Below is an instruction from Human. Write a response.
    ### Instruction:
    How many people are affected by systemic lupus erythematosus ?
    ### Response:
    For unknown reasons, in industrialized Western countries SLE has become 10 times more common over the past 50 years. While estimates of its prevalence vary, SLE is believed to affect 14.6 to 68 per 100,000 people in the United States, with females developing SLE more often than males.
    