In this study, in addition to the conventional tests (IgG index calculation, Reiber Diagram, CSF Isofocusing test) (Table 1), we investigated other B lymphocyte-related parameters in CSF (the κFLC and λFLC metrics, the chemokine CXCL13) and studied their performance for MS diagnosis and their correlation with the intrathecal humoral immune response (Table 2). This evidence concerns the gene CXCL13 and myeloid sarcoma.