A Prospective Study of Cyclophosphamide in Systemic Lupus Erythematosus Treatment

Inclusion Criteria: * The American College of Rheumatology established eleven criteria in 1982,which were revised in 1997 as a classificatory instrument to operationalise the definition of SLE in clinical trials. 1. Malar rash (rash on cheeks). 2. Discoid rash (red, scaly patches on skin that cause scarring). 3. Serositis: Pleurisy (inflammation of the membrane around the lungs) or pericarditis (inflammation of the membrane around the heart). 4. Oral ulcers (includes oral or nasopharyngeal ulcers). 5. Arthritis: nonerosive arthritis of two or more peripheral joints, with tenderness, swelling, or effusion. 6. Photosensitivity (exposure to ultraviolet light causes rash, or other symptoms of SLE flareups). 7. Blood-hematologic disorder-hemolytic anemia (low red blood cell count) or leukopenia (white blood cell count\<4000/µl), lymphopenia (\<1500/µl) or thrombocytopenia (\<100000/µl) in the absence of offending drug. Hypocomplementemia is also seen, due to either consumption of C3 and C4 by immune complex-induced inflammation or to congenitally complement deficiency, which may predispose to SLE. 8. Renal disorder: More than 0.5 g per day protein in urine or cellular casts seen in urine under a microscope. 9. Antinuclear antibody test positive. 10. Immunologic disorder: Positive anti-Smith, anti-ds DNA, antiphospholipid antibody, and/or false positive serological test for syphilis. Presence of anti-ss DNA in 70% of cases (though also positive with rheumatic disease and healthy persons). 11. Neurologic disorder: Seizures or psychosis. For the purpose of identifying patients for clinical studies, a person has SLE if any 4 out of 11 symptoms are present simultaneously or serially on two separate occasions. In the meantime, the case has one of the following conditions or more; <!-- --> 1. HIV (-); 2. Signed the informed consent; 3. Taking contraceptive measures during treatment period. Exclusion Criteria: * Poor compliance; * With lupus mental damage complication, occurrence of epilepsy or unable to express subjective symptoms during the observation period. * Taking drugs that affect cytochrome P450 2B6, cytochrome P450 3A4 and cytochrome P450 2C19, except corticosteroids. * Abnormal liver function.