Autoantibodies key to early diagnosis of autoimmune diseases.
Getting a correct diagnosis may be difficult in the beginning stages, but it is imperative because the inability to quickly identify an autoimmune disease can take a serious toll on a patient, both physically and mentally. The recognition of common early symptoms and the detection of autoantibodies is an essential element in making a timely diagnosis and monitoring disease progression in patients with autoimmune diseases.
Like allergies, autoimmune diseases can range from mild to life-threatening. In fact, the National Institutes of Health esti-mates up to 23.5 million Americans suffer from an autoimmune disease and the prevalence continues to rise. Autoimmune diseases most often strike middle-aged women, so the symptoms can easily be blamed on hormone changes or lifestyle stresses from too much work or too little sleep.
Among about 80 different conditions, the major ones include Grave's disease, Hashimoto's, rheumatoid arthritis, diabetes type 1, lupus, Sjogren's syndrome, and scleroderma. Several risk factors and symptoms point to autoimmune disease, such as joint or muscle pain, fatigue, dry eyes, dry mouth, weight loss, gastrointestinal distress, depression, and concentration or memory problems. Many of the symptoms overlap or occur in early stages, and many patients have more than one condition. For all of these reasons, diagnosis is difficult and the role of improved diagnostic techniques is vital.
An important approach to the diagnosis of autoimmune diseases is the recognition of common and persistent early symptoms followed by the use of in vitro diagnostic tests and the early detection of autoantibodies which can have a major impact on the future diagnosis and treatment of these diseases. The development of specific profiles involving a number of different antibody tests may help this approach.
Autoimmune disease is often not considered until the disease has progressed to a point where severe, classic, or hallmark symptoms occur--though antibodies may already be present. We now know that autoantibodies can be present up to 10 years or more before the outbreak of autoimmune disease. One example is anti-dsDNA antibodies which precede the development of systemic lupus erythematosus (SLE) by five to 10 years. Another example is rheumatoid arthritis, where ACPAs (anti-citrullinated protein antibodies, CCP) may be identified more than 10 years before the occurrence of the first hallmark symptoms. Although ACPAs had been recognized for several years, it took a long time for them to be accepted as a diagnostic criterion. Only last year, ACPA detection, along with the well-known rheumatoid factor, has been included in the American College of Rheumatology guidelines as diagnostic criteria for rheumatoid arthritis. This is crucial in consideration of the importance of the predictive value of the tests.
A timely diagnosis due to the recognition of early symptoms offers the possibility of therapeutic action at the earliest possible time, which can often slow (e.g., erosion of joints in RA) or even halt disease progression (e.g., celiac disease). The use of biomarkers for the early detection of autoimmune disease will result in safer and better treatment with fewer side effects for patients and the efficient use of drugs--thus, cost savings and the appropriate utilization of healthcare resources for health insurers and consumers. This would achieve the goal of "patient-oriented treatment" being demanded from all sides.
What is the role of the laboratory in this setting? If the purpose of the laboratory is to aid the clinician in patient management, then it is essential that the methods of detecting autoantibodies are specific, sensitive, reliable, and reproducible. In addition, laboratories must identify markers which can help to identify disease activity, remission, and impending relapse. By making analytic methods such as enzyme immunoassays available that can satisfy these criteria, the laboratory assumes an essential role in the proper management of the patient.
Robert Reinhardt, MD, is currently the chief medical officer at Phadia U.S., an associate professor at Michigan State University, and a graduate of the Michigan State University College of Human Medicine and the Brown University Family Practice Residency. Find out about Phadia's ImmunoCAP Specific IgE, EISA autoimmune assays, and automated laboratory system technology platforms at www.phadia.com.
By Robert Reinhardt, MD
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|Title Annotation:||Special feature|
|Publication:||Medical Laboratory Observer|
|Date:||Aug 1, 2011|
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