Detection of Chlamydia and complement factors in neovascular membranes of patients with age-related macular degeneration.

Purpose: To investigate whether Chlamydia pneumoniae and complement factors were present in surgically removed choroidal neovascular membranes (CNV) of patients with age-related macular degeneration (AMD).
Methods: Paraffin sections of 26 CNV were stained for C. pneumoniae or the complement factors H (CFH) and C5, whereas macrophages were identified by positive CD68 staining. Clinical characteristics have been correlated to the immunohistochemical findings.
Results: C. pneumoniae was found in 68% of the investigated membranes, and 88% of these membranes were also positive for CD68. Staining for CFH and C5 gave a positive reaction in 68 and 41% of the membranes, respectively. Patients with C5-positive membranes had significantly larger CNV mean area and were younger than patients with CFH-positive membranes at the operation time point.
Conclusions: Correlations between clinical symptoms and complement factor C5 could be shown. The results strengthen the hypothesis of an involvement of the complement system in AMD.