title: Human T-lymphotropic virus type 1 (HTLV-1) prevalence and quantitative detection of DNA proviral load in individuals with indeterminate/positive serological results.
abstract: BACKGROUND
  HTLV-1 infection is currently restricted to endemic areas. To define the prevalence of HTLV-1 infection in patients living in Italy, we first carried out a retrospective serological analysis in a group of people originating from African countries referred to our hospital from January 2003 to February 2005. We subsequently applied a real time PCR on peripheral blood mononuclear cells from subjects with positive or indeterminate serological results.
  
  
  METHODS
  All the sera were first analysed by serological methods (ELISA and/or Western Blotting) and then the peripheral blood mononuclear cells from subjects with positive or inconclusive serological results were analyzed for the presence of proviral DNA by a sensitive SYBR Green real time PCR. In addition, twenty HTLV-I ELISA negative samples were assayed by real time PCR approach as negative controls.
  
  
  RESULTS
  Serological results disclosed serum reactivity by ELISA (absorbance values equal or greater than the cut-off value) in 9 out of 3408 individuals attending the Sexually Transmitted Diseases Clinic and/or Oncology Department, and 2 out 534 blood donors enrolled as a control population. Irrespective of positive or inconclusive serological results, all these subjects were analyzed for the presence of proviral DNA in peripheral blood mononuclear cells by SYBR real time PCR. A clear-cut positive result for the presence of HTLV-1 DNA was obtained in two subjects from endemic areas.
  
  
  CONCLUSIONS
  SYBR real time PCR cut short inconclusive serological results. This rapid and inexpensive assay showed an excellent linear dynamic range, specificity and reproducibility readily revealing and quantifying the presence of virus in PBMCs. Our results highlight the need to monitor the presence of HTLV-1 in countries which have seen a large influx of immigrants in recent years. Epidemiological surveillance and correct diagnosis are recommended to verify the prevalence and incidence of a new undesirable phenomenon.
authors.affiliation: Department of Clinical and Experimental Medicine, University of Bologna, 47900 Rimini, Italy. vitonfra@yahoo.it
authors.forename: Francesca
authors.initials: F
authors.lastname: Vitone
authors.forename: Davide
authors.initials: D
authors.lastname: Gibellini
authors.forename: Pasqua
authors.initials: P
authors.lastname: Schiavone
authors.forename: Antonietta
authors.initials: A
authors.lastname: D'Antuono
authors.forename: Lorenzo
authors.initials: L
authors.lastname: Gianni
authors.forename: Isabella
authors.initials: I
authors.lastname: Bon
authors.forename: Maria Carla
authors.initials: MC
authors.lastname: Re
mesh_terms: D000349:Africa / Q000453:epidemiology; D015153:Blotting, Western; D045744:Cell Line, Tumor; D004279:DNA, Viral / Q000032:analysis* / Q000235:genetics; D015490:HTLV-I Infections / Q000175:diagnosis* / Q000276:immunology / Q000821:virology; D015368:Human T-lymphotropic virus 1 / Q000235:genetics / Q000302:isolation & purification*; D006801:Humans; D016133:Polymerase Chain Reaction / Q000379:methods; D015995:Prevalence; D011533:Proviruses / Q000235:genetics / Q000302:isolation & purification*; D012189:Retrospective Studies; D012680:Sensitivity and Specificity; D019562:Viral Load
chemical_list: D004279:DNA, Viral