AIM To explore the status of extrahepatichepatitis C virus(HCV)infection and replicationin hepatitis C patients,and its potentialimplication in HCV infection and pathogenicity.METHODS By reverse-transcriptase poly-merase chain reaction(RT-PCR),in situhybridization(ISH)and immunohistochemistry,HCV RNA,HCV replicative intermediate(minus-strand of HCV RNA),and HCV antigens weredetected in 38 autopsy extrahepatic tissuespecimens(including 9 kidneys,9 hearts,9pancreas,5 intestines,2 adrenal glands,2spleens,1 lymph node,and 1 gallbladder)from 9hepatitis C patients,respectively;and thestatus of HCV replication in extrahepatic tissueswas studied.RESULTS By RT-PCR,all 9 patients werepositive for HCV RNA in kidney,heart,pancreas,and intestine,but only 6(66.7%)patients were positive for HCV replicativeintermediate.HCV RNA and HCV antigens weredetected in kidney,heart,pancreas,intestine,adrenal gland,lymph node,and gallbladder in 5(55.6%)and 6(66.7%)patients by ISH andimmunohistochemistry,respectively.HCV RNA and HCV antigens were not detected in theseextrahepatic organs in 3(33.3%)patients,although their livers were positive for HCV.HCVreplicative intermediate detected by RT-PCR wasconsistent with HCV RNA and HCV antigensdetected by ISH and immunohistochemistry(Kappa=0.42-0.75).HCV RNA and HCVantigens were detected in myocardial cells,epithelial cells of intestinal gladular,interstitialcells of kidney,epithelial cells of tubules andglomerulus,pancreas acinar cells and epithelialcells of pancreatic duct,epithelial cells ofmucous membrane sinus of gallbladder,cortexand medulla cells in adrenal gland,andmononuclear cells in lymph node.HCV RNA wasalso detected in bile duct epithelial cells,sinusoidal cells,and mononuclear cells in livertissues by ISH.CONCLUSION HCV can infect extrahepatictissues,and many various tissue cells maysupport HCV replication;extrahepatic HCVinfection and replication may be of“concomitantstate”in most of patients with hepatitis C.Theinfected extrahepatic tissues might act as areservoir for HCV,and play a role in both HCVpersistence and reactivation of infection.HCVas an etiologic agent replicating and expressingviral proteins in extrahepatic tissues itselfcontributes to extrahepatic syndromeassociated.HCV infection in a few patients withchronic HCV infection. AIM To explore the status of extrahepatic hepatitis C virus (HCV) infection and replication in hepatitis C patients, and its potential in replication in HCV infection and pathogenicity. METHODS By reverse-transcriptase poly-merase chain reaction (RT-PCR), in situ hybridization (ISH) immunohistochemistry, HCV RNA, HCV replicative intermediate (minus-strand of HCV RNA), and HCV antigens were detected in 38 autopsy extrahepatic tissuespecimens (including 9 kidneys, 9 hearts, 9 pancreas, 5 intestines, 2 adrenal glands, 2pleens, 1 lymph node, and 1 gallbladder from 9 hepatopathy C patients, respectively; and the stage of HCV replication in extrahepatic tissues were studied .RESULTS By RT-PCR, all 9 patients werepositive for HCV RNA in kidney, heart, pancreas, and intestine, but only 6 (66.7% patients were positive for HCV replicative intermediate. HCV RNA and HCV antigens weredetected in kidney, heart, pancreas, intestine, adrenal gland, lymph node, and gallbladder in 5 (55.6%) and 6 (66.7%) patients by ISH andimmunohistochemistry, respecti although their livers were positive for HCV. HCV Replicative intermediate detected by RT-PCR wascontenttent with HCV RNA and HCV antigens detected by ISH and immunohistochemistry (Kappa = 0.42-0.75). HCV RNA and HCV antigens were detected in myocardial cells, epithelial cells of intestinal gladular, interstitial cells of kidney, epithelial cells of tubules and glomerulus, pancreas acinar cells and epithelial cells of pancreatic duct, epithelial cells of mucous membrane sinus of gallbladder, cortex and medulla cells in adrenal gland, and mononuclear cells in lymph node. HCV RNA wasalso detected in bile duct epithelial cells, sinusoidal cells, and mononuclear cells in livertissues by ISH. CONCLUSION HCV can infect extrahepatictissues, and many various tissue cells maysupport HCV replication; extrahepatic HCV infection and replication may be of “concomitantstate ” in most of patients with hepatitis C. Theinfected extrahepatic bodies might act as are reservoirs for HCV, and play a role in both HCV persistence and reactivation of infections. HCV an etiologic agent replicating and expressing viral proteins in extrahepatic tissues itself controversies to extrahepatic syndrome associated. HCV infection in a few patients with chronic HCV infection.