[Antibodies to types II and IV collagens, tumor necrosis factor-alpha and circulating immune complexes in lacrimal fluid and serum of patients with diabetic retinopathy and different stages].

Clinical and immunological examinations are carried out in patients with preclinical, nonproliferative, preproliferative, and proliferative diabetic retinopathy (DR). On the whole, DR is characterized by a notable increase in antibody-dependent immune response, associated with appearance of antibodies to collagen of the II and IV types in the lacrimal fluid and serum, with the "local" reactions predominating. The level of reactions of cellular autoimmune response (tumor necrosis factor-alpha) and cell-to-cell reactions in the lacrimal fluid and serum is low. Increased level of circulating immune complexes in the serum and almost complete absence of free antibodies to collagen in the blood may be indicative of formation of pathogenic immune complexes precipitating on vascular walls and in other tissues. Various forms of immune response were revealed, conducive to a favorable or unfavorable course of DR.