title: 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.
authors.affiliation: School of Mathematics and Statistics, Faculty of Science, University of New South Wales, Sydney, Australia.
authors.forename: Sally
authors.initials: S
authors.lastname: Galbraith
authors.forename: Barbara
authors.initials: B
authors.lastname: Cameron
authors.forename: Hui
authors.initials: H
authors.lastname: Li
authors.forename: Diana
authors.initials: D
authors.lastname: Lau
authors.forename: Ute
authors.initials: U
authors.lastname: Vollmer-Conna
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Lloyd
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D018354:Alphavirus Infections / Q000150:complications*; D016022:Case-Control Studies; D020031:Epstein-Barr Virus Infections / Q000150:complications*; D015673:Fatigue Syndrome, Chronic / Q000235:genetics* / Q000821:virology; D005260:Female; D015870:Gene Expression; D020869:Gene Expression Profiling; D006801:Humans; D008137:Longitudinal Studies; D008297:Male; D008875:Middle Aged; D020411:Oligonucleotide Array Sequence Analysis; D016133:Polymerase Chain Reaction; D011778:Q Fever / Q000150:complications*; D012398:Ross River virus; D055815:Young Adult