CXCL13 and pseudolymphoma: However, two of these patients presented with acute facial nerve palsy and anti-Borrelia IgM antibodies in serum (one with a Borrelia lymphocytoma on the ipsilateral side) possibly indicating two very early LNB patients with pleocytosis but with no intrathecally produced anti-Borrelia antibodies and no CXCL13 in CSF at the time of lumbar puncture.