Exploring potential biomarkers and therapeutic targets of long COVID-associated inflammatory cardiomyopathy

Background: The negative impact of long COVID on social life and human health is increasingly prominent, and the elevated risk of cardiovascular disease in patients recovering from COVID-19 has also been fully confirmed. However, the pathogenesis of long COVID-related inflammatory cardiomyopathy is still unclear. Here, we explore potential biomarkers and therapeutic targets of long COVID-associated inflammatory cardiomyopathy.

Methods: Datasets that met the study requirements were identified in Gene Expression Omnibus (GEO), and differentially expressed genes (DEGs) were obtained by the algorithm. Then, functional enrichment analysis was performed to explore the basic molecular mechanisms and biological processes associated with DEGs. A protein–protein interaction (PPI) network was constructed and analyzed to identify hub genes among the common DEGs. Finally, a third dataset was introduced for validation.

Results: Ultimately, 3,098 upregulated DEGs and 1965 downregulated DEGs were extracted from the inflammatory cardiomyopathy dataset. A total of 89 upregulated DEGs and 217 downregulated DEGs were extracted from the dataset of convalescent COVID patients. Enrichment analysis and construction of the PPI network confirmed VEGFA, FOXO1, CXCR4, and SMAD4 as upregulated hub genes and KRAS and TXN as downregulated hub genes. The separate dataset of patients with COVID-19 infection used for verification led to speculation that long COVID-associated inflammatory cardiomyopathy is mainly attributable to the immune-mediated response and inflammation rather than to direct infection of cells by the virus.

Conclusion: Screening of potential biomarkers and therapeutic targets sheds new light on the pathogenesis of long COVID-associated inflammatory cardiomyopathy as well as potential therapeutic approaches. Further clinical studies are needed to explore these possibilities in light of the increasingly severe negative impacts of long COVID.

Source: Peng Qi, Mengjie Huang and Haiyan Zhu. Exploring potential biomarkers and therapeutic targets of long COVID-associated inflammatory cardiomyopathy. Front. Med., 29 June 2023. Sec. Infectious Diseases: Pathogenesis and Therapy. Volume 10 – 2023 | https://doi.org/10.3389/fmed.2023.1191354 https://www.frontiersin.org/articles/10.3389/fmed.2023.1191354/full (Full text)

Prevalence of abnormal cardiac wall motion in the cardiomyopathy associated with incomplete multiplication of Epstein-barr Virus and/or cytomegalovirus in patients with chronic fatigue syndrome

Abstract:

We reported unique incomplete herpesvirus (Epstein-Barr Virus (EBV) and/or nonstructural (HCMV) cytomegalovirus) multiplication in 2 distinct subsets of CFS patients. The CFS subsets were identified by: a) presence of IgM serum antibodies to HCMV nonstructural gene products p52 and CM2 (UL44 and UL57), and/or b) IgM serum antibodies to Epstein-Barr virus viral capsid antigen (EBV, VCA IgM).

Diagnostic IgM serum antibodies were found in two independent blinded studies involving 49 CFS patients, but the same antibodies were absent in 170 control patients (p<0.05). Abnormal 24 Hr-electrocardiographic monitoring, tachycardias at rest and, in severe chronic cases, abnormal cardiac wall motion (ACWM) were seen in these same CFS patients.

We now report a prospective consecutive case control study from 1987–1999 of cardiac dynamics as measured by radionuclide ventriculography in 98 CFS patients from 1987–1999. Controls were patients with various malignancies who were evaluated in protocols requiring radionuclide ventriculography before initiation of cardiotoxic chemotherapeutic agents.

The prevalence of abnormal cardiac wall motion (ACWM) at rest in CFS patients was 10 out of 87 patients (11.5%). With stress exercise, 21 patients (24.1%) demonstrated ACWM. Cardiac biopsies in 3 of these CFS patients with ACWM showed a cardiomyopathy. Among the controls, ACWM at rest was present in 4 out of 191 patients (2%) (p=0.0018). A progressive cardiomyopathy caused by incomplete virus multiplication of EBV and/or HCMV in CFS patients is present.

 

Source: Lerner AM, Dworkin HJ, Sayyed T, Chang CH, Fitzgerald JT, Beqaj S, Deeter RG, Goldstein J, Gottipolu P, O’Neill W. Prevalence of abnormal cardiac wall motion in the cardiomyopathy associated with incomplete multiplication of Epstein-barr Virus and/or cytomegalovirus in patients with chronic fatigue syndrome. In Vivo. 2004 Jul-Aug;18(4):417-24. http://iv.iiarjournals.org/content/18/4/417.long (Full article)

 

A small, randomized, placebo-controlled trial of the use of antiviral therapy for patients with chronic fatigue syndrome

Comment on: Editorial response: microbial persistence and idiopathic dilated cardiomyopathy. [Clin Infect Dis. 1999]

 

SIR—We have presented controlled and observational data that are consistent with the hypothesis that subsets of cases of chronic fatigue syndrome (CFS) result from cardiac disease due to a single, persisting infection caused by Epstein-Barr virus (EBV) or, in turn, to a single, persisting infection caused by human cytomegalovirus (HCMV) in immunocompetent patients [1]. Patients who have a separate subset of CFS have simultaneous coinfection with EBV and HCMV. Cardiomyopathic changes are observed in right ventricular endomyocardial biopsy specimens obtained from such patients, and abnormal findings on Holter monitoring (e.g., oscillating abnormal T-wave flattenings and T-wave inversions) are “uniformly” present [2–4]. Left ventricular dysfunction is manifested by sinus tachycardia at rest, abnormal cardiac-wall motion, and decreased left ventricular ejection fractions (rest/stress) in those patients with CFS who are most ill [5]. These findings belie the relatively normal findings observed on standard 12-lead electrocardiograms [6].

In January 1995, a double-blinded, placebo-controlled, phase III crossover study of patients with CFS was initiated. Eleven patients who had CFS (10 of whom were women) were each followed for 18 consecutive months. The mean patient age was 42.7 years, and the mean duration of CFS was 35.1 months. Before antiviral nucleosides were administered, endomyocardial biopsies were performed. Cardiac tissues and blood samples tested negative for isolation of HCMV in cultures of human fibroblast tissues. Two cardiac biopsy specimens that were obtained from patients who had CFS tested positive for HCMV nucleic acids by means of PCR. No cardiac specimen that was obtained from a patient with CFS tested positive for EBV nucleic acids. (Cardiac tissue samples that were obtained from 4 of 21 control patients who had coronary artery disease but who did not have CFS also tested positive for HCMV nucleic acids.) Cardiomyopathic degenerative findings (e.g., myofiber disarray, interstitial fibrosis, increased intracellular granules, and interstitial fat) were noted in patients who had CFS. One patient who had CFS had myocarditis with focal lymphocytic infiltrates.

You can read the rest of this article here: http://cid.oxfordjournals.org/content/32/11/1657.long

 

Source: Lerner AM, Zervos M, Chang CH, Beqaj S, Goldstein J, O’Neill W, Dworkin H, Fitgerald T, Deeter RG. A small, randomized, placebo-controlled trial of the use of antiviral therapy for patients with chronic fatigue syndrome. Clin Infect Dis. 2001 Jun 1;32(11):1657-8. http://cid.oxfordjournals.org/content/32/11/1657.long (Full article)

 

Enterovirus infections in new disguise

Abstract:

Enteroviruses (Coxsackie A and B, echovirus, poliovirus) belong to a group of small RNA-viruses, picomavirus, which are widespread in nature. Enteroviruses cause a number of well known diseases and symptoms in humans, from subclinical infections and the common cold to poliomyelitis with paralysis. The development of polio vaccines is the greatest accomplishment within the field of enterovirus research and the background work was awarded the Nobel prize in 1954. New knowledge implies that enteroviruses play a more important part in the morbidity panorama than was previously thought. Chronic (persistent) enteroviruses were formerly unknown.

Serologic and molecular biology techniques have now demonstrated that enteroviral genomes, in certain situations, persist after the primary infection (which is often silent). Persistent enteroviral infection or recurrent infections and/or virus-stimulated autoimmunity might contribute to the development of diseases with hitherto unexplained pathogenesis, such as post polio syndrome, dilated cardiomyopathy, juvenile (type 1) diabetes and possibly some cases of chronic fatigue syndrome.

 

Source: Fohlman J, Friman G, Tuvemo T. Enterovirus infections in new disguise. Lakartidningen. 1997 Jul 9;94(28-29):2555-60. [Article in Swedish] http://www.ncbi.nlm.nih.gov/pubmed/9254324

 

Myalgic encephalomyelitis: postviral fatigue and the heart

Note: This letter appeared in the November 11, 1989 issue of the British Medical Journal.

 

SIR, The controversial subject of myalgic encephalomyelitis has surfaced once more,(1) and I would like to contribute to the debate about its viral origins.

Persistent virus infections impair the specialised functions of cells. These include the synthesis of specific products such as heavy and light myosin chains, melanin, hormones, and immune functions.(2) Evidence of persistent enterovirus infection has been found in both dilated cardiomyopathy,(3-5) an organic disease discussed at a recent symposium,(3) and the more controversial myalgic encephalomyelitis.(6,7)

In murine myocarditis induced by Coxsackie viruses, more severe and lasting disease is associated with immunopathological processes, which include virus specific, cross reactive, and autoimmune reactions.(3, 8, 9) In Coxsackie viral myocarditis and cardiomyopathy of humans the antibodies that cross react with Coxsackie B antigens are reported.(3) Serum samples from patients with.cardiomyopathy may react with cardiac ,B adrenoreceptors, with mitochondrial ADP/ATP carriers, and with cell surface protein of the calcium channel causing calcium overload of myocytes and consequent dysfunction.(3) Thus a complex pattern of pathogenic mechanisms is emerging to explain dilated cardiomyopathy, which was formerly considered to be idiopathic but is now recognised as a late sequel of a proportion of cardiac infections with certain enteroviruses, particularly those of the Coxsackie B group. This does not exclude the possible role of other viruses-for example, arboviruses where these are prevalent-as initiators of such pathogenic processes.

It seems likely that similar immunological and metabolic disturbances in myalgic encephalomyelitis may also result from chronic infection, usually with enteroviruses, providing the organic basis of the postviral fatigue syndrome.(10) This condition is characterised by severe fatiguability and recuperation through rest. The myocardium, however, cannot rest-except terminally. Does “postviral dilated cardiomyopathy” represent the result of postviral fatigue syndrome of the unresting heart?

~NORMAN R GRIST Communicable Diseases (Scotland) Unit, Ruchill Hospital, Glasgow G20 9NB

 

References

1 Harris F, Taitz LS. Damaging diagnoses of myalgic encephalitis in children. BrMedj 1989;299:790. (23 September.)

2 Southern P, Oldstone MBA. Medical consequences of persistent viral infection. N Englj Med 1986;314:359-67.

3 Schultheiss HP, ed. New concepts in viral heart disease. Berlin: Springer, 1988.

4 Bowles NE, Richardson PJ, Olsen EGJ, Archard LC. Detection of Coxsackie-B-virus-specific RNA sequences in myocardial biopsy samples from patients with myocarditis and dilated cardiomyopathy. Lancet 1986;i: 1120-3.

5 Kandolf R, Kirschner P, Amies D, et al. Enteroviral heart disease: diagnosis by in situ hybridization. In: Schultheiss HP, ed. New concepts in viral heart disease. Berlin: Springer, 1988:337-48.

6 Yousef GE, Mann GF, Smith DG, et al. Chronic enterovirus infection in patients with postviral fatigue syndrome. Lancet 1988;i: 146-50.

7 Archard LC, Bowles NE, Behan PO, Bell EJ, Doyle D. Postviral fatigue syndrome: persistence of enterovirus RNA in muscle and elevated creatinine kinase. J R Soc Med 1988;81:326-9.

8 Huber SA. The role of immune mechanisms in pathogenesis. In: Bendinelli M, Friedman H, eds. Coxsackieviruses, a general update. New York: Plenum, 1988:103-16.

9 Beisel KW, Rose NR. Relationship of coxsackievirus to cardiac autoimmnunity. In: Bendinelli M, Friedmann H, eds. Coxsackievinruses, a general update. New York: Plenum, 1988:271-92.

10 Behan PO, Behan WMH, Bell EJ. The post-viral fatigue syndrome-an analysis of the findings in 50 cases. J Infect 1985;10:21 1-22.

 

Source:  N. R. Grist. Myalgic encephalomyelitis: postviral fatigue and the heart. BMJ. 1989 Nov 11; 299(6709): 1219. http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1838100/pdf/bmj00258-0049b.pdf