CCL5 and neuromyelitis optica: In addition, together with the increase in IP-10 secretion by BMECs following exposure to NMO sera, increased levels of MCP-1 and RANTES may also be involved in the leukocyte transendothelial migration across the BBB during the acute phase of NMO, although previous reports have demonstrated that the levels of these markers were not elevated in the CSF samples from NMO patients [14].