Sensitivity of hepatitis B virus DNA transcription-mediated amplification testing in hepatitis B surface antigen-positive blood donations

BACKGROUND: The objective was to evaluate the performance of nucleic acid testing (NAT) in the detection of hepatitis B virus (HBV) infection in hepatitis B surface antigen (HBsAg)-positive blood donations. STUDY DESIGN AND METHODS: A total of 253 HBsAg- and anti-hepatitis B core antigen (HBc)-positive samples (50 hepatitis B e antigen [HBeAg]-positive and 203 anti-HBe-positive) from blood donations collected in France were studied. The samples were investigated with a blood screening assay (Procleix Ultrio, Chiron/Gen-Probe) in minipool (MP; x8) and in individual-donation (ID) testing. All nonreactive samples were retested once, and nonreactive MP samples were assayed for viral load (VL). RESULTS: All 50 HBeAg-positive samples were reactive in MP-NAT and ID-NAT. Of the 203 anti-HBe-positive donations, 80.3 percent were MP- and ID-reactive, 17.2 percent were MP-nonreactive and ID-reactive, and 2.5 percent were nonreactive in ID-NAT. Overall the sensitivity of ID-NAT was 98 percent versus 84 percent for MP-NAT. After retesting, 16 of the 35 MP-nonreactive and/or ID-reactive donations became MP-reactive and 2 of the ID-nonreactive donations became NAT-reactive. The capacity of Procleix Ultrio to detect HBV DNA was not related to HBsAg subtype, but correlated with the VL: the mean VL in the group of MP-nonreactive samples was 1,420 copies per mL vs. 17,000 copies per mL in the group of 40 MP-reactive samples. CONCLUSION: These results demonstrate that HBV-NAT in ID format is far more effective in detecting viremia in chronic HBsAg carriers than in MP-NAT. The sensitivity of the NAT assay needs to be improved to be considered for replacing the current HBsAg assays, especially when anti-HBc testing is not performed.     

Discontinuation of lamivudine treatment for hepatitis flare after kidney or heart transplantation in hepatitis B surface antigen-positive patients: A retrospective case series

BACKGROUND: Limited data are available on the clinical course of hepatitis B virus (HBV) infection after discontinuation of lamivudine prescribed for kidney or heart posttransplantation hepatitis flare OBJECTIVE: The purpose of this study was to investigate the reasons for discontinuation, subsequent reappearance of HBV DNA, and mortality in heart and kidney transplant recipients who discontinued lamivudine treatment. METHODS: This retrospective case series followed up male and female hepatitis B surface antigen (HBsAg)-positive Taiwanese transplant recipients from the National Taiwan University Hospital, Taipei, Taiwan, between July 1989 and January 1999. Biochemical, virologic, and serologic parameters and liver-related mortality of patients who discontinued lamivudine 100 mg QD prescribed for posttransplantation hepatitis flare were compared with those in a group of patients who continued use of lamivudine administered for the same indication over the same period of time. Serum HBV DNA levels were checked in all patients before and after discontinuation of lamivudine, and after resumption of lamivudine treatment and in patients with breakthrough hepatitis flare. RESULTS: A total of 39 HBsAg-positive transplant recipients (mean [SD] age, 45 [10.0] years) were identified during regular follow-up visits. Nine patients discontinued lamivudine use; 11 patients who continued it were selected as a control group. No significant between-group differences were observed in mean (SD) age (46 [14.0] vs 45 [6.9] years), sex (men/women,vs 1), type of transplant received (heart/kidney,vs ), or pretransplantation liver function test results. The reasons for discontinuation were informed patient decision (4 patients); YMDD mutation (2); self-discontinuation without physician consultation (2); and pregnancy (1). Of those who discontinued lamivudine, serum HBV DNA was undetectable at a mean of 30 (range, 9-47) months' follow-up in 6 (66.7%) of 9 patients. Lamivudine treatment was resumed in 3 patients on reappearance of HBV DNA, and a subsequent rapid decline in the serum HBV DNA was observed. The liver-related mortality rate was not significantly higher in patients who discontinued treatment compared with continuously treated patients (both, 0%). The between-group difference in overall mortality rates was not significant (22.2% and 18.2%, respectively). CONCLUSIONS: This case series illustrated a variety of clinical situations in which discontinuation of lamivudine treatment prescribed for posttransplantation hepatitis flare may occur. However, liver-related mortality was not increased in these patients compared with those who continued lamivudine treatment.     

Epidemiology of hepatitis B in Canadian blood donors

BACKGROUND: The residual risk of hepatitis B is higher than for other markers such as human immunodeficiency virus and hepatitis C virus in nonendemic countries. Evaluating the potential for further risk reduction requires a better understanding of the relationship between donor selection criteria, immigration from endemic countries, and public health vaccination strategies. STUDY DESIGN AND METHODS: Age and sex trends of hepatitis B surface antigen (HBsAg)‐positive donors from 1997 to 2006 were analyzed using a Poisson model. All HBsAg‐positive donors in 2005/2006 plus four matched control donors for every HBsAg‐positive donor who participated were invited to participate in a risk factor interview and predictors of HBsAg positivity identified by logistic regression. A survey of 40,000 donors who did not react for all markers asked about vaccination history and country of birth. RESULTS: Most HBsAg‐positive donations were from first‐time donors (86%), have been decreasing in donors under the age of 30 (p < 0.01), and were correlated with geographic regions with more donors from higher‐prevalence countries (p < 0001). Birth in a higher‐prevalence country predicted HBsAg positivity (p < 0.01). Fifty‐six percent of donors reported being vaccinated for hepatitis including approximately 80 percent of donors under age 30 who reported being vaccinated as part of regular school programs. CONCLUSION: HBsAg‐positive donations are decreasing in donors under age 30, those most frequently vaccinated through provincial vaccination programs. HBsAg‐positive donations largely reflect immigration from high‐prevalence countries without other deferrable risk factors, mainly chronic cases that will be detected by current testing. Furthermore, risk of incident infections should decrease with increasing vaccination rates in donors, especially the younger cohort now receiving universal vaccination.     

Lengths of hepatitis B viremia and antigenemia in blood donors: preliminary evidence of occult (hepatitis B surface antigen-negative) infection in the acute stage

BACKGROUND: The Japanese Red Cross (JRC) implemented a fully automated pooling and nucleic acid amplification test (NAT) system for testing seronegative donations. The JRC sample repository and repeat blood donations allowed for lookback and follow-up studies of hepatitis B virus (HBV) DNA-positive donors, who tested negative for hepatitis B surface antigen (HBsAg) and anti-hepatitis B core antigen in the JRC screening system. STUDY DESIGN AND METHODS: From February 1, 2000, to March 31, 2003, 17,314,486 units were tested in 50-sample pools with a semiautomated multiplex assay system (AMPLINAT MPX test, Roche). During this period, 328 HBV DNA-positive donations were found. From 26 of these donors, sequential samples were available at short intervals. This enabled us to examine the dynamics of viral markers in acute HBV infection. The length of detectable periods of plasma viremia and antigenemia were estimated by regression analysis from the results obtained in the quantitative polymerase chain reaction assay (JRC) and HBsAg enzyme immunoassay (Auszyme II, AxSYM, Abbott) and chemiluminescence immunoassay (Abbott). RESULTS: The median length of detectable HBV DNA in individual donation and 20-sample minipool (MP) NAT format was estimated to be 74 and 50 days, respectively, whereas the median length of detectable HBsAg was estimated to be 42 days. Six of the 26 donors were infected with mutant viruses, and 3 of these 6 donors did not develop detectable HBsAg during the entire observation period, despite a moderately high viral load of 10(4) to 10(5) HBV DNA copies per mL. CONCLUSION: Transmission of mutant virus may cause occult HBV infection in the acute stage. HBV NAT, even in MP configuration, is more effective than HBsAg testing and capable of interdicting infected donors in the pre- and post-HBsAg window periods.     

Improved detection of hepatitis B surface antigen (HBsAg) in blood donors by monoclonal radioimmunoassay

We evaluated the performance of a monoclonal radioimmunoassay (M-RIA) with enhanced sensitivity and high specificity for hepatitis B surface antigen (HBsAg) in blood donors. The results were compared to a conventional RIA that used polyvalent antibodies (P-RIA). Analysis of 6409 American blood donors not reactive by P-RIA revealed an additional 1.4 HBsAg-positive donors per 1000 by M-RIA, or an approximate 60 percent, improvement in HBsAg detection rate. Furthermore, in 995 Israeli blood donors negative by P-RIA, 11 additional HbsAg-positive donors were identified. The 55 percent improvement in detection rate was similar to that observed with American blood donors. Since several of the newly identified HBsAg-positive blood donors had antibodies to the core antigen (anti-HBc) as the only serologic evidence of recent or past hepatitis B exposure, we studied an additional 68 anti-HBc-positive individuals with the M-RIA. It was found that 26 percent (18/68) reacted only by M-RIA and not by P-RIA. These findings suggest that there are blood donors with HBsAg undetectable by P-RIA.     

献血者血液乙型肝炎病毒表面抗原确认试验

目的 对使用国产HBsAg酶联免疫吸附试验(ELISA)一步法试剂盒检测无偿献血者血液(包括机采血小板献血体检者)的可靠性进行评价.方法 对无偿献血者血液样品,使用国产的HBsAg酶联免疫吸附试验(ELISA)试剂盒进行测定.结果 呈阳性反应者、3种试剂检测结果不一致的部分可疑结果者和3种试剂检测为阴性者,使用珠海丽珠试剂公司研发的乙型肝炎病毒表面抗原(HBsAg)确认试剂盒(中和试验法) 初步进行确认试验.确认试验方法参照丽珠公司提供的说明书进行.结果 132例样品中阳性反应或可疑阳性反应者123例被确认为阳性者106例,其中有17例可疑结果者常规确认试验结果为"阴性".经3种试剂再测,结果仍为可疑.9例0.074≤样品A值＜Cut off的样品和随机抽取的9例阴性样品常规确认试验结果仍为阴性.8例单一试剂呈阳性反应者常规确认为假阳性.结论 国产HBsAg ELISA试剂测定结果为阳性、弱阳性和可疑的样品应使用适当方法进行确认,排除假阳性,以保证结果准确.目前国产HBsAg酶联免疫吸附试验(ELISA)一步法试剂盒有较高的灵敏度,特异性尚待提高.     

Prevalence of antibodies to hepatitis B core antigen and occult hepatitis B virus infections in Korean blood donors

BACKGROUND: This study was performed to determine the prevalence of antibodies to hepatitis B core antigen (anti‐HBc) among Korean blood donors and frequencies of hepatitis B virus (HBV) DNA and antibodies to hepatitis B surface antigen (anti‐HBs) in anti‐HBc–positive donors. STUDY DESIGN AND METHODS: A total of 12,461 consenting blood donors were consecutively enrolled from Korean Red Cross Blood Services from April to October 2008. All of the donors were screened for anti‐HBc with an electrochemiluminescence immunoassay. Repeat‐reactive anti‐HBc–positive donors were assayed for anti‐HBs and for HBV DNA using a multiplex test (Cobas TaqScreen, Roche Molecular Systems) on individual donation. RESULTS: Of the 12,461 donors, 1682 (13.5%) were reactive for anti‐HBc. Among different age groups, there was a steady increase in the anti‐HBc–positive rate, ranging from 2.0% in the age group of less than 20 years to 80.0% in the age group of 60 years and older (p < 0.0001). Of the anti‐HBc–positive donors, 1523 (90.5%) were anti‐HBs positive. HBV DNA was detected in two donors who were anti‐HBc positive and hepatitis B surface antigen negative. The prevalence of occult HBV infection was 0.016%, and the HBV nucleic acid test (NAT) yield was 1 in 838 (0.12%). CONCLUSION: This study helps to determine the current status of hepatitis B infection and the prevalence of occult HBV infection in the blood donor population in Korea. We estimate that in Korea, up to 161 units per million donated units from blood donors may contain HBV DNA. Although the potential infectivity of these units has been debated upon, the HBV NAT assay could prevent certain transfusion‐transmitted HBV infections.     

Antibody to hepatitis B core antigen in blood donors with a history of hepatitis

Sera and questionnaires from 3,230 prospective U.S. volunteer blood donors were obtained in an earlier study to determine the prevalence of serologic markers of hepatitis B virus (HBV) and hepatitis A virus (HAV) among prospective blood donors with or without a history of either hepatitis or blood transfusion. These sera were reevaluated using a radioimmunoassay for antibody to hepatitis B core antigen (anti- HBc). Anti-HBc in the absence of hepatitis B surface antigen (HBsAg) or its antibody (anti-HBs) was detected in 30 of 1,151 (2.6%) prospective donors with a history of hepatitis, compared to four of 1,086 (0.4%) with no history of hepatitis (p less than 0.001). Although end-point dilution titers of anti-HBc greater than or equal to 1:100 and the presence of IgM anti-HBc were more frequently detected among donors with a history of hepatitis than among donors with no history of hepatitis, the difference was not statistically significant. Unlike a history of hepatitis, a history of transfusion or a history of exposure to persons with hepatitis had no significant association with the detection of anti-HBc in the absence of other HBV serologic markers.     

Seroprevalence of hepatitis B surface antigen (HBsAg) among first-time and sporadic blood donors in Greece: 1991-1996

Hepatitis B surface antigen (HBsAg) seroprevalence among three major groups of sporadic voluntary blood donors in Greece was studied and compared to the seroprevalence in regular donors. These three groups share many characteristics with the general population. A 6-year retrospective seroepidemiological study was carried out (1991-1996). The study population consisted of donors who were (i) military recruits (n = 80 302), (ii) enlisted military personnel (n = 86 920) and (iii) directed family donors (n = 75403). A specimen was considered as HBsAg positive when found repeatedly reactive by a 3rd-generation immunoassay and confirmed by RIA. The Mantel-Haenszel chi2 procedure was used for stratified analysis of the prevalence rates and Greenland/Robins confidence intervals of the respective weighted relative risk (MHRR) were calculated. The 6-year overall HBsAg seroprevalence among the three sporadic donor groups was 0.84%; this was twice the seroprevalence among a sample of regular donors (n = 45504) in Greece. Seroprevalence was higher among enlisted personnel (1.21 < MHRR = 1.34 < 1.50), during years prior to 1995. Directed family donors had the same overall seropositivity rate as recruits and enlisted personnel. After 1995, all groups had a seroprevalence below 1%, possibly indicating a shift towards lower endemicity in the Greek population.     

上海地区献血人群免疫球蛋白A缺乏调查

目的筛查免疫球蛋白缺乏症(IgAD)患者,了解上海地区献血者中IgAD缺乏频率,以预防IgA输血过敏反应风险发生。方法采用IgA完全缺乏检测标准(IgA含量<0.05 mg/dl),以ELISA法对上海地区22 609名健康献血者的血清标本作初步筛查,IgAD者再用凝胶免疫法确认,同时对IgAD标本作抗-IgA检测。结果在22609份健康献血者标本中,有7例确认为IgA含量<0.05 mg/dl,由此推算出上海地区献血人群完全IgAD缺乏比例为0.031%(7/22 609);另有7例血清IgA含量在(0.39~3.70)mg/dl,表现为相对IgAD。在这14例IgAD(IgA<5mg/dl)标本中鉴定出2例含抗-IgA。结论上海地区健康献血者中IgA缺乏发生频率介于日本人种与高加索人种之间,但对IgAD者的输血仍存在潜在的风险,需要采取一定措施预防和规避输血过敏反应的发生。     

A nationwide survey for hepatitis E virus prevalence in Japanese blood donors with elevated alanine aminotransferase

BACKGROUND: Although we reported two cases of transfusion‐transmitted hepatitis E in Japan, the prevalence of hepatitis E virus (HEV) in Japanese blood donors is not very clear. STUDY DESIGN AND METHODS: Blood samples of donors who were deferred from donation because of elevated alanine aminotransferase (ALT) levels were collected from all Japanese Red Cross Blood Centers and subjected to HEV tests. RESULTS: Among the 41 donors with elevated ALT levels higher than 500 IU per L in Hokkaido, HEV RNA was detected in 8 (19.5%) samples. In 1389 donor samples with ALT levels of higher than 200 IU per L in nationwide Japan, the numbers of positive HEV RNA, immunoglobulin M (IgM) anti‐HEV, and immunoglobulin G (IgG) anti‐HEV samples were 15 (1.1%), 14 (1.0%), and 45 (3.2%), respectively. Although RNA‐positive donors were predominantly male and found in any geographic area of Japan, they tended to be higher in number in eastern Japan including Hokkaido and lower in number in western Japan. Of the 23 HEV‐positive samples, 19 were Genotype 3 and 4 were Genotype 4. DNA sequences of the 9 isolates showed more than 98.5 percent homology with the known swine HEV isolates. In 1062 donor samples with ALT levels of 61 to 199 IU per L, the percentages of IgM and IgG anti‐HEV–positive samples were 0.1 and 2.7 percent, respectively, although there was no HEV RNA–positive sample. CONCLUSION: HEV markers (HEV RNA and anti‐HEV) were detected in donors with elevated ALT levels who were widely distributed over Japan. The prevalence and incidence were higher in eastern Japan than in western Japan.