Neurology and Neurosurgery

April 23, 2022

Mayo Clinic researchers have validated a new antibody test for the diagnosis of multiple sclerosis (MS). The cerebrospinal fluid test measures immunoglobulin kappa free light chains rather than oligoclonal bands, the target of current gold standard testing. As described in a study to be published in Mayo Clinic Proceedings, the new antibody test's results are available in about 20 minutes.

The researchers analyzed paired cerebrospinal fluid and serum samples from 702 patients who had immunoglobulin kappa cerebrospinal fluid (KCSF) testing and oligoclonal band testing at Mayo Clinic. The test results' specificity and sensitivity for MS diagnosis were evaluated to determine a KCSF value comparable to the detection of oligoclonal bands. The KCSF value was then validated in 657 prospective paired samples.

Key points

• A KCSF measure of 0.1 mg/dL provides similar sensitivity and specificity for the diagnosis of MS compared to oligoclonal band testing.
• KCSF testing is less labor-intensive, time-consuming and costly than oligoclonal band testing.
• KCSF testing is more automated than oligoclonal band testing, substantially limiting subjective visual interpretation.

The researchers note that the study results meet class I criteria for the diagnostic accuracy of KCSF as an MS biomarker.

For more information

Saadeh RS, et al. CSF kappa free light chains: Cutoff validation for diagnosing multiple sclerosis. Mayo Clinic Proceedings. 2022:97;738.

Refer a patient to Mayo Clinic.