Susumu Imoto

Sequence variation in hepatitis C virus nonstructural protein 5A predicts clinical outcome of pegylated interferon/ribavirin combination therapy.

A substantial proportion of hepatitis C virus (HCV)‐1b–infected patients still do not respond to interferon‐based therapy. This study aims to explore a predictive marker for the ultimate virological response of HCV‐1b–infected patients treated with pegylated interferon/ribavirin (PEG‐IFN/RBV) combination therapy. Nonstructural protein 5A (NS5A) sequences of HCV in the pretreated sera of 45 patients infected with HCV‐1b were analyzed. The mean number of mutations in the variable region 3 (V3) plus its upstream flanking region of NS5A (amino acid 2334–2379), referred to as IFN/RBV resistance‐determining region (IRRDR), was significantly higher for HCV isolates obtained from patients who later achieved sustained virological response (SVR) by PEG‐IFN/RBV than for those in patients undergoing non‐SVR. The receiver operating characteristic curve analysis estimated six mutations in IRRDR as the optimal threshold for SVR prediction. Indeed, 16 (76%) of 21 SVR, but only 2 (8%) of 24 non‐SVR, had HCV with six or more mutations in IRRDR (IRRDR ≥ 6) (P < 0.0001). All of 18 patients infected with HCV of IRRDR of 6 or greater examined showed a significant (≥1 log) reduction or disappearance of serum HCV core antigen titers within 24 hours after initial dose of PEG‐IFN/RBV, whereas 10 (37%) of 27 patients with HCV of IRRDR of 5 or less did (P < 0.0001). The positive predictive value of IRRDR of 6 or greater for SVR was 89% (16/18; P = 0.0007), with its negative predictive value for non‐SVR being 81% (22/27; P = 0.0008). Conclusion: A high degree (≥6) of sequence variation in IRRDR would be a useful marker for predicting SVR, whereas a less diverse (≤5) IRRDR sequence predicts non‐SVR. (HEPATOLOGY 2008.)

Prediction of efficient virological response to pegylated interferon/ribavirin combination therapy by NS5A sequences of hepatitis C virus and anti-NS5A antibodies in pre-treatment sera.

A considerable number of patients infected with Hepatitis C virus subtype 1b (HCV‐1b) do not respond to pegylated interferon/ribavirin combination therapy. In this study we explored a useful factor(s) to predict treatment outcome. A total of 47 HCV‐1b‐infected patients were treated with pegylated interferon/ribavirin for 48 weeks. Sera of the patients were examined for the entire NS5A sequence of the HCV genome, HCV RNA titers and anti‐NS5A antibodies. According to their responses, the patients were divided into two groups, early viral responders who cleared the virus by week 16 (EVR[16w]) and those who did not (Non‐EVR[16w]). The mean number of mutations in the V3 region (aa 2356 to 2379) or that in the V3 region plus its N‐terminally flanking region, which we refer to as interferon/ribavirin resistance‐determining region (IRRDR; aa 2334 to 2379), of NS5A obtained from the pretreatment sera was significantly larger for EVR(16w) compared with Non‐EVR(16w). Moreover, HCV‐1b isolates with ≥5 mutations in V3 or those with ≥6 mutations in IRRDR were almost exclusively found in EVR(16w). Also, the presence of detectable levels of anti‐NS5A antibodies in the pretreatment sera was closely associated with EVR(16w). In conclusion, a high degree of sequence variation in V3 (≥5) or IRRDR (≥6) and the presence of detectable levels of anti‐NS5A antibodies in the pretreatment sera would be useful factors to predict EVR(16w). On the other hand, a less diverse sequence in V3 (≤4) or IRRDR (≤5) together with the absence of detectable anti‐NS5A antibodies could be a predictive factor for Non‐EVR(16w).

Polymorphisms of Hepatitis C Virus Non-Structural Protein 5A and Core Protein and Clinical Outcome of Pegylated-Interferon/Ribavirin Combination Therapy

Objective: Hepatitis C virus (HCV genome) polymorphisms are thought to influence the outcome of pegylated-interferon/ribavirin (PEG-IFN/RBV) therapy. This study aimed to examine non-structural protein 5A (NS5A) polymorphisms, e.g. IFN/RBV resistance-determining region (IRRDR) and IFN sensitivity-determining region (ISDR), and core protein polymorphism as predictive therapeutic markers. Methods: Pretreatment sequences of NS5A and core regions were analyzed in 68 HCV-1b-infected patients treated with PEG-IFN/RBV. Results: Of 24 patients infected withHCV having an IRRDR with 6 or more mutations (IRRDR≧6), 18 (75%) patients achieved sustained virological response (SVR), whereas only 11 (25%) of 44 patients infected with HCV having IRRDR≤5 did. IRRDR≧6 was significantly associated with SVR (p < 0.0001). On the other hand, ISDR≧2 was significantly associated with relapse (either before [breakthrough] or after end-of-treatment response [ETR[-]relapse]) (p < 0.05) and a point mutation of the core protein from Arg to Gln at position 70 (Gln70) was significantly associated with null-response (p < 0.05). Multivariate analysis identified IRRDR≧6 as the only viral genetic factor that independently predicted SVR. Conclusion: NS5A (IRRDR and ISDR) and core protein polymorphisms are associated with the outcome of PEG-IFN/RBV therapy for chronic hepatitis C. In particular, IRRDR≧6 is a useful marker for prediction of SVR.

Superiority of CT Arterioportal Angiography to Contrast-Enhanced CT and MRI in the Diagnosis of Hepatocellular Carcinoma in Nodules Smaller than 2 cm

To evaluate the effectiveness of computed tomography (CT) arterioportal angiography in the diagnosis of hepatocellular carcinoma (HCC) in nodules smaller than 2 cm, we compared the findings of CT during arteriography (CTA) and CT during arterial portography (CTAP) with those of enhanced CT and enhanced magnetic resonance imaging (MRI). Sixty-eight nodules smaller than 2 cm in 53 patients with liver cirrhosis were classified into three groups of CTA and CTAP: (group 1) hyperattenuation on CTA, and hypoattenuation on CTAP (56 nodules, 41 patients); (group 2) hypoattenuation on CTA, and hypoattenuation on CTAP (10 nodules, 10 patients); (group 3) hypoattenuation on CTA, and hyperattenuation on CTAP (2 nodules, 2 patients). Histologically, 96% (54/56), 80% (8/10), and 100% (2/2) of the nodules in groups 1, 2 and 3, respectively, were diagnosed as HCC. In group 1, enhanced CT or enhanced MRI confirmed hypervascularity in only 77% (30/39) and venous washout in 21% (8/39). In groups 2 and 3, enhanced CT or enhanced MRI on 7 and 2 nodules, respectively, revealed no hypervascularity (0%). The results suggested that CT arterioportal angiography is superior to enhanced CT and MRI in nodules smaller than 2 cm for diagnosing HCC (p < 0.01 group 1, p < 0.01 group 2).

Inflammatory pseudotumor of the liver in a patient with chronic hepatitis C: difficulty in differentiating it from hepatocellular carcinoma.

A case of an inflammatory pseudotumor of the liver in a 75‐year‐old female with chronic hepatitis C whose radiologic features simulated that of hepatocellular carcinoma (HCC) is presented. On imaging studies, hypervascularity by CO2 ultrasound (US) angiography, enhancement at an early phase and isodensity at a late phase by incremental dynamic computed tomography (CT), perfusion defect by CT during arteriography (CTAP), and clinical background of hepatitis C virus (HCV) infection strongly suggested HCC. A US‐guided needle biopsy revealed a mainly diffuse and polyclonal proliferation of lymphocytes positive for leukocyte common antigen (pan‐lymphocyte cells), L‐26 (B cell lymphocytes), and UCHL‐1 (T cell lymphocytes), negative for both κ and λ light chains and sparsely distributed neutrophils and histiocytes. No lymphoid follicles were observed. The liver tissue around this tumor showed chronic hepatitis with mild activity and mild fibrosis. These histopathologic findings suggested that the diagnosis of inflammatory pseudotumor of the liver was tenable. As it is difficult to differentiate between inflammatory pseudotumor of the liver and HCC by imaging studies alone, supplemental biopsy, where possible, should be obtained when diagnostic imaging of tumors suggesting HCC is carried out. We emphasize that histopathology is a true gold standard in the diagnosis of this disease.

Sequence Heterogeneity in NS5A of Hepatitis C Virus Genotypes 2a and 2b and Clinical Outcome of Pegylated-Interferon/Ribavirin Therapy

Pegylated-interferon plus ribavirin (PEG-IFN/RBV) therapy is a current standard treatment for chronic hepatitis C. We previously reported that the viral sequence heterogeneity of part of NS5A, referred to as the IFN/RBV resistance-determining region (IRRDR), and a mutation at position 70 of the core protein of hepatitis C virus genotype 1b (HCV-1b) are significantly correlated with the outcome of PEG-IFN/RBV treatment. Here, we aimed to investigate the impact of viral genetic variations within the NS5A and core regions of other genotypes, HCV-2a and HCV-2b, on PEG-IFN/RBV treatment outcome. Pretreatment sequences of NS5A and core regions were analyzed in 112 patients infected with HCV-2a or HCV-2b, who were treated with PEG-IFN/RBV for 24 weeks and followed up for another 24 weeks. The results demonstrated that HCV-2a isolates with 4 or more mutations in IRRDR (IRRDR[2a]≥4) was significantly associated with rapid virological response at week 4 (RVR) and sustained virological response (SVR). Also, another region of NS5A that corresponds to part of the IFN sensitivity-determining region (ISDR) plus its carboxy-flanking region, which we referred to as ISDR/+C[2a], was significantly associated with SVR in patients infected with HCV-2a. Multivariate analysis revealed that IRRDR[2a]≥4 was the only independent predictive factor for SVR. As for HCV-2b infection, an N-terminal half of IRRDR having two or more mutations (IRRDR[2b]/N≥2) was significantly associated with RVR, but not with SVR. No significant correlation was observed between core protein polymorphism and PEG-IFN/RBV treatment outcome in HCV-2a or HCV-2b infection. Conclusion: The present results suggest that sequence heterogeneity of NS5A of HCV-2a (IRRDR[2a]≥4 and ISDR/+C[2a]), and that of HCV-2b (IRRDR[2b]/N≥2) to a lesser extent, is involved in determining the viral sensitivity to PEG-IFN/RBV therapy.

CEA producing primary hepatic carcinoid

Imaging studies of a hepatic tumor in a 53-year-old woman with elevated serum levels of neuron-specific enolase (NSE), carcinoembryonic antigen (CEA) and 5-hydroxyindole acetic acid (5HIAA) revealed a hypervascular tumor in the right lobe. Grossly, the brownish tumor was measured 13.5x12 cm with four daughter nodules. Microscopically, the majority of these columnar and round tumor cells had ribbon-or rosette-like patterns with the expression of neuroendocrine marker proteins, such as Grimelius, NSE, chromogranin A, and synaptophysin, and moderate expression of CEA but without the expression of cytokeratin nos 7,8,14,18,19 and OV-6; the minority had glandular patterns with a strong expression of CEA but without the expression of cytokeratin nos 7,8,14,18,19 and OV-6. Ultrastructurally, most tumor cells contained populations of electron-dense core granules ranging between 100 and 200 nm in diameter. After hepatectomy, serum CEA, NSE, and 5HIAA reverted to normal ranges and persisted for 19 months. These findings suggested that the diagnosis of primary hepatic carcinoid was tenable and that the tumor might derive from hepatic stem cells which acquired the additional nature of producing CEA without cytokeratins characteristic of hepatocytes or bile duct cells. Some molecular based approaches have attributed unique biological behavior and histogenesis to this carcinoid tumor.

Multiple hypervascular liver nodules in a heavy drinker of alcohol

Abstract  A case of hypervascular nodules in the liver, but without hepatitis B or C virus infection in a 38‐year‐old woman with a history of alcohol abuse is presented. An ultrasound disclosed 1–2‐cm hypoechoic tumors in the right and left lobes. Magnetic resonance imaging showed high‐intensity tumors at both the T1‐weighted and T2‐weighted sequences. Incremental dynamic computed tomography and hepatic angiography revealed hypervascular tumors. Ultrasound‐guided needle biopsy revealed no evidence of hepatocellular carcinoma, metastatic liver cancer, hemangioendothelioma, inflammatory pseudotumors or pseudolymphoma, but demonstrated stellate‐scar fibrosis septa, which contained small unpaired arteries without hyperplasia dividing the nodule. Moreover, marked pericellular fibrosis, neutrophilic infiltration and Mallory bodies were observed in the cytoplasm. There was no evidence of bile duct proliferation. From these findings, the diagnosis of alcohol‐induced fibrosis, distinctly different from focal nodular hyperplasia, was tenable. Further studies may provide insights into the pathogenesis of nodule formation and hypervascularity in heavy drinkers of alcohol.

TTV positivity and transfusion history in non-B, non-C hepatocellular carcinoma compared with HBV- and HCV-positive cases.

The prevalence of TT virus (TTV) and its rate of transmission through transfusion were investigated to determine its possible hepatocarcinogenic role in non-B, non-C hepatocellular carcinoma (HCC) as compared with that in hepatitis B virus (HBV)- and hepatitis C virus (HCV)-positive HCC. Its transfection route in TTV-positive cases was also studied. Serum was positive for TTV in 77.8% (7/9) of HBV-positive, 36.4% (12/33) of HCV-positive, and 63.6% (7/11) of non-B, non-C cases of HCC. The rate of transmission through transfusion was 52.4% (11/21) in HBV-positive, 40.1% (61/152) in HCV-positive, 33.3% (2/6) in HBV+HCV-positive, and 40% (8/20) in non-B, non-C HCCs, while it was 48.3% (14/29) in TTV-positive and 39.3% (11/28) in TTV-negative cases. The association between TTV and HCC was limited, and the main route of infection of TTV was not through transfusion.

Eosionophilic pseudotumor of the liver due to Ascaris suum infection

A case of eosinophilic pseudotumor of the liver due to Ascaris (A) suum is described in a 34-year-old-man with a high serum level of immunoglobulin E and hypereosinophilia ascribed to a history of atopic dermatitis since childhood. Multiple hepatic hypoechoic nodules detected by ultrasound were confirmed as low-density nodules on computed tomography (CT), and as low and high signal intensity lesions on T1-and T2-weighted magnetic resonance imaging (MRI), respectively. CT during arteriography (CTA) and arterial portography revealed multiple nodules with ring-shaped enhancement and perfusion defect, respectively. Biopsied liver tissue specimens did not contain tumor cells or atypical cells; instead, they showed marked infiltration of eosinophils with necrosis and Charcot-Leyden crystals in the portal tracts and hepatic sinusoides, suggesting parasitic infection, although neither larvae nor eggs were detected. The diagnosis of visceral larva migrans (VLM) due to A. suum was based on immunoserological tests. The patient was a habitual consumer of raw bovine liver, which may explain the A. suum infection. After drug therapy with albendazole, the hypoechoic nodules disappeared. Differential diagnoses and the possible transfection route of A. suum are discussed.