Autologous Serum Tear Production in Anticoagulated Patients

Autologous serum tears (ASTs) are produced from serum obtained by blood draw and used to treat severe dry eye diseases. Multiple cases of failed AST production occurred due to serum becoming a solidified, gel-like substance after centrifugation. The aim of this study was to identify risk factors associated with inability to compound AST.

From January 2019 to December 2022, 99 patients received AST produced at Mayo Clinic in Arizona. Patient demographics, medical diagnoses, medications, laboratory results, and events surrounding blood draws were obtained through an IRB-approved retrospective chart review. The laboratory and pharmacy protocol procedures were observed in person after the occurrence of the last production issue.

Ten total clotted serum episodes occurred in 4 patients, each with multiple occurrences. The indication for AST was chronic ocular graft-vs-host disease (n = 3) and Sjögren syndrome (n = 1). Eighty percent of episodes were associated with either a systemic infection (n = 7) or pulmonary embolism (n = 1) within the prior month. At the time of blood draw, all 4 patients were treated with antiplatelet and/or anticoagulation medications, including rivaroxaban, apixaban, aspirin, and low-molecular-weight heparin.

The AST protocol was increased from 30 to 60 minutes of resting time to allow clotting before centrifugation. Inadequate clotting during this stasis period likely resulted in fibrinogen remaining suspended in the serum, leading to solidified plasma instead of liquid serum. We hypothesize risk of inadequate clotting would be increased in patients taking anticoagulation or antiplatelet medications. Our recommendations include ensuring 60-minute collection tube resting time for all patients, including those on anticoagulation medication.