Immunoglobulins induce increased myelin debris clearance by mouse macrophages

The present study investigated the effect of human immunoglobulins on migra tion and myelin phagocytosis by macrophages. Mouse sciatic nerves and macro phages were cocultured and treated with 1, 10 and 20 mg/ml immunoglobulins for 10 days in vitro. Numbers of invading macrophages, myelin density withi n the nerves and macrophage myelin load were determined in semithin section s. Human immunoglobulins lead to an increased myelin removal by macrophages as proven by a statistically significant higher myelin load of the macroph age cytoplasm when compared with untreated control macrophages. The results suggest that one possible action of immunoglobulins in demyelinating disea ses is an improved clearance of lesional debris with the removal of myelin- associated inhibitory molecules. (C) 1999 Elsevier Science Ireland Ltd. All rights reserved.