Immune cells in the human choroid.

Area of Science:

• Ophthalmology
• Immunology
• Cell Biology

Background:

• Age-related macular degeneration (AMD) is a leading cause of vision loss.
• The role of inflammatory cells in the pathogenesis of AMD is not fully understood.
• Leukocyte infiltration in the macula may contribute to AMD development.

Purpose of the Study:

• To characterize leucocyte populations in human macular choroid.
• To compare leucocyte presence in maculas with and without drusen.
• To investigate leucocyte profiles in eyes with advanced AMD and fibrovascular scarring (FVS).

Main Methods:

• Human macular biopsies from nine donors (55-91 years) were analyzed.
• Immunohistochemistry was used to detect leucocyte antigens (CD45, CD4, CD8, CD14, CD83).
• Samples were categorized as without drusen, with drusen, or with FVS.

Main Results:

• CD45 (total leucocytes), CD4 (T-helper cells), and CD14 (monocytes) levels were similar across groups.
• CD8-positive cells (cytotoxic T-cells) were more abundant in macular choroid with drusen.
• CD83-positive cells (dendritic cells/monocytes) were found only in one FVS eye.

Conclusions:

• Human choroid contains comparable CD4-positive cells and monocytes regardless of drusen presence.
• Increased CD8-positive cells in the presence of drusen suggest an inflammatory component.
• The presence of hematopoietic cells supports the involvement of inflammatory cells in AMD pathogenesis.