Sjögren's syndrome ( /ˈʃoʊɡrɨnz/ shoh-grinz), also known as "Mikulicz disease" and "Sicca syndrome",[1] is a systemic autoimmune disease in which immune cells attack and destroy the exocrine glands[2] that produce tears and saliva.
It is named after Swedish ophthalmologist Henrik Sjögren[3] (1899–1986) who first described it.
Nine out of ten Sjögren's patients are women and the average age of onset is late 40s, although Sjögren's occurs in all age groups in both women and men.[citation needed] It is estimated to strike as many as 4 million people in the United States alone making it the second most common autoimmune rheumatic disease.[citation needed]
Sjögren's syndrome can exist as a disorder in its own right (primary Sjögren's syndrome) or it may develop years after the onset of an associated rheumatic disorder such as rheumatoid arthritis, systemic lupus erythematosus, scleroderma, primary biliary cirrhosis etc. (secondary Sjögren's syndrome).[citation needed]
An autoantigen is alpha-Fodrin.[4]
It should not be confused with the Sjögren–Larsson syndrome, also denoted T. Sjögren syndrome in early studies
Signs and symptomsThe hallmark symptom of the disorder is a generalized dryness, typically involving dry mouth and dry eyes (part of what are known as sicca symptoms). In addition, Sjögren's syndrome may cause skin, nose, and vaginal dryness, and may affect other organs of the body, including the kidneys, blood vessels, lungs, liver, pancreas, peripheral nervous system (distal axonal sensorimotor neuropathy) and brain.
Sjögren's syndrome is associated with increased levels of IL-1RA in CSF, an interleukin 1 antagonist, suggesting that there was first increased activity in the interleukin 1 system, then an auto-regulatory up-regulation of IL-RA in attempts to reduce the successful binding of Interleukin 1 to its receptors. It is likely that Interleukin 1 is the marker for fatigue, however IL-1RA increases are observed in the CSF and is associated with increased fatigue through cytokine induced sickness behavior.[5] Patients with secondary Sjögren's syndrome also often exhibit signs and symptoms of their primary rheumatic disorders, such as SLE, Rheumatoid Arthritis or Systemic Sclerosis.
[edit] DiagnosisDiagnosing Sjögren's syndrome is complicated by the range of symptoms a patient may manifest, and the similarity between symptoms from Sjögren's syndrome and those caused by other conditions. Nevertheless, the combination of several tests can lead to a diagnosis of Sjögren's syndrome.
Blood tests can be done to determine if a patient has high levels of antibodies that are indicative of the condition, such as anti-nuclear antibody (ANA) and rheumatoid factor (because SS frequently occurs secondary to rheumatoid arthritis), which are associated with autoimmune diseases. Typical Sjögren's syndrome ANA patterns are SSA/Ro and SSB/La, of which SSB/La is far more specific; SSA/Ro is associated with numerous other autoimmune conditions but are often present in Sjögren's.[6] [7]
The Schirmer test measures the production of tears: a strip of filter paper is held inside the lower eyelid for five minutes, and its wetness is then measured with a ruler. Producing less than five millimeters of liquid is usually indicative of Sjögren's syndrome. However, lacrimal function declines with age or may be impaired from other medical conditions. An alternative test is nonstimulated whole saliva flow collection, in which the patient spits into a test tube every minute for 15 minutes. A resultant collection of less than 1.5 mL is considered a positive result.[8] It takes longer time to perform than a Schirmer test, but does not require specific equipment.
A slit-lamp examination is done to look for dryness on the surface of the eye. Salivary gland function can be tested by collecting saliva and determining the amount produced in a five minute period. A lip biopsy can reveal lymphocytes clustered around salivary glands, and damage to these glands due to inflammation.
Ultrasound examination of the salivary glands is the simplest confirmatory test and has the added advantage of being non-invasive with no complications. The parenchyma of the gland demonstrates multiple, small-2-6 mm hypoechoic lesions which are representations of the lymphocytic infiltrates. Often sialectasis with calculi are demonstrated if the disease is advanced. The sonographic findings have excellent symptom correlation. The other advantage of ultrasound is that complications of the disease such as extra-nodal lymphomas can often be detected as larger 1–4 cm hypoechoic intra-parenchymal masses.
A radiological procedure can also be used as a reliable and accurate way of diagnosing Sjögren's syndrome. A contrast agent is injected into the parotid duct (of Stensen), which is a duct opening from the cheek into the vestibule of the mouth opposite the neck of the upper second molar tooth. Widespread puddling of the injected contrast scattered throughout the gland indicates Sjögren's syndrome.
The Revised Classification Criteria for Sjögren's Syndrome[9] requires the presence of signs, symptoms, and lab findings.
Patient-reported symptoms must include both ocular symptoms, such as daily, persistent, troublesome dry eyes for more than 3 months, and oral symptoms, such as needing to drink water to swallow food.
Objective evidence of eye involvement relies on Schirmer's test and the Rose bengal score (or similar). Histopathology studies should show focal lymphocytic sialadenitis. Objective evidence of salivary gland involvement is tested through ultrasound examinations, the level of unstimulated whole salivary flow, a parotid sialography, or salivary scintigraphy. Autoantibodies against Ro (SSA) and/or La (SSB) antigens are also expected.
SS can be excluded from people with past head and neck radiation therapy, hepatitis C infection, Acquired immunodeficiency syndrome (AIDS), pre-existing lymphoma, sarcoidosis, graft-versus-host disease, and use of anticholinergic drugs (since a time shorter than 4-fold life of the drug).
http://en.wikipedia.org/wiki/Sj%C3%B6gren's_syndrome
