Immunoglobulin Free Light Chains as New Putative Markers in Diagnosis and Disease Activity Estimation in Pediatric Multiple Sclerosis

Identification of new biomarkers is important to overcome the difficulties in diagnosis and management of pediatric multiple sclerosis (MS). Here we demonstrate the utility of our recently developed technique involving Western blot analysis of free light chain (FLC) for diagnosis and monitoring of pediatric MS. By this technique, FLC monomers (M) and dimers (D) were analyzed in patients’ cerebrospinal fluid (CSF), serum and saliva. MS patients in relapse showed abnormally increased CSF levels of kappa or/and lambda dimers {10 of10 cases) typically observed in MS [1], thus confirming the diagnostic utility of this method. FLC M-D pattern abnormalities were also observed in the saliva of these patients (9 of 10 cases); these abnormalities were invariably associated with enhanced lesions in brain or spinal cord MRI. In contrast, patients in remission showed normal saliva FLC patterns in 8 of 10 MS and in 6 of 8 CIS cases; none of these patients demonstrated enhanced lesions by MRI. Saliva FLC patterns in 7 of 8 patients with non-demyelinating diseases (such as Rasmussen disease, CADASIL, uveitis, chorea) were also normal, as compared to those in healthy children (n=10). Notably, under treatment with steroids, patients with MS (n=3) and CIS (n=2) showed normal FLC patterns. These observations suggest that saliva FLC pattern analysis may serve as a new non-invasive tool for disease activity assessment in MS.

Taken together, FLC M-D analysis in different bodily fluids is a new methodological approach which may assist in the diagnosis and monitoring of pediatric MS.

References: [1] E.Ganelin-Cohen et al. Clin Chem Lab Med (2018) 56(7), 1081-1089.