title: Helios expression in T-regulatory cells in patients with di George Syndrome.
abstract: OBJECTIVE
  Syndrome diGeorge is associated amongst other clinical signs with various degrees of thymic dysplasia, related immunodeficiency and autoimmune disorders. Helios, a transcription factor from Ikaros family, has been proposed as a marker for thymus derived Tregs. We therefore examined Helios + Tregs in a cohort of patients with genetically proven diGeorge syndrome with typical T cell lymphopenia due to the thymic pathology.
  
  
  METHODS
  T cells, FoxP3+ Tregs and Helios + FoxP3+ Tregs were examined in 52 samples from 37 patients. One patient with diGeorge/CHARGE syndrome with total thymic aplasia was also included. Statistical analysis was performed using a linear regression comparison.
  
  
  RESULTS
  Total absolute Tregs were significantly lower in diGeorge patients as compared to controls in all age groups (0-20 years) (p = 0.0016). The difference was more expressed in the first four years of age. Relative Treg numbers expressed as the percentage of Tregs in CD4+ T-cells, however, were not different in patients and controls in all age groups (p = 0.661), neither could we find any significant difference in the percentage of Helios + Tregs between patients and controls (p = 0.238). Helios + Tregs were still present in a patient with diGeorge/CHARGE syndrome with complete athymia 7 years after partially matched unrelated repeated T lymphocytes infusions.
  
  
  CONCLUSIONS
  Our findings show that while there was a significant decrease in absolute numbers of Tregs in patients with diGeorge syndrome, the relative percentage of this population did not differ between patients and controls. Low absolute Tregs thus reflected typical T cells lymphopenia in patients. Helios expression was not affected in diGeorge syndrome.
authors.affiliation: Department of Immunology, 2nd Faculty of Medicine, Charles University and University Hospital Motol, Prague, Czech Republic, adam.klocperk@fnmotol.cz.
authors.forename: Adam
authors.initials: A
authors.lastname: Klocperk
authors.forename: Jarmila
authors.initials: J
authors.lastname: Grecová
authors.forename: Kristýna
authors.initials: K
authors.lastname: Šišmová
authors.forename: Jana
authors.initials: J
authors.lastname: Kayserová
authors.forename: Eva
authors.initials: E
authors.lastname: Froňková
authors.forename: Anna
authors.initials: A
authors.lastname: Šedivá
mesh_terms: D000293:Adolescent; D000328:Adult; D015415:Biomarkers / Q000378:metabolism*; D002452:Cell Count; D002648:Child; D002675:Child, Preschool; D015331:Cohort Studies; D004062:DiGeorge Syndrome / Q000276:immunology*; D005260:Female; D051858:Forkhead Transcription Factors / Q000378:metabolism; D006801:Humans; D051740:Ikaros Transcription Factor / Q000235:genetics / Q000378:metabolism*; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D050378:T-Lymphocytes, Regulatory / Q000276:immunology*; D013950:Thymus Gland / Q000276:immunology* / Q000473:pathology; D055815:Young Adult
chemical_list: D015415:Biomarkers; C418974:FOXP3 protein, human; D051858:Forkhead Transcription Factors; C111431:IKZF2 protein, human; D051740:Ikaros Transcription Factor