ACR SLE classification criteria modified by SLICC in 2009 Clinical criteria: ① acute or subacute cutaneous lupus; ② chronic cutaneous lupus; ③ oral and nasal ulcers; ④ hair loss, non-scarring; ⑤ arthritis; ⑥ pluritis: pleurisy and pericarditis; ⑦ renal lesions: urine protein/creatinine ratio >0.5mg/mg, or 24-hour urine protein >0.5g/d, or with erythrocyte tubularity (8) neuropathy: seizures or psychosis, polyneuritis mononeuritis, myelitis, peripheral or cerebral neuropathy, encephalitis; (9) hemolytic anemia; (10) leukopenia (at least 1 < 4.0×109/L) or lymphopenia (at least 1 < 1.0×109/L); (11) thrombocytopenia (at least 1 < 100< span="">×109/L). Immunological criteria: (1) ANA titer above reference standard; (2) anti-dsDNA titer above reference standard (≥ 2 times required for ELISA); (3) anti-Sm positive; (4) antiphospholipid antibodies: lupus anticoagulant positive/syphilis serologic test false positive/anti-cardiolipin antibodies above 2 times normal or elevated anti-β2GPI above medium titer; (5) hypocomplementation: C3/C4/ CH50; (6) no hemolytic anemia but positive Coombs test Patients are classified as SLE if they meet at least one of the following criteria: 1. there is biopsy-proven lupus nephritis with positive ANA or positive anti-ds-DNA; 2. the patient meets four of the classification criteria, including at least one clinical criterion and one immunological criterion Applying this criterion in enrolled patients Patients were more sensitive than the ACR criteria (94% vs. 86%) and had approximately the same specificity as the ACR criteria (92% vs. 93%), with a significant reduction in misclassification.