Systemic lupus erythematosus (SLE) is a systemic autoimmune disease, where different organs and tissues can be affected due to attacks by the immune system, resulting in various clinical manifestations. Some manifestations are typical and characteristic of SLE, such as a butterfly-shaped rash on the face or photosensitivity. However, some manifestations are not specific and can resemble symptoms of other diseases, such as hair loss, fever, and joint pain. To reach an accurate diagnosis, patients must undergo clinical examinations and laboratory tests. 

Whether it is the early American College of Rheumatology (ACR 1982, revised 1997) criteria or the more recent Systemic Lupus International Collaborating Clinics (SLICC, 2012) criteria, the classification of SLE is determined based on the classification criteria. These criteria involve evaluating clinical manifestations from different organs, combined with serological or immunological tests, to make a diagnosis. This emphasizes that we cannot rely solely on individual symptoms or blood test results to confirm or exclude a diagnosis of SLE. 

These classification criteria were initially developed for medical research and patient recruitment purposes but also hold value in everyday clinical diagnosis. The SLICC criteria, published in 2012, present 17 criteria for diagnosing SLE, including clinical examinations (11 criteria) and immunological tests (6 criteria). If a patient meets four or more criteria, with at least one criterion from each category, a diagnosis of SLE can be made. 

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