Sjogren syndrome is an autoimmune disorder causing conditions such as xerostomia and Xerophthalmia. It was first discovered by Henrick Sjogren. The symptoms associated with this disorder are often chronic and occur due to damage or impairment of the exocrine glands caused due to the lymphocytic infiltrates and hypersensitivity reactions. The onset of Sjogren syndrome predominantly occurs in the region of salivary glands and lacrimal glands. The primary form of Sjogren syndrome is generally associated with external glandular symptoms such as dry eyes and dry mouth without any connective tissue damage. The secondary form of the Sjogren syndrome usually occurs because of preexisting autoimmune disorders.
Clinical manifestations of Sjogren syndrome
Sjogren syndrome usually occurs in the older age group; however exceptions have been reported on it affecting younger persons. The factors causing Sjogren syndrome are predominantly genetical or environmental. Neuro-endocrine impairment plays a significant role in the onset of the Sjogren syndrome. HLA-DR genotype is the predominant factor in the genetic propagation of the disease.
Sjogren syndrome is associated with a cascade of symptoms related to many organ systems and their functions. The affected regions are ocular, oral, ontological, laryngeal, vascular, neurologic and endocrine systems respectively. The effect of the Sjogren syndrome is mainly on the head and neck region and hence the sense organs are affected to a larger extent. Other clinical conditions include loss of hearing, arthralgia, myalgia and also frequent epistaxis. Sjogren syndrome if not treated, can lead to serious conditions such as lymphoma and renal failure.
Diagnosis and treatment of Sjogren syndrome
Sjogren syndrome is diagnosed by using radiological, pathological and serological analysis. Schirmer's test is used in the diagnosis of Xerophthalmia. It is used to estimate the tear secretion level of patients suffering with dry eye conditions. The decreased levels or absence of tear secretion indicates probability of Sjogren syndrome. Salivary biopsy is advised for patients suffering xerostomia. The pathological analysis of the salivary glands also reveals underlying infiltration and damage caused to the exocrine glands. Serological analysis of the Sjogren syndrome are generally associated with low WBC counts, increased erythrocyte sedimentation rates, elevated levels of protein and hyper-gammaglobulinemia of IgM. Careful clinical study of the diagnostic parameters along with symptoms is necessary to rule out false positive results.
The treatment of Sjogren syndrome is generally a slow process because it is an autoimmune disorder. Immunosuppressive drugs and salivary substitutions are some of the methods administered to manage Sjogren syndrome. Pilocarpine an FDA approved tear stimulating drug is widely used for the treatment of dry eyes.
Rheumatoid Factor Test
Rheumatoid factor test is used to measure the amount of rheumatoid factor in the blood. Rheumatoid factors are proteins produced by the body's immune system that can attack healthy tissue in the body. Antibodies are normal protein found in the blood, functioning within the immune system. Rheumatoid factor is an immunoglobulin i.e. antibody that can bind other antibodies. It may be present in 1-2% of the healthy population. In older people aged 65 and above, 20% have elevated level of rheumatoid factor.
Elevated levels of rheumatoid factor in the blood show up as autoimmune diseases, such as rheumatoid arthritis and Sjogren's syndrome. Many a time, rheumatoid factor may be detected in few healthy people and at times some people with autoimmune diseases have normal levels of rheumatoid factor. Patients with negative rheumatoid factor but suffering from the condition are classified as having seronegative rheumatoid arthritis. But largely, healthy people do not produce rheumatoid factor.
A sample of blood is drawn from the vein in the arm and sent to the laboratory for test. The RF test helps to diagnose rheumatoid arthritis and may also help the physician choose the line of treatment. A positive result, i.e. test result indicating the presence of rheumatoid factor in the blood may confirm rheumatoid arthritis in a person. About 80% of adults who have rheumatoid arthritis test high for rheumatoid factor.
This test helps differentiate between rheumatoid and inflammatory arthritis from other types of arthritis. High level of rheumatoid factor may also result from the presence of other autoimmune diseases in the body such as:
- Sjogren's syndrome
- Chronic infections
- Mixed connective tissue disease
- Inflammatory lung disease like Sarcoidosis
- Systemic lupus erythematosus
When is the test ordered?
Rheumatoid factor test is ordered for persons suffering from the following symptoms:
- Stiffness in the joints
- Increased pain in the joints in the morning
- Bone loss
- Loss of cartilage
- Nodules under the skin
- Warmth and swelling in the joints.
Rheumatoid arthritis test principle
Rheumatoid factor can be identified in the laboratory by its ability to bind and form clumps with latex particles or red blood cells that have human immunoglobulin (IgG). If the patient being tested has rheumatoid factor, then it attaches to the IgG coating the latex particles causing lumps. This process is called agglutination. Agglutination is a positive reaction that indicates the presence of rheumatoid factor at a detectable level.
Rheumatoid Factor Results
The antibody titer is a test that measures the quantity of the blood that can be diluted before RF antibodies become indistinguishable. The following results will be considered as normal:
Less than 40 - 60 units/ml
Less than 1:80 (1 to 80) titer.
A low number (normal result) generally indicates that the person being tested does not have rheumatoid arthritis or Sjogren syndrome. However, a few people who have the condition may still have a normal or low rheumatoid factor (RF). Normal ranges may vary from laboratory to laboratory.
An abnormal result may mean the test is positive. Most patients with this result may have rheumatoid arthritis or Sjogren's syndrome. The higher the level, the more likely the condition is present. There are other tests that may be used to diagnose the condition.
- False positive results can occur when the fat content in the blood is high.
- Inaccurate results may show up when the blood specimen is handled improperly.
- A negative rheumatoid factor does not rule out the presence of rheumatoid arthritis.
Most often, dry eyes are due to Blepharitis (inflammation of the eyelid) , Sjogren syndrome, aging, eye infections, corneal ulcers or other factors. Schirmer's Test is done to check for dry eyes or even severely watering eyes. A special strip of paper is placed inside the lower eyelids for about 5 minutes. The paper strips are then checked for level of moisture to determine the eye's ability to produce tears. How far down the tears reach on the paper strips is also noticed. In some cases, anaesthetic drops are applied prior to administering this test. Another alternative to the Schirmer's Test is the Phenol Red Thread test wherein red strips of special thread are used instead of special paper strips. Remove contact lenses before this test and do not wear for a couple of hours after it.