Mayo study shows cerebrospinal fluid Kappa free light chain testing could be used to diagnose MS


diagnose multiple sclerosis, which can reduce costs and turnaround times compared to standard tests.

Maria Alice Willrich, Ph.D., Mayo Clinic pathologist and lead author of the study published in Mayo Clinic Proceedingsand colleagues compared the standard diagnostic test that detects oligoclonal bands (OCBs) – proteins in cerebrospinal fluid that indicate central nervous system inflammation – with the measurement of free kappa light chains, also in cerebrospinal fluid. spinal.

Free kappa light chains are a component of antibodies. Free light chain blood tests are used in the diagnosis of multiple myeloma and other plasma cell disorders.

“Measurement of free kappa light chain in cerebrospinal fluid is relatively new, and various published studies have attempted to decide what is the best medical decision point for optimal test performance,” Willrich said in a statement. Press release. “Based on the data from our study, we have identified the optimal performance of the test for a large US-based population.”

OCB tests are proven but also have drawbacks. It is labor intensive and requires approximately four hours of analytical processing. It also involves subjective visual interpretation, Willrich noted. In contrast, the results of a kappa free light chain test are available in about 20 minutes. Light chain testing without Kappa should yield “significant” cost savings, Willrich said.

Willrich and colleagues tested 702 retrospective and 657 prospective cerebrospinal/serum samples from residual waste samples from physician-ordered OCB tests. The graphs were reviewed by a neurologist unaware of the kappa free light chain results.

The specificity and sensitivity for the diagnosis of MS were assessed to establish a diagnostic threshold value in the retrospective cohort, then validated in the prospective cohort.

Of more than 1,300 patients, 12% were diagnosed with MS.

“The KCSF (measurement of kappa free light chain from cerebrospinal fluid) value of 0.1 mg/dL is a valid alternative to the OCB test, providing a standardized quantitative measurement, eliminating human error, reducing costs and turnaround times, with no significant difference in sensitivity and specificity,” Willrich wrote.

“One of the advantages of measuring kappa is that it’s a much easier test to run in the lab,” echoed Ruba Saadeh, a neuroimmunology researcher at Mayo Clinic Department of Laboratory Medicine and Pathology, and the first author of the study. “Our results represent a cost saving as well as an automated alternative to the arsenal of tests used to diagnose multiple sclerosis.”

Additionally, training for lab technologists can be standardized due to the automation involved in the process, according to Willrich.


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