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Concordance rate between oligoclonal bands and the Kappa index in patients with suspected multiple sclerosis (MS)
Renan Barros Domingues1, Márcio Vega Dos Santos1, Daiane Salomão1
1Senne Liquor Diagnóstico, São Paulo SP, Brazil.
Insights
Oligoclonal bands (OCBs) and the Kappa index (KI) show high agreement in diagnosing multiple sclerosis (MS). The KI offers a potentially faster and simpler alternative to OCBs for detecting intrathecal immunoglobulin synthesis.
Area of Science:
- Neurology
- Immunology
- Clinical Chemistry
Background:
- Oligoclonal bands (OCBs) and Kappa free light chains (FLCs) in cerebrospinal fluid (CSF) indicate intrathecal IgG synthesis.
- These markers are crucial for diagnosing multiple sclerosis (MS).
Purpose of the Study:
- To assess the concordance between OCBs and the Kappa index (KI) in patients with suspected MS.
- To evaluate the KI as a potential alternative diagnostic marker.
Main Methods:
- Collected paired CSF and serum samples from 171 patients with suspected MS.
- Detected OCBs and determined the KI in all samples.
- Calculated the percentage of agreement between OCB and KI results.
Main Results:
- High concordance (94.2%) was observed between OCBs and KI.
- Both methods were positive in 43.3% and negative in 50.9% of cases.
- Discrepancies occurred in 10 cases (KI+/OCB- in 8, OCB+/KI- in 2).
Conclusions:
- The Kappa index (KI) demonstrates a high level of agreement with OCBs for detecting intrathecal immunoproduction.
- The KI presents a promising, potentially more efficient alternative to the standard OCB test for suspected MS diagnosis.
Background:
Oligoclonal bands (OCBs) and Kappa free light chains (FLCs) in the cerebrospinal fluid (CSF) are sensitive markers of intrathecal immunoglobulin (Ig)G synthesis in patients with multiple sclerosis.
Objective:
To evaluate the concordance rate between OCBCs and the Kappa index (KI) in patients with suspected multiple sclerosis (MS).
Methods:
Patients with suspected MS were referred to a specialized CSF laboratory as part of their diagnostic investigation. Paired CSF and serum samples were collected and submitted to detection of OCBs and determination of the KI. Positive and negative results were determined with both methods, and the percentage of agreement between them was established.
Results:
In total, 171 serum and CSF samples from 171 patients were included in the analysis. The mean age of the patients was of 40 ± 14.2 years; 18.9% of them were male, and 81.1% were female. The OCBs and KI presented concordant results in 161 (94.2%) samples: in 74 (43.3%), both were positive, and in 87 (50.9%), both were negative. In 10 cases, the results were discrepant: KI positive/OCB negative in 8 and OCB positive/KI negative in 2 cases.
Conclusion:
The KI and OCBs presented high concordance level. Currently, the detection of OCBs in the CSF is the standard method for MS diagnosis, but it is time-consuming, and its visual interpretation can be difficult. The results suggest that the KI is a good alternative for the detection of intrathecal immunoproduction in cases of suspected MS.
