Oligoclonal bands (OCBs) are a type of protein that can occur in the cerebrospinal fluid (CSF). The presence of oligoclonal bands may mean a person has multiple sclerosis (MS).

MS is a disease that affects the CNS, which consists of the brain and spinal cord. CSF is the clear fluid that is present around the spinal cord and the brain.

This article discusses the link between OCBs and MS and what the testing involves.

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The presence of OCBs in the CSF is an important factor in diagnosing MS. The presence of OCBs can indicate inflammation in the central nervous system (CNS).

A study from 2016 noted that more than 95% of all people living with MS have elevated levels of OCBs.

However, testing for OCB levels alone is not enough to diagnose MS. The reason for this is that the presence of OCBs can also indicate other conditions that cause inflammation in the CNS.

According to a 2019 study, a lack of OCBs in those who present with MS-like symptoms may indicate that another underlying condition is present, such as migraine.

A doctor may use a CSF oligoclonal banding test to help confirm MS, but they will also need to consider other diagnostic criteria.

To detect OCB levels, a doctor may order a CSF oligoclonal banding test, which requires a sample of the CSF. The doctor will collect the sample by performing a lumbar puncture, or spinal tap.

People who receive a diagnosis of MS typically have positive test results, indicating that OCB is present in the CSF.

The test alone is not enough to diagnose MS. A doctor must also find:

  • at least two areas of damage to, or lesions in, the brain or spinal cord
  • evidence that the damage occurred at different times
  • evidence that another disease has not caused the damage to the CNS

The CSF oligoclonal banding screening involves undergoing a procedure called a lumbar puncture. A doctor will insert a needle through the skin and into the spine. Before the test, a doctor may order imaging tests, such as a CT scan or an MRI scan, to ensure that it is safe for the person to undergo the procedure.

A person does not need to do much to prepare for the test itself. However, they should let the doctor know about any medications they are taking, including blood thinners, and any medical history that relates to their spine.

A person’s healthcare team should make them aware of any additional steps they should take to prepare for the test.

A person will need to go to a hospital or another clinical setting for the test.

The procedure can vary depending on the doctor’s practices and the person’s health status. Some doctors may perform a lumbar puncture using medical imaging for guidance, such as an ultrasound or interventional radiology.

During the procedure, a person will lie on their side with their legs pulled up toward their chin and their chin tucked in. This helps the doctor insert the needle more easily.

The doctor or nurse will then perform the following steps:

  1. They will clean the skin and numb the area using a local anesthetic.
  2. They will insert the thin needle between the two bones in the lower back and extract the sample. At this point, a person can expect to feel some pressure, but it should not be painful.
  3. They will remove the needle and apply a dressing.

Lab technicians will then analyze the CSF sample for OCBs.

The results of the CSF oligoclonal banding test can indicate the presence of OCBs or elevated levels of OCB.

A test that reveals elevated levels of OCBs could indicate MS. However, as the National Multiple Sclerosis Foundation states, test scores are not enough to confirm a diagnosis.

The diagnostic process will also involve the doctor:

  • reviewing a person’s medical history
  • performing a neurological examination
  • using imaging tests, such as an MRI

If elevated OCB levels are present but a person does not fit the criteria for MS, a doctor will likely continue to search for the underlying cause.

A doctor may use a CSF oligoclonal banding test to help confirm a diagnosis of MS. If they find that a person has MS, they will work with the individual to develop a treatment plan based on their particular needs.

If the test comes back positive for OCB levels, but a doctor cannot diagnose MS, they will likely order further testing to determine the underlying cause of the elevated OCB levels.

Similarly, if a test comes back negative but a person is experiencing symptoms, additional tests may be necessary to confirm what is causing the symptoms.

If a person receives a diagnosis of MS, they can find resources and support from the following organizations:

OCBs appear in the CSF of the vast majority of people living with MS. However, their presence alone does not mean that a person definitely has MS. A doctor will need to conduct additional testing to determine the presence of MS.

To test OCB levels, a doctor will need to perform a CSF oligoclonal banding test, which involves inserting a needle into the spine to collect CSF. Tests that show an elevated level of OCBs indicate that a person might be living with MS. However, there are other possible causes of elevated OCB levels.