Multiple Sclerosis
Free light chain analysis in CSF can support the diagnosis of multiple sclerosis
Multiple Sclerosis (MS) is an autoimmune inflammatory disease estimated to affect 2.5 million people globally1. Early diagnosis and treatment is important to limit its impact on patients’ quality of life.
A diagnosis of MS is made primarily on the basis of medical history and physical examination, with magnetic resonance imaging (MRI) used to identify neurological lesions.2 Detection of intrathecal immunoglobulins can support a diagnosis of MS.
Elevated concentrations of intrathecal free light chains (FLCs), especially κ FLCs, are being increasingly used as markers of intrathecal immunoglobulin synthesis. Studies have shown that an increased κ FLC index ( [κ FLC CSF/ κ FLC serum ]/[albuminCSF/albuminserum] ) can support a diagnosis of MS (Figure 1)3-6 and assist in differentiating MS from neurological disorders (Figure 2).3,6
Elevated κ FLC has excellent concordance with other methods used to detect intrathecal immunoglobulins such as oligoclonal band (OCB) analysis and has equivalent diagnostic sensitivity and specificity (Table 1).
| Technique | Sensitivity % | Specificity % |
| OCB3,4,7 | 88-94 | 94 |
| κ FLC index (non-linear threshold)4 | 97 | 98 |
Table 1: Comparison of sensitivity and specificity of immunoglobulin OCB and κ FLC index as markers for MS
- Atlas of MS 2013 - Multiple Sclerosis International Federation (MSIF): 2013
- Polman CH et al. Ann Neurol 2011;69:292-302
- Presslauer S et al. J. Neurol. 2008; 255: 1508-14
- Presslauer S et al. PLosONE. 2014; 9e89945
- Brivio et al. Hematology reports 2015; 7(s1), 63
- Cavaletti et al. poster at XLII congress of Italian society of neurology, Genoa, Italy 2015
- Dobson R et al. J Neurol Neurosurg Psychiatry 2013; 84: 909-14