postinfectious fatigue syndrome – American ME and CFS Society

Is SARS-CoV-2 the only cause of long-COVID?

Abstract:

Around 10% of adults infected with SARS-CoV-2 that survive a first episode of COVID-19 appear to experience long-term clinical manifestations. The signs and symptoms of this post-acute COVID-19 syndrome (PACS) include fatigue, dyspnea, joint pain, myalgia, chest pain, cough, anosmia, dysgeusia, headache, depression, anxiety, memory loss, concentration difficulties, and insomnia. These sequelae remind the constellation of clinical manifestations previously recognized as myalgic encephalomyelitis (ME) or chronic fatigue syndrome (CFS).

This condition has been described following distinct infectious events, mostly acute viral illnesses. In this way, the pathophysiology of PACS might overlap with mechanisms involved in other post-infectious fatigue syndromes. The risk of PACS is more frequent in women than men. Additional host genetic factors could be involved.

There is a dysregulation of multiple body organs and systems, involving the immune system, the coagulation cascade, endocrine organs, autonomic nervous system, microbiota-gut-brain axis, hypothalamic-pituitary-adrenal axis, hypothalamic-pituitary-thyroid axis, etc. Hypothetically, an abnormal response to certain infectious agents could trigger the development of postinfectious fatigue syndromes.

Source: Pintos-Pascual I, Moreno-Torres V, Ibánez-Estéllez F, Corrales-Rodriguez P, Treviño A, Corpas M, Corral O, Soriano V, de Mendoza C. Is SARS-CoV-2 the only cause of long-COVID? AIDS Rev. 2022 Nov 25. doi: 10.24875/AIDSRev.22000025. Epub ahead of print. PMID: 36427058. https://pubmed.ncbi.nlm.nih.gov/36427058/

Peripheral blood gene expression in postinfective fatigue syndrome following from three different triggering infections

Abstract:

BACKGROUND: Several infections trigger postinfective fatigue syndromes, which share key illness characteristics with each other and with chronic fatigue syndrome (CFS). Previous cross-sectional case-control studies of CFS have suggested that unique gene expression signatures are evident in peripheral blood samples.

METHODS: Peripheral blood transcriptomes in samples collected longitudinally, in 18 subjects with a fatigue syndrome lasting ≥ 6 months after acute infection due to Epstein-Barr virus, Ross River virus, or Coxiella burnetii (Q fever), and 18 matched control subjects who had recovered promptly, were studied by microarray (n = 127) and confirmatory quantitative polymerase chain reaction (PCR). Gene expression patterns associated with CFS were sought by univariate statistics and regression modeling.

RESULTS: There were 23 genes with modest differential expression (0.6-2.3-fold change) in within-subject comparisons of early, symptomatic time points with late, recovered time points. There were modest differences found in 63 genes, either in cross-sectional comparison of cases and controls at 6 months after infection onset or in the regression model. There were 223 genes significantly correlated with individual symptom domains. Quantitative PCR confirmed 33 (73%) of 45 genes-none were consistent across cohorts.

CONCLUSIONS: Although the illness characteristics of patients with postinfective fatigue syndromes have more similarities than differences, no reliable peripheral blood gene expression correlate is evident.

Source: Galbraith S, Cameron B, Li H, Lau D, Vollmer-Conna U, Lloyd AR. Peripheral blood gene expression in postinfective fatigue syndrome following from three different triggering infections. J Infect Dis. 2011 Nov 15;204(10):1632-40. doi: 10.1093/infdis/jir612. Epub 2011 Sep 29. http://jid.oxfordjournals.org/content/204/10/1632.long (Full article)

Autonomic hyper-vigilance in post-infective fatigue syndrome

Abstract:

This study examined whether post-infective fatigue syndrome (PIFS) is associated with a disturbance in bidirectional autonomic signalling resulting in heightened perception of symptoms and sensations from the body in conjunction with autonomic hyper-reactivity to perceived challenges.

We studied 23 patients with PIFS and 25 healthy matched control subjects. A heartbeat discrimination task and a pressure pain threshold test were used to assess interoceptive sensitivity. Cardiac response was assessed over a 4-min Stroop task. PIFS was associated with higher accuracy in heartbeat discrimination and a lower pressure pain threshold. Increased interoceptive sensitivity correlated strongly with current symptoms and potentiated differences in the cardiac response to the Stroop task, which in PIFS was characterized by insensitivity to task difficulty and lack of habituation.

Our results provide the first evidence of heightened interoceptive sensitivity in PIFS. Together with the distinct pattern in cardiac responsivity these findings present a picture of physiological hyper-vigilance and response inflexibility.

Source: Kadota Y, Cooper G, Burton AR, Lemon J, Schall U, Lloyd A, Vollmer-Conna U/ Autonomic hyper-vigilance in post-infective fatigue syndrome. Biol Psychol. 2010 Sep;85(1):97-103. doi: 10.1016/j.biopsycho.2010.05.009. Epub 2010 Jun 2. https://www.ncbi.nlm.nih.gov/pubmed/20678991

Chronic fatigue and chronic fatigue syndrome: shifting boundaries and attributions

Abstract:

The subjective symptom of “fatigue” is one of the most widespread in the general population and is a major source of healthcare utilization. Prolonged fatigue is often associated with neuropsychological and musculoskeletal symptoms that form the basis of several syndromal diagnoses including chronic fatigue syndrome, fibromyalgia, and neurasthenia, and is clearly not simply the result of a lack of force generation from the muscle.

Current epidemiologic research in this area relies predominantly on self-report data to document the prevalence and associations of chronic fatigue. Of necessity, this subjective data source gives rise to uncertain diagnostic boundaries and consequent divergent epidemiologic, clinical, and pathophysiologic research findings.

This review will highlight the impact of the case definition and ascertainment methods on the varying prevalence estimates of chronic fatigue syndrome and patterns of reported psychological comorbidty. It will also evaluate the evidence for a true postinfective fatigue syndrome.

Source: Lloyd AR. Chronic fatigue and chronic fatigue syndrome: shifting boundaries and attributions. Am J Med. 1998 Sep 28;105(3A):7S-10S. http://www.ncbi.nlm.nih.gov/pubmed/9790475

Is there a postinfection fatigue syndrome?

Abstract:

Prolonged fatigue syndromes are common in general practice. Most of these syndromes are secondary to other common medical or psychological disorders. It appears, however, that some specific infectious illnesses are associated with prolonged recovery. Theories as to the mechanisms for such post infection fatigue syndromes include a range of immunological, psychological and neurobiological processes. Current evidence suggests disruption of fundamental central nervous system mechanisms, such as the sleep-wake cycle and the hypothalamic-pituitary-adrenal axis, may underpin the clinical features of this disorder. Treatment should focus on the provision of continuous medical care, physical rehabilitation and adjunctive psychological therapies.

Source: Hickie I, Lloyd A, Wakefield D, Ricci C. Is there a postinfection fatigue syndrome? Aust Fam Physician. 1996 Dec;25(12):1847-52. http://www.ncbi.nlm.nih.gov/pubmed/9009004

A chronic “postinfectious” fatigue syndrome associated with benign lymphoproliferation, B-cell proliferation, and active replication of human herpesvirus-6

Abstract:

A 17-year-old, previously healthy woman developed an acute “mononucleosis-like” illness with an associated “atypical” pneumonitis, followed by years of debilitating chronic fatigue, fevers, a 10-kg weight loss, night sweats, and neurocognitive symptoms. Thereafter, her sister developed a similar but less severe illness.

The patient developed marked, chronic lymphadenopathy and splenomegaly, with associated persistent relative lymphocytosis and atypical lymphocytosis and with thrombocytopenia. After 3 years of illness, a splenectomy was performed, which resulted in some symptomatic improvement, prompt weight gain, and resolution of all hematologic abnormalities. Serial immunologic studies revealed a strikingly elevated number of activated B lymphocytes and a T lymphopenia, which improved but did not return to normal postsplenectomy. No causal association was found with any of several infectious agents that could produce such a lymphoproliferative illness.

However, both the patient and her sister had evidence of active infection with the recently discovered human herpesvirus-6. Seven years after the onset of the illness, the patient and her sister remain chronically ill.

Source: Buchwald D, Freedman AS, Ablashi DV, Sullivan JL, Caligiuri M, Weinberg DS, Hall CG, Ashley RL, Saxinger C, Balachandran N, et al. A chronic “postinfectious” fatigue syndrome associated with benign lymphoproliferation, B-cell proliferation, and active replication of human herpesvirus-6. J Clin Immunol. 1990 Nov;10(6):335-44. http://www.ncbi.nlm.nih.gov/pubmed/1964694