title: Analysis of lymphocyte subgroups in Crimean-Congo hemorrhagic fever.
abstract: OBJECTIVE
  This study examined the association between lymphocyte subgroups and mortality in patients with Crimean-Congo hemorrhagic fever (CCHF) in Turkey.
  
  
  METHODS
  During the spring and summer of 2007, peripheral blood was collected from hospitalized patients with suspected CCHF. Lymphocyte subgroups were characterized by fluorescence-activated cell sorting. CCHF cases were confirmed by detecting viral RNA by PCR and/or IgM antibodies by ELISA. Lymphocyte subgroups were compared between fatal and non-fatal cases. The correlation between lymphocyte subgroups and viral loads was also investigated.
  
  
  RESULTS
  Seventy-seven confirmed cases of CCHF were included in this study (five cases were fatal (6.5 %)). No differences in lymphocyte subgroups were found between fatal and non-fatal cases, except for significantly higher CD3+CD8+ T cells in the fatal cases (p=0.017). A positive correlation between viral load and CD3+CD8+ T cells was also detected (p=0.044). There was no correlation between other lymphocyte subgroups and viral load.
  
  
  CONCLUSIONS
  Higher levels of CD3+CD8+ T lymphocytes were detected in fatal compared to non-fatal CCHF cases. Despite this cytotoxic immune activation, a fatal outcome could not be prevented. We hypothesize that high viral load and other factors may influence this outcome, although more studies are required to explain the pathogenesis of CCHF.
authors.affiliation: Clinic of Infectious Diseases and Clinical Microbiology, Ankara Numune Education and Research Hospital, Samanpazari, Ankara, Turkey. esragulakinci@yahoo.com
authors.forename: Esragül
authors.initials: E
authors.lastname: Akinci
authors.forename: Mesude
authors.initials: M
authors.lastname: Yilmaz
authors.forename: Hürrem
authors.initials: H
authors.lastname: Bodur
authors.forename: Pinar
authors.initials: P
authors.lastname: Ongürü
authors.forename: Fatma Nurhayat
authors.initials: FN
authors.lastname: Bayazit
authors.forename: Ayşe
authors.initials: A
authors.lastname: Erbay
authors.forename: Gülsüm
authors.initials: G
authors.lastname: Ozet
mesh_terms: D000293:Adolescent; D000328:Adult; D017252:CD3 Complex / Q000378:metabolism; D018414:CD8-Positive T-Lymphocytes / Q000276:immunology; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D005434:Flow Cytometry; D003225:Hemorrhagic Fever Virus, Crimean-Congo / Q000276:immunology*; D006479:Hemorrhagic Fever, Crimean / Q000276:immunology* / Q000401:mortality* / Q000503:physiopathology / Q000821:virology; D006801:Humans; D007075:Immunoglobulin M / Q000097:blood; D016131:Lymphocyte Subsets / Q000276:immunology*; D008297:Male; D008875:Middle Aged; D012367:RNA, Viral / Q000097:blood; D014421:Turkey / Q000453:epidemiology; D019562:Viral Load; D055815:Young Adult
chemical_list: D017252:CD3 Complex; D007075:Immunoglobulin M; D012367:RNA, Viral