Case Reports and Reviews: Open Access

Abstract

Background: DNA methylation–based epigenetic clocks are increasingly used to estimate biological age and to track aging-related physiology in both chronic disease management and longevity-focused care. These assessment tools are heterogeneous: some models prioritize chronological-age prediction, whereas others emphasize morbidity/mortality risk, methylation variability (“biological noise”), organ-system aging patterns, or pace-of-aging metrics. In rheumatoid arthritis (RA), inflammation has been associated with epigenetic age acceleration, including findings reported using second-generation clocks such as GrimAge and GrimAge2. Multilineage-differentiating stress-enduring (MUSE) cells are endogenous, non-tumorigenic reparative stem cells with reported damage-site homing and immunomodulatory effects; contemporary reviews and clinical-trial experience describe intravenous administration of donor MUSE cells without human leukocyte antigen (HLA) matching or immunosuppression in select indications. 

Objective: To describe the clinical outcomes and epigenetic aging findings observed following MUSE cell and exosome therapy in two patients undergoing regenerative and longevity-focused treatment. 

Case presentation: We present two patients who underwent MUSE cell and exosome therapy. The first patient was a 45-year-old male with rheumatoid arthritis and chronic multisite inflammatory musculoskeletal pain. The second patient was a 52-year-old female pursuing longevity-focused care after demonstrating elevated biological age estimates and unfavorable pace-of-aging metrics. 

Conclusion: In this two-patient case series, following MUSE cell and exosome therapy, favorable patient-reported and epigenetic aging outcomes were reported. These outcomes included improved mobility, reduced inflammatory symptoms, decreased analgesic use, and improvements in biological aging metrics such as OrganSystemAge, OmniAge, and pace-of-aging outputs. These findings support further investigation into the relationship between regenerative therapies and biological aging metrics.

Keywords: MUSE cells; Exosomes; Rheumatoid arthritis; Immune system aging; Epigenetic aging; DNA methylation biomarkers; SystemAge; TruDiagnostic; Glucocorticoids; Metabolic dysfunction; Regenerative medicine.