Sjögren’s syndrome, like SLE, is a type of autoimmune connective tissue disorder that may have both genetic and environmental causes. Connective tissue disorders are chronic inflammatory autoimmune disorders affecting the connective tissues. All connective tissues, i.e. joints, muscles, skin and blood vessels can be affected and therefore the disorders have multiple effects on many different organs throughout the body.
They may develop slowly over many years, or they may present abruptly and show rapid progression. There are more than 200 different disorders affecting connective tissues, including SLE, Sjögren’s syndrome, scleroderma and mixed connective tissue disease.
The presence of autoantibodies in the serum of patients is a very typical phenomenon for connective tissue disorders. Most of the autoantibodies are not specific and can be detected in patients with different diseases. However, in some cases, autoantibodies occur specifically in a certain disease and can aid in the diagnosis.
Ninety per cent of Sjögren's patients are women and the average age of onset is late 40s, although Sjögren's may appear in all age groups in both women and men. It is estimated to be the second most common autoimmune rheumatic disease in the United States. Sjögren's syndrome can exist as a primary disease or may develop as an associate disease 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).
The hallmark symptom of Sjögren's syndrome is a generalized dryness, typically including xerostomia (dry mouth) and xerophthalmia (dry eyes), part of what are known as sicca symptoms. The disease is therefore sometimes referred to asthe Sicca syndrome. In addition, Sjögren's syndrome may cause dryness to several other tissues such as skin, nose, and vagina, and may significantly affect a number of other organs of the body, including the kidneys, blood vessels, lungs, liver, pancreas, peripheral nervous systemand brain. In addition to the sicca symptoms that may be serious patients can experience several other symptoms. Debilitating fatigue and joint paincan seriously impair quality of life. Some patients can develop renal involvement leading to proteinuria, and distal renal tubular acidosis. Patients with Sjögren's syndrome have a higher rate of non-Hodgkin lymphoma compared to both patients with other autoimmune diseases and healthy people. About 5% of patients with Sjögren's syndrome will develop some form of lymphoid malignancy. Sjögren's syndrome in women who become pregnant has been linked to increased incidence of neonatal lupus erythematosus which is associated with the development of congenital heart block. A condition often requiring a pacemaker.