What is a CSF IgG index?
CSF stands for cerebrospinal fluid. It is a clear, colorless liquid found in your brain and spinal cord. The brain and spinal cord make up your central nervous system. Your central nervous system controls and coordinates everything you do, including muscle movement, organ function, and even complex thinking and planning.
IgG stands for immunoglobulin G, a type of antibody. Antibodies are proteins made by the immune system to fight viruses, bacteria, and other foreign substances. A CSF IgG index measures the levels of IgG in your cerebrospinal fluid. High levels of IgG can mean you have an autoimmune disorder. An autoimmune disorder causes your immune system to attack healthy cells, tissues, and/or organs by mistake. These disorders can cause serious health problems.
Other names: cerebrospinal fluid IgG level, cerebrospinal fluid IgG measurement, CSF IgG level, IgG (Immunoglobulin G) spinal fluid, IgG synthesis rate
What is it used for?
A CSF IgG index is used to check for diseases of the central nervous system. It is often used to help diagnose multiple sclerosis (MS). MS is a chronic autoimmune disorder that affects the central nervous system. Many people with MS have disabling symptoms including severe fatigue, weakness, difficulty walking, and vision problems. About 80 percent of MS patients have higher than normal levels of IgG.
Why do I need a CSF IgG index?
You may need a CSF IgG index if you have symptoms of multiple sclerosis (MS).
Symptoms of MS include:
- Blurred or double vision
- Tingling in the arms, legs, or face
- Muscle spasms
- Weak muscles
- Dizziness
- Bladder control problems
- Sensitivity to light
- Double vision
- Changes in behaviour
- Confusion
What happens during a CSF IgG index?
Your cerebrospinal fluid will be collected through a procedure called a spinal tap, also known as a lumbar puncture. A spinal tap is usually done in a hospital. During the procedure:
- You will lie on your side or sit on an exam table.
- A health care provider will clean your back and inject an anaesthetic into your skin, so you won’t feel pain during the procedure. Your provider may put a numbing cream on your back before this injection.
- Once the area on your back is completely numb, your provider will insert a thin, hollow needle between two vertebrae in your lower spine. Vertebrae are the small backbones that make up your spine.
- Your provider will withdraw a small amount of cerebrospinal fluid for testing. This will take about five minutes.
- You’ll need to stay very still while the fluid is being withdrawn.
- Your provider may ask you to lie on your back for an hour or two after the procedure. This may prevent you from getting a headache afterwards.
Will I need to do anything to prepare for the test?
You don’t need any special preparations for a CSF IgG index, but you may be asked to empty your bladder and bowels before the test.
Are there any risks to the test?
There is very little risk of having a spinal tap. You may feel a little pinch or pressure when the needle is inserted. After the test, you may get a headache, called a post-lumbar headache. About one in 10 people will get a post-lumbar headache. This can last for several hours or up to a week or more. If you have a headache that lasts longer than several hours, talk to your health care provider. He or she may be able to provide treatment to relieve the pain.
You may feel some pain or tenderness in your back at the site where the needle was inserted. You may also have some bleeding at the site.
What do the results mean?
If your CSF IgG index shows higher than normal levels, it may indicate:
- Multiple sclerosis
- Another autoimmune disease, such as lupus or rheumatoid arthritis
- Chronic infection such as HIV or hepatitis
- Multiple myeloma, cancer that affects white blood cells
If your IgG index shows lower than normal levels, it may indicate:
- A disorder that weakens the immune system. These disorders make it hard to fight infections.
If your IgG index results are not normal, it may not mean you have a medical condition needing treatment. Results can vary depending on a variety of factors including your age and overall health, and medicines you are taking. If you have questions about your results, talk to your health care provider.
Is there anything else I need to know about a CSF IgG index?
The CSF IgG index is often used to help diagnose multiple sclerosis (MS), but it is not specifically an MS test. There is no single test that can tell you whether you have MS. If your health care provider thinks you have MS, you will probably have several other tests to confirm or rule out a diagnosis.
While there is no cure for MS, there are many treatments available that can help relieve symptoms and slow the progression of the disease.
References
- Allina Health [Internet]. Minneapolis: Allina Health; Cerebrospinal fluid IgG measurement, quantitative; [cited 2020 Jan 1]; [about 3 screens]. Available from: https://account.allinahealth.org/library/content/49/150438
- Johns Hopkins Medicine [Internet]. The Johns Hopkins University; c2020. Health: IgG Deficiencies; [cited 2020 Jan 1]; [about 3 screens]. Available from: https://www.hopkinsmedicine.org/health/conditions-and-diseases/igg-deficiencies
- Johns Hopkins Medicine [Internet]. The Johns Hopkins University; c2020. Health: Lumbar Puncture; [cited 2020 Jan 1]; [about 3 screens]. Available from: https://www.hopkinsmedicine.org/health/treatment-tests-and-therapies/lumbar-puncture
- Lab Tests Online [Internet]. Washington D.C.; American Association for Clinical Chemistry; c2001–2018. Autoimmune Diseases; [updated 2017 Oct 10; cited 2018 Jan 13]; [about 3 screens]. Available from: https://labtestsonline.org/conditions/autoimmune-diseases
- Lab Tests Online [Internet]. Washington D.C.; American Association for Clinical Chemistry; c2001–2020. Cerebrospinal Fluid (CSF) Testing; [updated 2019 Dec 24; cited 2020 Jan 1]; [about 2 screens]. Available from: https://labtestsonline.org/tests/cerebrospinal-fluid-csf-analysis
- Lab Tests Online [Internet]. Washington D.C.; American Association for Clinical Chemistry; c2001–2018. Multiple Sclerosis; [updated 2017 Oct 10; cited 2018 Jan 13]; [about 3 screens]. Available from: https://labtestsonline.org/conditions/multiple-sclerosis
- Mayo Clinic: Mayo Medical Laboratories [Internet]. Mayo Foundation for Medical Education and Research; c1995–2018. Test ID: SFIN: Cerebrospinal Fluid (CSF) IgG Index; [cited 2018 Jan 13]; [about 4 screens]. Available from: https://www.mayomedicallaboratories.com/test-catalog/Clinical+and+Interpretive/8009
- Merck Manual Consumer Version [Internet]. Kenilworth (NJ): Merck & Co. Inc.; c2018. Tests for Brain, Spinal Cord, and Nerve Disorders [cited 2018 Jan 13]; [about 2 screens]. Available from: http://www.merckmanuals.com/home/brain,-spinal-cord,-and-nerve-disorders/diagnosis-of-brain,-spinal-cord,-and-nerve-disorders/tests-for-brain,-spinal-cord,-and-nerve-disorders
- National Cancer Institute [Internet]. Bethesda (MD): U.S. Department of Health and Human Services; NCI Dictionary of Cancer Terms: multiple myeloma [cited 2018 Jan 13]; [about 3 screens]. Available from: https://www.cancer.gov/publications/dictionaries/cancer-terms?cdrid=4579
- National Institute of Neurological Disorders and Stroke [Internet]. Bethesda (MD): U.S. Department of Health and Human Services; Multiple Sclerosis: Hope Through Research; [cited 2018 Jan 13]; [about 3 screens]. Available from: https://www.ninds.nih.gov/Disorders/Patient-Caregiver-Education/Hope-Through-Research/Multiple-Sclerosis-Hope-Through-Research#3215_4
- National Multiple Sclerosis Society [Internet]. National Multiple Sclerosis Society; Diagnosing MS; [cited 2018 Jan 13]; [about 3 screens]. Available from: https://www.nationalmssociety.org/Symptoms-Diagnosis/Diagnosing-MS
- National Multiple Sclerosis Society [Internet]. National Multiple Sclerosis Society; MS Symptoms; [cited 2018 Jan 13]; [about 4 screens]. Available from: https://www.nationalmssociety.org/Symptoms-Diagnosis/MS-Symptoms
- NIH U.S. National Library of Medicine: Genetics Home Reference [Internet]. Bethesda (MD): U.S. Department of Health and Human Services; Multiple Sclerosis; 2018 Jan 9 [cited 2018 Jan 13]; [about 3 screens]. Available from: https://ghr.nlm.nih.gov/condition/multiple-sclerosis
- University of Rochester Medical Center [Internet]. Rochester (NY): University of Rochester Medical Center; c2018. Health Encyclopedia: Quantitative Immunoglobulins; [cited 2018 Jan 13]; [about 2 screens]. Available from: https://www.urmc.rochester.edu/encyclopedia/content.aspx?contenttypeid=167&contentid;=quantitative_immunoglobulins
- University of Rochester Medical Center [Internet]. Rochester (NY): University of Rochester Medical Center; c2020. Health Encyclopedia: Spinal Tap (Lumbar Puncture) for Children; [cited 2020 Jan 1]; [about 2 screens]. Available from: https://www.urmc.rochester.edu/encyclopedia/content.aspx?contenttypeid=90&contentid=P02625
- UW Health [Internet]. Madison (WI): University of Wisconsin Hospitals and Clinics Authority; c2018. Immunoglobulins: Test Overview; [updated 2017 Oct 9; cited 2018 Jan 13]; [about 2 screens]. Available from: https://www.uwhealth.org/health/topic/medicaltest/immunoglobulins/hw41342.html
- UW Health [Internet]. Madison (WI): University of Wisconsin Hospitals and Clinics Authority; c2018. Immunoglobulins: Results; [updated 2017 Oct 9; cited 2018 Jan 13]; [about 8 screens]. Available from: https://www.uwhealth.org/health/topic/medicaltest/immunoglobulins/hw41342.html#hw41354