SLE-ME/CFS Overlap and Shared Fatigue Mechanisms

1 Schwarting et al. 2019 — Anti-NMDAR Autoantibodies and Fatigue in SLE

Full Citation:: Schwarting A, Möckel T, Lütgendorf F, Triantafyllias K, Grella S, et al. Fatigue in SLE: diagnostic and pathogenic impact of anti-N-methyl-D-aspartate receptor (NMDAR) autoantibodies. Annals of the Rheumatic Diseases. 2019;78:1226–1233. DOI:: 10.1136/annrheumdis-2019-215098 PMID:: 31186256 Key Findings::

- Anti-NR2 (NMDAR) antibodies correlate with fatigue severity in 426 SLE patients independent of neuropsychiatric lupus
- Anti-NR2 detected in CSF; bind hippocampus in situ; downregulate neuronal energy metabolism without cytotoxicity
- Belimumab therapy (n=86) ≥6 months reduces both anti-NR2 and fatigue

Conclusion:: Anti-NR2 antibodies are a diagnostic and therapeutic target for SLE fatigue; mechanism involves neuronal metabolic suppression — directly parallels ME/CFS energy metabolism hypotheses. Limitations:: Cross-sectional; treatment subgroup not randomized. Certainty:: 0.85

2 Zheng et al. 2024 — Shared Fatigue Mechanisms SLE and ME/CFS

Full Citation:: Zheng D, Li X, Wang P, Zhu Q, Huang Z, et al. Exploring the shared mechanism of fatigue between systemic lupus erythematosus and myalgic encephalomyelitis/chronic fatigue syndrome: monocytic dysregulation and drug repurposing. Frontiers in Immunology. 2024;15:1440922. DOI:: 10.3389/fimmu.2024.1440922 PMID:: 39845969 Key Findings::

- 58 overlapping genes between SLE and ME/CFS (IL1β, CCL2, TLR2, STAT1, IFIH1)
- Classical monocytes enriched with shared targets at single-cell level
- Drug repurposing predicts N-acetyl-L-cysteine and simvastatin

Conclusion:: Monocytic dysregulation links inflammation and fatigue in both SLE and ME/CFS; shared innate immune pathway. Limitations:: Bioinformatics + in vitro only; no patient validation. Certainty:: 0.60

3 Parodis et al. 2025 — Poor HRQoL Despite SLE Remission

Full Citation:: Parodis I, Lindblom J, Palazzo L, Tsoi A, Cetrez N, et al. Poor health-related quality of life despite Lupus Low Disease Activity State or Definitions of Remission in SLE: results from a clinical trial setting. RMD Open. 2025;11:e006061. DOI:: 10.1136/rmdopen-2025-006061 PMID:: 41173511 Key Findings::

- Pooled analysis of 4 phase III belimumab RCTs (n=2406): 18.5--26.2% report FACIT-F $<30$ despite LLDAS/DORIS remission
- PCS scores remain below population norms even after 52 weeks of treatment

Conclusion:: Current therapeutic goal definitions do not capture patient-reported fatigue; fatigue is an unmet need in SLE even when inflammation is controlled. Limitations:: Post-hoc analysis; clinical trial population. Certainty:: 0.80

4 Arcani et al. 2023 — Type 1/2 Categorization of SLE Fatigue

Full Citation:: Arcani R, Jouve E, Chiche L, Jourde-Chiche N. Categorization of patients with systemic lupus erythematosus using disease activity, patient-reported outcomes, and transcriptomic signatures. Clinical Rheumatology. 2023;42:2061–2070. DOI:: 10.1007/s10067-023-06525-8 PMID:: 36759402 Key Findings::

- SLE patients categorized as type 1 (inflammatory, n=37%) vs type 2 (fatigue/pain, n=9%) vs mixed (15%)
- Type 2 symptoms showed NO correlation with interferon signatures or immunological biomarkers

Conclusion:: SLE fatigue is a biologically distinct dimension, not merely a reflection of inflammatory activity. Limitations:: Small cohort (n=50); single center. Certainty:: 0.60

5 Fluder et al. 2026 — Mitochondrial Dysfunction Drives NK Cell Dysfunction in SLE

Full Citation:: Fluder N, Humbel M, Recazens E, Jourdain AA, Ribi C, et al. Mitochondrial dysfunction drives natural killer cell dysfunction in systemic lupus erythematosus. JCI Insight. 2026. (Fluder et al. 2026) DOI:: 10.1172/jci.insight.195170 PMID:: 41628153 Key Findings::

- SLE NK cells accumulate enlarged, dysfunctional mitochondria with impaired mitophagy
- Defective NK cytotoxicity and cytokine production — mirrors ME/CFS NK cell dysfunction

Conclusion:: Mitochondrial dysfunction drives NK cell impairment in SLE; shared mechanistic node with ME/CFS. Limitations:: Preclinical; sample size not specified. Certainty:: 0.75

6 Morand et al. 2020 — Anifrolumab in Active SLE (TULIP-2)

Full Citation:: Morand EF, Furie R, Tanaka Y, Bruce IN, Askanase AD, et al. Trial of Anifrolumab in Active Systemic Lupus Erythematosus. New England Journal of Medicine. 2020;382:211–221. DOI:: 10.1056/NEJMoa1912196 PMID:: 31851795 Key Findings::

- Phase 3 RCT: anifrolumab (anti-IFNAR) met primary endpoint in moderate-to-severe SLE
- Fatigue improvement as secondary outcome; IFN blockade reduces disease activity

Conclusion:: Type I IFN blockade effective in SLE; fatigue improvement accompanies reduced disease activity. Limitations:: Fatigue was secondary endpoint; mechanism not directly studied. Certainty:: 0.90

7 Weissman-Tsukamoto et al. 2025 — Diffuse Neuropsychiatric Lupus

Full Citation:: Weissman-Tsukamoto R, Carroll KR, Diamond B. Diffuse neuropsychiatric lupus: clinical evidence, immune-mediated mechanisms, and therapeutic insights. Seminars in Immunology. 2025;78:101981. DOI:: 10.1016/j.smim.2025.101981 PMID:: 40818249 Key Findings::

- NPSLE affects >50% of SLE patients; fatigue among most debilitating symptoms
- Brain-reactive autoantibodies cross compromised BBB causing neuronal dysfunction

Conclusion:: Diffuse NPSLE has identifiable immune-mediated mechanisms; treatable. Limitations:: Review; primarily animal model data. Certainty:: 0.75

8 Mertz et al. 2020 — Practical Management of Fatigue in SLE

Full Citation:: Mertz P, Schlencker A, Schneider M, Gavand PE, Martin T, et al. Towards a practical management of fatigue in systemic lupus erythematosus. Lupus Science & Medicine. 2020;7:e000441. DOI:: 10.1136/lupus-2020-000441 PMID:: 33214160 Key Findings::

- 2/3 of SLE patients report significant fatigue; 1/3 severe
- Fatigue occurs both with and without disease activity
- Algorithm separates SLE vs non-SLE causes; in remission, non-pharmacological approaches

Conclusion:: Fatigue management in SLE requires separating inflammatory from non-inflammatory drivers. Limitations:: Expert opinion; limited trial evidence. Certainty:: 0.50

9 Rubio and Kyttaris 2023 — Undifferentiated Connective Tissue Disease

Full Citation:: Rubio J, Kyttaris VC. Undifferentiated connective tissue disease: comprehensive review. Current Rheumatology Reports. 2023;25:98–106. DOI:: 10.1007/s11926-023-01099-5 PMID:: 36884206 Key Findings::

- UCTD: clinical + lab autoimmunity without fulfilling SLE/SSc criteria
- Fatigue common; subcategorized as evolving vs stable; 18% evolve to defined CTD

Conclusion:: UCTD represents a population with autoimmune fatigue below diagnostic thresholds — potential overlap with ME/CFS. Limitations:: UCTD definition varies; fatigue not primary focus. Certainty:: 0.65

10 Spinelli et al. 2023 — Exercise Modulates Interferon Signature in SLE

Full Citation:: Spinelli FR, Berti R, Farina G, Ceccarelli F, Conti F. Exercise-induced modulation of Interferon-signature: a therapeutic route toward management of Systemic Lupus Erythematosus. Autoimmunity Reviews. 2023;22:103412. DOI:: 10.1016/j.autrev.2023.103412 PMID:: 37597604 Key Findings::

- IFNα-signature central to SLE pathogenesis; exercise can modulate IFN signature
- Physical activity reduces pro-inflammatory cytokines; improves fatigue and QoL

Conclusion:: Exercise may reduce IFN signature providing mechanistic basis for fatigue improvement. Limitations:: Narrative review; does not address post-exertional malaise. Certainty:: 0.65

11 Paroli and Sirinian 2025 — Neuroimmune Crosstalk in Rheumatic Diseases

Full Citation:: Paroli M, Sirinian MI. Pathogenic crosstalk between the peripheral and central nervous system in rheumatic diseases: emerging evidence and clinical implications. International Journal of Molecular Sciences. 2025;26:6036. DOI:: 10.3390/ijms26136036 PMID:: 40649815 Key Findings::

- Fatigue, cognitive dysfunction, ANS disturbances in SLE/Sjögren's/RA not fully explained by peripheral inflammation
- Glial activation, SFN, central sensitization, and ANS dysfunction contribute

Conclusion:: Neuroimmune dysregulation produces fatigue through mechanisms distinct from peripheral inflammation. Limitations:: Narrative review; broad scope. Certainty:: 0.55

12 Aboagye et al. 2025 — Digital Biomarkers of Fatigue in Chronic Diseases

Full Citation:: Aboagye NY, Hinchliffe C, Del Din S, Ng WF, Baker KF, et al. Systematic review: digital biomarkers of fatigue in chronic diseases. NPJ Digital Medicine. 2025;8:317. DOI:: 10.1038/s41746-025-01939-x PMID:: 41062803 Key Findings::

- Systematic review of digital biomarkers (wearables) for fatigue; covers SLE, CFS, RA, MS, Long COVID, Sjögren's
- Reduced physical activity, increased sedentary behavior, and ANS dysfunction associated with fatigue across all conditions

Conclusion:: Objective digital biomarkers reveal disease-specific fatigue patterns; cross-disease convergence on ANS and activity metrics. Limitations:: Heterogeneous device types; disease-specific biomarkers not fully characterized. Certainty:: 0.70

13 Andreoli and Tincani 2017 — UCTD, Fibromyalgia and Environment

Full Citation:: Andreoli L, Tincani A. Undifferentiated connective tissue disease, fibromyalgia and the environmental factors. Current Opinion in Rheumatology. 2017;29:380–386. DOI:: 10.1097/BOR.0000000000000392 PMID:: 28368979 Key Findings::

- UCTD and fibromyalgia share undefined clinical features; environmental exposures as triggers
- Both may fit under ASIA framework

Conclusion:: UCTD and fibromyalgia (and by extension ME/CFS) may share environmental triggers and fatigue as common endpoint. Limitations:: Opinion review; ASIA framework controversial. Certainty:: 0.55

14 Urbańska-Krawiec and Hrycek 2010 — CFS with Focus on SLE

Full Citation:: Urbańska-Krawiec D, Hrycek A. Chronic fatigue syndrome with special focus on systemic lupus erythematosus. Polski Merkuriusz Lekarski. 2010;29(172):260–264. PMID:: 21268918 Key Findings::

- CFS diagnostic criteria reviewed; SLE as model for CFS
- Fatigue in 80% of SLE patients; immune, hormonal, and neurotransmitter mechanisms in both

Conclusion:: SLE and CFS share fatigue as central symptom; SLE can serve as model for CFS pathophysiology. Limitations:: Polish-language journal; narrative review; 2010 publication. Certainty:: 0.25

15 Kulapatana et al. 2025 — Blood Volume Deficit in POTS by CO Rebreathing

Full Citation:: Kulapatana S, Urechie V, Rigo S, et al. Blood volume deficit in postural orthostatic tachycardia syndrome assessed by semiautomated carbon monoxide rebreathing. Clinical Autonomic Research. 2025;35(2):267–276. DOI:: 10.1007/s10286-024-01091-8 PMID:: 39614968 Key Findings::

- Semiautomated CO rebreathing confirms significant total blood volume deficit in POTS (n=47 vs n=40 controls)
- Replicates Raj 2005 hypovolemia finding with improved method
- Blood volume deficit correlates with symptom severity

Conclusion:: Hypovolemia is a reproducible, quantifiable feature of POTS. Limitations:: Moderate n; single center; CO rebreathing requires specialized equipment. Certainty:: 0.70

16 van Campen et al. 2024 — Two Hemodynamic Responses in ME/CFS+POTS

Full Citation:: van Campen CLMC, Rowe PC, Visser FC. Two different hemodynamic responses in ME/CFS patients with postural orthostatic tachycardia syndrome during head-up tilt testing. Journal of Clinical Medicine. 2024;13(24):7726. DOI:: 10.3390/jcm13247726 PMID:: 39768649 Key Findings::

- ME/CFS+POTS patients show two distinct hemodynamic responses during HUT: hypovolemic-like (reduced SV, low CO) and hyperadrenergic-like (high HR, normal SV)
- Hypovolemic subtype may benefit from volume expansion; hyperadrenergic from rate-slowing
- Demonstrates that POTS in ME/CFS is not a single entity

Conclusion:: Hemodynamic subtyping in ME/CFS+POTS may enable targeted treatment. Limitations:: Single center; moderate sample size; retrospective analysis. Certainty:: 0.55

17 Malik et al. 2026 — Brain Structural Changes in POTS

Full Citation:: Malik V, Roy B, Sarkar A, et al. Brain tissue changes, network dysfunction, and cerebral hemodynamic deficits in postural orthostatic tachycardia syndrome. Heart Rhythm. 2026. doi: 10.1016/j.hrthm.2026.02.020. DOI:: 10.1016/j.hrthm.2026.02.020 PMID:: 41740821 Key Findings::

- First demonstration of structural brain changes in POTS (gray matter volume reductions)
- Altered functional network connectivity on resting-state fMRI
- Cerebral hemodynamic deficits correlate with symptom severity

Conclusion:: POTS involves structural and functional brain changes, not just peripheral autonomic dysfunction. Limitations:: Moderate n; cross-sectional; causality unclear. Certainty:: 0.55

18 Miranda-Hurtado et al. 2026 — Stroke Volume, ETCO2, and CBF in POTS

Full Citation:: Miranda-Hurtado M, Hira R, Bourne KM, et al. Stroke volume reduction impairs cerebrovascular regulation through ETCO2 in postural orthostatic tachycardia syndrome. Clinical Autonomic Research. 2026;36(2):257–269. DOI:: 10.1007/s10286-025-01181-1 PMID:: 41398115 Key Findings::

- Reduced stroke volume in POTS lowers end-tidal CO2 (hypocapnia)
- Hypocapnia impairs cerebral autoregulation, reducing CBF
- Establishes mechanistic pathway: low SV → ETCO2↓ → CBF↓

Conclusion:: Cerebral hypoperfusion in POTS is mediated by SV-driven hypocapnia. Limitations:: Controlled physiology lab setting; may not capture real-world variability. Certainty:: 0.65

19 Seeley et al. 2025 — Brain SPECT in POTS Cognitive Dysfunction

Full Citation:: Seeley MC, O’Brien H, Wilson G, et al. Novel brain SPECT imaging unravels abnormal cerebral perfusion in patients with postural orthostatic tachycardia syndrome and cognitive dysfunction. Scientific Reports. 2025;15(1):3487. DOI:: 10.1038/s41598-025-87748-4 PMID:: 39875497 Key Findings::

- First brain SPECT study in POTS shows region-specific hypoperfusion
- Perfusion deficits in frontal, temporal, and parietal regions
- Hypoperfusion correlates with objective cognitive test scores

Conclusion:: Objective cerebral perfusion deficits underlie POTS cognitive symptoms. Limitations:: Pilot study; moderate n; no ME/CFS subgroup analysis. Certainty:: 0.50

20 Kwok et al. 2026 — Midodrine for POTS Meta-Analysis

Full Citation:: Kwok CS, Lee S, Afzal A, et al. Midodrine hydrochloride as a treatment for postural orthostatic tachycardia syndrome: A systematic review and meta-analysis. Journal of Cardiovascular Pharmacology. 2026. doi: 10.1097/FJC.0000000000001822. DOI:: 10.1097/FJC.0000000000001822 PMID:: 41949563 Key Findings::

- 14 studies, n=968: midodrine improves symptom response vs placebo in pediatric POTS (RR 1.52, p=0.01)
- Midodrine marginally superior to beta-blockers in children (RR 1.16, p=0.02)
- Evidence in adults is limited; hypertension in 8.2%

Conclusion:: Midodrine can be considered second/third-line for POTS, especially pediatric. Limitations:: High heterogeneity (I²=78%); mostly pediatric studies; adults under-studied. Certainty:: 0.65

21 Hedge et al. 2026 — Diagnostic Reliability of Supine-to-Stand Tests in POTS

Full Citation:: Hedge ET, Grappe SR, Ivey E, et al. Test-retest reliability of clinical supine-to-stand tests in patients with postural orthostatic tachycardia syndrome: A cautionary tale. Heart Rhythm. 2026. doi: 10.1016/j.hrthm.2026.03.1915. DOI:: 10.1016/j.hrthm.2026.03.1915 PMID:: 41887448 Key Findings::

- Clinical supine-to-stand tests show poor test-retest reliability in POTS
- Day-to-day HR variability may lead to misdiagnosis or misclassification
- Questions validity of simple office-based diagnostic tests

Conclusion:: More standardized and repeated testing needed for reliable POTS diagnosis. Limitations:: Single center; moderate n; does not test tilt-table reliability. Certainty:: 0.60

22 Marchetta et al. 2025 — Ivabradine and Symptom Burden in POTS

Full Citation:: Marchetta M, Lopez RI, Hogwood AC, et al. Heart rate lowering with ivabradine and burden of symptoms in patients with postural orthostatic tachycardia syndrome. Journal of Cardiovascular Pharmacology. 2025;86(1):28–32. DOI:: 10.1097/FJC.0000000000001705 PMID:: 40294227 Key Findings::

- Ivabradine effectively reduces HR in POTS
- Symptom burden improvement does NOT correlate with HR reduction
- Supports view that tachycardia is compensatory, not causal

Conclusion:: Rate-slowing alone may not improve symptoms; root cause treatment needed. Limitations:: Moderate n; uncontrolled; single center. Certainty:: 0.50

23 Ekman et al. 2025 — Sensory Neuropathy and GI Symptoms in POTS

Full Citation:: Ekman L, Tufvesson H, Englund E, Dahlin LB, Ohlsson B. Symptoms and objective signs of peripheral sensory neuropathy in POTS and correlations to gastrointestinal symptoms. PLoS One. 2025;20(7):e0327549. DOI:: 10.1371/journal.pone.0327549 PMID:: 40608783 Key Findings::

- Objective signs of sensory neuropathy in POTS using quantitative sensory testing
- Neuropathy severity correlates with GI symptom burden
- Suggests SFN contributes to both pain and dysautonomia in POTS

Conclusion:: Peripheral neuropathy is common in POTS and linked to GI dysfunction. Limitations:: Cross-sectional; moderate n; no skin biopsy. Certainty:: 0.50

24 Mathew and Novak 2026 — Central Sensitization in POTS

Full Citation:: Mathew GT, Novak P. Prevalence of central sensitization in postural tachycardia syndrome. JAMA Network Open. 2026;9(1):e2553694. DOI:: 10.1001/jamanetworkopen.2025.53694 PMID:: 41528744 Key Findings::

- 67% of POTS patients meet criteria for central sensitization
- Prevalence far exceeds general population
- Central sensitization may explain pain, fatigue, and cognitive symptoms in POTS

Conclusion:: Central sensitization is highly prevalent in POTS and may be a treatment target. Limitations:: Questionnaire-based; single center; no ME/CFS comparison. Certainty:: 0.55

25 Chopra 2026 — Compensatory Tachycardia Hypothesis

Full Citation:: Chopra P. Postural orthostatic tachycardia syndrome: when dysautonomia misleads — a mechanistic argument for compensatory orthostatic tachycardia. Frontiers in Neurology. 2026;17:1806502. DOI:: 10.3389/fneur.2026.1806502 PMID:: 42037722 Key Findings::

- Argues POTS tachycardia is compensatory (defends CBF when SV drops)
- Questions whether tachycardia itself should be a treatment target
- Proposes focusing on root causes: hypovolemia, venous pooling, deconditioning

Conclusion:: Treatment paradigm shift: target hypoperfusion, not heart rate. Limitations:: Review/opinion; not original data; speculative. Certainty:: 0.35

26 Lukáčová et al. 2025 — Autoantibodies in Orthostatic Intolerance

Full Citation:: Lukáčová M, Mitro P, Lazúrová Z, Hijová E, Bertková I, Valová K. Autoimmune antibodies in orthostatic intolerance syndromes. Physiological Research. 2025;74(2):255–262. DOI:: 10.33549/physiolres.935504 PMID:: 40432440 Key Findings::

- Autoantibodies to α1-AR and β1-AR detected in POTS patients
- No correlation with clinical severity
- Adds to mixed evidence on GPCR autoantibodies (cf. Vernino 2022 null)

Conclusion:: Autoantibodies are present in some POTS patients but clinical significance unclear. Limitations:: Moderate n; single center; CellTrend ELISA specificity concerns. Certainty:: 0.45

27 Uppal et al. 2026 — Patient Perspectives on POTS Medications

Full Citation:: Uppal J, Deol P, Giri P, Sheldon RS, King-Shier K, Raj SR. Do medications actually help in patients with postural orthostatic tachycardia syndrome? A qualitative study. CJC Open. 2026;8(5):543–549. DOI:: 10.1016/j.cjco.2026.01.002 PMID:: 42146286 Key Findings::

- Patient-reported medication effectiveness is modest
- Most patients try multiple medications with limited benefit
- Non-pharmacological strategies (salt, compression, exercise) are valued

Conclusion:: Clinical trials may overestimate real-world medication effectiveness. Limitations:: Qualitative; self-selected sample; single center (Raj lab). Certainty:: 0.55

References

Fluder, Natalia, Morgane Humbel, Emeline Recazens, Alexis A Jourdain, Camillo Ribi, et al. 2026. “Mitochondrial Dysfunction Drives Natural Killer Cell Dysfunction in Systemic Lupus Erythematosus.” JCI Insight. https://doi.org/10.1172/jci.insight.195170.