Macrophages in human epiretinal and vitreal membranes in patients with proliferative intraocular disorders.

PURPOSE

Macrophages are versatile cells and have been known as a cellular component of epiretinal membranes of proliferative intraocular disorders (PID). However, the origin and functions of these cells in the membranes are not yet clear. In the present study we investigated the characterization of macrophages/monocytes in various types of human epiretinal membranes from patients with proliferative vitreortinopathy (PVR), proliferative diabetic retinopathy (PDR) and ocular perforating injury by means of immunohistochemical techniques.

METHODS

A total of 49 epiretinal membranes of PID in which 24 were PDR specimens, 17 were PVR and 8 were proliferations after perforating eye injury were studied. Monoclonal antibodies against human macrophages, monocytes, HLA-DR antigen and interleukin-1 (IL-1) were used. The alkaline phosphatase anti-alkaline phosphatase (APAAP) technique was performed.

RESULTS

The results showed that 19 out of 24 PDR specimens (79%), 15 out of 17 PVR specimens (88%) and 7 out of 8 traumatic specimens (87%) contained macrophages, HLA-DR antigen was detected in 20 out of the 24 PDR membranes (83%), 14 out of 17 PVR membranes (82%) and 5 out of 8 traumatic membranes (63%); monocytes were only detected in 10 out of the 24 PDR specimens (41%). In addition, in a group of PDR specimens, interleukin-1 (IL-1) was detected in 8 out of 13 tested specimens (62%).

CONCLUSION

The results revealed that the macrophages in the membranes were in an active stage and may play a significant role in the development of proliferative intraocular disorders through either inducing inflammatory reactions or immune responses, or the effects of their cytokines.