Kotaro Kumagai

Increased rate of death related to presence of viremia among hepatitis C virus antibody–positive subjects in a community-based cohort study†

The overall mortality of patients infected with hepatitis C virus (HCV) has not been fully elucidated. This study analyzed mortality in subjects positive for antibody to HCV (anti‐HCV) in a community‐based, prospective cohort study conducted in an HCV hyperendemic area of Japan. During a 10‐year period beginning in 1995, 1125 anti–HCV‐seropositive residents of Town C were enrolled into the study and were followed for mortality through 2005. Cause of death was assessed by death certificates. Subjects with detectable HCV core antigen (HCVcAg) or HCV RNA were considered as having hepatitis C viremia and were classified as HCV carriers; subjects who were negative for both HCVcAg and HCV RNA (i.e., viremia‐negative) were considered as having had a prior HCV infection and were classified as HCV noncarriers. Among the anti–HCV‐positive subjects included in the analysis, 758 (67.4%) were HCV carriers, and 367 were noncarriers. A total of 231 deaths occurred in these subjects over a mean follow‐up of 8.2 years: 176 deaths in the HCV carrier group and 55 in the noncarrier group. The overall mortality rate was higher in HCV carriers than in noncarriers, adjusted for age and sex (hazard ratio, 1.53; 95% confidence interval, 1.13‐2.07). Although liver‐related deaths occurred more frequently among the HCV carriers (hazard ratio, 5.94; 95% confidence interval, 2.58‐13.7), the rates of other causes of death did not differ between HCV carriers and noncarriers. Among HCV carriers, a higher level of HCVcAg (≥100 pg/mL) and persistently elevated alanine aminotransferase levels were important predictors of liver‐related mortality. Conclusion: The presence of viremia increases the rate of mortality, primarily due to liver‐related death, among anti–HCV‐seropositive persons in Japan. (HEPATOLOGY 2009.)

Serum manganese superoxide dismutase and thioredoxin are potential prognostic markers for hepatitis C virus-related hepatocellular carcinoma.

AIM To evaluate the clinical significance of oxidative stress markers in patients with hepatitis C virus (HCV)-related hepatocellular carcinoma (HCC). METHODS Sixty-four consecutive patients who were admitted to Kagoshima University Medical and Dental Hospital were enrolled in this retrospective study. All patients had chronic liver disease (CLD) due to infection with HCV. Thirty patients with HCV-related HCC, 34 with HCV-related CLD without HCC (non-HCC), and 20 healthy volunteers (HVs) were enrolled. Possible associations between serum manganese superoxide dismutase (MnSOD) and thioredoxin (TRX) levels and clinical parameters or patient prognosis were analyzed over a mean follow-up period of 31.7 mo. RESULTS The serum MnSOD levels were significantly higher in patients with HCV-related HCC than in patients without HCC (P = 0.03) or HVs (P < 0.001). Similarly, serum TRX levels were also significantly higher in patients with HCV-related HCC than in patients without HCC (P = 0.04) or HVs (P < 0.01). However, serum levels of MnSOD and TRX were not correlated in patients with HCC. Among patients with HCC, the overall survival rate (OSR) was lower in patients with MnSOD levels ≥ 110 ng/mL than in patients with levels < 110 ng/mL (P = 0.01), and the OSR tended to be lower in patients with TRX levels < 80 ng/mL (P = 0.05). In addition, patient prognosis with HCC was poorest with serum MnSOD levels ≥ 110 ng/mL and serum TRX levels < 80 ng/mL. Furthermore, a multivariate analysis using a Cox proportional hazard model and serum levels of five factors (MnSOD, prothrombin time, serum albumin, serum α-fetoprotein (AFP), and serum des-γ-carboxy prothrombin) revealed that MnSOD levels ≥ 110 ng/mL (risk ratio: 4.12, 95% confidential interval: 1.22-13.88, P = 0.02) and AFP levels ≥ 40 ng/mL (risk ratio: 6.75; 95% confidential interval: 1.70-26.85, P < 0.01) were independent risk factors associated with a poor patient prognosis. CONCLUSION Serum MnSOD and TRX levels are potential clinical biomarkers that predict patient prognosis in HCV-related HCC.

Highly sensitive lens culinaris agglutinin-reactive α-fetoprotein is useful for early detection of hepatocellular carcinoma in patients with chronic liver disease

The fucosylated fraction of α-fetoprotein (AFP-L3) is a specific marker for hepatocellular carcinoma (HCC). However, conventional AFP-L3% (c-AFP-L3%) has not always been reliable in cases with low serum α-fetoprotein (AFP) levels. In this study, we evaluated the clinical utility of a newly developed assay, highly sensitive AFP-L3% (hs-AFP-L3%). Subjects included 74 patients with benign liver disease (BLD), including chronic hepatitis and cirrhosis, and 94 with HCC. Serum hs-AFP-L3% was significantly higher than c-AFP-L3% in patients with early-stage HCC (solitary or <20 mm in diameter). Additionally, hs-AFP-L3% was significantly increased in patients with well-differentiated HCC. In patients with serum AFP <20 ng/ml, the sensitivities of c-AFP-L3% and hs-AFP-L3% were 12.5 and 44.6%, respectively, at a cut-off value of 5%. In 59 BLD patients with serum AFP <20 ng/ml, the HCC-positive rate in patients with hs-AFP-L3% ≥ 5% was significantly higher compared to those with hs-AFP-L3% <5% during the follow-up period (median, 35 months; range, 5-48 months). Importantly, none of the BLD patients with both serum AFP <20 ng/ml and hs-AFP-L3% <5% developed HCC. These results indicated that hs-AFP-L3% is useful for early detection of HCC in BLD patients, even for those with serum AFP <20 ng/ml. Furthermore, since hs-AFP-L3% increases before HCC is detectable by various advanced imaging modalities, this assay may help identify BLD patients with a higher risk of HCC.

Glycoprotein Nonmetastatic Melanoma B (Gpnmb)-Positive Macrophages Contribute to the Balance between Fibrosis and Fibrolysis during the Repair of Acute Liver Injury in Mice.

Background and aims Glycoprotein nonmetastatic melanoma B (Gpnmb), a transmembrane glycoprotein that is expressed in macrophages, negatively regulates inflammation. We have reported that Gpnmb is strongly expressed in the livers of rats fed a choline-deficient, L-amino acid-defined (CDAA) diet. However, the role of macrophage-expressed Gpnmb in liver injury is still unknown. This study aimed to clarify the characteristics of infiltrating macrophages that express Gpnmb, and the involvement of Gpnmb in the repair process in response to liver injury. Methods C57BL/6J, DBA/2J [DBA] and DBA/2J-Gpnmb+ [DBA-g+] mice were treated with a single intraperitoneal injection of carbon tetrachloride (CCl4) at a dose of 1.0 mL/kg body weight. Mice were sacrificed at predetermined time points, followed by measurement of serum alanine aminotransferase (ALT) levels and histological examination. Expression of Gpnmb, pro-/anti-inflammatory cytokines, and profibrotic/antifibrotic factors were examined by quantitative RT-PCR and/or Western blotting. Immunohistochemistry, fluorescent immunostaining and flow cytometry were used to determine the expression of Gpnmb, CD68, CD11b and α-SMA, phagocytic activity, and the presence of apoptotic bodies. We used quantitative RT-PCR and ELISA to examine TGF-β and MMP-13 expression and the concentrations and supernatants of isolated infiltrating hepatic macrophages transfected with siGpnmb. Results In C57BL/6J mice, serum ALT levels increased at two days after CCl4 injection and decreased at four days. Gpnmb expression in the liver was stimulated four days after CCl4 injection. Histological examination and flow cytometry showed that Gpnmb-positive cells were almost positive for CD68-positive macrophages, contained engulfed apoptotic bodies and exhibited enhanced phagocytic activity. Isolated infiltrating hepatic macrophages transfected with siGpnmb showed high MMP-13 secretion. There was no significant difference in the magnitude of CCl4-induced liver injury between DBA-g+ and DBA mice. However, hepatic MMP-13 expression, as well as α-SMA expression and collagen production, increased significantly in DBA-g+ compared with DBA mice. Conclusions Gpnmb-positive macrophages infiltrate the liver during the recovery phase of CCl4–induced acute liver injury and contribute to the balance between fibrosis and fibrolysis in the repair process following acute liver injury.

Clinical Features of Hepatitis C Virus Carriers With Persistently Normal Alanine Aminotransferase Levels

Hepatitis C virus (HCV) infection causes chronic hepatitis, which frequently leads to hepatic fibrosis and hepatocellular carcinoma (HCC). Alanine aminotransferase (ALT) is a biomarker of hepatocyte injury and is associated with the progression of hepatic fibrosis. Advanced hepatic fibrosis also predisposes HCV carriers to a risk of HCC. In contrast, some cases with persistent HCV infection have normal ALT levels that persist for a long time, and these HCV carriers have no or mild hepatitis and hepatic fibrosis. These HCV carriers are defined as persistent normal ALT (PNALT) cases and their risk of HCC is low compared to HCV carriers with abnormal ALT. However, there are various definitions of normal ALT and PNALT, and advanced hepatic fibrosis may be missed without a liver biopsy. In addition, there is also a risk of ALT elevation in HCV carriers with PNALT, which increases the risk of progression to hepatic fibrosis and HCC. Most HCV carriers with PNALT have asymptomatic or nonspecific symptoms. HCV carriers with PNALT are also considered to be responsive to interferon-based treatment. Thus, assessment of hepatic fibrosis is important in HCV carriers, and the eradication of HCV infection is more likely in HCV carriers with evidence of hepatic fibrosis, regardless of their ALT levels.

Efficacy of vasopressin V2 receptor antagonist tolvaptan in treatment of hepatic edema

Tolvaptan, an oral active vasopressin V2 receptor antagonist, is widely used for hepatic edema in Japan, but its clinical benefits have yet to be fully clarified. The present study evaluated the efficacy of tolvaptan in hepatic edema.

Impact of antibody to hepatitis B core antigen on the clinical course of hepatitis C virus carriers in a hyperendemic area in Japan: A community-based cohort study

Subjects positive for antibody to hepatitis B core antigen (HBcAb) and negative for hepatitis B surface antigen (HBsAg) are considered to have occult hepatitis B virus (HBV) infection. The aim of this study was to determine the impact of occult HBV infection on aggravation of the clinical course in hepatitis C virus (HCV) carriers.

Expression of glycoprotein nonmetastatic melanoma protein B in macrophages infiltrating injured mucosa is associated with the severity of experimental colitis in mice

Glycoprotein nonmetastatic melanoma protein B (Gpnmb) is a transmembrane glycoprotein, which negatively regulates the inflammatory responses of macrophages. However, the role of Gpnmb in intestinal macrophages remains to be fully elucidated. The present study aimed to investigate the expression of Gpnmb and its effects on colonic mucosal injuries associated with dextran sulfate sodium (DSS)‑induced colitis in BALB/c mice, DBA/2J (D2) mice lacking Gpnmb and Gpnmb‑transgenic DBA/2J mice (D2‑gpnmb+). The colonic expression of Gpnmb increased with the severity of DSS‑induced colitis in BALB/c mice, and macrophages infiltrating the inflamed mucosa were found to express Gpnmb. The D2 mice lacking Gpnmb exhibited more severe DSS‑induced colitis, which was accompanied by higher levels of pro‑inflammatory cytokines, including interleukin (IL)‑1β and IL‑6, compared with the D2‑gpnmb+ mice. Following lipopolysaccharide stimulation, macrophages from the D2 mice expressed higher levels of pro‑inflammatory cytokines and lower levels of IL‑10, compared with the D2‑gpnmb+mice. In addition, in the RAW264.7 murine macrophage cell line, knockdown of Gpnmb by small interfering RNA was associated with increased production of pro‑inflammatory cytokines, which were potentially mediated by the extracellular signal‑regulated kinase (ERK) and p38 signaling pathways. The results of the present study indicated that macrophages infiltrating injured mucosa express Gpnmb, and that Gpnmb‑positive macrophages may ameliorate inflammation in the intestinal mucosa by decreasing pro‑inflammatory cytokine production via the ERK and p38 signaling pathways.

Copper Accumulates in Hemosiderins in Livers of Patients with Iron Overload Syndromes.

In biology, redox reactions are essential and sometimes harmful, and therefore, iron metabolism is tightly regulated by cuproproteins. Since the state of copper in iron overload syndromes remains unclear, we investigated whether copper metabolism is altered in these syndromes. Eleven patients with iron overload syndromes participated in this study. The clinical diagnoses were aceruloplasminemia (n=2), hemochromatosis (n=5), ferroportin disease (n=2), and receiving excess intravenous iron supplementation (n=2). Liver specimens were analyzed using a light microscope and transmission electron microscope equipped with an X-ray analyzer. In addition to a large amount of iron associated with oxygen and phosphorus, the iron-rich hemosiderins of hepatocytes and Kupffer cells contained small amounts of copper and sulfur, regardless of disease etiology. Two-dimensional imaging clearly showed that cuproproteins were distributed homogenously with iron complexes within hemosiderins. Copper stasis was unlikely in noncirrhotic patients. The enhanced induction of cuproproteins by excess iron may contribute to copper accumulation in hemosiderins. In conclusion, we have demonstrated that copper accumulates in hemosiderins in iron overload conditions, perhaps due to alterations in copper metabolism.

Impact of a single nucleotide polymorphism upstream of the IL28B gene in patients positive for anti‐HCV antibody in an HCV hyperendemic area in Japan

The influence of genetic variation at the interleukin‐28B (IL28B) locus on the natural course of hepatitis C virus (HCV) infection has not been fully investigated. The goal of this study was to examine whether an IL28B polymorphism (rs8099917) is associated with natural clearance of HCV and with disease parameters of HCV infection in an HCV hyperendemic area of Japan. The patients were 502 anti‐HCV antibody‐positive residents who participated in liver disease screening program from 2002 to 2004. Patients who underwent interferon‐based therapy or had hepatocellular carcinoma were excluded. Of these patients, 149 were negative for HCV RNA (prior infection) and 353 were positive for HCV RNA or HCV core antigen (HCV carriers). In multivariate analysis, the IL28B TT genotype was a predictor for prior HCV infection. In addition, nine of the patients with prior HCV infection were positive for anti‐HCV antibody with positive for HCV core antigen or HCV RNA before 2001, and these nine patients all had the IL28B TT genotype. Furthermore, the IL28B TT genotype was associated independently with higher HCV core antigen levels in HCV carriers. In contrast, the IL28B genotype did not affect the biochemical markers, such as alanine aminotransferase, hepatic fibrosis markers, and α‐fetoprotein, and the degree of hepatic fibrosis assessed by transient elastography in HCV carriers. We concluded that IL28B polymorphism (TT genotype) is associated with spontaneous clearance of HCV and conversely with high viral loads in HCV carriers. In contrast, the IL28B genotype does not affect disease progression such as hepatic fibrosis. J. Med. Virol. 86:1877–1885, 2014.