A research paper which is seeking to explain the symptoms of a disease, or the progression of a disease can be done with a question like, "How does (name the disease) affect the body?" but a better wording might be:
"What are the symptoms of (disease)?"
"How is (disease) diagnosed?"
However, that sort of descriptive paper is not really a research paper that investigates a question about a disease or health condition which does not have an already-agreed-upon answer. The second question, "What causes Lupus?" can be a good research question if the disease is not completely understood. Since Lupus is an auto-immune disease and since there is still research being done to understand all of the causes, that question would work well. Here are some other research questions which can be used for a health condition:
What is the most effective treatment for (disease or condition)?
Do alternative therapies (you could name a specific one) really work for (disease or condition)?
What genetic or environmental risks make people vulnerable to (disease or condition)?