Low-cost protocol for the production of autologous serum eye drops by blood collection and processing centres for the treatment of ocular surface diseases.

OBJECTIVES: To create a low-cost protocol for the production of autologous serum eye drops (ASEs) by blood collection and processing centres using standard equipment and staff already available. The protocol must observe local and federal regulatory authorities' requirements for good manufacturing practice. AIM: The final aim is to improve accessibility to ASEs for patients who need them and to implement similar production parameters at all institutions producing ASEs. BACKGROUND: Despite evidence of the beneficial effects of ASEs in the treatment of severe ocular surface diseases, ASEs are not approved by most federal regulatory bodies in the United States or Europe. In some countries, such as the United States, access to ASEs is extremely limited and cost-prohibitive. Blood processing centres are in optimal position to help in increasing accessibility and lowering the cost of these products. MATERIALS/METHODS: Standard blood processing equipment, staff and materials were chosen for the protocol. The protocol was designed to minimise the risk of contamination as much as possible. RESULTS: A low-cost, open system protocol for production of ASEs was generated that can be implemented by most blood collection and processing centres in the United States and Europe. CONCLUSION: Efforts should be made to propagate a similar protocol for the production of ASEs in blood centres capable of collecting and processing blood products, making this service affordable and uniformly accessible to patients.

Immunological evidence for methylglyoxal-derived modifications in vivo. Determination of antigenic epitopes.

The Maillard reaction, a non-enzymatic reaction of ketones and aldehydes with amino groups of proteins, contributes to the aging of proteins and to complications associated with diabetes. Methylglyoxal (MG) is a 2-oxoaldehyde derived from glycolytic intermediates and produced during the Maillard reaction. We reported previously the formation of a lysine-lysine protein cross-linking structure (imidazolysine) and a fluorescent arginine modification (argpyrimidine) from the Maillard reaction of MG. Here we show that rabbit antibodies to MG-modified ribonuclease A identify proteins modified by the Maillard reaction of glucose, fructose, ribose, glyceraldehyde, glyoxal, ascorbate, and ascorbate oxidation products (dehydroascorbate, 2,3-diketogulonate, L-xylosone, and L-threose) in addition to those modified by MG. The antibody recognized imidazolysine and argpyrimidine and a glyoxal-derived lysine-lysine cross-link. It did not react with Nepsilon-carboxymethyllysine. Incubations with amino acids revealed strongest reactivity with Nalpha-t-butoxycarbonylarginine and MG, and we identified argpyrimidine as one of the epitopes from this incubation mixture. Serum proteins from human diabetics reacted more strongly with the antibody than those from normal individuals, and the levels correlated with glycemic control. Collagen from human corneas contained MG-derived modifications, with those from older subjects containing higher levels of modified proteins than those from younger ones. An immunoaffinity-purified antibody showed higher reactivity with old corneas than with younger ones and localized the antigens primarily within the stromal region of the cornea. These results confirm reported MG-derived modifications in tissue proteins and show that dicarbonyl-mediated protein modification occurs during Maillard reactions in vivo.