title: Occult HCV infection: an unexpected finding in a population unselected for hepatic disease.
abstract: BACKGROUND
  Occult Hepatitis C virus (HCV) infection is a new pathological entity characterized by presence of liver disease and absence or very low levels of detectable HCV-RNA in serum. Abnormal values of liver enzymes and presence of replicative HCV-RNA in peripheral blood mononuclear cells are also observed. Aim of the study was to evaluate occult HCV occurrence in a population unselected for hepatic disease.
  
  
  RESULTS
  We chose from previous epidemiological studies three series of subjects (n = 276, age range 40-65 years) unselected for hepatic disease. These subjects were tested for the presence of HCV antibodies and HCV-RNA in plasma and in the peripheral blood mononuclear cells (PBMCs) by using commercial systems. All subjects tested negative for HCV antibodies and plasma HCV-RNA and showed normal levels of liver enzymes; 9/276 patients (3.3%) were positive for HCV-RNA in PBMCs, identifying a subset of subjects with potential occult HCV infection. We could determine the HCV type for 8 of the 9 patients finding type 1a (3 patients), type 1b (2 patients), and type 2a (3 patients).
  
  
  CONCLUSIONS
  The results of this study show evidence that occult HCV infection may occur in a population unselected for hepatic disease. A potential risk of HCV infection spread by subjects harbouring occult HCV infection should be considered. Design of prospective studies focusing on the frequency of infection in the general population and on the clinical evolution of occult HCV infection will be needed to verify this unexpected finding.
authors: Unit of Cancer Epidemiology, C.E.R.M.S., University of Turin, Turin, Italy. gilliotos_demarco@yahoo.it
authors: Laura
authors: L
authors: De Marco
authors: Anna
authors: A
authors: Gillio-Tos
authors: Valentina
authors: V
authors: Fiano
authors: Guglielmo
authors: G
authors: Ronco
authors: Vittorio
authors: V
authors: Krogh
authors: Domenico
authors: D
authors: Palli
authors: Salvatore
authors: S
authors: Panico
authors: Rosario
authors: R
authors: Tumino
authors: Paolo
authors: P
authors: Vineis
authors: Franco
authors: F
authors: Merletti
authors: Lorenzo
authors: L
authors: Richiardi
authors: Carlotta
authors: C
authors: Sacerdote
mesh_terms: D000328:Adult; D000368:Aged; D005260:Female; D016174:Hepacivirus / Q000276:immunology / Q000302:isolation & purification; D006526:Hepatitis C / Q000097:blood / Q000175:diagnosis / Q000453:epidemiology* / Q000276:immunology; D006801:Humans; D008297:Male; D008875:Middle Aged