Abstract:
As the primary intrinsic immune effector cell of the CNS, microglia are involved in virtually all pathological processes of the brain and spinal cord including
inflammatory, neurodegenerative, traumatic, neoplastic and vascular diseases.
Despite its important role, there is a lack of data concerning microglia distribution and protein expression in the human spinal cord.
In this study, we immunohistochemically investigated 10 normal human spinal cords to establish reference data and compared these results to 15 pathological human spinal cords deriving from distinct pathologies. Each spinal cord was evaluated at 8 different levels for 3 white and 2 gray matter areas for both constitutive (MHC-II, CD68, IL-16, AIF-1, LCA, CD4) and reactive (MRP-8, MRP-14) microglial antigens. Whereas previous studies revealed significant regional differences in microglial distribution and protein expression in human brain, normal spinal cord displayed a uniform expression pattern, reaching levels of up to 17% MHC-II positive cells of the total cell population. This data formed the basis for the further evaluation of microglia expression levels in pathological spinal cords, where levels of up to 45% positive cells were observed.
Our results represent important reference values for future neuropathological diagnostic and therapeutical approaches in spinal cord pathologies.