Hepatitis C virus infection in patients with chronic liver disease or chronic renal failure and blood donors in Thailand

Prevalence of HCV genotypes and subtypes in Southeast Asia: A systematic review and meta-analysis

Known for its high genetic diversity and variation in genotypic presence in different regions of the world, hepatitis C virus (HCV) is estimated to infect about 71 million people globally. Selection of an appropriate therapeutic regimen largely depends on the identification of the genotype responsible for the infection. This systematic review and meta-analysis was conducted to provide a comprehensive view of HCV genotype and subtype distribution in Southeast Asia (SEA). The review was conducted according to the Preferred Reporting Items for Systematic Reviews and Meta-analysis (PRISMA). We searched five databases without year and language restrictions. Data from 90 eligible studies involving 15,089 genotypes and 9,646 subtypes representing 10 SEA countries were analyzed. The pooled estimates showed that genotype 1 (46.8%) [95% CI, 43.2–50.4; I² = 92.77%; p < 0.001] was the most dominant HCV genotype in the region, followed by genotype 3 (23.1%) [95% CI, 19.4–27.2; I² = 93.03%; p < 0.001], genotype 6 (16.5%) [95% CI, 13.8–19.6], genotype 2 (4.6%) [95% CI, 3.5–5.9], genotype 4 (1.1%) [95% CI, 0.7–1.5] and genotype 5 (0.8%) [95% CI, 0.4–1.3]. Philippines had the highest prevalence of genotypes 1 and 2. Genotype 6 became more prevalent after year 2000. Over 40 different subtypes were identified, with subtypes 1b (26.3%), 1a (21.3%), and 3a (14.3%) being the most prevalent of all the reported subtypes. Although on a global scale, genotype 6 is considered highly prevalent in SEA, evidence from this study reveals that it is the third most prevalent genotype within the region.

Cancer Screening of Renal Transplant Patients Undergoing Long-Term Immunosuppressive Therapy

OBJECTIVE

With this study we aimed to research the effects of immunosuppressive drugs, their cumulative doses, and viral infections on development of malign tumors in patients who have undergone treatment for 5 years.

METHODS

We examined 100 patients who underwent renal transplantation from 2004 to 2009. Patients had mycophenolate mofetil and steroid in addition to cyclosporine, sirolimus, or tacrolimus as immunosuppressive treatment. For malignancy screening, physical examination, radiologic and endoscopic screening were done, and immunosuppressive drugs and their cumulative doses, age, sex, body mass index (BMI), dialysis history, and viral infection history were investigated.

RESULTS

The mean age of patients was 42.03 ± 11.30 years. There were 1 colon cancer patient, 1 retroperitoneal liposarcoma, 1 renal oncocytoma, 3 Kaposi sarcoma patients treated with cyclosporine; in those treated with Tac there were 1 basal cell carcinoma, 1 Kaposi sarcoma, 2 thyroid carcinoma, 1 breast carcinoma, 1 bladder carcinoma, 1 renal cell carcinoma, and 1 colon carcinoma patients. The mean age of patients having carcinoma was statistically significant compared with those without cancer (P < .01). The prednisolone cumulative dose was significantly higher in carcinoma patients than in patients without carcinoma (P < .01).

RESULTS

The use of long-term chronic immunosuppressive therapy may increase the development of cancer. The risk of carcinoma increases with increasing drug dose and time period of the immunosuppressive drug. There was not a negative effect on cancer prevalence in patients with cyclosporine or tacrolimus. But the cumulative dose of steroids significantly increased malignancy occurence.

Hepatitis C virus infection and dialysis: 2012 update

Hepatitis C virus infection is still common among dialysis patients, but the natural history of HCV in this group is not completely understood. Recent evidence has been accumulated showing that anti-HCV positive serologic status is significantly associated with lower survival in dialysis population; an increased risk of liver and cardiovascular disease-related mortality compared with anti-HCV negative subjects has been found. According to a novel meta-analysis (fourteen studies including 145,608 unique patients), the adjusted RR for liver disease-related death and cardiovascular mortality was 3.82 (95% CI, 1.92; 7.61) and 1.26 (95% CI, 1.10; 1.45), respectively. It has been suggested that the decision to treat HCV in patients with chronic kidney disease be based on the potential benefits and risks of therapy, including life expectancy, candidacy for kidney transplant, and co-morbidities. According to recent guidelines, the antiviral treatment of choice in HCV-infected patients on dialysis is mono-therapy but fresh data suggest the use of modern antiviral approaches (i.e., pegylated interferon plus ribavirin). The summary estimate for sustained viral response and drop-out rate was 56% (95% CI, 28-84) and 25% (95% CI, 10-40) in a pooled analysis including 151 dialysis patients on combination antiviral therapy (conventional or pegylated interferon plus ribavirin).

Seronegative hepatitis C virus infection in a child infected via mother-to-child transmission

Hepatitis C virus (HCV) infection typically leads to antibody response within weeks after primary infection. Here, we describe the case of a child infected with HCV by mother-to-child transmission who remained persistently seronegative despite the presence of high levels of circulating HCV RNA.

HPV-related (pre)malignancies of the female anogenital tract in renal transplant recipients

Renal transplantations (RTs) are performed routinely in many countries. After RT, the administration of lifelong immunosuppressive therapy is required. As a consequence, renal transplant recipients (RTRs) have a high risk to develop virus-associated (pre)malignancies, such as Human papillomavirus (HPV) related anogenital (pre)malignancies. It is known that the majority of the RTRs are infected with HPV and that these women have a 14-fold increased risk of cervical cancer, up to 50-fold of vulvar cancer and up to 100-fold of anal cancer. Often, treatment of these lesions requires concessions and may be suboptimal as radiation therapy and extensive surgery may damage the renal transplant. Therefore, prognosis may be compromised due to inadequately treated malignancies. Especially for these immunocompromised patients prevention is of utmost importance. Yearly cervical cancer screening for RTRs is advised, but appears to be executed poorly. For the future, optimizing screening and prevention of anogenital (pre)malignancies is an important issue for women after RT. This review gives a broad overview of all aspects regarding HPV-related (pre)malignancies of the female anogenital tract in RTRs.

Seropositivity for anti-HCV core antigen is independently associated with increased all-cause, cardiovascular, and liver disease-related mortality in hemodialysis patients

Background

It is not known whether chronic or past hepatitis C virus (HCV) infection contributes to the high mortality rate in hemodialysis patients.

Methods

This prospective study of 1077 adult hemodialysis patients without hepatitis B virus infection used Poisson regression analysis to estimate crude and sex- and age-adjusted rates (per 1000 patient-years) of all-cause, cardiovascular, infectious disease-related and liver disease-related mortality in patients negative for HCV antibody (group A), patients positive for HCV antibody and negative for anti-HCV core antigen (group B), and patients positive for anti-HCV core antigen (group C). The relative risks (RRs) for each cause of death in group B vs group C as compared with those in group A were also estimated by Poisson regression analysis after multivariate adjustment.

Results

A total of 407 patients died during the 5-year observation period. The sex- and age-adjusted mortality rate was 71.9 in group A, 80.4 in group B, and 156 in group C. The RRs (95% CI) for death in group B vs group C were 1.23 (0.72 to 2.12) vs 1.60 (1.13 to 2.28) for all-cause death, 0.75 (0.28 to 2.02) vs 1.64 (0.98 to 2.73) for cardiovascular death, 1.64 (0.65 to 4.15) vs 1.58 (0.81 to 3.07) for infectious disease-related death, and 15.3 (1.26 to 186) vs 28.8 (3.75 to 221) for liver disease-related death, respectively.

Conclusions

Anti-HCV core antigen seropositivity independently contributes to elevated risks of all-cause and cause-specific death. Chronic HCV infection, but not past HCV infection, is a risk for death among hemodialysis patients.

A shift in the hepatitis C virus genotype dominance in blood donor samples from Thailand

Hepatitis C virus (HCV) can be classified into six major genotypes. The HCV genotypes variability accounts for its geographical distribution, its responses to treatments and the clinical outcomes. The aim of this study was to determine the distribution of HCV genotypes among volunteer blood donors in Thailand. Samples from 135 anti-HCV positive blood donors were analyzed. HCV RNA and genotyping was carried out using nested polymerase chain reaction (PCR) and genotype-specific primer PCR for a portion of the core region. HCV RNA was detected in 109 samples (80.7%). Genotype analysis demonstrated four different genotypes. The most common was genotype 3a (36.7%), followed by genotype 6 (29.4%), 1a (19.3%), 1b (6.4%) and mixed infection (1.8%). Seven samples were untyped (6.4%) in the present study. In several previous reports, the prevalence found in Thailand was HCV genotypes 3, 1 and 6. The present results show an increasing importance of the genotype 6 in HCV infections. This study has also described for the first time in Thailand mixed infections of HCV genotypes.

Human immunodeficiency virus-hepatitis C virus co-infection in pregnant women and perinatal transmission to infants in Thailand

OBJECTIVES

The objectives of this study were to assess the prevalence and factors associated with hepatitis C virus (HCV) infection in human immunodeficiency virus (HIV)-infected and -uninfected Thai pregnant women and the rate of HCV transmission to their infants.

PATIENTS AND METHODS

Study subjects included 1435 HIV-infected pregnant women and their infants, enrolled in a perinatal HIV prevention trial, and a control group of 448 HIV-uninfected pregnant women. Women were screened for HCV antibodies with an enzyme immunoassay. Positive results were confirmed by recombinant immunoblot and HCV RNA quantification. Infants were tested for HCV antibodies at 18 months or for HCV RNA at between 6 weeks and 6 months.

RESULTS

Of the HIV-infected women, 2.9% were HCV-infected compared to 0.5% of HIV-uninfected women (p=0.001). Only history of intravenous drug use was associated with HCV infection in HIV-infected women. Ten percent of infants born to co-infected mothers acquired HCV. The risk of transmission was associated with a high maternal HCV RNA (p=0.012), but not with HIV-1 load or CD4 count.

CONCLUSIONS

Acquisition of HCV through intravenous drug use partially explains the higher rate of HCV infection in HIV-infected Thai women than in HIV-uninfected controls. Perinatal transmission occurred in 10% of infants of HIV-HCV-co-infected mothers and was associated with high maternal HCV RNA.

Standardized prevalence ratios for chronic hepatitis C virus infection among adult Japanese hemodialysis patients

Background

Many studies have estimated the prevalence of anti-hepatitis C virus (HCV) antibody among hemodialysis (HD) patients; however, the prevalence of HCV core antigen—which indicates the presence of chronic HCV infection—is not known.

Methods

Standardized prevalence ratios (SPRs) for anti-HCV antibody and HCV core antigen among HD patients (n = 1214) were calculated on the basis of data from the general population (n = 22 472) living in the same area.

Results

The prevalences of anti-HCV antibody and HCV core antigen were 12.5% and 7.8%, respectively, in male hemodialysis patients, and 8.5% and 4.1% in female hemodialysis patients. The SPRs (95% confidence interval) for anti-HCV antibody and HCV core antigen were 8.39 (6.72–10.1) and 12.9 (9.66–16.1), respectively, in males, and 5.42 (3.67–7.17) and 8.77 (4.72–12.8) in females.

Conclusions

The prevalences of chronic HCV infection among male and female HD patients were 13-fold and 9-fold, respectively, those of the population-based controls. Further studies should therefore be conducted to determine the extent of chronic HCV infection among HD patients in other populations and to determine whether chronic HCV infection contributes to increased mortality in HD patients.

Liver cirrhosis and hepatocellular carcinoma in hepatic vena cava disease, a liver disease caused by obstruction of inferior vena cava

PURPOSE

Hepatic vena cava disease (HVD), a form of Budd-Chiari syndrome, is caused by the obstruction of hepatic portion of the inferior vena cava. It is a chronic disease characterized by the development of liver cirrhosis (LC) and hepatocellular carcinoma (HCC). As HVD occurred in areas with high incidence of hepatitis B virus (HBV) infection and some patients tested HBsAg positive, it was thought to be the cause of LC and HCC. To assess the pathogenesis of LC or HCC in HVD, a long-term follow-up study was done.

METHOD

Fifty-six patients with HVD diagnosed by ultrasound (US) and confirmed by cavography in 31 and liver biopsy in 34 were followed up for an average of 14.8 +/- 9 years. The occurrence of LC was diagnosed by US and/or liver biopsy and that of HCC by US, elevated level of alpha-fetoprotein, and liver biopsy or fine-needle aspiration cytology, or computed tomographic scan. Other risk factors for LC/HCC such as alcohol use and HBV and hepatitis C virus (HCV) infections were assayed.

RESULTS

Forty-four (78.5%) and 6 (10.7%) patients developed cirrhosis and HCC, respectively. LC/HCC occurred more frequently among those who had severe or frequent acute exacerbations (P = 0.017), but it was not related to alcohol use or HBV and HCV infections.

CONCLUSION

HVD is independent risk factors for LC and HCC. Severe and/or recurrent loss of hepatocytes caused by hepatic venous outflow obstruction and/or thrombotic obstruction of small radicals of hepatic and portal veins that occurred during acute exacerbations was considered important in the pathogenesis of LC and HCC in HVD.

Viral hepatitis infections among dialysis patients: Thailand registry report

BACKGROUND

Patients on dialysis are at high risk of acquiring viral hepatitis infections. However, there were only few data from Thailand. The aim of the present study was to assess the prevalence, incidence and associated risk factors of viral hepatitis infections among dialysis patients.

METHODS

A retrospective study was conducted to evaluate 5179 medical records of dialysis patients from the Thailand Renal Replacement Therapy Registry.

RESULTS

In 2002, the seroprevalence of hepatitis B virus (HBV) and hepatitis C virus (HCV) infections were 6.3% (n = 2454) and 4.8% (n = 2167), respectively. HBV and HCV seroprevalence became 6.5% (n = 2585) and 4.3% (n = 2399) in 2003. The incidence of HBV and HCV infections were 1.5 and 2.4 cases per 1000 patient-years, respectively. Logistic regression analysis showed that age and gender were significant risk factors for HBV infection, but not for HCV infection.

CONCLUSION

In Thailand, it was not uncommon for dialysis patients to acquire viral hepatitis infections. However, our prevalence is similar to reports from some other South-East Asian countries.

[Risk of hepatitis C related to traditional medicine: a case control study in Ho Chi Minh City, Vietnam]

BACKGROUND

The transmission of hepatitis C virus (HCV) is strongly associated with blood transfusion and drug abuse. However, in about a third of HCV-infected subjects, the risk factors are not clearly identified though some cases are likely to be healthcare associated. In an Asian country such as Vietnam, invasive procedures used for traditional and beauty care could be potential risk factors. The aim of the present study was to identify the risk factors of HCV infection in a population sample in Ho Chi Minh City.

METHOD

A case-control study matched by gender and age was performed among blood adults donors at the Centre of hematological diseases and blood transfusion. Cases were defined as blood donors with HCV-positive Elisa. Controls were selected at random among ELISA HCV-negative donors. A standardized questionnaire was used to collect data focusing on invasive medical procedures, beauty care and on invasive procedures related to traditional medicine.

RESULT

Among the 80 cases and 240 controls, the independent predictors of anti-HCV positivity using a stepwise logistic regression were: blood transfusion, intravenous drug abuse, acupuncture, ventoused scarification and practice of scarification (adjusted odds ratio and IC95%: 3.8 [1.1-13.1], 3.5 [1.7-7.3], 5.4 [2.3-12.7], 5.4 [2.5-11.7], 6.6 [1.6-26.4] respectively). The other risk factors such as past hospitalization surgery, tattooing, being a healthcare worker, or practising tattooing or piercing were not associated with HCV infection.

CONCLUSION

To be exposed to ventoused scarifications or acupuncture are risk factors for the transmission of HCV in Vietnam. A wide information campaign on hygiene practices for general population as well as the practitioners is needed to ensure safer health cares in traditional medicine.

The contributions of hepatitis B virus and hepatitis C virus infections to cirrhosis and primary liver cancer worldwide

BACKGROUND/AIMS

End-stage liver disease accounts for one in forty deaths worldwide. Chronic infections with hepatitis B virus (HBV) and hepatitis C virus (HCV) are well-recognized risk factors for cirrhosis and liver cancer, but estimates of their contributions to worldwide disease burden have been lacking.

METHODS

The prevalence of serologic markers of HBV and HCV infections among patients diagnosed with cirrhosis or hepatocellular carcinoma (HCC) was obtained from representative samples of published reports. Attributable fractions of cirrhosis and HCC due to these infections were estimated for 11 WHO-based regions.

RESULTS

Globally, 57% of cirrhosis was attributable to either HBV (30%) or HCV (27%) and 78% of HCC was attributable to HBV (53%) or HCV (25%). Regionally, these infections usually accounted for >50% of HCC and cirrhosis. Applied to 2002 worldwide mortality estimates, these fractions represent 929,000 deaths due to chronic HBV and HCV infections, including 446,000 cirrhosis deaths (HBV: n=235,000; HCV: n=211,000) and 483,000 liver cancer deaths (HBV: n=328,000; HCV: n=155,000).

CONCLUSIONS

HBV and HCV infections account for the majority of cirrhosis and primary liver cancer throughout most of the world, highlighting the need for programs to prevent new infections and provide medical management and treatment for those already infected.

Characterization of host-range and cell entry properties of the major genotypes and subtypes of hepatitis C virus

Because of the lack of a robust cell culture system, relatively little is known about the molecular details of the cell entry mechanism for hepatitis C virus (HCV). Recently, we described infectious HCV pseudo-particles (HCVpp) that were generated by incorporating unmodified HCV E1E2 glycoproteins into the membrane of retroviral core particles. These initial studies, performed with E1E2 glycoproteins of genotype 1, noted that HCVpp closely mimic the cell entry and neutralization properties of parental HCV. Because sequence variations in E1 and E2 may account for differences in tropism, replication properties, neutralization, and response to treatment in patients infected with different genotypes, we investigated the functional properties of HCV envelope glycoproteins from different genotypes/subtypes. Our studies indicate that hepatocytes were preferential targets of infection in vitro, although HCV replication in extrahepatic sites has been reported in vivo. Receptor competition assays using antibodies against the CD81 ectodomain as well as ectopic expression of CD81 in CD81-deficient HepG2 cells indicated that CD81 is used by all the different genotypes/subtypes analyzed to enter the cells. However, by silencing RNA (siRNA) interference assays, our results show that the level of Scavenger Receptor Class-B Type-I (SR-BI) needed for efficient infection varies between genotypes and subtypes. Finally, sera from chronic HCV carriers were found to exhibit broadly reactive activities that inhibited HCVpp cell entry, but failed to neutralize all the different genotypes. In conclusion, we characterize common steps in the cell entry pathways of the major HCV genotypes that should provide clues for the development of cell entry inhibitors and vaccines.

High prevalence of antibodies to hepatitis A and E viruses and viremia of hepatitis B, C, and D viruses among apparently healthy populations in Mongolia

The prevalence of infection with hepatitis A virus (HAV), HBV, HCV, HDV, and HEV was evaluated in 249 apparently healthy individuals, including 122 inhabitants in Ulaanbaatar, the capital city of Mongolia, and 127 age- and sex-matched members of nomadic tribes who lived around the capital city. Overall, hepatitis B surface antigen (HBsAg) was detected in 24 subjects (10%), of whom 22 (92%) had detectable HBV DNA. Surprisingly, HDV RNA was detectable in 20 (83%) of the 24 HBsAg-positive subjects. HCV-associated antibodies were detected in 41 (16%) and HCV RNA was detected in 36 (14%) subjects, none of whom was coinfected with HBV, indicating that HBV/HCV carriers account for one-fourth of this population. Antibodies to HAV and HEV were detected in 249 (100%) and 28 (11%) subjects, respectively. Of 22 HBV DNA-positive subjects, genotype D was detected in 21 subjects and genotype F was detected in 1 subject. All 20 HDV isolates recovered from HDV RNA-positive subjects segregated into genotype I, but these differed by 2.1 to 11.4% from each other in the 522- to 526-nucleotide sequence. Of 36 HCV RNA-positive samples, 35 (97%) were genotype 1b and 1 was genotype 2a. Reflecting an extremely high prevalence of hepatitis virus infections, there were no appreciable differences in the prevalence of hepatitis virus markers between the two studied populations with distinct living place and lifestyle. A nationwide epidemiological survey of hepatitis viruses should be conducted in an effort to prevent de novo infection with hepatitis viruses in Mongolia.

Prevalence and clinical significance of hepatitis C virus infection in Thai patients with thalassemia

Hepatitis C virus (HCV) infection is a common cause of liver disease in thalassemia major patients in Western, especially Mediterranean, countries. Its significance in thalassemic patients from Southeast Asia has not been critically evaluated. In this report, we describe our study of the prevalence of HCV infection among Thai patients with thalassemia. The relationships of the infection to blood transfusion and the infection's effects on liver function have also been determined. Of the 104 patients studied, 21 (20.2%) tested positively by enzyme immunoassay for anti-HCV antibody, whereas only 2 patients (2%) had the hepatitis B surface antigen. There was no significant relationship between the presence of anti-HCV antibodies and the number and frequency of blood transfusions. In fact, 2 patients (10%) who tested positive for anti-HCV antibodies had never received transfusions. Patients with anti-HCV antibodies had significantly abnormal liver functions, such as higher levels of serum aspartate aminotransferase (SGOT) and alanine aminotransferase (SGPT) and lower levels of serum albumin, compared with patients without anti-HCV antibodies (P = .021, .017, and .004, respectively). However, there were also significant correlations between iron status as indicated by transferrin saturation or serum ferritin levels and SGOT, SGPT, and gamma-glutamyltransferase (GGT) levels. Moreover, abnormal liver function as represented by elevated levels of SGOT, SGPT, GGT, and serum alkaline phosphatase was observed more frequently in patients with iron overload than in patients with a lower degree of iron burden. The presence of HCV did not alter the effects of iron overload on liver function. The findings suggest that both HCV and iron overload are the main causes of abnormal liver function in Thai patients with thalassemia. The treatment of both problems, if coexisting in patients with thalassemia, is required to prevent progression to chronic liver disease.

Tumours after kidney transplantation

PURPOSE OF REVIEW

With the improved long-term outcome of renal allograft recipients, malignant tumours or cardiovascular disease become increasingly important. Malignant tumours develop in 15-20% of graft recipients after 10 years, and thus contribute substantially to the morbidity and mortality of these patients. In contrast to the general population, skin tumours and lymphoproliferative disorders are the most frequent malignancies in transplant recipients. Malignancies can develop in three ways: de-novo occurrence in the recipient; recurrent malignancy in the recipient; or transmission of malignancy from the donor.

RECENT FINDINGS

The immunosuppressive strategies after renal transplantation differ with respect to the development of malignancies, with cell-depleting antibodies being the highest risk, whereas newer immunosuppressants such as rapamycin could possess anti-tumour potential. The relationship of chronic viral infections to skin tumours and lymphoproliferative diseases has become clearer during recent years. Concomitantly, experience in the management of such diseases has grown. Furthermore, as older donors are accepted, awareness of the possibility of transferring malignancies from the donor to the recipient must increase.

SUMMARY

Malignancies are a major contributor to morbidity and mortality among kidney transplant recipients as such diseases gain importance with longer graft survival. Immunosuppression and chronic viral infections in combination with the transmission of malignant cells from the donor or recurrent malignancies contribute to the increased incidence of cancer. In kidney transplant recipients, screening before and after transplantation and an individualized choice of immunosuppression are thus mandatory.

Full-length core sequence dependent complex-type glycosylation of hepatitis C virus E2 glycoprotein

AIM

To study HCV polyprotein processing is important for the understanding of the natural history of HCV and the design of vaccines against HCV. The purpose of this study is to investigate the affection of context sequences on hepatitis C virus (HCV) E2 processing.

METHODS

HCV genes of different lengths were expressed and compared in vaccinia virus/T7 system with homologous patient serum S94 and mouse anti-serum M( E2116) raised against E.coli -derived E2 peptide, respectively. Deglycosylation analysis and GNA ( Galanthus nivalus ) lectin binding assay were performed to study the post-translational processing of the expressed products.

RESULTS

E2 glycoproteins with different molecular weights (-75 kDa and -60 kDa) were detected using S94 and M( E2116), respectively. Deglycosylation analysis showed that this difference was mainly due to different glycosylation. Endo H resistance and its failure to bind to GNA lectin demonstrated that the higher molecular weight form (75 kDa) of E2 was complex-type glycosylated, which was readily recognized by homologous patient serum S94. Expression of complex-type glycosylated E2 could not be detected in all of the core-truncated constructs tested, but readily detected in constructs encoding full-length core sequences.

CONCLUSION

The upstream conserved full-length core coding sequence was required for the production of E2 glycoproteins carrying complex-type N-glycans which reacted strongly with homologous patient serum and therefore possibly represented more mature forms of E2. As complex-type N-glycans indicated modification by Golgi enzymes, the results suggest that the presence of full-length core might be critical for E1/E2 complex to leave ER. Our data may contribute to a better understanding of the processing of HCV structural proteins as well as HCV morphogenesis.

Malignancy after renal transplantation

Malignancy following renal transplantation is an important medical problem during the long-term follow-up. The overall incidence of malignancy at this time is 3 to 5 times higher than in the general population. The most common malignancies are lymphoproliferative disorders (early after transplantation) and skin carcinomas (late after transplantation). The type of malignancy is different in various countries and dependent on genetic and environmental factors. Another important confounder for risk of malignancy after renal transplantation is the type of immunosuppression. Previous use of cytotoxic drugs (eg, cyclophosphamide) or a history of analgesic abuse are additional risk factors. Malignancy may even be transplanted by the graft. Previous cancer treatment in a uremic patient on the transplant waiting list is of great importance in relation to waiting time and postmalignancy screening. Finally, every dialysis patient on the waiting list should undergo a regular screening program before and after renal transplantation to detect a potentially malignant tumor in an early stage. In addition to specific oncological treatment, managing a malignancy after renal transplantation should include modification of immunosuppression.

Infection with an unenveloped DNA virus (TTV) associated with posttransfusion non-A to G hepatitis in hepatitis patients and healthy blood donors in Thailand

An unenveloped single-stranded DNA virus (TTV) has been reported in association with posttransfusion and acute and chronic hepatitis of unknown etiology. DNA of TTV was tested for by polymerase chain reaction with heminested primers in 127 patients with chronic liver disease and 105 healthy blood donors in Thailand. TTV DNA was detected in 23 (59%) of the 39 patients without hepatitis B surface antigen or RNA of hepatitis C virus, at a frequency significantly higher than the detection in 21 (36%) of the 59 patients with HBsAg (P < 0.05) or in 38 (36%) of the 105 blood donors (P< 0.05). Among patients with chronic liver disease, TTV DNA occurred in those with liver cirrhosis and hepatocellular carcinoma more frequently than in those with chronic hepatitis (35 of 65 or 54% vs. 20 of 62 or 32%, P< 0.05). There were no differences in age, sex, or markers of infection with hepatitis B, C and GBV-C/HGV viruses, indicating a mode of transmission of TTV different from those of the other hepatitis viruses. Phylogenetic analysis indicated three different genotypes of TTV with six distinct subtypes in Thailand. Based on these results, TTV would have a role in the development of chronic liver disease of unknown etiology in Thailand.

The role of serum ferritin in the diagnosis of iron deficiency anaemia in patients with liver cirrhosis

OBJECTIVES

To determine the diagnostic values of serum ferritin and other conventional laboratory tests in the diagnosis of iron deficiency anaemia in patients with liver cirrhosis.

DESIGN

Cross-sectional study for diagnostic tests.

SETTING

University hospital.

SUBJECTS

Seventy-two consecutive patients with liver cirrhosis in whom the haemoglobin level was less than 13.0 g dL(-1) for men and 12.0 g dL(-1) for women. The diagnosis of liver cirrhosis was based on characteristic clinical and hepatic ultrasonographic findings.

MAIN OUTCOME MEASURES

By using absence of bone marrow iron as the standard criterion, the diagnostic powers of mean corpuscular volume, transferrin saturation, serum ferritin and the presence of hypochromic red cells in the diagnosis of iron deficiency were compared by analysing the likelihood ratios, the area under the receiver operating curves (ROC) and the stepwise logistic regression associated with each test.

RESULTS

Twenty-nine patients (40.3%) demonstrated no stainable iron in the bone marrow. The likelihood ratios, the area under the ROC and the stepwise logistic regression indicated that serum ferritin was the most powerful test predictive of iron deficiency. Other tests added little further diagnostic values. The likelihood ratios associated with the serum ferritin levels were as follows: <50 microg L(-1), 22.3; 51-200 microg L(-1), 1.5-1.8; 201-400 microg L(-1), 1.0; >400 microg L(-1), <1. These results indicate that serum ferritin level <50 microg L(-1) depict a very high probability of iron deficiency anaemia (0.83-0.99) irrespective of the patient's pre-test probability.

CONCLUSION

Serum ferritin is the most powerful noninvasive test for the diagnosis of iron deficiency anaemia in patients with liver cirrhosis. It should be the primary test of choice in patients suspected of having the disease. When the level was less than 50 microg L(-1), iron supplement may be prescribed without necessitating bone marrow aspiration.

High prevalence of hepatitis G viremia among kidney transplant patients in Thailand

Patients receiving kidney transplants (KT) are at high risk for blood borne viral infections. To determine the prevalence of a recently discovered hepatitis G virus (HGV) in this patient group, reverse transcription-polymerase chain reaction (RT-PCR) employing primers derived from the NS5 region of the viral genome was utilized. HGV RNA was detected in 40 of 94 KT patients (43%), as compared to 3 of 69 healthy subjects (4.3%). Cocirculation of HGV and hepatitis C virus (HCV) RNA was detected in 12 patients (13%). Comparison of patients with and without HGV revealed that the former had received hemodialysis before transplantation for a significantly longer duration than the latter (28 vs. 17 months, respectively; P < 0.05). The amount of blood transfused and mean levels of liver enzymes, including alkaline phosphatase, alanine transaminase, and aspartate transaminase, were the same in both groups. Sequence analysis of 275-base pair DNA clones obtained from 2 patients revealed approximately 92% sequence homology to the published HGV and GB virus C sequences. These results suggested that HGV infection among Thai KT patients was high and the role of HGV in causing liver disease remains to be determined.

Genotypic distribution of hepatitis C virus in different regions of Thailand

The genotypic distribution of hepatitis C virus (HCV) isolated from blood donors from four major regions of Thailand was studied by reverse hybridization assays. PCR-amplified products from the 5' noncoding and core regions of the viral genome were hybridized to genotype- and subtype-specific probes which were immobilized on the nitrocellulose membrane. Of 332 anti-HCV-positive plasma samples studied, 71% contained HCV RNA. HCV genotype 3a was the most prevalent genotype (39%), followed by genotype 1b (20%) and genotype 6 group variants (18%). HCV genotype 1a was identified among 9% of all isolates. Other genotypes (genotype 1 which was neither 1a nor 1b, genotype 3b, and an unclassified genotype) were uncommon. There was no difference in the mean age of the donors infected with different HCV genotypes. The genotypic distribution pattern of HCV was similar among HCV isolates from different regions of Thailand.

Genotyping of hepatitis C virus isolates from Basque Country, Spain

The genotype of HCV was determined in 161 chronic HCV-infected patients. The patients were classified into three groups on the basis of the origin of the HCV infection: 50 patients had a history of intravenous drug use (IVDU) but no HIV infection; 41 patients had received blood transfusions, and 70 patients had no known exposure. The distribution of HCV genotypes was associated with the origin of infection and age of patients: genotype 1b was predominant among patients who had received blood transfusions and those without evidence of parenteral exposure (84.6% and 67.7%, respectively), whereas genotype 3a was present in 65.3% of IVDUs. Patients with genotype 1b were older than those with genotypes 1a or 3a: 50.3 +/- 12 vs. 34.1 +/- 9.9 and 31 +/- 5.4 years, respectively. These findings suggest that the pattern of HCV genotypes in our region is changing and that genotype 1b may be substituted by 3a as the dominant genotype in the future.

Hepatitis C virus genotypes in patients with hepatocellular carcinoma and cholangiocarcinoma in Thailand

The prevalences of infections with hepatitis C virus (HCV) and hepatitis B virus (HBV) were determined in 110 Thai patients with liver cancer, of whom 80 and 30 had histological diagnoses of hepatocellular carcinoma (HCC) and cholangiocarcinoma (CCA), respectively. Hepatitis B surface antigen was detected in 63.8% of HCC patients and 16.7% of those with CCA. Antibodies to HCV, detected by a third-generation enzyme immunoassay, were found in 11.3% of HCC patients and in no CCA patient. HCV ribonucleic acid (RNA) was detected by polymerase chain reaction in 6 anti-HCV positive patients, and also in 2 patients who had no detectable anti-HCV antibody. A total of 11 patients had evidence of HCV infection, 8 of whom were infected with HCV alone. HCV genotypes were determined in all 8 patients who had HCV RNA; genotype 3a was the most common (62.5%). These results demonstrate that, in Thailand where both HBV and HCV are endemic, HBV infection is still the most important risk factor for HCC, but HCV also has an important role in those without HBV infection. In addition, the genotypic distribution of HCV in HCC in Thailand is similar to that in the general population. No specific association between genotype 1b and HCC was observed.

Genotype analysis of hepatitis C virus among blood donors and inmates in Metro Manila, The Philippines

Antibodies against hepatitis C virus (HCV) were detected in 18 (2.3%) of 800 sera from commercial blood donors and 23 (4.6%) of 502 sera from inmates in Metro Manila, the Philippines. The difference in the antibody prevalence between the two groups was statistically significant (P < 0.05). HCV RNA was detected in 14 (78%) of the 18 antibody-positive sera from blood donors and 19 (83%) of the 23 antibody-positive sera from inmates. Genotype analysis revealed that HCV-2a (7%). Among inmates, on the other hand, HCV-1a (68%) was most common, followed by HCV-1b (11%), HCV-2a (5%) and HCV-2b (5%). Overall, HCV-1a and HCV-1b appeared to be predominant among them. Thus, the genotype prevalence in the Philippines was distinct from those in other Southeast Asian countries such as Thailand, Vietnam and Indonesia, and also distinct from those in the Far East including Taiwan, Mainland China and Japan.

Hepatitis C virus (HCV) subtype prevalence in Chiang Mai, Thailand, and identification of novel subtypes of HCV major type 6

Subtype analysis of hepatitis C viruses (HCVs) obtained from patients with chronic liver disease in Chiang Mai, Thailand, was performed. Of 46 HCV isolates, 13 (28%) were shown to belong to HCV subtype 3a (HCV-3a), 10 (22%) to belong to HCV-1a, 7 (15%) to belong to HCV-1b, 1 (2%) to belong to HCV-3b, and 1 (2%) to belong to a variant group, as determined from partial nucleotide sequences of the NS5B region of the viral genome. Analysis of 5' untranslated region sequences identified five other isolates (11%) of HCV type 1 and two other isolates (4%) of type 3. Detailed phylogenetic positions for the variant described above and those previously obtained from blood donors and drug addicts in Chiang Mai were determined by a six-parameter neighbor-joining method on the basis of core, E1, and NS5B region sequences. The results revealed that those sequence variants represent novel subtypes of HCV type 6. The HCV type 6 isolates appear to be antigenically different from isolates of HCV types 1 and 2, as determined by a serotyping method that utilizes recombinant peptides corresponding to a portion of the NS4 protein. The significance of subtype analysis around this area is discussed.

Survey of type 6 group variants of hepatitis C virus in Southeast Asia by using a core-based genotyping assay

Previous surveys of the prevalences of genotypes of hepatitis C virus (HCV) in different populations have often used genotyping assays based upon analysis of amplified sequences from the 5' noncoding region (5'NCR), such as restriction fragment length polymorphism (RFLP) or hybridization with type-specific probes (e.g., InnoLipa). Although highly conserved, this region contains several type-specific nucleotide polymorphisms that allow major genotypes 1 to 6 to be reliably identified. Recently, however, novel HCV variants found in Vietnam and Thailand that are distantly related to the type 6a genotype (type 6 group) by phylogenetic analysis of coding regions of the genome often have sequences in the 5'NCR that are similar or identical to those of type 1 and could therefore not be identified by an assay of sequences in this region. We developed a new genotyping assay based upon RFLP of sequences amplified from the more variable core region to investigate their distribution elsewhere in southeast (SE) Asia. Among 108 samples from blood donors in seven areas that were identified as type 1 by RFLP in the 5'NCR, type 6 group variants were found in Thailand (7 from 28 samples originally identified as type 1) and Burma (Myanmar) (1 of 3) but were not found in Hong Kong (n = 43), Macau (n = 8), Taiwan (n = 6), Singapore (n = 2), or Malaysia (n = 18). Although this small survey suggests a relatively limited distribution for type 6 group variants in SE Asia, larger studies will be required to explore their distribution in other geographical regions and the extent to which their presence would limit the practical usefulness of 5'NCR-based genotyping assays for clinical or epidemiological purposes.