Figure 8. Distribution of CD68-positive and iron-positive cells in MS lesions with and without phase rim.

Iron-laden CD68-positive macrophages/activated microglia were more common at the lesion edge than at the lesion center and within the surrounding white matter. On the other hand, lesions without phase rim showed varying degrees of non–iron-laden CD68-positive cells, not significantly different from the surrounding white matter. Lesions 1–4 belong to patient 1, lesions 5 and 6 to patient 2, and lesions 7–10 to patient 3 (see Supplemental Appendix for details). *P < 0.0001 in edge versus center and edge versus white matter (ANOVA, post hoc analysis and Bonferroni correction for multiple comparisons).