Accelerating Research on ME/CFS

Accelerating Research On ME/CFS

Summary of the NIH meeting.... and reflections on how far we’ve come and still have to go Anthony L. Komaroff, MD Brigham and Women’s Hospital, Harvard Medical School

April 5, 2019, National Institutes of Health No significant conflicts of interest Mid-1980’s: Where Were We?

An illness characterized by only symptoms and no consistent objective abnormalities: • No consistent physical exam abnormalities • No diagnostic tests • No proven treatments • No information on prognosis • No evidence of underlying biological abnormalities Hence, a suspect illness 2019: Where Are We? 2019: Where Are We?

Cases differ from healthy controls (and sometimes disease comparison controls):

• Central and autonomic nervous system

• Metabolism (particularly energy metabolism)

• Immune phenotype and function

• Microbiome (?)

• Gene structure, gene expression and other epigenetic differences (?) 2019: The Questions Going Forward

• What causes the symptoms of the illness?

• What causes the abnormalities in various systems?

• What links together these different abnormalities? And what triggers them?

• Is there a hypothetical disease model that fits with the abnormalities reported? Agenda for this Talk

• Summarize data presented at this conference, and in prior literature, regarding the various abnormalities that have been reported

• Consider several alternative models that might explain much of the data Neurologic Changes

Structural & functional brain imaging Autonomic abnormalities CNS Involvement in ME/CFS • Neuroendocrine dysfunction: Impairment of multiple limbic-hypothalamic-pituitary axes (involving cortisol, prolactin, & growth hormone) and serotonin (5-HT) system • Cognition: Impairments in information processing speed, memory and attention — not explained by concomitant psychiatric disorders • Autonomic dysfunction: Impaired sympathetic and parasympathetic function, 30-80% • MRI: Multiple anatomic and functional abnormalities • SPECT: Areas of reduced signal • PET: Immune cell activation (neuroinflammation) • EEG abnormalities: sharp/spike waves, distinctive spectral coherence pattern, impaired connectivity PET Evidence of Brain Inflammation Distinguishes ME/CFS from Healthy

P<0.001

CFS: N=9 Controls: N=10.

From: Nakatomi Y, et al. J Nucl Med 2014; 55:945–950 MR Spectroscopy of the Brain Suggests Neuroinflammation

• 15 women with ME/CFS and 15 matched healthy controls

• Abnormalities were found in multiple brain regions, particularly left anterior cingulate

• Metabolite ratios in 7 regions correlated with fatigue

• Increased ratio of choline/creatinine, and increased lactate, were prominent findings

From: Mueller C, et al. Brain Imaging and Behavior 2019; doi.org/10.1007/x11682-018-0029-4 Lactate in Spinal Fluid in ME/CFS: In vivo Proton MR Spectroscopy 0.86 ±0.5 90

80 P<0.001 for each, compared to ME/CFS 70

60 50 0.29 0.25 40 ±0.3 ±0.2 30

0 ME/CFS Anxiety Healthy Mathew SJ, et al. NMR Biomed 2008 (DOI 10.1002/nbm.1315) Conclusions •The majority of adult and all pediatric studies show OI is strongly associated with ME/CFS •Upright posture consistently aggravates ME/CFS symptoms, even in the absence of HR and BP changes •CBF reductions are substantial •Primary causes of OI in ME/CFS need further elucidation (auto-antibodies? MCAS? Vascular compliance in EDS?) •Open treatment of OI is associated with improvement in fatigue and other symptoms. More practical clinical trials needed. Even in ME/CFS patients with a normal HR and BP response during TTT: abnormal decrease of cerebral blood flow

Courtesy of Peter Rowe, NIH, April 2019 Metabolic Changes

Impaired ATP production Hypometabolism Oxidative/Nitrosative Stress Early Lessons From Metabolomics

Studies employing optimal techniques (e.g., mass spect) for identifying levels of hundreds of metabolites in patients with ME/CFS compared to matched healthy controls • Levels of most metabolites are lower, as occurs in hibernation1 • Abnormalities incriminate impairment of cellular energy (regulated by the availability of NADPH) 1 and oxidative phosphorylation2 • Possibly a defect in one critical enzyme, pyruvate dehydrogenase3 • Defects in pathways converting sugars, lipids and amino acids into energy 1-5

From: 1Naviaux RK, et al. PNAS 2016;113:E5472-80; 2Tomas C, et al. PLoS ONE 2017;12(10):e0186802. 3Fluge O, et al. JCI Insight 2016;1:e89376; 4Yamano E, et al. Sci Rep 2016;6:34990; 5Germain A, et al. Mol BioSyst 2017;13: 371-379. Mitochondrial Damage to nucleic acids ↑ Anaerobic dysfunction and lipid membranes metabolism: ↑ lactate ↑ Oxidative Stress ↑ COX-2 ↓ antioxidant levels (Zn, DHEA, glutathione, vit E, CoQ10) ↑ peroxide & superoxide ↑ isoprostane & oxidized LDL ↓ α-tochopherol ↑ NFκB ↑ Nitrosative Stress ↑ iNOS, NO, nitrate, peroxynitrite ↑ iNOS ↑ IgM against nitro-[amino acids] Courtesy of Maureen Hansen, NIH, April 2019 Putative Targets

 Cross referencing with PharmGKB database

 242 gene-drug interactions

 92 FDA-approved drugs affecting

 39 targetable gene products

 Treatable targets in 37 of the 50 gene modules

 23 identified to have a significant association with symptoms

 Including Adaptive Immune System, B-cell receptors, TNFa

 11 targetable gene products show significant change from HC in ME/CFS

 NCOA1, UBE21, TRAF1, FKBP5, AHR, FYN, IKBKG, CASP9, CA9, DDIT3, CTNNB1

Jeffrey et al. "Treatment Avenues in Myalgic Encephalomyelitis/Chronic Fatigue Syndrome: A Split-gender Pharmacogenomic Study of Gene-expression Modules. Clinical Therapeutics. (in press) Based on the thirteen panels 43 CSF proteins were significantly different between the ME/CFS patients and matched controls with p-value <0.05.

Generally increased levels of markers for neuroinflammation, cell damage and repair in ME/CFS patients.

Both significant similarities and differences found when comparing ME/CFS and MS patients.

Unpublished data Viral-Mitochondrial Connection

• Mitochondrial architecture essential for innate immunity

• Active (not latent) HHV-6 infection, at least in one cell line, fragments mitochondria

• And inhibits ability of mitochondria to fuse

• And reduces ATP production

• Serum from ME/CFS fragments mitochondria, and removing serum resolves fragmentation

Courtesy of Bhupesh Prusty, NIH, April 2019

Comparison of 20 CFS Cases and 20 Healthy Controls

) Zre ( N =

Patients 20 (CCC)

Controls 20

P = 1X 10-9 Impedance (Ohm) /Normalized to the the Impedanceto baseline (Ohm) /Normalized

Courtesy of Ronald W. Davis, NIH, April 2019 Immunologic Changes

Lymphocyte phenotype and function Cytokines HLA Associations Highly simplified overview of the diverse stimuli and potential consequences of mast cell activation and secretion of cytokines, chemokines, and growth factors.

Mukai K/Galli SJ. Immunological Reviews 2018; 282: 121–150 Immunological Abnormalities in ME/CFS

• Increased levels of circulating immune complexes • Increased levels of immunoglobulin G • Decreased levels of certain IgG subsets • Increased numbers of CD8 + “cytotoxic” T cells bearing activation antigens (CD38 +, HLA-DR) • Poorly functioning natural killer (NK) cells • Increased blood levels of, and lymphocyte production of pro-inflammatory cytokines Cytokine Findings

• Blood levels of many cytokines are significantly higher in ME/CFS patients than in healthy controls—in the first three years of illness, but not after1

• Levels of many cytokines in spinal fluid also distinguish patients from healthy controls2

• Levels of many circulating cytokines correlate positively with the severity of symptoms3

1Hornig M, et al. Science Advances 2015 (Feb 27);1:e1400121 2Hornig M, et al. Molecular Psychiatry (2016) 21, 261–269 3Montoya JG, et al. PNAS 2017;114:E7150-7158 Circulating Cytokines in ME/CFS Patients

❖ Innate (e.g. GM-CSF), adaptive (e.g. IFN--γ, IL-12), cross-talk (e.g. IL-17) immunity

❖ Th1 (e.g. IFN-γ), Th2 (e.g. IL-4, IL-5, IL-13), Th17 (e.g. IL-17)

❖ Leptin: perpetuation of inflammation, predominance in females, neuroinflammation

❖ TGF-β risk for non-Hodgkin’s lymphoma

❖ Of seventeen cytokines that correlated with severity, ten can be produced or induced by mast cells (Mukai K/Galli SJ. Immunological Reviews 2018; 282: 121–150)

❖ Mast cell: microglia interactions may influence neuroinflammation (Hendriksen et al, Neuroscience and Biobehavioral Reviews 2017 79:119-133)

❖ Could a central feature of ME/CFS be a dysregulated mast cell?

CCL11, CXCL1, CXCL10, G-CSF, GM-CSF, IFN-γ, IL-4, IL-5, IL-7, IL-12p70, IL-13, IL-17F, leptin, leukemia inhibitory factor (LIF), nerve growth factor, stem cell factor (SCF), and TGF-α. HLA Associations

• Association with ME/CFS:

• ↑ risk: DRB4*01:01 (OR 2.30)

• ↓ risk: C*05:01 (OR 0.60), DRBR*01:03 (OR 0.6)

• Association with severe ME/CFS

• ↑ risk: Four HLA factors (OR 3-4.4)

• ↓ risk: One HLA factor (OR 0.38)

Courtesy of Jose G. Montoya, NIH, April 2019 ME/CFS CD4 and CD8 T cell subset differences grouped by age

Unpublished data, Courtesy of Derya Unutmaz, NIH, April 2019 Courtesy of Mark Davis, NIH, April 2019 Epigenetic Studies Epigenetic Changes in ME/CFS Comparing ME/CFS to healthy controls: • The DNA methylome is different, particularly with regard to glucocorticoid sensitivity genes1 and in genes important in cellular metabolism2 • Expression of microRNAs is different, particularly in natural killer cells3 • Difference in transcription factor levels: increased levels of NFĸB4 • Increased HDAC expression, leading to decreased gene expression5

1 deVega WC, et al. PLoS One 2014;9:e104757 2 deVega WC, et al. BMC Med Genomics 2017;doi 10.1186/ s12920-017-0248-3 3 Petty RD, et al. PLoS One 2016 DOI:10.1371/journal.pone.0150904 4 Maes M, et al. Neuro Endocrinology Letters 2007;28: 456. 5 Jason L, et al. Brain Behav Immun. 2011;25:1544. PRELIMINARY RESULTS (4) 17 Possible contribution of miR-150-5p in mental fatigue?

o According to Ingenuity Pathway Analysis (IPA), SLC6A2 is a predicted target of miR160-5p.

o SLC6A2 encodes a multipass membrane protein that is responsible for the reuptake of norepinephrine into presynaptic nerve terminations.

o A clinical study1 on the effect of the drug Duloxetine, a SLCA2 inhibitor, on ME/CFS patients, has shown an improvement in mental fatigue, according to the MFI-20 questionnaire of patients taking the drug, compared to ME/CFS patients treated with the placebo.

1 L. M. Arnold, T. J. Blom, J. A. Welge, E. Mariutto, and A. Heller, “A Randomized, Placebo-Controlled, Double-Blinded Trial of Duloxetine in the Treatment of General Fatigue in Patients With Chronic Fatigue Syndrome,” Psychosomatics, vol. 56, no. 3, pp. 242–253, 2015. MOLECULAR PROFILING OF ME/CFS 24 Symptoms reported after the stress test SUBGROUP 3 SubgroupSUBGROUP1 1 SUBGROUPSubgroup 2 2 Subgroup 3 No Relapse Throat Ache No Symptoms Headache Symptoms No Symptoms of the 17% 16% 14% 34% 15% disease Throat Ache 33% 14% Intense Insomnia pain in the Insomnia 15% Arm 17% 17% General Leg Muscle Pain Weakness Headache 14% 14% Nausea Intense pain in the Arm 33% 33% SUBGROUP 5 14% SUBGROUP 4 Subgroup 5 Subgroup 4 Headache Flu-like 14% symptoms General 25% Muscle Pain No 14% Vertigo / Symptoms Dizziness 50% 29% Nausea Mental 25% Fogginess 14% Flu-like symptoms…

Courtesy of Alain Moreau, NIH, April 2019 Provocation Studies

Exercise challenge Cognitive challenge Orthostatic challenge The Rationale For Provocation Studies

• Biomarkers seen in resting people with ME/CFS may or may not have anything to do with causing their symptoms

• When challenges (physical, cognitive) that make people feel worse also make biomarkers worse, it’s more likely those biomarkers are linked to the symptoms of illness

• We need to understand the underlying physiology of post-exertional malaise (PEM) in ME/CFS, given its centrality in the illness

Abnormal Responses To Exercise Anaerobic threshold Anaerobic

From: Jones DEJ, et al. Eur J Clin Invest 2012;42:186. Central Sensitization in ME/CFS: Pressure Pain Thresholds Pre- & Post-Exercise

P<0.009

3.5 3 2.5 2 1.5 1 0.5 0 Baseline Post-Exercise ME/CFS Healthy N=20 N=20 From: Malfleit A, et al. Pain Physician 2018; 21:E13-E24 ↑ pooling,↓ vasoconstriction ↓ intra-vascular volume

Standing/Tilt test ↓ cerebral blood flow

↑ sympatho-adrenal response

OH dOH NMH POTS Normal HR and BP

Courtesy of Peter Rowe, NIH, April 2019 Chronotropic Intolerance

• Low exertional:

• Heart rate

• Ventilation

• Blood pressure

• Particularly on the 2nd day of 2-day CPET

• Probably a manifestation of autonomic dysfunction

Courtesy of Betsy Keller, NIH, April 2019 Putting It All Together

Central & autonomic nervous system Metabolism Immune system phenotype & function Epigenetic differences Microbiome differences Provocable abnormalities involving these systems Alternative Disease Models for ME/CFS Several Alternative Models

• Excessive cellular senescence, with generation of fatigue-inducing molecules1,2 • Sickness behavior/inflammation3,4,5 • Dauer/hibernation-torpor6 • Cell danger response/incomplete healing7 • Microbiome8

1He S, Sharpless NE. Cell 2017;169:1000. 2Demaria M, et al. Cancer Discov 2017;7:165-76. 3Morris G, et al. BMC Med 2013;11:64. 4Dantzer R, et al. Trends Neurosci 2014;37:39-46. 5VanElzakker MB. Front Neurol 2019; 10.3389/fneur.2018.01033 6Naviaux RK, et al. Proc Natl Acad Sci USA 2016;113:E5472-80. 7Naviaux, R.K., Mitochondrion, 2018 https://doi.org /10.1016/ j.mito.2018.08.001 8Nagy-Szakal D, et al. Microbiome 2017;5:44. Several Alternative Models

What do we feel like when we’re sick?

Sickness Behavior

• Seen in most animals, even invertebrates

• A temporary response to injury and infection: to focus body’s energy stores on fighting infection & healing injury (acute inflammation & fever) the brain decreases energy-consuming activities: lethargy, social withdrawal, achiness, sleepiness, loss of libido, difficulty thinking, depression, anorexia

• Are there circumstances in which this acute physiology could become chronic, with sickness symptoms becoming chronic?

From: Morris G, et al. BMC Medicine 2013;11:64. What Causes the Symptoms of ME/CFS? Speculative Model: Many Triggers, Final Common Pathway

Fatigue nucleus: in basal ganglia/ prefrontal cortex/ ant. cingulate?

From: Capuron L, et al. Neuropsychopharmacology 2007;32:2384-92. What Causes the Symptoms of ME/CFS? Speculative Model: Many Triggers, Final Common Pathway

Fatigue nucleus: in basal ganglia/ prefrontal cortex/ ant. cingulate?

Activation of brain’s innate immune system (e.g., microglia) yields cytokines that trigger fatigue nucleus

From: Capuron L, et al. Neuropsychopharmacology 2007;32:2384-92. What Causes the Symptoms of ME/CFS? Speculative Model: Many Triggers, Final Common Pathway

Fatigue nucleus: in basal ganglia/ prefrontal cortex/ ant. cingulate? Infection of the brain Auto-Abs Activation of brain’s Infection/ Toxins innate immune system inflammation Obesity (e.g., microglia) yields elsewhere in the Chronic cytokines that trigger body, signaling stress fatigue nucleus the brain leptin

From: Capuron L, et al. Neuropsychopharmacology 2007;32:2384-92; Younger J, et al. J Womens Health 2016;25:752-60; Stringer EA, et al. J Transl Med 2013;11:93. How Can Inflammation Outside the Brain Activate the Innate Immune System Inside the Brain?

Innate immune system in the brain can be activated by infection elsewhere in the body due to: • Humoral: A blood-brain barrier made “porous” by inflammation, allowing entry into the brain of circulating immune cells and molecules (via circumventricular organs and brain endothelial cells)

From: Poon DC-H, et al. Neuroscience and Biobehavioral Reviews 2015;57:30–45 The Blood-Brain Barrier

Drawing in 1899 by Santiago Ramón y Cajal How Can Inflammation Outside the Brain Activate the Innate Immune System Inside the Brain?

From: Poon DC-H, et al. Neuroscience and Biobehavioral Reviews 2015;57:30–45 Sickness Behavior: The Neural Route

Brain directs energy-conserving “sickness behavior”

Vagus signals enter brain (nucleus tractus solitarius)

Glial cells enveloping the vagus, and sensory vagus paraganglia, have many chemoreceptors for these molecules

... Neuroexcitatory molecules: proinflammatory cytokines, excitatory amino acids (e.g., glutamate), NO, ROS, prostaglandins

Infection outside brain triggers innate immune response, producing...

From: Vollmer-Conna U, et al. PsycholMed 2004;34:1289. VanElzakker MB. Medical Hypotheses 2013;81:414-23. Morris G, et al. BMC Medicine 2013;11:64. Potential Sites of Peripheral Inflammation

• The nerves themselves, particularly if there is a latent infection of the immune dendritic cells that wrap themselves around the nerves... Or perhaps due to neurodynamic stresses

• Any tissue in the body with nerve endings— i.e., virtually any tissue/organ

• Could neurodynamic strain be a trigger?

• Particularly, the gut: there’s increasing evidence that the gut can be a source of chronic inflammation, due to its microbiome Dauer / Hibernation-Torpor Model for ME/CFS What Purpose is Served by Dauer and Hibernation / Torpor?

• Dauer in C. elegans, and hibernation/torpor in larger animals (including mammals) is a temporary state prompted by harsh environmental conditions that helps an animal survive, but at the expense of considerably reduced functional capacity

• Energy-requiring reactions, and the need for oxygen as a source of energy, are reduced to a bare minimum Similarities: Dauer and Hibernation/Torpor Both states: • Are triggered by food shortage and temperature change • Allow only essential energy-requiring functions: hypometabolic1

• Are transient and reversible: • Allow temporary arousals (in most animals)1 • Torpor can even occur in warm temperatures (estivation).

1Drew KL, J. Neurochem 2007;102:1713. Similarities: Dauer and Hibernation/Torpor

Both states • Are regulated by the transcription factor genes FOXO/DAF-161 – and those genes also are involved in the stress response, detoxification of ROS, & innate immunity • Involve increased glycolysis and decreased aerobic respiration2 • May involve alterations in the microbiome (at least in hibernation)3

1 Lin XX. Nat Commun 2018;9/10.1038/s41467-018-06624-0. 2Fielenbach N. Genes & Development 2008;22:2149. 3Carey HV, Annu Rev Nutr 2017;37:477. The Autonomic Nervous System in Dauer and Hibernation/Torpor

• In C. elegans, three chemosensory neurons act to control dauer entry & recovery1 • In mammals, the hypothalamus controls entry into & recovery from torpor through the sympathetic system2 • Norepinephrine mediates recovery from torpor 3 • Muscarinic signaling mediates recovery from dauer

1Bargmann C, Horvitz HR. Neuron. 1991;7:729. 2Jastroch M. J Neuroendocrinol 2016;28:10.1111/jne.12437 3Sokolova TN. J Stress Physiol & Biochem 2011;7:269 Cell Danger Response/ Incomplete Healing Model for ME/CFS Cell Danger Response • Since the earliest forms of life, cells and tissues have developed systems for identifying and then healing injury, including: • Injury signals (e.g., extracellular ATP) • Initiation of cell danger response mediated by metabokines and cytokines • Progression of injured tissue through three stages of the cell danger response (CD1-3) • When the response gets stuck and is incomplete, chronic disease (including ME/CFS) can result.

From: Naviaux, R.K., Mitochondrion, 2018 https://doi.org /10.1016/ j.mito.2018.08.001 Three Sequential Stages of the CDR Comprise the Healing Cycle

Circadian, autonomic, and New information, neuroendocrine control of NSetrwesinsf,oIrnmjuartyio, n, Integrated oxphos, LTeoaxrinnins,gI,nSfetrcetsiosn, , aerobic glycolysis, DAedvjuevloapnmtse,nMt etals, and glycolysis Pollution CDR Off: Wakeful eATP decreased Activity CDR On: CDR COPff3: CeADTRP Oincnr:eased eATP decreased Healthy eATP increased DHeevaelltohpCmyecnlte Cell loss, excitotoxicity Differentiation & Cycle Containment & Development No Yes Restorative Sleep Innate Immunity Autonomous Restorative Sleep Adaptation and Recovery Glycolysis Oxidative CDR3 Adaptation and Recovery CDR1 Phosphorylation Healing and No Apoptosis/ Autoimmunity, Decreased SIGLECs & I Aging Cycle Excess metabolic or Efferocytosis, Excitotoxicity, Sia-SAMPs Yes structural damage Necrosis/ Chronic pain, Phagocytosis Neurologic & Persistent I Psychiatric release of CP2 I I Yes CP1 Symptoms DAMPs & CDR2 Mis-repairs: calcification, DARMs Yes Yes Mechanical strain Aerobic granulomas, gliosis, Fibroblasts + Oxygen Glycolysis fibrosis, scarring, failed ± sunlight tissue remodeling Increased SIGLECs and Sia-SAMPs Cancer Proliferation Senescence Dominant and recessive Excess DNA damage blocks to replication arrest and senescence

CDR Stages 1-3; separated by Quality Control Checkpoints CP1-3 “Chronic disease results because of blocks in the healing cycle.” “Autism and ME/CFS are the result of blocks at checkpoint #3.” Microbiome

Skew toward proinflammatory species Evidence of “leaky gut” How the Microbiome May Affect The Brain • The human microbiome: Contains more than 100 times as many genes as we have human genes — a 2nd human genome, additional endocrine organ: • Microbial genes produce molecules that affect human physiology: – Synthesize hormones and neurotransmitters (e.g. norepinephrine, serotonin, dopamine, ACh, GABA) – Synthesize molecules of inflammation (cytokines, prostaglandins) and elicit the production of inflammatory molecules by the gut immune system – Inflammation causes the gut to become “leaky”: the tight junctions that bind gut epithelial cells together become loosened — allowing bacteria and bacterial toxins to enter the blood, eliciting a systemic innate immune response From: Navaneetharaja N, et al. J Clin Med 2016;5:55 Exercise Causes Gut Bacteria to Enter the Blood in People with ME/CFS

From: Shukla SK, et al. PLoS ONE 2015;10(12): e0145453. doi:10.1371/journal.pone.0145453 Gut Barrier Damage May Trigger Innate Immunity

Breach in gut barrier LPS translocate to blood LPS binding protein (LBP) up + sCD14 (LPS-LBP receptor) up:

Triggering innate immunity (pg/mL) LPS

/mL)

LBP (pg/mL) LBP sCD14 ( sCD14

From: Giloteaux L, et al. Microbiome 2016 4:30, doi 10.1186/s40168-016-0171-4 Metagenomic Gut Microbiome Study

• 50 ME/CFS and 50 matched healthy controls • Relative abundance of several genera were significantly associated with ME/CFS: Faecalibacterium, Roseburia, Dorea, Coprococcus, Ruminococcus, Coprobacillus • Several bacterial metabolic pathways also were significantly associated with ME/CFS • The relative abundance of those bacterial taxa, and those same bacterial metabolic pathways, not only were associated with ME/CFS: they also were positively correlated with the severity of symptoms — particularly fatigue and pain

From: Nagy-Szakal D….Lipkin WI. Microbiome 2017;5:44 Metagenomic Gut Microbiome Study

• Lipkin group and Julia Oh group both find deficiency on butyrate-producing species in people with ME/CFS Can the Different Models Be United? Uniting These ME/CFS Disease Models

• All 3 models — sickness behavior and inflammation, dauer/hibernation-torpor, and cell danger response/incomplete healing —involve ancient biological mechanisms that preserve energy in order to prevent or heal injury, but at the expense of temporarily impaired function

• The 4th model, the microbiome, is one plausible source of injury/inflammation, in some patients

• Do the symptoms of ME/CFS result from activation of these ancient mechanisms, and a pathological inability to turn them off? In Summary...

• This conference and the scientific literature reveal robust, replicated evidence of underlying organic abnormalities in patients with the symptoms that define ME/CFS

• Those abnormalities have considerable overlap with several well documented models of disease

• More needs to be done to solidify and expand our understanding of each of these abnormalities, and of their relationship with each other... and of the triggers that set them all in motion