SYSTEMIC LUPUS ERYTHEMATOSUS


Systemic lupus erythematosus (SLE) is a chronic inflammatory disease that has protean manifestations and follows a relapsing and remitting course. More than 90% of cases of SLE occur in women, frequently starting at childbearing age

SYMPTOMS

PATHOPHYSIOLOGY

DIAGNOSIS

The diagnosis of SLE is based on a combination of clinical findings and laboratory evidence. Familiarity with the diagnostic criteria helps clinicians to recognize SLE and to subclassify this complex disease based on the pattern of target-organ manifestations.

The presence of 4 of the 11 American College of Rheumatology (ACR) criteria yields a sensitivity of 85% and a specificity of 95% for SLE.

When the Systemic Lupus International Collaborating Clinics (SLICC) group revised and validated the ACR SLE classification criteria in 2012, they classified a person as having SLE in the presence of biopsy-proven lupus nephritis with ANA or anti-dsDNA antibodies or if 4 of the diagnostic criteria, including at least 1 clinical and 1 immunologic criterion, have been satisfied.

ACR mnemonic of SLE diagnostic criteria

The following are the ACR diagnostic criteria in SLE, presented in the "SOAP BRAIN MD" mnemonic:

• Serositis
• Oral ulcers
• Arthritis
• Photosensitivity
• Blood disorders
• Renal involvement
• Antinuclear antibodies
• Immunologic phenomena (eg, dsDNA; anti-Smith [Sm] antibodies)
• Neurologic disorder
• Malar rash
• Discoid rash

                             Testing

The following are useful standard laboratory studies when SLE is suspected:

• CBC with differential
• Serum creatinine
• Urinalysis with microscopy
• ESR or CRP results
• Complement levels
• Liver function tests
• Creatine kinase assay
• Spot protein/spot creatinine ratio
• Autoantibody tests

                          Imaging studies

The following imaging studies may be used to evaluate patients with suspected SLE:

• Joint radiography
• Chest radiography and chest CT scanning
• Echocardiography
• Brain MRI/ MRA
• Cardiac MRI

                           Procedures

Procedures that may be performed in patients with suspected SLE include the following:

• Arthrocentesis
• Lumbar puncture
• Renal biopsy

                         Management

Management of SLE often depends on the individual patient’s disease severity and disease manifestations,although hydroxychloroquine has a central role for long-term treatment in all SLE patients.

Pharmacotherapy

Medications used to treat SLE manifestations include the following:

• Biologic DMARDs (disease-modifying antirheumatic drugs): Belimumab, rituximab, IV immune globulin
• Nonbiologic DMARDS: Cyclophosphamide, methotrexate, azathioprine, mycophenolate, cyclosporine
• Nonsteroidal anti-inflammatory drugs (NSAIDS; eg, ibuprofen, naproxen, diclofenac)
• Corticosteroids (eg, methylprednisolone, prednisone)
• Antimalarials (eg, hydroxychloroquine)