However, these criteria were primarily established for use in scientific research, including selection for randomized controlled trials, which require higher confidence levels. As a result, many people with SLE may not meet the full ACR criteria. Criteria
The American College of Rheumatology (ACR) established eleven criteria in 1982, which were revised in 1997 as a classificatory instrument to operationalise the definition of SLE in clinical trials. They were not intended to be used to diagnose individuals and do not do well in that capacity. For the purpose of identifying people for clinical studies, a person has SLE if any 4 out of 11 symptoms are present simultaneously or serially on two separate occasions. Malar rash (rash on cheeks); sensitivity = 57%; specificity = 96%. Discoid rash (red, scaly patches on skin that cause scarring); sensitivity = 18%; specificity = 99%. Serositis: Pleurisy (inflammation of the membrane around the lungs) or pericarditis (inflammation of the membrane around the heart); sensitivity = 56%; specificity = 86% (pleural is more sensitive; cardiac is more specific). Oral ulcers (includes oral or nasopharyngeal ulcers); sensitivity = 27%; specificity = 96%. Arthritis: nonerosive arthritis of two or more peripheral joints, with tenderness, swelling, or effusion; sensitivity = 86%; specificity = 37%. Photosensitivity (exposure to ultraviolet light causes rash, or other symptoms of SLE flareups); sensitivity = 43%; specificity = 96%. Blood—hematologic disorder—hemolytic anemia (low red blood cell count), leukopenia (white blood cell count<4000/µl), lymphopenia (<1500/µl), or low platelet count (<100000/µl) in the absence of offending drug; sensitivity = 59%; specificity = 89%.
In addition, differences in GnRH signalling have also been shown to contribute to the onset of SLE. While females are more likely to relapse than males, the intensity of these relapses is the same for both sexes.In addition to hormonal mechanisms, specific genetic influences found on the X chromosome may also contribute to the development of SLE. Studies indicate that the X chromosome can determine the levels of sex hormones. A study has shown an association between Klinefelter syndrome and SLE. XXY males with SLE have an abnormal X–Y translocation resulting in the partial triplication of the PAR1 gene region. Changing rate of disease
The rate of SLE in the United States increased from 1.0 in 1955 to 7.6 in 1974. Whether the increase is due to better diagnosis or an increased frequency of the disease is unknown. History
The history of SLE can be divided into three periods: classical, neoclassical, and modern. In each period, research and documentation advanced the understanding and diagnosis of SLE, leading to its classification as an autoimmune disease in 1851, and to the various diagnostic options and treatments now available to people with SLE. The advances made by medical science in the diagnosis and treatment of SLE have dramatically improved the life expectancy of a person diagnosed with SLE. Etymology
There are several explanations ventured for the term lupus erythematosus. Lupus is Latin for "wolf", and "erythro" is derived from ερυθρός, Greek for "red". All explanations originate with the reddish, butterfly-shaped malar rash that the disease classically exhibits across the nose and cheeks.