Clinical utility of a molecular signature in inflammatory demyelinating disease.

Objective We sought to develop molecular biomarkers of intrathecal inflammation to assist neurologists in identifying patients most likely to benefit from a range of immune therapies. Methods We used Luminex technology and index determination to search for an inflammatory activity molecular signature (LAMS) in patients with inflammatory demyelinating disease (IDD), other neuroinflammatory diagnoses, and noninflammatory controls. We then followed the clinical characteristics of these patients to find how the presence of the signature might assist in diagnosis and prognosis. Results A CSF molecular signature consisting of elevated CXCL13, elevated immunoglobulins, normal albumin CSF/serum ratio (Q(albumin)), and minimal elevation of cytokines other than CXCL13 provided diagnostic and prognostic value; absence of the signature in IDD predicted lack of subsequent inflammatory events. The signature outperformed oligoclonal bands, which were frequently false positive for active neuroinflammation. Conclusions A CSF TAMS may prove useful in the diagnosis and management of patients with IDD and other neuroinflammatory syndromes. Classification of evidence This study provides Class IV evidence that a CSF LAMS identifies patients with IDD.