Are paired serum and cerebrospinal fluid (CSF) samples required for oligoclonal band (OLG) detection via electrophoresis?

From the Guidelines

Yes, paired serum and cerebrospinal fluid (CSF) samples are required for oligoclonal band (OLG) detection via electrophoresis.

Key Points

• The presence of oligoclonal IgG bands in CSF that are different from any such bands in serum is a key criterion for diagnosing multiple sclerosis (MS) 1.
• To determine this, paired serum and CSF samples must be analyzed using techniques such as isoelectric focusing 1.
• The International Panel on the diagnosis of MS recommends that CSF analysis include the detection of oligoclonal bands, and that this be done in a reproducible fashion with state-of-the-art technology 1.
• A positive CSF result is determined by the presence of oligoclonal bands detected by established methods, different from any such bands in serum, or by a raised IgG index 1.
• Some key details to consider when analyzing CSF and serum samples include:
  • The quality of CSF analysis can vary among laboratories, regions, or countries 1.
  • Lymphocytic pleocytosis should be less than 50/mm3 1.
  • The IgG index should be elevated to support the diagnosis of MS 1.

From the Research

Oligoclonal Band Detection via Electrophoresis

• The detection of oligoclonal bands (OCBs) in cerebrospinal fluid (CSF) is a crucial diagnostic tool for various neurological conditions, including multiple sclerosis 2, 3, 4.
• To determine the presence of OCBs, CSF samples are often analyzed alongside paired serum samples using techniques such as isoelectric focusing and immunofixation 2, 3.
• The analysis of paired serum and CSF samples can help identify five different immunofixation patterns, which can aid in diagnosing neurological conditions 2.
• These patterns include:
  • Type 1: normal physiological state with no intrathecal IgG synthesis
  • Type 2: evidence for intrathecal IgG synthesis, with CSF-restricted OCBs
  • Type 3: evidence for intrathecal IgG synthesis, with CSF-restricted OCBs, but with additional, identical bands in the CSF and serum
  • Type 4: absence of intrathecal IgG synthesis, but with identical OCBs in CSF and serum
  • Type 5: absence of intrathecal IgG synthesis, with a monoclonal band in CSF and serum
• The use of paired serum and CSF samples is essential for accurate OCB detection, as it allows for the identification of CSF-restricted bands and helps to differentiate between various neurological conditions 3, 4.
• Studies have shown that the detection of OCBs in CSF using isoelectric focusing is more sensitive than other methods, such as agarose gel electrophoresis 3.
• However, the clinical significance of single or double bands in CSF isoelectric focusing is still a topic of debate, and further research is needed to fully understand its implications 5.
• Other bodily fluids, such as tears, have been investigated as potential alternatives to CSF for OCB detection, but their use is not recommended due to limited concordance and high rates of insufficient sample material 6.