title: Evaluation of the plasma micro RNA expression levels in secondary hemophagocytic lymphohistiocytosis.
abstract: BACKGROUND
  Hemophagocytic lymphohistiocytosis (HLH) is a life threatening hyper inflammatory disease. Micro RNAs (miRNA) are about 22 nucleotide-long, small RNAs encoded with genes, and they have regulatory functions in immune response.
  
  
  OBJECTIVE
  To determine the miRNA expression levels of 11 secondary HLH patients, we evaluated the associations of miRNA levels with pathogenesis, clinical presentation, and prognosis of the disease.
  
  
  METHODS
  Patients who were diagnosed with secondary HLH from January 2011 to December 2012 were included in this study. We profiled the expressions of 379 miRNAs in plasma of both HLH patients and healthy controls. Patients were evaluated regarding with age, clinical findings, miRNA expresions, laboratory data, treatment, and prognosis, by using descriptive statistics.
  
  
  RESULTS
  A total of 11 secondary HLH patients and 11 healthy children were included in this study. miR-205-5p was expressed in all case and controls and expression level of miR-205-5p was found 6.21 fold higher than control group (p=0.01). We detected the second highest expression percent in miR-194-5p with 81% of cases and controls. Expression level of miR-194-5p was found to have 163 fold higher than controls (p= 0.009). miR-30c-5p showed 77% expression percent in cases and controls together. The expression level of this miRNA was detected 9 fold decreased in HLH patients compared to healthy children (p= 0.031).
  
  
  CONCLUSIONS
  We showed that miR-205-5p, miR-194-5p and miR-30c-5p could be useful plasma biomarkers for HLH. Further research is needed in larger and homogenous study groups, especially for these miRNAs as biomarkers for HLH.
authors.affiliation: Gaziantep University Department of Pediatrics Division of Pediatric Hematology Gaziantep/Turkey.
authors.forename: Ali
authors.initials: A
authors.lastname: Bay
authors.affiliation: Gaziantep University Department of Pediatrics, Gaziantep/Turkey.
authors.forename: Enes
authors.initials: E
authors.lastname: Coskun
authors.affiliation: Gaziantep University Department of Medical Biology, Gaziantep/Turkey.
authors.forename: Serdar
authors.initials: S
authors.lastname: Oztuzcu
authors.affiliation: Gaziantep University Department of Medical Biology, Gaziantep/Turkey.
authors.forename: Sercan
authors.initials: S
authors.lastname: Ergun
authors.affiliation: Gaziantep University Department of Pediatrics Division of Pediatric Hematology Gaziantep/Turkey.
authors.forename: Fatih
authors.initials: F
authors.lastname: Yilmaz
authors.affiliation: Gaziantep University Department of Pediatrics Division of Pediatric Hematology Gaziantep/Turkey.
authors.forename: Elif
authors.initials: E
authors.lastname: Aktekin