PCR – American ME and CFS Society

Evidence of a Novel Mitochondrial Signature in Systemic Sclerosis Patients with Chronic Fatigue Syndrome

Abstract:

Symptoms of myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) are common in rheumatic diseases, but no studies report the frequency of these in early systemic sclerosis. There are no known biomarkers that can distinguish between patients with ME/CFS, although mitochondrial abnormalities are often demonstrated.

We sought to assess the prevalence of ME/CFS in limited cutaneous SSc (lcSSc) patients early in their disease (<5 years from the onset of non-Raynaud’s symptoms) and to determine if alterations in mitochondrial electron transport chain (ETC) transcripts and mitochondrial DNA (mtDNA) integrity could be used to distinguish between fatigued and non-fatigued patients.

All SSc patients met ACR/EULAR classification criteria. ME/CFS-related symptoms were assessed through validated questionnaires, and the expression of ETC transcripts and mtDNA integrity were quantified via qPCR.

SSc patients with ME/CFS could be distinguished from non-fatigued patients through ETC gene analysis; specifically, reduced expression of ND4 and CyB and increased expression of Cox7C. ND4 and CyB expression correlated with indicators of disease severity.

Further prospective and functional studies are needed to determine if this altered signature can be further utilized to better identify ME/CFS in SSc patients, and whether ME/CFS in early SSc disease could predict more severe disease outcomes.

Source: van Eeden C, Redmond D, Mohazab N, Larché MJ, Mason AL, Cohen Tervaert JW, Osman MS. Evidence of a Novel Mitochondrial Signature in Systemic Sclerosis Patients with Chronic Fatigue Syndrome. International Journal of Molecular Sciences. 2023; 24(15):12057. https://doi.org/10.3390/ijms241512057 https://www.mdpi.com/1422-0067/24/15/12057 (Full text)

HERV-K and HERV-W transcriptional activity in myalgic encephalomyelitis/chronic fatigue syndrome

Abstract:

BACKGROUND: Chronic fatigue syndrome/myalgic encephalomyelitis (CFS/MS) is an incapacitating chronic disease that dramatically compromise the life quality. The CFS/ME pathogenesis is multifactorial, and it is believed that immunological, metabolic and environmental factors play a role. It is well documented an increased activity of Human endogenous retroviruses (HERVs) from different families in autoimmune and neurological diseases, making these elements good candidates for biomarkers or even triggers for such diseases.

METHODS: Here the expression of Endogenous retroviruses K and W (HERV-K and HERV-W) was determined in blood from moderately and severely affected ME/CFS patients through real time PCR.

RESULTS: HERV-K was overexpressed only in moderately affected individuals but HERV-W showed no difference.

CONCLUSIONS: This is the first report about HERV-K differential expression in moderate ME/CFS. Although the relationship between HERVs and ME/CFS has yet to be proven, the observation of this phenomenon deserves further attention.

Source: Rodrigues LS, da Silva Nali LH, Leal COD, Sabino EC, Lacerda EM, Kingdon CC, Nacul L, Romano CM. HERV-K and HERV-W transcriptional activity in myalgic encephalomyelitis/chronic fatigue syndrome. Auto Immun Highlights. 2019 Nov 15;10(1):12. doi: 10.1186/s13317-019-0122-8. eCollection 2019 Dec. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7065355/ (Full text)

Differential-display PCR of peripheral blood for biomarker discovery in chronic fatigue syndrome

Abstract:

We used differential-display PCR of peripheral blood mononuclear cells (PBMCs) to search for candidate biomarkers for chronic fatigue syndrome(CFS). PBMCs were collected from a subject with CFS and an age- and sex-matched control before and 24 h after exercise. RNA expression profiles were generated using 46 primer combinations, and the similarity between the individuals was striking.

Differentially expressed bands were excised, reamplified, and sequenced, yielding 95 nonredundant sequences, of which 50 matched to known gene transcripts, 38 matched to genes with unknown functions, and 7 had no similarity to any database entry. Most (86%) of the differences between the two subjects were present at baseline.

Differential expression of ten genes was verified by real-time reverse-transcription PCR: five (cystatin F, MHC class II, platelet factor 4, fetal brain expressed sequence tag, and perforin) were downregulated, and the remaining five genes (cathepsin B, DNA polymerase epsilon4, novel EST PBMC191MSt, heparanase precursor, and ORF2/L1 element) were upregulated in the subject with CFS. Many of these genes have known functions in defense and immunity, thus supporting prior suggestions of immune dysregulation in the pathogenesis of CFS.

Differential-display PCR is a powerful tool for identification of candidate biomarkers. Investigation of these markers in samples from well-designed epidemiological studies of CFS will be required to determine the validity of these candidate biomarkers. The real-time reverse-transcription PCR assays that we developed for assay of these biomarkers will facilitate high-throughput testing of these additional samples.

Source: Steinau M, Unger ER, Vernon SD, Jones JF, Rajeevan MS. Differential-display PCR of peripheral blood for biomarker discovery in chronic fatigue syndrome. J Mol Med (Berl). 2004 Nov;82(11):750-5. Epub 2004 Oct 14. http://www.ncbi.nlm.nih.gov/pubmed/15490094

Detection of Mycoplasma genus and Mycoplasma fermentans by PCR in patients with Chronic Fatigue Syndrome

Abstract:

Mycoplasma fermentans and other Mycoplasma species are colonizers of human mucosal surfaces and may be associated with human immunodeficiency virus infection. While many infectious agents have been described in different percentages of patients with Chronic Fatigue Syndrome (CFS), little is known about the prevalence of mycoplasmas and especially M. fermentans in CFS patients.

A polymerase chain reaction (PCR)-based assay was used to detect Mycoplasma genus and M. fermentans genomes in peripheral blood mononuclear cells (PBMC) of CFS patients. Blood was collected from 100 patients with CFS and 50 control subjects. The amplified products of 717 bp of Mycoplasma genus, and 206 bp of M. fermentans were detected in DNA purified from blood samples in 52% and 34% of CFS samples, respectively. In contrast, these genomes were found in only 14% and 8% of healthy control subjects respectively (P < 0.0001).

All samples were confirmed by Southern blot with a specific probe based on internal sequences of the expected amplification product. Several samples, which were positive for Mycoplasma genus, were negative for M. fermentans indicating that other Mycoplasma species are involved. A quantitative PCR was developed to determine the number of M. fermentans genome copies present in 1 microg of DNA for controls and CFS patients.

Mycoplasma copy numbers ranging from 130 to 880 and from 264 to 2400 were detected in controls and CFS positive subjects, respectively. An enzyme immunoassay was applied for the detection of antibodies against p29 surface lipoprotein of M. fermentans to determine the relationship between M. fermentans genome copy numbers and antibody levels. Individuals with high genome copy numbers exhibited higher IgG and IgM antibodies against M. fermentans specific peptides. Isolation of this organism by culture from clinical specimens is needed in order to demonstrate specificity of signal detected by PCR in this study.

Source: Vojdani A, Choppa PC, Tagle C, Andrin R, Samimi B, Lapp CW. Detection of Mycoplasma genus and Mycoplasma fermentans by PCR in patients with Chronic Fatigue Syndrome. FEMS Immunol Med Microbiol. 1998 Dec;22(4):355-65. http://femsim.oxfordjournals.org/content/22/4/355.long (Full article)

Investigation by polymerase chain reaction of enteroviral infection in patients with chronic fatigue syndrome

Abstract:

1. Chronic fatigue syndrome is characterized by muscle fatigue and pain at rest, symptoms which are usually exacerbated with exercise. Although various studies have shown minor, non-specific morphological and biochemical changes in muscle of patients with chronic fatigue syndrome, no consistent defect has been identified. Some have suggested that an enteroviral infection in muscle may cause the chronic muscle fatigue seen in patients with chronic fatigue syndrome, with acute infection directly and irreversibly impairing mitochondrial function, and persistent infection depressing muscle protein synthesis and metabolism.

2. To clarify the involvement of enterovirus infection in chronic fatigue syndrome, muscle biopsies from a group of patients with chronic fatigue syndrome were examined for the presence of enteroviral RNA by reverse transcriptase-polymerase chain reaction techniques in relation to functional studies of muscle mitochondria and the muscle RNA/DNA ratio.

3. Fifty-eight percent of patients reported an uncharacterized ‘viral infection’ before the onset of their illness, but none of the muscle samples from 34 patients contained detectable amounts of enteroviral RNA. Muscle tissue had a general reduction in the RNA/DNA ratio and mitochondrial enzyme activities with no specific abnormality in the activity of enzymes encoded partially on the mitochondrial genome (cytochrome-c oxidase) or nuclear genome (citrate synthase, succinate reductase).

4. These data provide no evidence of an enteroviral infection in muscle of patients with chronic fatigue syndrome, although this does not exclude a role of enterovirus in initiating the disease process. The general reduction in RNA/DNA ratio and mitochondrial enzyme activities is consistent with a general reduction in habitual activity.

Source: McArdle A, McArdle F, Jackson MJ, Page SF, Fahal I, Edwards RH. Investigation by polymerase chain reaction of enteroviral infection in patients with chronic fatigue syndrome. Clin Sci (Lond). 1996 Apr;90(4):295-300. http://www.ncbi.nlm.nih.gov/pubmed/8777836

Demonstration of Borna disease virus RNA in peripheral blood mononuclear cells derived from Japanese patients with chronic fatigue syndrome

Abstract:

CFS, a recently named heterogeneous disorder, is an illness of unknown etiology. The association of CFS with viral infections has been suggested. A common association between CFS and several viruses examined has not been confirmed.

Here, we centered on the possible link between CFS and BDV infection. By nested RT-PCR followed by hybridization, BDV RNA was demonstrated as a clear signal in PBMCs in 3 out of 25 CFS patients. The amplified cDNA fragments were cloned and sequenced. A total of 16 clones were studied. Intra-patients divergencies of the p24 were 2-9%, 3-20%, and 3-11% in the deduced amino acids. Inter-patient divergencies among the 16 clones were 3-24%. Antibodies to recombinant BDV p24 protein were detected in 6 CFS patients including one carrying BDV RNA.

Overall, these gave the prevalence of 32% (8/25) in Japanese CFS patients, suggesting that Japanese CFS is highly associated with active infection of BDV, or a related agent.

Source: Nakaya T, Takahashi H, Nakamura Y, Asahi S, Tobiume M, Kuratsune H, Kitani T, Yamanishi K, Ikuta K. Demonstration of Borna disease virus RNA in peripheral blood mononuclear cells derived from Japanese patients with chronic fatigue syndrome. FEBS Lett. 1996 Jan 8;378(2):145-9. http://onlinelibrary.wiley.com/doi/10.1016/0014-5793(95)01439-X/epdf (Full article)

No findings of enteroviruses in Swedish patients with chronic fatigue syndrome

Abstract:

Enteroviruses have been proposed to cause an immune complex disease in the chronic fatigue syndrome. Altogether 34 patients with the chronic fatigue syndrome, according to criteria of the Centers for Disease Control, USA, were studied evenly over the seasons for the possible presence of a chronic enterovirus infection.

In 11 patients, 1-5 faecal samples were collected at about 6 month intervals for virus isolation before and after acid treatment, followed by ultracetrifugation at pH 3 to dissolve possible enterovirus-antibody complexes. Another 14 fecal samples were subjected to routine virus isolation alone.

Seven pairs of serum-cerebrospinal fluid samples were analysed for cross-reactive IgG antibody activity to enteroviruses. In 29 patients a muscle biopsy was collected for enterovirus polymerase chain reaction (PCR).

We were unable to identify enteroviruses in any of these samples by any of these techniques. Our study does not confirm evidence for persistent enterovirus infection in the chronic fatigue syndrome.

Source: Lindh G, Samuelson A, Hedlund KO, Evengård B, Lindquist L, Ehrnst A. No findings of enteroviruses in Swedish patients with chronic fatigue syndrome. Scand J Infect Dis. 1996;28(3):305-7. http://www.ncbi.nlm.nih.gov/pubmed/8863367

Comparison of coxsackie B neutralisation and enteroviral PCR in chronic fatigue patients

Abstract:

Coxsackie B enteroviruses have been implicated repeatedly as agents associated with chronic fatigue syndrome (CFS). The objective of this study was to compare the serological evidence for the presence of Coxsackie B virus neutralising antibody, with the polymerase chain reaction (PCR) detecting a portion of the 5′ nontranslated region (NTR) of the enterovirus genome.

Serum samples from 100 chronic fatigue patients and from 100 healthy comparison patients were used in this study. In the CFS study group, 42% patients were positive for enteroviral sequences by PCR, compared to only 9% of the comparison group. Using the neutralisation assay, 34% of study patients were positive, compared to 41% of comparison patients.

In the study group, 66/100 patient results correlated, i.e., they were either positive/positive or negative/negative for both tests. Of those that did not correlate, the majority were PCR-positive/Coxsackie B antibody-negative (21/34).

In the comparison group, 58/100 patient results correlated. Of those that did not, the majority were PCR-negative/Coxsackie B antibody-positive (37/42).

The Coxsackie B antibody neutralisation assay was not able to differentiate the CFS study group from the healthy comparison group, and thus the clinical relevance of this assay may be questioned. The PCR assay did differentiate the two groups with significantly more CFS patients having evidence of enterovirus than the comparison group.

Source: Nairn C, Galbraith DN, Clements GB. Comparison of coxsackie B neutralisation and enteroviral PCR in chronic fatigue patients. J Med Virol. 1995 Aug;46(4):310-3. http://www.ncbi.nlm.nih.gov/pubmed/7595406

African green monkey origin of the atypical cytopathic ‘stealth virus’ isolated from a patient with chronic fatigue syndrome

Abstract:

BACKGROUND: A cytomegalovirus-like ‘stealth virus’ had previously been isolated from a patient with the chronic fatigue syndrome (CFS).

OBJECTIVE: To determine the original derivation of this virus.

STUDY DESIGN: DNA sequencing of cloned regions of the virus was performed and the sequences were compared using BLASTN and FASTA analyses against the entire GenBank database. Viral sequences were also used to design primers for the polymerase chain reaction (PCR).

RESULTS: DNA and amino acid sequence comparisons showed that the stealth virus was more closely related to the Colburn strain of simian cytomegalovirus (SCMV) than to CMV of either human or rhesus monkey origin or to any other sequenced herpesvirus. Similarity, but non-identity, between the stealth virus and SCMV, was confirmed using PCR.

CONCLUSION: The findings implicate the African green monkey as the probable source of the virus isolated from this CFS patient.

Source: Martin WJ, Ahmed KN, Zeng LC, Olsen JC, Seward JG, Seehrai JS. African green monkey origin of the atypical cytopathic ‘stealth virus’ isolated from a patient with chronic fatigue syndrome. Clin Diagn Virol. 1995 Jul;4(1):93-103. http://www.ncbi.nlm.nih.gov/pubmed/15566831