HLA B27 test introduction
The HLA-B27 test detects the gene variation. The immune system’s capacity to recognise and react to foreign chemicals depends on the HLA-B27 gene.
Ankylosing spondylitis, reactive arthritis, psoriatic arthritis, and inflammatory bowel disease are linked to the HLA-B27 gene variation.
When a doctor detects or confirms one of these disorders, the HLA-B27 test is done. A lab analyses a blood sample. The test detects HLA-B27 gene variants in DNA.
The HLA-B27 test is not diagnostic. Positive results suggest the gene variation but do not guarantee illness. A negative result does not exclude having one of these disorders.
The HLA-B27 test is used alongside medical history, physical examination, and other diagnostic tests like imaging or joint fluid analysis to diagnose autoimmune illnesses and guide therapy.
For correct examination, test interpretation, and treatment recommendations, visit a healthcare expert.
purpose
The HLA-B27 test detects the gene variation. Useful information:
Autoimmune diseases: Ankylosing spondylitis and reactive arthritis are highly related with the HLA-B27 gene variation. HLA-B27 testing may confirm a diagnosis based on symptoms, medical history, and clinical examination.
Differential diagnosis: The HLA-B27 gene variation might assist narrow down a person’s probable diagnoses if they have many symptoms. Inflammatory back pain may indicate ankylosing spondylitis if HLA-B27 is positive.
Risk assessment: HLA-B27 testing may predict autoimmune disease risk. However, a positive test does not mean a person will acquire the related disease, nor does a negative result rule it out. Healthcare practitioners assess risk using numerous factors, including test results.
therapy: The HLA-B27 gene variation affects autoimmune disease therapy. It may assist choose drugs or treatments that work better in HLA-B27 positive people.
The HLA-B27 test helps doctors diagnose, risk evaluate, and treat autoimmune illnesses linked to the gene variation. However, the test is just one technique used to assess and treat these disorders.
procedure
HLA-B27 testing follows these steps:
Consultation with a healthcare professional: First, make an appointment with a doctor or expert (rheumatologist, immunologist, etc.). Discuss your symptoms, medical history, and concerns in this appointment. HLA-B27 testing will be determined by your doctor.
Blood sample collection: The healthcare expert will draw blood for the HLA-B27 test. A tiny needle is used to draw blood from an arm vein. The healthcare expert cleans the region with an antiseptic, applies a tourniquet to make veins visible, inserts the needle into a vein, and collects a little volume of blood into a vial or tube.
Laboratories analyse the blood sample. Lab professionals will isolate and extract DNA from blood samples. They will next screen for the HLA-B27 gene variation using PCR or SSOP.
findings: The healthcare practitioner who requested the test receives the lab findings. The laboratory’s turnaround time determines the results’ delivery time. Your doctor will analyse and advise you on the test findings.
The technique may vary based on the healthcare institution, laboratory, and testing method. Your doctor will provide you pre- and post-test instructions.
indication
When to test for HLA-B27:
Suspected Ankylosing Spondylitis (AS): AS is a chronic inflammatory spine and sacroiliac joint condition. Positive HLA-B27 results support AS diagnosis.
Suspected Reactive Arthritis: Reactive arthritis results from a bodily infection. Reactive arthritis patients with gastrointestinal or genitourinary infections often have HLA-B27.
Evaluating Undifferentiated Spondyloarthropathy: These inflammatory rheumatic disorders are comparable to ankylosing spondylitis but do not match the complete diagnostic criteria. HLA-B27 testing aids diagnosis.
Assessing Family Risk: HLA-B27 is a genetic marker that increases the risk of related disorders. HLA-B27-related illness risk may be assessed by testing family members.
Helping Diagnose Related Conditions: HLA-B27 is linked to psoriatic arthritis, reactive arthritis, juvenile idiopathic arthritis, and inflammatory bowel illness. HLA-B27 testing may help diagnose or assess various disorders.
The HLA-B27 test alone cannot diagnose these disorders. It is used alongside medical history, physical examination, imaging studies, and other laboratory testing to diagnose and manage these disorders. Healthcare professionals base HLA-B27 testing on symptoms, medical history, and clinical presentation.
types
There are various HLA-B27 gene variant assays. Labs and technology determine test methods. Common HLA-B27 tests:
PCR may amplify particular DNA sequences. PCR amplifies the HLA-B27 gene variation from blood samples for the test. This detects gene variants.
SSOP analysis employs short DNA sequences (oligonucleotide probes) unique to the HLA-B27 gene variation. The HLA-B27 gene variation is detected by analysing the probes’ binding pattern to the patient’s amplified DNA.
SSP PCR for HLA-B27 testing. It involves PCR amplification using HLA-B27 gene variant-targeted primers. Amplification pattern determines HLA-B27 gene variant presence.
Flow cytometry analyses and sorts cells by their physical and chemical characteristics. Flow cytometry can identify HLA-B27 on white blood cells in HLA-B27 testing. Flow cytometric HLA-B27 analysis is used.
These HLA-B27 testing are frequent. Labs utilise different methods. Your doctor or lab will choose the best test technique for your circumstances.
risk
HLA-B27 increases the risk of autoimmune disorders. However, possessing the HLA-B27 gene variation does not ensure these illnesses or offer a thorough risk assessment. Other genetic and environmental variables cause autoimmune disorders.
The HLA-B27 gene variation raises relative risk for some diseases, although the absolute risk varies by illness. HLA-B27-related conditions and risk estimations are listed below:
HLA-B27 closely links AS. 90-95% of AS patients have HLA-B27. HLA-B27 positive people seldom acquire AS. HLA-B27-positive people have a 1-2% lifetime risk of AS.
Reactive Arthritis: HLA-B27 significantly links reactive arthritis. HLA-B27 increases reactive arthritis risk after some infections. However, risk depends on the triggering infection and other circumstances.
Psoriatic arthritis, inflammatory bowel disease, and various kinds of juvenile idiopathic arthritis are also linked to HLA-B27. HLA-B27 positive people’s risk estimations vary according to genetic and environmental variables.
Remember that the HLA-B27 test is just one part of measuring risk for certain illnesses. If symptoms or other signs imply certain disorders, a positive HLA-B27 test may justify careful monitoring and examination by a healthcare expert. Regular checkups, early identification, and effective care may reduce the burden of many disorders.
If you have concerns about your unique risk or particular health issues, visit a healthcare expert for personalised advice.
results
An HLA-B27 test usually shows if the gene mutation is in the tested person’s DNA. Tests might be positive or negative.
Positive result: HLA-B27 gene variation found in DNA. This indicates HLA-B27 gene variant.
Negative result: DNA does not contain the HLA-B27 gene variation. The person lacks the HLA-B27 gene variation.
HLA-B27 positivity does not guarantee autoimmune illness. A negative result does not rule out getting these illnesses. The HLA-B27 test is used alongside other clinical examinations to diagnose and treat.
Healthcare professionals must evaluate the patient’s symptoms, medical history, and other considerations when interpreting HLA-B27 test findings. The doctor will utilise the test findings and other clinical data to diagnose and treat the patient.
Your healthcare practitioner should explain the HLA-B27 test findings and any necessary next steps.
conclusion
Finally, the HLA-B27 test detects the gene variation in an individual’s DNA. It is usually used to diagnose autoimmune illnesses such ankylosing spondylitis, reactive arthritis, psoriatic arthritis, and inflammatory bowel disease.
The gene variation is present if HLA-B27 is positive and absent if it is negative. A positive test does not imply linked illnesses, nor does a negative result rule them out. The HLA-B27 test and other clinical examinations help diagnose, risk evaluate, and treat many disorders.
Healthcare professionals should interpret HLA-B27 test findings in the context of the patient’s clinical picture. They’ll utilise test findings and other clinical data to establish an accurate diagnosis and choose a treatment strategy.
FAQs
A positive HLA-B27 result means what?
A: The HLA-B27 gene variation was found in the individual’s DNA. It raises the likelihood of autoimmune illnesses such ankylosing spondylitis and reactive arthritis. Despite a promising outcome, more clinical assessment is required to confirm these diseases.
Q: Does a negative HLA-B27 result exclude ankylosing spondylitis or related diseases?
A negative HLA-B27 test does not rule out ankylosing spondylitis or related disorders. HLA-B27 raises risk but does not diagnose. Symptoms, physical exam, imaging, and further lab tests help diagnose.
Q: Can HLA-B27 testing screen?
A: HLA-B27 testing is not recommended for general screening. It is employed in clinical settings where HLA-B27-associated autoimmune disorders are suspected. A comprehensive clinical assessment by a healthcare practitioner enhances the test.
Can HLA-B27 testing predict autoimmune disease severity or progression?
A: HLA-B27 alone cannot predict autoimmune disease severity or progression. HLA-B27 positive increases risk, however illness severity varies greatly. Genetics and environment affect illness development and severity.
HLA-B27 testing at home?
Home HLA-B27 testing is not available. It needs specialised laboratory equipment and skilled personnel to correctly execute and interpret the test. Clinical or diagnostic laboratories do it under quality control.
myth vs fact
Myth: HLA-B27 positivity guarantees autoimmune illness.
Fact: The HLA-B27 gene variation raises the chance of autoimmune disorders such ankylosing spondylitis and reactive arthritis, but it does not ensure them. HLA-B27-positive people seldom acquire autoimmune diseases.
Myth: A negative HLA-B27 test excludes autoimmune illness.
Fact: A negative HLA-B27 test does not exclude autoimmune illness. Some HLA-B27-associated autoimmune disorders have negative gene variants. Autoimmune illnesses are diagnosed using clinical evaluations, symptoms, physical examination, and other laboratory procedures, not only HLA-B27 testing.
Myth: HLA-B27 can screen the general population.
HLA-B27 testing is not recommended for general screening. It is employed in clinical settings where HLA-B27-associated autoimmune disorders are suspected. HLA-B27 testing does not screen for common diseases with screening criteria.
Myth: HLA-B27 testing predicts autoimmune disease severity and progression.
HLA-B27 testing cannot predict autoimmune disease severity or progression. The HLA-B27 gene variation increases risk, although illness severity varies. Genetic and environmental variables affect disease development and severity, requiring extensive clinical examination.
Myth: HLA-B27 testing is home-based.
HLA-B27 testing is not home-useable. It needs specialised laboratory equipment and skilled personnel to correctly execute and interpret the test. Clinical or diagnostic laboratories do quality-controlled HLA-B27 testing.
terms
Autoimmune disease: The immune system assaults healthy cells and tissues, producing inflammation and damage.
Ankylosing spondylitis and reactive arthritis are significantly linked to HLA-B27, a gene variation.
Ankylosing spondylitis: A chronic inflammatory illness that causes spine and sacroiliac joint discomfort, stiffness, and gradual fusion.
Reactive arthritis: Joint discomfort, edoema, and inflammation caused by a bodily infection.
Psoriatic arthritis: Joint discomfort, stiffness, and edoema caused by psoriasis.
Inflammatory bowel disease (IBD): Chronic gastrointestinal inflammation that includes Crohn’s disease and ulcerative colitis.
Genetic marker: A gene or DNA sequence that may detect genetic variants or connections with characteristics, conditions, or illnesses.
Diagnosis: Identifying a disease or condition using symptoms, medical history, physical examination, and diagnostic testing.
Rheumatologist: A doctor who treats joint, muscle, and bone problems, including autoimmune ailments such ankylosing spondylitis and reactive arthritis.
Immunologist: A expert in immune system illnesses, especially autoimmune diseases.
Polymerase Chain Reaction (PCR): A lab method that amplifies DNA sequences to discover genetic markers like HLA-B27.
Sequence-Specific Oligonucleotide Probe (SSOP) Analysis: A molecular biology method that detects genetic variants like HLA-B27 using short DNA sequences.
Flow cytometry: Used to analyse and classify cells by their physical and chemical properties, frequently to identify HLA-B27 molecules on white blood cells.
Sensitivity: A test’s genuine positive rate.
Specificity: The genuine negative rate of a test.
False positive: A ailment or gene variation that is not existent.
False negative: A test result that falsely shows an ailment or gene variation is absent.
Risk factor: A trait or condition that enhances the risk of a disease.
Genetic predisposition: An elevated risk of a disease or illness due to genetic differences.
Prevalence: The percentage of a population with a disease or condition.
Gene variation: A gene variant may impact an individual’s attributes or illness risk.
Disease progression: The progression of a disease, including changes in symptoms, severity, and function.
Management: Methods to reduce illness symptoms and progression.
Genetic and environmental aspects: Genetic factors include inherited characteristics and variations, whereas environmental ones include lifestyle, nutrition, chemicals, and infections.