CXCL13 and autoimmune disease: Since 2005, various studies have confirmed that the detection of CXCL13 in CSF is a useful marker for the diagnosis of early LNB, irrespective of the causative Borrelia species (24), even though elevated CSF CXCL13 levels have also been found in patients with other bacterial (14, 24, –, 29) and viral (21, 25, –, 28, 30, –, 32, 54) central nervous system (CNS) infections, autoimmune diseases (19, 28, 33), and white blood cell line malignancies (26, 34).