Studies on hepatitis C virus infection in haemodialysis patients]

To examine the prevalence of hepatitis C virus (HCV) in haemodialysis patients without blood transfusion in Hiroshima Prefecture, antibody to HCV (anti-HCV) was studied by the Ortho ELISA Kit in sera from 393 consecutive haemodialysis patients and in sera from 510 age and sex matched healthy members of the general population (control). An additional confirmatory test was done by a recombinant immunoblot assay. 1) Anti-HCV was detected in 70 of the 393 dialysis patients and 3 of the 510 healthy controls (17.8% vs 0.6%, p less than 0.01). Prevalence of anti-HCV in haemodialysis patients sera was increased by the volume of blood transfusion, and even in dialysis patients who had no blood transfusion, the frequency of anti-HCV positivity (9.2%) was greater than the healthy controls (p less than 0.01). Thus, the major route of HCV transmission in haemodialysis patients without blood transfusion may be via the haemodialysis treatment. 2) The prevalence of anti-HCV increased significantly with the ALT level and abnormal ALT activity of the anti-HCV positive group were significantly greater than that of the negative group. Thus, it is suggested that HCV infection may be an etiologic factor of liver dysfunction in haemodialysis patients.     

输血后丙型肝炎的回顾性研究

用酶免疫法（ＥＩＡ）检测１９８４年１０月至１９８５年２月在我院接受输血的９２例患者冻存血清中的抗ＨＣＶ，结果发现输血后丙型肝炎（临床型ＨＣＶ感染）３例，亚临床ＨＣＶ感染１１例，故ＨＣＶ总感染率为１５．２％，临床型ＨＣＶ感染占总ＨＣＶ感染的２１．４％；这１４例受血者抗ＨＣＶ的检出率在受血后１～２个月，３～４个月和５～６个月分别为２８．６％，５７．２％和１００％。用巢式逆转录－聚合酶链反应（ＲＴ－ＰＣＲ）的方法检测这１４例受血者抗ＨＣＶ阳转前１个月的血清，发现有８例ＨＣＶ－ＲＮＡ阳性（５７．１％），ＨＣＶ－ＲＮＡ最早可在受血者输血第一个月的血清中检测到。用ＥＩＡ法检测同期献血员冻存血清标本４００份，发现抗ＨＣＶ阳性者１１份（２．７５％）。这些结果提示我国献血员中ＨＣＶ感染率较高，受血者发生ＨＣＶ感染的危险性较大。因此，今后对献血员要进行抗ＨＣＶ的检测，以减少ＨＣＶ的传播。     

Prevalence and role of hepatitis C viraemia in haemodialysis patients in Japan

A second generation assay for antibody to hepatitis C virus (anti-HCV) was used in order to establish the exact prevalence of HCV infection in haemodialysis patients. HCV RNA was sought by the polymerase chain reaction in order to determine whether haemodialysis patients with anti-HCV had been infected with HCV in the past or were presently infected. Of 357 patients, 198 (55·5 %) were positive for anti-HCV, compared to 113 (31·7 %) positive for original antibody to c100-3 protein (P < 0·001). HCV RNA was detected in 171 (86·4 %) of the 198 patients with anti-HCV. Liver dysfunction was found in 63 (17·6 %) of all haemodialysis patients. Of these, 55 (87·3 %) had HCV infection, one (1·6 %) hepatitis B virus infection while, in the remaining seven, the origin was unknown. Thus, in almost all anti-HCV-positive patients, HCV viraemia was present. We conclude that HCV is an important cause of liver disease in haemodialysis patients.     

Prospective study in 142 cases of hepatitis C virus infection

AIM: There is limited information on the natural history ofHCV infection in China. We investigated the outcome ofHCV infection after nine-year follow-up and the risk factorsin blood donors in China in order to provide the foundationfor prevention and therapy.METHODS: A total of 172 cases of HCV infection with anti-HCV positive and ALT abnormality were enrolled in thearchives when was screened blood in Hebei Province in1993. In them 142 blood donors were followed up till July2002. No antiviral treatment was applied to them duringthe period of infection. In the present study, anti-HCV, HCV-RNA and aminotransferase were detected and genotypingwas conducted by the method of restriction fragment lengthpolymorphism(RFLP). B-type ultrasound detection wasperformed in all the patients. Age, sex, alcohol consumptionand clinical symptoms were questioned.RESULTS: After nine years‘ follow-up, 10.56% (15/142)of the cases were negative for anti-HCV and 16.42% (12/134)of them were negative for HCV-RNA. The genotypes lb,2a and lb/2a were 91.07%, 6.25% and 2.68% respectively.Twelve cases (8.45%) were negative for both HCV RNAand anti-HCV. The rate of chronicity in this group was83.58% (112/134), and the rate of viral spontaneousresolution was 16.42% (22/134). The mean level of ALT,AST, y-GT in HCV RNA positive cases was significantlyhigher than that in HCV RNA negative cases (P&lt;0.001).The abnormal rate of ALT and/or AST in male donors wassignificantly higher than that in female donors (P = 0.005).The rate of progression to liver cirrhosis from chronic hepatitisC was significantly higher in the cases of super-infectionwith HBV than that in the cases of single HCV infection.Overdose alcohol consumption promoted the progressionto chronicity.CONCLUSION: This area (Hebei Province) has a higherrate of chronicity in HCV infection, and measures shouldbe taken to prevent its progression to serious liver diseases,especially for patients super-infected with HCV and HBV.     

河北省某县有偿献血丙型肝炎病毒感染者血清抗-HIV检测分析

目的：调查并分析河北省某县有偿献血员中丙型肝炎病毒(HCV)感染者艾滋病病毒Ⅰ型(HIV-1)感染情况。方法：采用实时定量聚合酶链反应(PCR)和酶联免疫吸附试验(ELISA)法等检测了抗-HCV、HCV核糖核酸(RNA)和抗-HIV。结果：共检测109例受HCV感染的献血员，其中ALT异常者为38．53％(42／109)，抗-HCV阳性率为95．41％(104／109)，HCV RNA阳性率为70.64％(77／109)，抗-HIV阳性率为0(0／109)。结论：在该县有偿献血HCV感染者中HIV-1感染率为0，HCV感染者中HIV-1感染存在地区差异，并非所有地区HCV感染者HIV感染率均高。     

Superinfection of TT virus and hepatitis C virus among chronic haemodialysis patients

BACKGROUND: The TT virus (TTV), a new DNA virus found in Japan from a patient with post-transfusion hepatitis non-A-non-G, is frequently positive in the sera of patients with liver disease. It is not established whether this virus causes liver damage. We studied the frequency of superinfection of this virus and hepatitis C virus (HCV) known to be endemic among haemodialysis patients, and the possible deleterious effect of TTV on HCV-induced chronic liver disease. METHODS: We used primers from a conservative region in the TTV genome (Okamoto, 1998) to detect TTV. Sera from 163 dialysis patients positive for anti-HCV and 77 dialysis patients negative for anti-HCV (control) were tested. RESULTS: TT Virus positivity was 35% among HCV antibody (anti-HCV)-positive patients and 45.4% among anti-HCV-negative patients. TT Virus positivity was unrelated to the length of haemodialysis or amounts of blood the patients had received in the past. More anti-HCV-positive patients had a history of transfusion, but TTV positivity was not as closely associated with transfusion as anti-HCV positivity. The severity of chronic liver disease was estimated from peak serum alanine aminotransferase levels in the preceding 6 months. Among anti-HCV positives, TTV-positive patients tended to have less active disease; at least there was no indication that TTV superinfection aggravated chronic hepatitic C in long-term dialysis patients. Four of 35 anti-HCV-negative, TTV-positive patients had chronic active liver disease, while none of the anti-HCV-negative and TTV-negative patients did. CONCLUSIONS: TT Virus infection is prevalent among haemodialysis patients. Its transmission occurs not only by blood transfusion, but also by non-parenteral infection. Superinfection of TTV does not exert deleterious effects on the liver disease induced by HCV. However, it may cause chronic hepatitis in a limited number of patients, but remains dormant most of the time. Triple infection, HCV and TTV plus HBV or HGV (one case each), did not cause severe liver disease.     

HCV RNA in serum of asymptomatic blood donors involved in post-transfusion hepatitis (PTH).

A group of blood donors involved in post-transfusion hepatitis was investigated for the presence of the anti-HCV antibody and of HCV RNA as a more direct infection marker. RNA was extracted from serum, reverse transcribed and amplified using primers which belonged to the non structural region. The amplified product of the PCR reaction was 582 base pairs. Seven (25.9%) of the 27 blood donors examined were found anti-HCV-positive by ELISA; five (71.4%) of these were HCV RNA positive. Among the 20 anti-HCV-negative blood donors, four (20.0%) were HCV RNA positive. ALT levels were below 45 UI/l in 18 donors, while the other nine had ALTs over the limit accepted for transfusion. The anti-HCV-negative HCV RNA-positive blood donors had normal ALTs. Our study offers a direct explanation for the substantial proportion of residual cases of anti-HCV-positive post-transfusion hepatitis and suggests the necessity of creating a register of blood donors who have at some time presented blood enzyme abnormalities and for whom second level investigations such as HCV RNA should be used.     

Prevalence of hepatitis C infection and risk factors in hospitalized diabetic patients: results of a cross-sectional study

OBJECTIVES: Although there may exist a nosocomial risk of hepatitis C virus (HCV) infection in patients with type 1 or type 2 diabetes, this risk has not been fully investigated thus far and its magnitude is unknown. The aim of this multicenter cross-sectional study was to evaluate the prevalence of, and risk factors for, hepatitis C infection in consecutive hospitalized patients with diabetes and to assess the nosocomial risk and magnitude of HCV infection in these patients. PATIENTS AND METHODS: Consecutive hospitalized patients with diabetes seen in 11 French hepatogastroenterology and diabetology departments were studied. The prevalence of anti-HCV antibodies was compared with that observed in healthy blood donors and individuals seen during routine medical checkup. Diabetic patients with anti-HCV antibodies were compared with patients without anti-HCV antibodies for assessment of risk factors. RESULTS: In total 1561 patients were studied. Independent risk factors for HCV infection were assessed through multivariate analysis. Thirty-three patients (2.11%) had anti-HCV antibodies and 21 (63.70%) had HCV identified risk factors. The prevalence of HCV infection was higher in patients with diabetes than in blood donors (0.08%) or healthy controls (0.20%) (P<0.001). Multivariate analysis identified four independent risk factors for HCV infection: blood transfusion before 1991 [odds ratio (OR)=2.88, P=0.033], intravenous drug use (OR=21.37, P=0.012), treatment in a hepatogastroenterology center (OR=4.17, P=0.002) and a high number (>2) of previous admissions since the onset of diabetes (OR=2.52, P=0.039). CONCLUSION: A nosocomial source of HCV infection in hospitalized diabetic patients is suggested by the increased risk of HCV infection associated with the number of hospitalizations. This may account for at least 36% of cases of HCV infection.     

The distribution of hepatitis C virus genotypes in Turkish patients

Summary. The distribution of hepatitis C virus (HCV) genotypes was investigated in 89 HCV-infected Turkish patients. Blood samples were collected from haemodialysis patients ( n = 45), chronic liver disease (CLD) patients ( n = 38), acute non-A, non-B (NANB) hepatitis patients ( n = 2) and blood donors ( n = 4). HCV RNA sequences were amplified in the 5" non-coding region and were typed by restriction fragment length polymorphism analysis. The predominant genotype was 1b (75.3%), followed by 1a (19.1%), 2 (3.4%) and 4 (2.2%). While there was no significant difference in the distribution of HCV genotypes with respect to age, sex, transfusion history, alanine aminotransferase levels or liver histology (in the CLD group), type 1a-infected patients were younger than type 1b-infected patients ( P < 0.05) in the haemodialysis group. Serological reactivity to recombinant HCV proteins was assessed in 58 samples using the Chiron RIBA-2 assay. The reactivity of samples from patients infected with type 1b with 5–1–1 and c100 antigens was significantly lower ( P < 0.05) than the reactivity of samples from those infected with type 1a. These results, together with the results of two previous studies, indicate that HCV genotypes 1, 2, 3 and 4 are prevalent in different frequencies in the Turkish population. Determination of the genotype distribution of HCV in a geographical area may provide important clues for studying the epidemiology, transmission and pathogenesis of HCV-related diseases and may also aid in improving serological assays to detect HCV infection.     

Occult hepatitis C virus infection among haemodialysis patients

Background and study aims

Hepatitis C virus (HCV) infection is a severe problem among patients on maintenance haemodialysis who are at particular risk for blood-borne infections because of prolonged vascular access and potential for exposure to contaminated equipment. Occult hepatitis C virus infection (OCI) is defined as the presence of HCV RNA in liver or peripheral blood mononuclear cells (PBMCs) in the absence of detectable HCV antibody or HCV RNA in the serum. In this study, we aimed to investigate the existence of occult hepatitis C virus infection in PBMCs of haemodialysis (HD) patients in one center. Moreover, we tried to link the condition to risk factors associated with HCV infection in those patients.

Hepatocellular carcinoma in Sweden: its association with viral hepatitis, especially with hepatitis C viral genotypes

Viral markers of chronic hepatitis were tested for in 95 frozen serum samples from 299 patients from Malm?, Sweden, with hepatocellular carcinoma (HCC), diagnosed between 1977 and 1994. Hepatitis B analysis included anti-HBc, HBsAg and, if anti-HBc positive, HBV DNA. Hepatitis C infection analysis included anti-HCV screening, RIBA, HCV RNA and HCV genotyping. HCV genotyping was also carried out in 9 HCV-viraemic HCC-patients from Gothenburg. HCV genotype distribution in HCC cases was compared with Swedish HCV-infected blood donors. Among the 95 patients from Malm?, 28 (29%) had anti-HBc, but only 5 (5%) were chronic HBV carriers, compared with 16 (17%) with chronic hepatitis C (p = 0.021). HCV-related HCC was more common among immigrants (8/16 vs. 8/79; p < 0.001). Genotyping of 25 HCV-infected cases showed genotype 1a in 6 (24%), genotype 1b in 13 (52%), genotype 2b in 4 (16%), and genotype 3a in 2 (8.0%) patients. Genotype 1b was more common among HCC patients than among blood donors (p < 0.001), but 8 of 13 genotype 1b-infected patients were from countries where genotype 1b is predominant. Among native Swedes there was no difference between the HCV genotypes infecting blood donors and those found in HCC patients.     

Epidemiology,serological markers,and hepatic disease of anti-HCV ELISA-2-positive blood donors

The epidemiology associated with hepatitis C virus (HCV) infection, serologic reactivity, and hepatic disease related to anti-HCV-positive donors of Granada were researched. From 1990 through 1993, medical and epidemiological information and anti-HCV and HCV RNA testing were evaluated in 46,741 blood donors. Serum samples were obtained for anti-HCV ELISA and RIBA and HCV RNA determination. A liver biopsy was conducted in all anti-HCV positives by confirmatory second-generation RIBA to analyze the hepatic lesion and the presence of HCV RNA. The anti-HCV prevalence was 1.12%. A total of 228 anti-HCV second-generation ELISA positive blood donors were analyzed. Intrafamiliar transmission rate was 1.7%. Transfusion and intravenous drug abuse (IVDA) antecedents were associated with a higher risk of seroconversion. A RIBA-positive result was related to high second- and third-generation ELISA ratios (90%), HCV RNA positivity (89%), and elevated alanine aminotransferase (ALT) levels (88%). Approximately 50% of donors with normal ALT levels had high ELISA ratios and second-generation RIBA and HCV RNA positive results. Of the second-generation RIBA indeterminate results, 42% and 82% of the c22 and 33% and 100% of the c100 reactivities were third-generation RIBA and HCV RNA positive, respectively. Liver biopsy was conducted in 85 donors, 74% of whom had a chronic hepatitis and 83% had detectable HCV RNA levels. Chronic hepatitis was diagnosed in 88% vs 43% of donors with elevated and normal alanine aminotransferase levels, respectively. ELISA and confirmatory HCV RNA determinations should be routinely employed in donor screening. A liver biopsy should be conducted in patients with elevated ALT levels and normal ALT levels when viremic.     

Incidence of Post-Transfusion Hepatitis before and after Screening for Hepatitis C Virus Antibody

To evaluate the effectiveness of screening test for antibody to hepatitis C virus (anti-HCV), the incidence of acute post-transfusion HCV infection in patients who underwent cardiovascular surgery and received blood transfusion was studied. All patients were followed prospectively with serum biochemistry tests and viral hepatitis markers before and periodically for at least 6 months after cardiovascular surgery. None of them had history of liver disease and none tested positive for anti-HCV prior to blood transfusion. Before blood donors were screened for anti-HCV with a second-generation HCV diagnostic kit, 28 (12.4%) of 226 patients or 0.49% of 5,690 unit transfusion had seroconverted to anti-HCV during a 6-month follow-up. The incidence of post-transfusion hepatitis (PTH) C in 91 patients who had received 1–12 units transfusion was significantly lower than in 135 patients who had received more than 12 units transfusion (6.6 vs. 16.3%, p<0.05). However, none of the 87 transfused patients, since anti-HCV screening in July 1992, developed PTH C (p<0.05). The result demonstrates that screening for anti-HCV by a more sensitive second-generation HCV diagnostic assay may protect the patients studied from PTH C. It further provides a firm argument for the necessity of a nation-wide blood donor screening.     

Frequency of the HIV-protective CC chemokine receptor 5-Delta32/Delta32 genotype is increased in hepatitis C

BACKGROUND & AIMS: A homozygous 32-base pair deletion in the CCR5 gene (CCR5-Delta32) protects against human immunodeficiency virus infection (HIV). However, the role of this mutation in other infections, such as hepatitis C virus (HCV) infection, has not been defined. METHODS: We determined the frequency of the CCR5-Delta32 mutation by polymerase chain reaction in anti-HCV(+) (n = 153), anti-HIV(+) (n = 102), and anti-HCV(+)/HIV(+) (n = 130) white patients as well as in 102 healthy blood donors. Then, HIV and HCV loads, aminotransferases, and CD4 and CD8 cell counts were compared between the resulting subsets of CCR5-Delta32/wild-type heterozygotes, CCR5-Delta32, and wild-type homozygotes, respectively. RESULTS: Twelve of 153 (7.8%) anti-HCV-seropositive patients and 1 of 102 (1.0%) healthy blood donors were CCR5-Delta32 homozygous, whereas CCR5-Delta32 homozygosity was absent in anti-HIV(+) and anti-HCV(+)/HIV(+) patients (P < 0.001). The frequency of the CCR5-Delta32 allele was higher in the anti-HCV(+) (16.0%, P < 0.05) and anti-HCV(+)/HIV(+) (12.7%, NS) patients than in healthy blood donors (8.3%) and anti-HIV(+) patients (9.3%), respectively. Anti-HCV(+) CCR5-Delta32 homozygotes occurred 3 times more frequently than expected from the Hardy-Weinberg equation (P < 0.0001) and had significantly higher HCV loads than wild-type patients (P = 0.045). CONCLUSIONS: The increased prevalence of CCR5-Delta32 homozygosity associated with increased viral loads in patients with chronic hepatitis C suggests that the CCR5-Delta32 mutation may be an adverse host factor in hepatitis C.     

慢性肝病与乙型,丙型肝炎病毒感染关系的探讨

采用ELISA法对25例慢性肝炎,105例肝硬化,64例肝癌以及8例急性黄疸型肝炎进行了HBV标志物及抗-HCV的检测.结果:HBV感染率为80.6%,抗-HCV检测阳性率为46%,二者均阳性的双重感染率为32%.其中肝癌组双重感染明显高于肝硬化组P<0.001.单纯抗-HCV检出率为10.8%,说明HBV是引起肝炎、肝硬化、肝癌的主要病因,而HCV感染也是致病因素.对有输血史的慢性肝炎、肝硬化、肝癌100例进行抗-HCV检测,其阳性率59%,而102例无输血史的肝病患者抗-HCV检出率为25%,输血组抗HCV检出率明显高于无输血组P<0.001.其中慢性肝炎、肝硬化、肝癌病人输血组抗-HCV检出率亦明显高于无输血组,各组P<0.001.故提示:HCV感染与输血有密切关系.50例HBV标志物阴性的健康献血员抗-HCV阳性率为6%.     

Seroepidemiology of hepatitis C and its risk factors in Khuzestan Province, South-West of Iran： A case-control study

AlM:To evaluate possible risk factors for the spread of hepatitis C infection and to analyze the characteristics of the epidemiological and clinical patterns among the patients with hepatitis C infection. METHODS: During a five-year period a cross-sectional study was conducted among HCV positive individuals referred to the Ahwaz JundiShapour University Hospitals (AJSUH) and Hepatitis Clinic from 1 Sept 1999 to 1 Sept 2003. The control group consisted of first time blood donors referred to the Regional Blood Transfusion organization. Enzyme-linked immunosorbent assay and recombinant immunoblot assay anti-hepatitis C virus (HCV) tests were performed for two groups. Positive serum specimens were retested using polymerase chain reaction (PCR) for HCV RNA. Risk factors were evaluated using a questionnaire. Reported risk factors among infected subjects ("HCV-positive") were compared to those of subjects never exposed ("HCV-negative") to HCV. RESULTS: A total of 514 subjects were studied for HCV, of which 254 were HCV-positive and 260 HCVnegative donors comprised the control group. Mean age of the patients was 28.4 (Std 15.22) years. HCV-positive subjects were more likely to be of male gender (63% versus 37%). Transfusion 132 (52%), non-intravenous (n-iv) drug abuse and iv drug abuse 37 (14.5%), haemodialysis 25 (10%), receiving wounds at war and extramarital sexual activities (2.4%), tattooing (3.6%) were found to be independent risk factors of being HCVpositive. No apparent risk factors could be demonstrated in 29 (11.2%) of the positive cases. CONCLUSION: Our data indicate that a history of transfusion and iv drug abuse and haemodialysis are important risk factors for HCV infection in our area and that more careful pretransfusion screening of blood for anti-HCV must be introduced in our blood banks. Improvements in certain lifestyle patterns, and customs in this area may be essential to prevent transmission of the infection.     

Anti-HCV in post-transfusion hepatitis: deductions from a prospective study

Stored sera from 52 patients who developed post-transfusion hepatitis (PTH) during a prospective study of PTH in Toronto in 1984/85, sera from 111 donors whose blood was transfused into these patients and sera from 50 patients with chronic active hepatitis with a remote history of blood transfusion were tested for anti-HCV. In patients with PTH seroconversion occurred relatively early. Ten converted in less than 14 weeks after transfusion. Only three of the 34 patients (9%) whose hepatitis resolved developed anti-HCV compared to 11 of 18 (61%) whose hepatitis became chronic. Patients who seroconverted had higher alanine aminotransferase (ALT) values during the phase of acute hepatitis than those who did not seroconvert. Most of the patients who developed PTH received blood that was negative for anti-HCV. Four donors whose blood was positive for anti-HCV transmitted hepatitis. Three of the patients developed anti-HCV and chronic hepatitis. One of the recipients did not seroconvert and the hepatitis resolved. Forty-two of the 50 patients (84%) with chronic hepatitis and a remote history of blood transfusion were positive for anti-HCV. We conclude that anti-HCV-positive donors may transmit hepatitis C; that if anti-HCV is diagnostic of hepatitis C, most cases of acute PTH are either not due to hepatitis C or may represent cases of hepatitis C in which the anti-HCV test was undetectable. On the other hand, most cases of PTH which progress to chronic hepatitis are caused by HCV.(ABSTRACT TRUNCATED AT 250 WORDS)     

Hepatitis C virus infection in patients with nonalcoholic chronic liver disease

STUDY OBJECTIVE: To determine the prevalence and meaning of antibodies to the hepatitis C virus (HCV) in patients with nonalcoholic chronic liver diseases. DESIGN: Cross-sectional study. SETTING: The liver unit of a referral-based university hospital. PATIENTS: Three hundred and forty-six consecutive patients, including 137 with cryptogenic chronic liver disease, 156 with chronic hepatitis B, 47 with primary biliary cirrhosis, and 8 with persistently abnormal aminotransferase serum levels and normal liver histology. Among patients with cryptogenic liver disease, 41 received blood transfusions before discovery of liver disease and 18 had circulating nonorgan-specific autoantibodies. For comparison, 1495 apparently healthy volunteer blood donors were included in the study. LABORATORY INVESTIGATIONS: The presence of anti-HCV antibodies (anti-HCV) was determined by a recently developed enzyme-linked immunoassay. MEASUREMENTS AND MAIN RESULTS: In patients with cryptogenic liver disease, the prevalence of anti-HCV was 82% (95% CI, 76% to 89%), being higher (P = 0.02) in patients with histories of blood transfusion than in those with unknown sources of exposure. Antibodies to HCV were not detected in patients with antinuclear antibodies at high titer. Among patients with chronic hepatitis B, anti-HCV were found in 11% (CI, 5% to 18%) of those with hepatitis B virus (HBV)-associated DNA in serum and in 29% (CI, 17% to 43%) of those with undetectable HBV replication (P less than 0.05). The prevalence of anti-HCV in blood donors was 1.2% (CI, 1.1% to 1.3%). CONCLUSIONS: Our results indicate that HCV infection probably plays an important etiologic role in cryptogenic liver disease and, in some patients, in chronic hepatitis B. Determining whether anti-HCV are present appears to be useful for differentiating viral from autoimmune chronic liver diseases.