Low Dose Rapamycin Alleviates Clinical Symptoms of Fatigue and PEM in ME/CFS Patients via Improvement of Autophagy

Abstract:

Background: mTOR activation is associated with chronic inflammation in ME/CFS. Previous studies have shown that sustained mTOR activation can cause chronic muscle fatigue by inhibiting ATG13-mediated autophagy. This highlights the pivotal role of mTOR in the pathogenesis of ME/CFS.

Methods: We conducted a decentralized, uncontrolled trial of rapamycin in 86 patients with ME/CFS to evaluate its safety and efficacy. Low-dose rapamycin (6 mg/week) was administered, and core ME/CFS symptoms were assessed on days 30 (T1), 60 (T2), and 90 (T3). Plasma levels of autophagy metabolites, such as pSer258-ATG13 and BECLIN-1, were measured and correlated with clinical outcomes, specifically MFI.

Results: Rapamycin (6 mg/week) was tolerated without any SAEs. Of the 40 patients, 29 (72.5%) showed strong recovery in PEM, fatigue, and OI, along with improvements in MFI fatigue domains and SF-36 aspects. High levels of BECLIN-1 were detected in T3. Plasma pSer258-ATG13 levels were strongly downregulated at T1. Spearman’s correlation analysis indicated an association between autophagy impairment and reduced activity.

Conclusions: Low-dose rapamycin effectively reduced PEM and other key symptoms in patients with ME/CFS, as measured by BAS, SSS, MFI, and SF-36.  Future studies should encompass dose optimization and develop a diagnostic tool to identify responders with mTOR-mediated autophagy disruption.

Source: Brian T. Ruan, Sarojini Bulbule, Amy Reyes et al. Low Dose Rapamycin Alleviates Clinical Symptoms of Fatigue and PEM in ME/CFS Patients via Improvement of Autophagy, 03 June 2025, PREPRINT (Version 1) available at Research Square [https://doi.org/10.21203/rs.3.rs-6596158/v1] https://www.researchsquare.com/article/rs-6596158/v1 (Full text)

mTORC1 syndrome (TorS): unifying paradigm for PASC, ME/CFS and PAIS

Abstract:

Post-acute SarS-Cov2 (PASC), Myalgia encephalomyelitis/Chronic fatigue syndrome (ME/CFS) and Post-acute infection syndrome (PAIS) consist of chronic post-acute infectious syndromes, sharing exhaustive fatigue, post exertional malaise, intermittent pain, postural tachycardia and neuro-cognitive-psychiatric dysfunction. However, the concerned shared pathophysiology is still unresolved in terms of upstream drivers and transducers. Also, risk factors which may determine vulnerability/progression to the chronic phase still remain to be defined.

In lack of drivers and a cohesive pathophysiology, the concerned syndromes still remain unmet therapeutic needs. ‘mTORC1 Syndrome’ (TorS) implies an exhaustive disease entity driven by sustained hyper-activation of the mammalian target of rapamycin C1 (mTORC1), and resulting in a variety of disease aspects of the Metabolic Syndrome (MetS), non-alcoholic fatty liver disease, chronic obstructive pulmonary disease, some cancers, neurodegeneration and other [Bar-Tana in Trends Endocrinol Metab 34:135-145, 2023]. TorS may offer a cohesive insight of PASC, ME/CFS and PAIS drivers, pathophysiology, vulnerability and treatment options.

Source: Bar-Tana J. mTORC1 syndrome (TorS): unifying paradigm for PASC, ME/CFS and PAIS. J Transl Med. 2025 Mar 10;23(1):297. doi: 10.1186/s12967-025-06220-z. PMID: 40059164. https://translational-medicine.biomedcentral.com/articles/10.1186/s12967-025-06220-z (Full text)