Is sle a serious type of disease? recently my sister was diagnosed with this disease, but the biopsy is yet to be conduct.

Sometimes: There are different types of lupus. Some basically just involve the skin. Another form is systemic and has the potential for involvement of various internal organs. Your sister should get an rheumatology consultation if she has not done so already.

Yes: Sle is systemic lupus. It is diagnosed based on a certain number of symptoms, signs and labs on a checklist. A biopsy can be very suggestive if positive for lupus but less helpful in ruling it out unless it shows another illness. I am glad you are there for your sister; as her sister, you have have only a moderately increased chance of coming down with the illness yourself.