Genetic Markers for Predicting Lupus Susceptibility
Autoimmune diseases have plagued millions of people from different parts of the world. These disorders have unknown etiologies and have no cure to this day. Many patients diagnosed with some kind of autoimmune disease have mustered the courage and determined the pace to coexist with their illness successfully. One of the most complex autoimmune diseases is lupus. Lupus can manifest as several types. The most common type of lupus is systemic lupus erythematosus (SLE), which affects people from different walks of life.
The Prevalence of Lupus
According to reports from the Centers for Disease Control and Prevention Lupus Registry for the year 2002-2004, lupus cases are more prevalent in patients of African-American descent than in Non-Hispanic European-Americans. That conclusion was supported by a study conducted in Washtenaw County and Wayne County, Michigan (111.6 vs. 47.5 per 100,000 people), and Fulton County and DeKalb County in Georgia (128.0 vs. 39.9 per 100,000 people). The registry also reports that the annual lupus prevalence for Alaskans (Native Americans) for the years 2007, 2008, and 2009 is 178 per 100,000 people.
The reports (Michigan = 9.3 vs. 1.5 per 100,000 people; Georgia = 145.8 vs. 17.5 per 100,000 people; Alaskan population = 271 vs. 54 per 100,000 people) also lead to the conclusion that lupus is more prevalent in women than in men.
Issues in the Diagnostic Testing for Lupus and Other Autoimmune Diseases
Numerous studies have been conducted in an attempt to find a way to detect and correct the early signs of lupus and other autoimmune diseases. Though the cause of autoimmune diseases is still undetermined, researchers have taken genetics, hormones, and environmental factors into consideration as they study the possible causes of these disorders.
Several tests are conducted in order to confirm suspected incidences of lupus or any autoimmune diseases. These tests are done once a patient exhibits several symptoms of a particular autoimmune disorder. However, the signs and symptoms, in themselves, can be variable and entirely inconclusive. This leads to either the underdiagnosis of autoimmune diseases or the misinterpretation of the symptoms during the process of differential diagnosis.
The increase in the mortality associated with autoimmune diseases can be partially attributed to wrong diagnoses. This occasion hinders patients from seeking the best and most applicable treatment option for their medical care. Fortunately, the years of extensive lupus studies conducted by highly-reputable researchers have yielded promising results. Researchers have identified several lupus biomarkers to aid in the detection of lupus. These lupus biomarkers give patients and physicians directions toward more precise lupus diagnoses and the most appropriate therapeutic approach.
Technological Advancement in Autoimmunity Research
The latest genetic studies related to autoimmunity have utilized the convenience of the Immunochip. This is the latest and most promising technology used for genotyping. It was specially designed for the analysis of genetics to map biological markers for autoimmune diseases.
Over the course of countless autoimmunity research studies, the following techniques have also been employed in an attempt to be a step closer to a potential breakthrough:
- Structural proteome analysis
- Flow cytometry (laser technology used for cell analysis and identification of biological markers)
- Autoantigen arrays for autoantibody profiling
- DNA microarrays for genetic transcription and profiling
Biomarkers – a Potential Key to Predicting Lupus
Biological markers, more popularly known as biomarkers, are substances, genetic products, molecules, or cells whose presence, absence, or anomalies can indicate the presence and development of a certain disorder. For example, an increase in leukocytes (white blood cells) in blood could signal the presence of a possible infection. Similarly, lupus can be predicted through the analysis of certain biological markers.
Lupus Biological Markers for Susceptibility
Studies on autoimmune diseases demonstrate that a person’s susceptibility to lupus and any other autoimmune diseases can be traced back to a person’s genetic makeup. In addition to genetic markers, environmental factors such as a person’s level of exposure to harmful conditions are believed to increase a person’s vulnerability to autoimmune diseases.
A series of experiments revealed that autoantibodies (proteins produced by the immune system to act against the person’s own proteins or tissues) have been present in patients with confirmed cases of systemic lupus erythematosus (SLE) years prior to the occurrence of symptoms for SLE. The growth and development of these autoantibodies exhibit a common developmental pattern before SLE patients begin to perceive or experience symptoms of lupus. That result of the examinations leads to the conclusion that a person’s immune system has been compromised long before they start showing any signs of lupus.
Scientists have discovered that there is no specific gene that has been proven to initiate or exacerbate autoimmunity. As a matter of fact, multiple genes have been tagged as biological markers for lupus. An article published on October 18, 2009, conveys the results of a replication study on the risk variants for SLE. The replication study identified five new risk loci (locus = position of chromosomal mutation or the gene itself) for lupus susceptibility.
Lupus and Ethnicity
Researchers from Wake Forest Baptist Medical Center in North Carolina, Oklahoma Medical Research Foundation, King’s College London, and Genentech Inc. in California began a large-scale, multi-ethnic study of the genetic markers for SLE.
The study gathered and analyzed genetic data from a sample multi-ethnic population of 27,574 people. Lupus shares various genetic markers with other autoimmune diseases. By the process of elimination, the genetic markers that are tagged to be unique to lupus patients have been identified.
The statistical analyses of successive, interrelated lupus research studies show that women are more susceptible than men to lupus. Furthermore, African-Americans, Hispanics, and Native Americans are seen to be more prone to more intense cases of lupus.
A report from St. Thomas Lupus Trust states that severe lupus cases are more likely to hit a non-Caucasian individual. Incidences of lupus are far more ordinary in Afro-Caribbean and Asian populations. That conclusion is supported by the results of the survey they conducted:
- 1 out of 750 Caucasian and/or European American females have lupus.
- 1 out of 250 Afro-Caribbean and Asian females have lupus.
The Credibility of Genetic Markers for Lupus
Identifying the specific genes, risk variants, and loci exclusive to lupus is certainly the biggest hurdle in the development of the research studies that attempt to theorize and predict a person’s vulnerability to lupus and any other autoimmune diseases.
In some cases, some valid biological markers for lupus that had been previously identified have been found to become inconclusive as time goes by. These genetic markers begin to shift the studies’ directions and somewhat contradict previous theories and conclusions. Constant changes that occur during the entire progression of lupus have already thrown off some initially informative cues from several research studies.
Despite the challenges in discovering the genetic markers for lupus, the latest technologies and breakthroughs have paved the way for substantial progress in the studies focused on the prediction and further understanding of the pathogenesis of lupus. A single genetic marker for lupus is yet to be identified. In spite of this, a significant number of research studies on autoimmune diseases have yielded positive results that continue to fuel hope for major developments on the potential cure and prevention of lupus and other autoimmune diseases.
