Is there any other disease/condition which cause leukocytes in urine other than uti ?

Yes: Elevated white cells in the urine do not specifically mean urinary tract infection. The urine can have elevated white cells associated with other problems. For example: appendicitis, pelvic infection, diverticulitis or other inflammatory conditions inside the body can elevate white cells in the urine. If you are having abdominal pain get checked.

AIN, bladder CA: Leukocytes are not seen in the urine routinely and can be a sign of inflammation or infection or abnormal cells anywhere within the urinary tract.