Category: Biomarker

Biomarkers in chronic fatigue syndrome: evaluation of natural killer cell function and dipeptidyl peptidase IV/CD26

Abstract:

BACKGROUND: Chronic Fatigue Syndrome (CFS) studies from our laboratory and others described decreased natural killer cell cytotoxicity (NKCC) and elevated proportion of lymphocytes expressing the activation marker, dipeptidyl peptidase IV (DPPIV) also known as CD26. However, neither these assays nor other laboratory tests are widely accepted for the diagnosis or prognosis of CFS. This study sought to determine if NKCC or DPPIV/CD26 have diagnostic accuracy for CFS.

METHODS/RESULTS: Subjects included female and male CFS cases and healthy controls. NK cell function was measured with a bioassay, using K562 cells and (51)Cr release. Lymphocyte associated DPPIV/CD26 was assayed by qualitative and quantitative flow cytometry. Serum DPPIV/CD26 was measured by ELISA. Analysis by receiver operating characteristic (ROC) curve assessed biomarker potential. Cytotoxic function of NK cells for 176 CFS subjects was significantly lower than in the 230 controls. According to ROC analysis, NKCC was a good predictor of CFS status. There was no significant difference in NK cell counts between cases and controls. Percent CD2+ lymphocytes (T cells and NK cells) positive for DPPIV/C26 was elevated in CFS cases, but there was a decrease in the number of molecules (rMol) of DPPIV/C26 expressed on T cells and NK cells and a decrease in the soluble form of the enzyme in serum. Analyses by ROC curves indicated that all three measurements of DPPIV/CD26 demonstrated potential as biomarkers for CFS. None of the DPPIV/C26 assays were significantly correlated with NKCC.

CONCLUSIONS: By ROC analysis, NKCC and three methods of measuring DPPIV/C26 examined in this study had potential as biomarkers for CFS. Of these, NKCC, %CD2+CD26+ lymphocytes and rMol CD26/CD2+ lymphocyte, required flow cytometry, fresh blood and access to a high complexity laboratory. Soluble DPPIV/C26 in serum is done with a standard ELISA assay, or with other soluble factors in a multiplex type of ELISA. Dipeptidyl peptidase IV on lymphocytes or in serum was not predictive of NKCC suggesting that these should be considered as non-redundant biomarkers. Abnormalities in DPPIV/CD26 and in NK cell function have particular relevance to the possible role of infection in the initiation and/or the persistence of CFS.

 

Source: Fletcher MA, Zeng XR, Maher K, Levis S, Hurwitz B, Antoni M, Broderick G, Klimas NG. Biomarkers in chronic fatigue syndrome: evaluation of natural killer cell function and dipeptidyl peptidase IV/CD26. PLoS One. 2010 May 25;5(5):e10817. doi: 10.1371/journal.pone.0010817. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2876037/ (Full article)

 

Plasma cytokines in women with chronic fatigue syndrome

Abstract:

BACKGROUND: Chronic Fatigue Syndrome (CFS) studies from our laboratory and others have described cytokine abnormalities. Other studies reported no difference between CFS and controls. However, methodologies varied widely and few studies measured more than 4 or 5 cytokines. Multiplex technology permits the determination of cytokines for a large panel of cytokines simultaneously with high sensitivity and with only 30 ul of plasma per sample. No widely accepted laboratory test or marker is available for the diagnosis or prognosis of CFS. This study screened plasma factors to identify circulating biomarkers associated with CFS.

METHODS: Cytokines were measured in plasma from female CFS cases and female healthy controls. Multiplex technology provided profiles of 16 plasma factors including the pro -inflammatory cytokines: tumor necrosis factor alpha (TNFalpha), lymphotoxin alpha (LTalpha), interleukin (IL) – IL-Ialpha, IL-1beta, IL-6; TH1 cytokines: interferon gamma (IFNgamma), IL-12p70, IL-2, IL-15; TH2: IL-4, IL-5; TH17 cytokines, IL-17 and IL-23; anti-inflammatory cytokines IL-10, IL-13; the inflammatory mediator and neutrophil attracting chemokine IL-8 (CXCL8). Analysis by receiver operating characteristic (ROC) curve assessed the biomarker potential of each cytokine.

RESULTS: The following cytokines were elevated in CFS compared to controls: LTalpha, IL-1alpha, IL-1beta, IL-4, IL-5, IL-6 and IL-12. The following cytokines were decreased in CFS: IL-8, IL-13 and IL-15. The following cytokines were not different: TNFalpha, IFNgamma, IL-2, IL-10, IL-23 and IL-17. Applying (ROC) curve analyses, areas under the curves (AUC) for IL-5 (0. 84), LTalpha (0.77), IL-4 (0.77), IL-12 (0.76) indicated good biomarker potential. The AUC of IL-6 (0.73), IL-15 (0.73), IL-8 (0.69), IL-13 (0.68) IL-1alpha (0.62), IL-1beta (0.62) showed fair potential as biomarkers.

CONCLUSION: Cytokine abnormalities are common in CFS. In this study, 10 of 16 cytokines examined showed good to fair promise as biomarkers. However, the cytokine changes observed are likely to more indicative of immune activation and inflammation, rather than specific for CFS. As such, they are targets for herapeutic strategies. Newer techniques allow evaluation of large panels of cytokines in a cost effective fashion.

 

Source: Fletcher MA, Zeng XR, Barnes Z, Levis S, Klimas NG. Plasma cytokines in women with chronic fatigue syndrome. J Transl Med. 2009 Nov 12;7:96. doi: 10.1186/1479-5876-7-96. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2779802/ (Full article)

 

Autoantibodies to lens epithelium-derived growth factor/transcription co-activator P75 (LEDGF/P75) in children with chronic nonspecific complaints and with positive antinuclear antibodies

Abstract:

Autoimmune fatigue syndrome (AIFS) is characterized by chronic nonspecific complaints, consistently positive antinuclear antibodies (ANA), and lack of alternate medical explanations. A newly recognized antibody, named anti-Sa, was detected in approximately 40% of the patients by Western blot (WB) using HeLa extract.

Some patients with AIFS later develop chronic fatigue syndrome (CFS), and most of them are positive for anti-Sa. On the other hand, Muro et al. reported anti-DFS70 in patients with CFS. Anti-Sa and anti-DFS70 were turned out to be same specificities by exchanging studies of blind sera. The target antigen of anti-DFS70 was identified as lens epithelium derived growth factor/transcription co-activator p75 (LEDGF/p75).

The objectives of this study are to confirm whether the target antigen of anti-Sa is also LEDGF/p75, and to develop ELISA system by using recombinant protein. Recombinant protein of LEDGF/p75 was purchased from Protein One (Bethesda, MD, USA). We developed an ELISA system to detect anti-LEDGF/p75 by coating this recombinant protein. 226 sera of AIFS patients (including 36 CFS patients) were applied to this ELISA assay and Western immunoblot, and it was revealed that anti-Sa-positive sera defined by WB and sera positive for anti-LEDGF/p75 on ELISA were identical.

Moreover, reactivities of anti-Sa on WB were inhibited by pre-incubating with recombinant LEDGF/p75, and eluted antibodies from the nitrocellulose membrane could react on the ELISA. These results confirm that the Sa antigen is LEDGF/p75. The ELISA assay using recombinant LEDGF/p75 could be a promising tool for measuring anti-Sa and consequently for diagnosing CFS.

 

Source: Kuwabara N, Itoh Y, Igarshi T, Fukunaga Y. Autoantibodies to lens epithelium-derived growth factor/transcription co-activator P75 (LEDGF/P75) in children with chronic nonspecific complaints and with positive antinuclear antibodies. Autoimmunity. 2009 Sep;42(6):492-6. Doi: 10.1080/08916930902736663. https://www.ncbi.nlm.nih.gov/pubmed/19657776

 

A gene signature for post-infectious chronic fatigue syndrome

Abstract:

BACKGROUND: At present, there are no clinically reliable disease markers for chronic fatigue syndrome. DNA chip microarray technology provides a method for examining the differential expression of mRNA from a large number of genes. Our hypothesis was that a gene expression signature, generated by microarray assays, could help identify genes which are dysregulated in patients with post-infectious CFS and so help identify biomarkers for the condition.

METHODS: Human genome-wide Affymetrix GeneChip arrays (39,000 transcripts derived from 33,000 gene sequences) were used to compare the levels of gene expression in the peripheral blood mononuclear cells of male patients with post-infectious chronic fatigue (n = 8) and male healthy control subjects (n = 7).

RESULTS: Patients and healthy subjects differed significantly in the level of expression of 366 genes. Analysis of the differentially expressed genes indicated functional implications in immune modulation, oxidative stress and apoptosis. Prototype biomarkers were identified on the basis of differential levels of gene expression and possible biological significance.

CONCLUSION: Differential expression of key genes identified in this study offer an insight into the possible mechanism of chronic fatigue following infection. The representative biomarkers identified in this research appear promising as potential biomarkers for diagnosis and treatment.

 

Source: Gow JW, Hagan S, Herzyk P, Cannon C, Behan PO, Chaudhuri A. A gene signature for post-infectious chronic fatigue syndrome. BMC Med Genomics. 2009 Jun 25;2:38. doi: 10.1186/1755-8794-2-38. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2716361/ (Full article)

 

Differential heat shock protein responses to strenuous standardized exercise in chronic fatigue syndrome patients and matched healthy controls

Abstract:

PURPOSE: Since physical exertion is known to exacerbate the symptoms of chronic fatigue syndrome (CFS) and metabolic changes and including oxidative stress can modulate heat shock protein (HSP) expression responses, we sought to determine whether HSP expression is altered in CFS patients before and after exercise. Heat shock proteins (HSPs) in peripheral blood mononuclear cells (PBMC) were examined from 6 chronic fatigue syndrome (CFS) patients and 7 controls before and after a standardized treadmill exercise. Basal hsp27 was significantly higher among CFS patients compared to controls, and decreased immediately post-exercise, remaining below basal levels even at 7 days. A similar pattern was observed for HSP60, which gradually decreased in CFS patients but increased in controls post-exercise. These findings suggest an abnormal adaptive response to oxidative stress in CFS, and raise the possibility that HSP profiling may provide a more objective biologic marker for this illness.

METHODS: HSP27, HSP60, HSP70 and HSP90 expression from 6 CFS patients and 7 age- and sex-matched controls were examined by western blot analysis of peripheral blood mononuclear cells immediately before, after, and at 1 day and 7 days following a standardized treadmill exercise.

RESULTS: Basal HSP27 was higher among CFS patients than in controls (0.54 +/- 0.13 vs. 0.19 +/- 0.06, mean +/- SEM; P < 0.01). In addition, these levels in CFS patients decreased immediately post-exercise (0.25 +/- 0.09; P < 0.05) and remained below basal levels at day 1 post-exercises (0.18 +/- 0.05; P < 0.05). P < 0.05). This declining expression of HSP27 during the post-exercise period among CFS patients was confirmed by one-way ANOVA analysis with repeated measures (P < 0.05). In contrast, HSP27 levels remained relatively constant following exercise among control subjects. Similar patterns of declining HSP levels in CFS patients were also observed for HSP60 (0.94 +/- 0.40 vs. 1.32 +/- 0.46; P < 0.05), and for HSP90 (0.34 +/- 0.09 vs. 0.49 +/- 0.10; P < 0.05) at day 7 post-exercise compared with basal levels, respectively. In contrast, HSP60 levels in control subjects increased at day 1 (1.09 +/- 0.27) and day 7 (1.24 +/- 0.50) post-exercise compared to corresponding levels immediately post-exercise (0.55 +/- 0.06) (P < 0.05, respectively).

CONCLUSION: These preliminary findings suggest an abnormal or defective adaptive response to oxidative stress in CFS, and raise the possibility that HSP profiling may provide a more objective biologic marker for this illness.

 

Source: Thambirajah AA, Sleigh K, Stiver HG, Chow AW. Differential heat shock protein responses to strenuous standardized exercise in chronic fatigue syndrome patients and matched healthy controls. Clin Invest Med. 2008 Dec 1;31(6):E319-27. https://www.ncbi.nlm.nih.gov/pubmed/19032901

 

Gene profiling of patients with chronic fatigue syndrome/myalgic encephalomyelitis

Abstract:

Chronic fatigue syndrome/myalgic encephalomyelitis (CFS/ME) is a multisystem disease, the pathogenesis of which remains undetermined. Following two microarray studies, we reported the differential expression of 88 human genes in patients with CFS; 85 of these genes were upregulated and 3 were downregulated.

The top functional categories of these 88 genes were hematologic disease and function, immunologic disease and function, cancer, cell death, immune response, and infection. Clustering of quantitative polymerase chain reaction data from CFS/ME patients revealed seven subtypes with distinct differences in Short Form (SF)-36 scores, clinical phenotypes, and severity. Gene signatures in each subtype implicate five human genes as possible targets for specific therapy.

Development of a diagnostic test for subtype status is now a priority. The possibility that these subtypes represent individual host responses to particular microbial infections is being investigated and may provide another route to specific therapies for CFS patients.

 

Source: Kerr JR. Gene profiling of patients with chronic fatigue syndrome/myalgic encephalomyelitis. Curr Rheumatol Rep. 2008 Dec;10(6):482-91. https://www.ncbi.nlm.nih.gov/pubmed/19007540

 

Evidence of inflammatory immune signaling in chronic fatigue syndrome: A pilot study of gene expression in peripheral blood

Abstract:

BACKGROUND: Genomic profiling of peripheral blood reveals altered immunity in chronic fatigue syndrome (CFS) however interpretation remains challenging without immune demographic context. The object of this work is to identify modulation of specific immune functional components and restructuring of co-expression networks characteristic of CFS using the quantitative genomics of peripheral blood.

METHODS: Gene sets were constructed a priori for CD4+ T cells, CD8+ T cells, CD19+ B cells, CD14+ monocytes and CD16+ neutrophils from published data. A group of 111 women were classified using empiric case definition (U.S. Centers for Disease Control and Prevention) and unsupervised latent cluster analysis (LCA). Microarray profiles of peripheral blood were analyzed for expression of leukocyte-specific gene sets and characteristic changes in co-expression identified from topological evaluation of linear correlation networks.

RESULTS: Median expression for a set of 6 genes preferentially up-regulated in CD19+ B cells was significantly lower in CFS (p = 0.01) due mainly to PTPRK and TSPAN3 expression. Although no other gene set was differentially expressed at p < 0.05, patterns of co-expression in each group differed markedly. Significant co-expression of CD14+ monocyte with CD16+ neutrophil (p = 0.01) and CD19+ B cell sets (p = 0.00) characterized CFS and fatigue phenotype groups. Also in CFS was a significant negative correlation between CD8+ and both CD19+ up-regulated (p = 0.02) and NK gene sets (p = 0.08). These patterns were absent in controls.

CONCLUSION: Dissection of blood microarray profiles points to B cell dysfunction with coordinated immune activation supporting persistent inflammation and antibody-mediated NK cell modulation of T cell activity. This has clinical implications as the CD19+ genes identified could provide robust and biologically meaningful basis for the early detection and unambiguous phenotyping of CFS.

 

Source: Aspler AL, Bolshin C, Vernon SD, Broderick G. Evidence of inflammatory immune signaling in chronic fatigue syndrome: A pilot study of gene expression in peripheral blood. Behav Brain Funct. 2008 Sep 26;4:44. doi: 10.1186/1744-9081-4-44. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2569951/ (Full article)

 

Bayesian biomarker identification based on marker-expression proteomics data

Abstract:

We are studying variable selection in multiple regression models in which molecular markers and/or gene-expression measurements as well as intensity measurements from protein spectra serve as predictors for the outcome variable (i.e., trait or disease state).

Finding genetic biomarkers and searching genetic-epidemiological factors can be formulated as a statistical problem of variable selection, in which, from a large set of candidates, a small number of trait-associated predictors are identified. We illustrate our approach by analyzing the data available for chronic fatigue syndrome (CFS).

CFS is a complex disease from several aspects, e.g., it is difficult to diagnose and difficult to quantify. To identify biomarkers we used microarray data and SELDI-TOF-based proteomics data. We also analyzed genetic marker information for a large number of SNPs for an overlapping set of individuals. The objectives of the analyses were to identify markers specific to fatigue that are also possibly exclusive to CFS. The use of such models can be motivated, for example, by the search for new biomarkers for the diagnosis and prognosis of cancer and measures of response to therapy. Generally, for this we use Bayesian hierarchical modeling and Markov Chain Monte Carlo computation.

 

Source: Bhattacharjee M, Botting CH, Sillanpää MJ. Bayesian biomarker identification based on marker-expression proteomics data. Genomics. 2008 Dec;92(6):384-92. doi: 10.1016/j.ygeno.2008.06.006. Epub 2008 Aug 15. http://www.sciencedirect.com/science/article/pii/S0888754308001420 (Full article)

 

Identification of marker genes for differential diagnosis of chronic fatigue syndrome

Abstract:

Chronic fatigue syndrome (CFS) is a clinically defined condition characterized by long-lasting disabling fatigue. Because of the unknown mechanism underlying this syndrome, there still is no specific biomarker for objective assessment of the pathological fatigue. We have compared gene expression profiles in peripheral blood between 11 drug-free patients with CFS and age- and sex-matched healthy subjects using a custom microarray carrying complementary DNA probes for 1,467 stress-responsive genes.

We identified 12 genes whose mRNA levels were changed significantly in CFS patients. Of these 12 genes, quantitative real-time PCR validated the changes in 9 genes encoding granzyme in activated T or natural killer cells (GZMA), energy regulators (ATP5J2, COX5B, and DBI), proteasome subunits (PSMA3 and PSMA4), putative protein kinase c inhibitor (HINT ), GTPase (ARHC), and signal transducers and activators of transcription 5A (STAT5A).

Next, we performed the same microarray analysis on 3 additional CFS patients and 20 other patients with the chief complaint of long-lasting fatigue related to other disorders (non-CFS patients) and found that the relative mRNA expression of 9 genes classified 79% (11/14) of CFS and 85% (17/20) of the non-CFS patients.

Finally, real-time PCR measurements of the levels of the 9 involved mRNAs were done in another group of 18 CFS and 12 non-CFS patients. The expression pattern correctly classified 94% (17/18) of CFS and 92% (11/12) of non-CFS patients. Our results suggest that the defined gene cluster (9 genes) may be useful for detecting pathological responses in CFS patients and for differential diagnosis of this syndrome.

 

Source: Saiki T, Kawai T, Morita K, Ohta M, Saito T, Rokutan K, Ban N. Identification of marker genes for differential diagnosis of chronic fatigue syndrome. Mol Med. 2008 Sep-Oct;14(9-10):599-607. doi: 10.2119/2007-00059.Saiki. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2442021/ (Full article)

 

Usefulness of an abnormal cardiovascular response during low-grade head-up tilt-test for discriminating adolescents with chronic fatigue from healthy controls

Abstract:

Hemodynamic dysfunction is documented in chronic fatigue syndrome (CFS). This study was conducted to investigate cardiovascular responses to orthostatic stress in adolescents with CFS, using a novel procedure for tilt-table testing.

A total of 27 adolescents with CFS and 33 healthy control subjects with equal age and gender distribution underwent 15 minutes of 20 degrees head-up tilt testing. Heart rate, systolic blood pressure (BP), mean BP, diastolic BP, stroke index, total peripheral resistance index, end-diastolic volume index, and acceleration index were continuously and noninvasively recorded.

At rest, patients with CFS had higher total peripheral resistance index values (p<0.01) and lower stroke index and end-diastolic volume index values (p<0.05) than controls. During 20 degrees head-up tilt testing, patients with CFS had greater increases in heart rate, diastolic BP (p<0.001), mean BP (p<0.01), and total peripheral resistance index (p<0.05) than controls and greater decreases in stroke index (p<0.05). Syncope or near syncope was not observed.

In conclusion, this study found that adolescents with CFS have significant abnormalities of cardiovascular regulation in response to mild orthostatic stress, differentiating them from healthy controls.

 

Source: Wyller VB, Due R, Saul JP, Amlie JP, Thaulow E. Usefulness of an abnormal cardiovascular response during low-grade head-up tilt-test for discriminating adolescents with chronic fatigue from healthy controls. Am J Cardiol. 2007 Apr 1;99(7):997-1001. Epub 2007 Feb 16. https://www.ncbi.nlm.nih.gov/pubmed/17398200