Diagnosis of occult hepatitis C without the need for a liver biopsy

The diagnosis of occult hepatitis C virus (HCV) infection is based on the presence of HCV‐RNA in the liver. This study aimed to evaluate the use of combining non‐invasive assays to diagnose occult HCV. A total of 122 patients with occult HCV (HCV‐RNA in the liver without detectable anti‐HCV and serum HCV‐RNA) and 45 patients with cryptogenic chronic hepatitis (without HCV‐RNA in the liver and negative for anti‐HCV and serum HCV‐RNA) were included. HCV‐RNA was tested in peripheral blood mononuclear cells (PBMCs) and in 2 ml of ultracentrifuged serum. Anti‐core HCV was examined by a non‐commercial enzyme‐linked immunosorbent assay. All controls were negative for the three HCV markers studied. Among patients with occult HCV, 36% were anti‐core HCV positive, 57% had serum HCV‐RNA after ultracentrifugation, and 61% had HCV‐RNA in PBMCs. Combining the results of the assays, 91% of the patients were positive for at least one marker. Intrahepatic HCV‐RNA load was significantly higher in patients who were positive simultaneously for the three HCV markers than in patients who were negative for all markers (P = 0.006) and than in those with one or two HCV markers (P = 0.039). Replication of HCV in liver was detected more frequently in patients with three (93%, P = 0.002), two (82%, P = 0.001), and one HCV marker (73%, P = 0.011) than in those without markers (27%). In conclusion, testing for all these markers allows diagnosis of occult HCV without the need for a liver biopsy and these assays may help to elucidate the clinical significance of occult HCV infection. J. Med. Virol. 82:1554–1559, 2010. © 2010 Wiley‐Liss, Inc.