Replicated blood-based biomarkers for Myalgic Encephalomyelitis not explicable by inactivity

Abstract:

Myalgic Encephalomyelitis (ME; sometimes referred to as chronic fatigue syndrome) is a relatively common and female-biased disease of unknown pathogenesis that profoundly decreases patients’ health-related quality-of-life. ME diagnosis is hindered by the absence of robustly-defined and specific biomarkers that are easily measured from available sources such as blood, and unaffected by ME patients’ low level of physical activity.

Previous studies of blood biomarkers have not yielded replicated results, perhaps due to low study sample sizes (n<100). Here, we use UK Biobank (UKB) data for up to 1,455 ME cases and 131,303 population controls to discover hundreds of molecular and cellular blood traits that differ significantly between cases and controls. Importantly, 116 of these traits are replicated, as they are significant for both female and male cohorts.

Our analysis used semi-parametric efficient estimators, an initial Super Learner fit followed by a one-step correction, three types of mediators, and natural direct and indirect estimands, to decompose the average effect of ME status on molecular and cellular traits. Strikingly, these trait differences cannot be explained by ME cases’ restricted activity.

Of 3,237 traits considered, ME status had a significant effect on only one, via the “Duration of walk” (UKB field 874) mediator. By contrast, ME status had a significant direct effect on 290 traits (9%). As expected, these effects became more significant with increased stringency of case and control definition.

Significant female and male traits were indicative of chronic inflammation, insulin resistance and liver disease. Individually, significant effects on blood traits, however, were not sufficient to cleanly distinguish cases from controls. Nevertheless, their large number, lack of sex-bias, and strong significance, despite the ‘healthy volunteer’ selection bias of UKB participants, keep alive the future ambition of a blood-based biomarker panel for accurate ME diagnosis.

Source: Sjoerd V Beentjes, Julia Kaczmarczyk, Amanda Cassar, Gemma Louise Samms, Nima S Hejazi, Ava Khamseh, Chris P Ponting. Replicated blood-based biomarkers for Myalgic Encephalomyelitis not explicable by inactivity. medRxiv 2024.08.26.24312606; doi: https://doi.org/10.1101/2024.08.26.24312606 https://www.medrxiv.org/content/10.1101/2024.08.26.24312606v1 (Full text available as PDF file)

Post-COVID-19 cholangiopathy: Systematic review

Abstract:

Background: The coronavirus disease 2019 (COVID-19) pandemic has had a profound impact on global health, primarily characterized by severe respiratory illness. However, emerging evidence suggests that COVID-19 can also lead to secondary sclerosing cholangitis (SC), referred to as post-COVID-19 cholangiopathy.

Aim: To synthesize currently reported cases to assess the current state of knowledge on post-COVID-19 cholangiopathy.

Methods: Medical Subject Headings and Health Sciences Descriptors were used to retrieve relevant studies, which were combined using Boolean operators. Searches were conducted on electronic databases including Scopus, Web of Science, and MEDLINE (PubMed). Studies published in English, Spanish, or Portuguese were included, with no restrictions on the publication date. Additionally, the reference lists of retrieved studies were manually searched. Simple descriptive analyses were used to summarize the results. Then the data were extracted and assessed based on Reference Citation Analysis (https://www.referencecitationanalysis.com/).

Results: The initial search yielded a total of 192 articles. After screening, 85 articles were excluded due to duplication, leaving 107 articles for further review. Of these, 63 full-length articles met the inclusion criteria and were included in the analyses. Most of the patients were male and exhibited elevated liver function tests (93.8%). Magnetic resonance imaging revealed duct thickening with contrast enhancement (47.7%), as well as beading of the intrahepatic ducts (45.7%) with peribiliary contrast enhancement on diffusion (28.7%). Liver biopsy results confirmed SC in most cases (74.4%). Sixteen patients underwent liver transplantation, with three experiencing successful outcomes.

Conclusion: Post-COVID-19 cholangiopathy is a serious condition that is expected to become increasingly concerning in the coming years, particularly considering long COVID syndromes. Although liver transplantation has been proposed as a potential treatment option, more research is necessary to establish its efficacy and explore other potential treatments.

Source: Rasheed MA, Ballotin VR, Bigarella LG, Soldera J. Post-COVID-19 cholangiopathy: Systematic review. World J Methodol. 2023 Sep 20;13(4):296-322. doi: 10.5662/wjm.v13.i4.296. PMID: 37771872; PMCID: PMC10523251. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10523251/ (Full text)

Familial chronic fatigue

A 53-year-old woman presented to her general practitioner with a long history of profound lethargy associated with insomnia and arthralgia mainly affecting her knees. The patient dated her symptoms to a ‘flu-like’ illness six months previously. Medical history was of hypertension treated with an angiotensin-converting enzyme inhibitor and thiazide diuretic. She had also been taking oestrogen replacement since the menopause two years earlier. She had been a blood donor until 13 years previously, donating a total of 24 units of blood. She drank four units of alcohol per week but did not smoke. Physical examination was normal. Initial investigations performed were full blood count, urea and electrolytes, liver function tests, thyroid function tests, random glucose, cholesterol, calcium and urate. All were normal. Rheumatoid factor was negative and viral serology showed a raised IgG antibody titre to Epstein Barr virus, indicative of a past infection. XRays of the knee joints were normal.

A diagnosis of chronic fatigue syndrome was made. Over the following months her symptoms impaired her ability to work, shop and perform household tasks. Further medical consultations revealed no new features or abnormal tests and she took early retirement on the grounds of poor health.

Two years after her initial presentation, her brother, who had also been suffering from longstanding fatigue, was diagnosed as having liver disease.

You can read the rest of this article here: http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2431297/pdf/postmedj00149-0057.pdf

 

Source: George DK, Evans RM, Gunn IR. Familial chronic fatigue. Postgrad Med J. 1997 May;73(859):311-3. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC2431297/