an ongoing autoimmune destruction in systemic lupus erythematosus patients.

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease, which can arise from a combination of genetic and environmental factors. In the past, infections (Epstein Barr virus, parvovirus B-19) have been indicated to play a causative role in the development of autoimmune diseases, such as SLE. On the other hand, with the emergence of the "hygiene hypothesis" infections have also shown to play a protective role in autoimmune diseases. Two case studies are presented which provide clinical evidence of SLE patients with severe, long-term disease, despite immunosuppresive therapy. The course of both diseases changed remarkably after they experienced infections with multiple microbes (bacterial, viral and fungal). Surprisingly, their clinical and laboratory signs of SLE normalized and they are now symptom-free after 5 and 3year follow-ups. The second patient has even had a normal pregnancy, which was a trigger factor for disease flare in the past. The infections presumably changed the host immune systems and the mechanisms of their protective effects are most likely multifactorial. Our cases illustrate that infections could be beneficial in SLE patients and re-directing research toward novel innate-based SLE therapy should be explored.