Expression of annexin-1 in multiple sclerosis plaques

This study describes the distribution and identity of annexin-1 positive cells in the central nervous system in patients with multiple sclerosis (MS). Glucocorticoid-inducible, anti-inflammatory properties have been ascribed to annexin-1, a member of a family of calcium-binding proteins that are referred to collectively as annexins. We have found annexin-1 to be spatially associated with active MS lesions and demonstrated a stage-dependent expression of annexin-1 in MS plaques. All of the most important pathogenetically involved cells of MS lesions showed a strong annexin-1 reactivity. Both correlation analysis and double staining procedures suggested annexin-1 expression in macrophages and perivascular lymphocytes, where a cytoplasmic reactivity was displayed, whereas in activated, gemistocytic astrocytes it was also concentrated close to the plasma membrane. Although the exact roles of annexin-1 in this setting are still to be determined, a possible contribution to anti-inflammatory processes might be suggested.