CCL4 and metachromatic leukodystrophy: For instance, increased levels of monocyte chemoattractant protein 1 (MCP-1), interleukin (IL)-1 receptor antagonist (IL-1Ra), IL-8, macrophage inflammatory protein 1β (MIP-1β) and vascular endothelial growth factor (VEGF) are detected in both plasma and cerebrospinal fluid (CSF) of patients with MLD.