Chronic graft-versus-host disease (cGvHD) is a significant complication that can occur after hematopoietic stem cell transplantation (HSCT), affecting a substantial percentage of patients. Among the various organs and tissues it can impact, the eyes are particularly vulnerable, with more than half of cGvHD cases leading to inflammation and immune cell infiltration, resulting in a condition known as keratoconjunctivitis sicca. Autologous serum eye drops (ASEDs) have proven effective in managing this condition, but the specific mechanisms by which ASEDs work are poorly understood.
A pilot study presented at the 11th Annual Meeting of the Society of Hematologic Oncology (SOHO), Houston, Texas, sought to investigate the characteristics of circulatory extracellular vesicles (EV) present in ASEDs from cGvHD patients in comparison to healthy individuals, aiming to learn more about the way ASEDs function.
The study authors isolated EVs from the serum of cGvHD patients undergoing ASED preparation (6 patients) and from healthy donors (6 individuals). These EVs were then thoroughly characterized, and the content of microRNAs was analyzed using advanced technology. In addition, bioinformatics tools were employed to identify specific microRNA targets associated with EVs.
The study found notable differences between EVs from ASEDs and those from healthy controls. ASED EVs were larger in size but contained lower RNA levels. They also carried a higher number of microRNAs. Interestingly, a distinct set of 62 microRNAs was identified as significantly differentially expressed in ASED EVs compared to controls. These microRNAs were associated with genes related to various pathways, including those associated with vision and ocular GvHD therapy.
This preliminary investigation suggests that EVs present in ASEDs from patients with ocular GvHD may play a role in the therapeutic mechanisms of ASEDs.
Bogdanic D, Schell KJ, Bojanic I, et al. Extracellular Vesicles (EVs) Contribute to the Mechanism of Action of Autologous Serum Eye Drops (ASEDs) as a Treatment Modality for Chronic Graft Versus Host Disease (cGvHD). Abstract CT-448. Presented at the 11th Annual Meeting of the Society of Hematologic Oncology; September 6-9, 2023; Houston, Texas.