What factors contribute to developing sle?

Unknown. Why the body attacks itself is a mystery however, some medications such as the antibiotic Doxycycline can cause drug- induced lupus. These reactions will typically resolve when the drug is stopped. Autoimmune disease often run in families suggesting that genetic factors are at play.
SLE. Lupus is an autoimmune disease. There is no way to "develop" lupus it is simply a disease where antibodies in our body recognize the body as "foreign" leading to the immune system turning on itself. A rheumatologist is the best to discuss sle.