Systemic lupus erythematosus criteria
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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Raviteja Guddeti, M.B.B.S. [2]
Classification of lupus
The 11 criteria for the diagnosis of lupus include:3,14
- Malar rash: butterfly-shaped rash across cheeks and nose
- Discoid rash: raised red patches
- Photosensitivity: skin rash as a result of unusual reaction to sunlight
- Oral or nose ulcers: usually painless
- Non-erosive arthritis (whereby the bones around joints do not get destroyed): involving 2 or more peripheral joints, characterized by tenderness, swelling, or effusion
- Pleuritis or pericarditis: inflammation of the lining around the heart (pericarditis) or lungs (pleuritis)
- Renal (kidney) disorder: excessive protein in the urine or cellular casts in the urine
- Neurologic disorder: seizures or psychosis/cognitive dysfunction
- Hematologic (blood) disorder: hemolytic anemia, low white blood cell count or low platelet count
- Immunologic disorder: antibodies to double-stranded DNA, antibodies to Sm, or antibodies to cardiolipin
- Positive ANA: positive test in the absence of drugs known to induce it.
There is frequent underdiagnosis of lupus due to the symptoms and signs not being specific. Equally, there is frequent overdiagnosis of the condition because doctors use a positive blood test (present in 5% of the healthy population) by itself to make a diagnosis.
Overview
Diagnostic Criteria
Some physicians make a diagnosis on the basis of the ACR classification criteria (see below). The criteria, however, were established mainly for use in scientific research (i.e. inclusion in randomized controlled trials), and patients may have lupus but never meet the full criteria.
Anti-nuclear antibody testing and anti-extractable nuclear antigen (anti-ENA) form the mainstay of serologic testing for lupus. Antiphospholipid antibodies occur more often in SLE, and can predispose for thrombosis. More specific are the anti-smith and anti-dsDNA antibodies. Other tests routinely performed in suspected SLE are complement system levels (low levels suggest consumption by the immune system), electrolytes and renal function (disturbed if the kidney is involved), liver enzymes and a complete blood count.
Formerly, the lupus erythematosus (LE) cell test was used for diagnosis, however those LE cells are only found in 50-75% of SLE patients, and are also found in some patients with rheumatoid arthritis, scleroderma, and drug sensitivities. Because of this, the LE cell test is now performed only rarely and is mostly of historical significance. [1]
The American College of Rheumatology (ACR) has established eleven criteria in 1982,[2] which were revised in 1997[3] as a classificatory instrument to operationalise the definition of SLE in clinical trials. They were not intended to be used to diagnose individual patients and do not do well in that capacity.
For inclusion in clinical trials, patients must meet the following three criteria to be classified as having SLE:
- (i) patient must present with four of the below eleven symptoms
- (ii) either simultaneously or serially
- (iii) during a given period of observation.
- Malar rash (rash on cheeks). sensitivity = 57%; specificity = 96%[4]
- Discoid lupus (red, scaly patches on skin which cause scarring) sensitivity = 18%; specificity = 99%[4]
- Photosensitivity (exposure to ultraviolet light causes rash). sensitivity = 43%; specificity = 96%[4]
- Oral ulcers: include oral or nasopharyngeal ulcers
- Arthritis: nonerosive arthritis of two or more peripheral joints, with tenderness, swelling or effusionsensitivity = 86%; specificity = 37%[4]
- Renal disorder: More than 0.5 g per day protein in urine, or cellular casts seen in urine under a microscope.sensitivity = 51%; specificity = 94%[4]
- Neurologic disorder: Seizures or psychosis. sensitivity = 20%; specificity = 98%[4]
- Serositis: Pleuritis (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)[4]
- Hematologic disorder: Hemolytic anemia (low red blood cell count) or leukopenia (white blood cell count<4000/ul), lymphopenia ( <1500/ul ) or thrombocytopenia (<100000/uL) in the absence of offending drug.sensitivity = 59%; specificity = 89%[4] 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.
- Anti-nuclear antibody test positive. sensitivity = 99%; specificity = 49%[4]
- Immunologic disorder: Positive anti-Sm, anti-ds DNA, anti-phospholipid antibody and/or false positive serological test for syphilis. sensitivity = 85%; specificity = 93%[4]. Presence of anti-ss DNA in 70% of patients (though also positive in patients with rheumatic disease and healthy persons[5])
A useful mnemonic for these 11 criteria is SOAP BRAIN MD
- Serositis
- Oral ulcers
- Arthritis
- Photosensitivity
- Blood Changes
- Renal involvement (proteinuria or casts)
- ANA
- Immunological changes
- Neurological signs (seizures, frank psychosis)
- Malar Rash
- Discoid Rash
Some patients, especially those with antiphospholipid syndrome, may have SLE without four criteria and SLE is associated with manifestations other than those listed in the criteria.[6][7][8]
Alternative criteria
Recursive partitioning has been used to identify more parsimonious criteria. [4] This analysis presented two diagnostic classification trees:
1. Simplest classification tree: LSE is diagnosed if the patient has an immunologic disorder (anti-DNA antibody, anti-Smith antibody, false positive syphilis test, or LE cells) or malar rash.
- sensitivity = 92%
- specificity = 92%
2. Full classification tree: Uses 6 criteria.
- sensitivity = 97%
- specificity = 95%
Other alternative criteria have been suggested.[9]
References
- ↑ NIM encyclopedic article on the LE cell test
- ↑ Rheumatology.org article on the classification of rheumatic diseases
- ↑ Revision of Rheumatology.org's diagnostic criteria
- ↑ 4.00 4.01 4.02 4.03 4.04 4.05 4.06 4.07 4.08 4.09 4.10 Edworthy SM, Zatarain E, McShane DJ, Bloch DA (1988). "Analysis of the 1982 ARA lupus criteria data set by recursive partitioning methodology: new insights into the relative merit of individual criteria". J. Rheumatol. 15 (10): 1493–8. PMID 3060613.
- ↑ UpToDate Patient information article on DNA antibodies
- ↑ Asherson RA, Cervera R, de Groot PG; et al. (2003). "Catastrophic antiphospholipid syndrome: international consensus statement on classification criteria and treatment guidelines". Lupus. 12 (7): 530–4. PMID 12892393.
- ↑ Sangle S, D'Cruz DP, Hughes GR (2005). "Livedo reticularis and pregnancy morbidity in patients negative for antiphospholipid antibodies". Ann. Rheum. Dis. 64 (1): 147–8. doi:10.1136/ard.2004.020743. PMID 15608315.
- ↑ Hughes GR, Khamashta MA (2003). "Seronegative antiphospholipid syndrome". Ann. Rheum. Dis. 62 (12): 1127. PMID 14644846.
- ↑ Hughes GR (1998). "Is it lupus? The St. Thomas' Hospital "alternative" criteria". Clin. Exp. Rheumatol. 16 (3): 250–2. PMID 9631744.