Antibody to hepatitis B core antigen as a paradoxical marker for non-A, non-B hepatitis agents in donated blood

Challenge Inoculum for Hepatitis C Virus Controlled Human Infection Model

For any controlled human infection model (CHIM), a safe, standardized, and biologically relevant challenge inoculum is necessary. For hepatitis C virus (HCV) CHIM, we propose that human-derived high-titer inocula of several viral genotypes with extensive virologic, serologic, and molecular characterizations should be the most appropriate approach. These inocula should first be tested in human volunteers in a step-wise manner to ensure safety, reproducibility, and curability prior to using them for testing the efficacy of candidate vaccines.

Chronic Hepatitis C

Hepatitis C virus (HCV) infection contributes significantly to liver cirrhosis and hepatocellular carcinoma (HCC), often requiring liver transplantation. Introducing direct-acting antiviral agents (DAAs) has radically changed HCV treatment. DAAs achieve high rates of sustained virological response (>98%). Even then, resistant-associated substitution and HCC during or after treatment have become prominent clinical concerns. Further, several clinically significant issues remain unresolved after successful HCV eradication by DAAs, including treating patients with chronic kidney disease or decompensated liver cirrhosis. Extensive and large-scale screening and treatment implementation programs are needed to make DAA therapies effective at the population level.

Breakthroughs in hepatitis C research: from discovery to cure

In the 1970s, an unknown virus was suspected for documented cases of transfusion-associated hepatitis, a phenomenon called non-A, non-B hepatitis. In 1989, the infectious transmissible agent was identified and named hepatitis C virus (HCV) and, soon enough, the first diagnostic HCV antibody test was developed, which led to a dramatic decrease in new infections. Today, HCV infection remains a global health burden and a major cause of liver cirrhosis, hepatocellular carcinoma and liver transplantation. However, tremendous advances have been made over the decades, and HCV became the first curable, chronic viral infection. The introduction of direct antiviral agents revolutionized antiviral treatment, leading to viral eradication in more than 98% of all patients infected with HCV. This Perspective discusses the history of HCV research, which reads like a role model for successful translational research: starting from a clinical observation, specific therapeutic agents were developed, which finally were implemented in national and global elimination programmes.

Blood Product (Donor) Noninfectious and Infectious Testing and Modification

Blood transfusion begins with safe donor selection and testing. In the United States, the blood supply and transfusion are highly regulated. Blood transfusion safety is multifaceted, whereby each of the elements of the blood safety value chain, spanning donor recruitment and qualification, to collection, blood processing, testing, transfusion practice, and posttransfusion surveillance, must be optimized to minimize risk. Pathogen inactivation is a promising approach to decrease bacterial contamination of platelets, inactivate parasites and viruses, and decrease risks associated with emerging and unidentified pathogens. This article offers an overview of blood donor infectious and noninfectious testing in the United States.

Trends in Prevalence and Characteristics of Resolved and Current Hepatitis B Among US-Born Persons: National Health and Nutrition Examination Survey, 2001-2018

BACKGROUND

After decades of decline, US acute hepatitis B incidence flattened since 2011. In persons aged ≥40 years and in jurisdictions affected by the opioid crisis, there is an increase in new cases. Data suggest new infections are occurring among US-born persons.

METHODS

We used National Health and Nutrition Examination Survey data during 2001-2018 to examine changes in total antibody to hepatitis B virus core antigen (anti-HBc) prevalence in US-born persons. During 2013-2018, the distribution of characteristics was examined.

RESULTS

During 2001-2006, 2007-2012, and 2013-2018, anti-HBc prevalence was 3.5%, 2.5%, and 2.6% among US-born persons, respectively. This corresponded to 5.7 (range, 4.8-6.6) million US-born persons with resolved or current HBV infection during 2013-2018, including 344 600 persons aged 6-29 years. The largest increase and highest prevalence was among persons who reported injection drug use (IDU), which increased from 35.3% during 2001-2006 to 58.4% during 2013-2018 (P = .07).

CONCLUSIONS

Anti-HBc prevalence among US-born persons remained flat during the most recent period, coinciding with a doubling of prevalence among persons reporting IDU. These data are consistent with acute hepatitis B surveillance trends, showing increasing incidence in subpopulations where prevention could be strengthened.Anti-HBc prevalence among US-born persons decreased from 2001-2006 to 2007-2012 and remained flat during 2013-2018, coinciding with a near doubling of prevalence among US-born persons reporting a history of injection drug use.

The Emergence of Zoonotic Pathogens as Agents of Concern in Transfusion Medicine

A variety of emerging infections are of interest to transfusion medicine clinicians, but zoonotic pathogens, those maintained in nonhuman hosts and transmitted to humans, have dominated recent discussions, especially emerging acute viral infections that can or might spread around a shrinking globe with unprecedented speed, in an infected human or an infected vector or reservoir host. Further, advanced pathogen discovery techniques (e.g., metagenomics) allow the identification of potential pathogens before their recognition as clinically relevant to transfusion medicine. In the aftermath of our experiences with HIV and posttransfusion hepatitis, our windows for response to such agents and infections have contracted rapidly. These characteristics pose difficult challenges for our development of surveillance and control regimes capable of timely, but appropriately nuanced, responses. This monograph surveys a selection of such agents, exploring their apparent relevance to transfusion medicine, closing with a framework for an ongoing approach to their surveillance, recognition, threat evaluation, and mitigation.

Impact of Different Sources of Infection on Therapy Response in Chronic Hepatitis C

Introduction:

Prior to the 1990s, the most common sources of HCV infections were blood transfusions, unsafe injections and I.V drug use. Screening of blood products for HCV has eradicated transfusion-transmitted hepatitis C in most countries since 1992–in Bosnia and Herzegovina, however, since 1995, due to the war.

Aim:

To investigate the impact of the source of HCV infection on the therapeutic response in patients treated for chronic HCV infection with dual combined therapy.

Methods:

We diagnosed chronic HCV infections amongst 246 patients over a period of five years and selected them according to the reported source of infection. Pegylated interferon alfa 2a or alfa 2b with ribavirin was administered during the time that was genotype-dependent. HCV RNA levels in sera were measured by real time PCR. Liver histology was evaluated in accordance with the level of necroinflammation activity and the stadium of fibrosis.

Results:

Regardless of the genotype of the virus and the source of infection, SVR was achieved in 67% of the patients. Therapeutic response (ETR) was not achieved in 25% of the patients who were infected with an untested blood transfusion and 6% of the patients who had had wartime surgery. Amongst the different sources of infections, patients with a war-surgery source of infection responded better to therapy than those with a blood transfusion source of infection (p = 0.023). A blood transfusion source of infection implies a larger fibrosis stage than in blood donors; (g = 1.177; s² = 0.577). A blood transfusion source of infection implies a significantly larger necroinflammatory activity than in blood donors; (g = 1.456; s² = 0.618).

Conclusions:

An untested blood transfusion was a significant risk factor for more advanced liver diseases in regards to necroinflammatory activity and the fibrosis stage. This source of infection was also a risk factor for low responses to antiviral therapy. At the same time, I.V. drug users had more progressive necroinflammatory activity, but a high therapeutic response to antiviral therapy.

Searching for unknown transfusion-transmitted hepatitis viruses: a binational cohort study of 1.5 million transfused patients

BACKGROUND

Both hepatitis B and C viruses were transmitted through blood transfusion before implementation of donor screening. The existence of additional, yet unknown transfusion transmittable agents causing liver disease could have important public health implications.

METHODS

Analyses were based on the Scandinavian Donations and Transfusions (SCANDAT2) database. Cox regression models were used to estimate the hazard ratio (HR) of developing chronic liver disease in recipients of blood from donors who later developed any chronic liver disease compared to recipients who received blood transfusion from healthy donors. We also studied whether the risk of liver disease was increased in patients who received units from 'high-risk' donors, defined as donors who had a higher than expected occurrence of liver disease amongst their previous recipients. All analyses were stratified before and after 1992 to account for the effect of screening for hepatitis C virus.

RESULTS

A total of 1 482 922 transfused patients were included in the analyses. Analyses showed evidence of transfusion transmission of liver diseases before, but not after the implementation of hepatitis C virus screening in 1992, with HRs for any liver disease of 1.38 [95% confidence interval (CI), 1.30-1.46] and 0.99 (95% CI, 0.91-1.07), before and after 1992, respectively. Similarly, blood components from 'high-risk' donors conferred increased risks before, but not after 1992.

CONCLUSIONS

Our data provide no evidence for transfusion transmission of agents causing liver disease after the implementation of screening for hepatitis B and C, and suggest that if such transmission does occur, it is rare.

Transfusion-Transmitted Infections: an Update on Product Screening, Diagnostic Techniques, and the Path Ahead

The mandated testing of blood components for infectious diseases, to prevent transfusion-transmitted infections (TTIs), began in the 1950s. Since then, changes in predonation questionnaires and advances in testing techniques have afforded more sensitive and specific tests for pathogens, in addition to allowing earlier detection. Given that these approaches have very low but detectable failure rates, the recent development and implementation of proactive pathogen reduction approaches is the new forefront of TTI prevention strategies. With globalization and the ability of pathogens to evolve rapidly, continuous redefining of testing standards and laboratory techniques is paramount for maintaining a safe blood supply.

Hepatitis C virus: Morphogenesis, infection and therapy

Hepatitis C virus (HCV) is a major cause of liver diseases including liver cirrhosis and hepatocellular carcinoma. Approximately 3% of the world population is infected with HCV. Thus, HCV infection is considered a public healthy challenge. It is worth mentioning, that the HCV prevalence is dependent on the countries with infection rates around 20% in high endemic countries. The review summarizes recent data on HCV molecular biology, the physiopathology of infection (immune-mediated liver damage, liver fibrosis and lipid metabolism), virus diagnostic and treatment. In addition, currently available in vitro, ex vivo and animal models to study the virus life cycle, virus pathogenesis and therapy are described. Understanding of both host and viral factors may in the future lead to creation of new approaches in generation of an efficient therapeutic vaccine.

Chronic hepatitis C virus infection and neurocognitive function in adult survivors of childhood cancer

BACKGROUND

Cancer survivors transfused with blood products before reliable screening for hepatitis C virus (HCV) are at risk for infection. This study examined the impact of HCV on neurocognitive function and health-related quality of life (HRQOL) among adult survivors of childhood cancer.

METHODS

Neurocognitive testing was conducted for 836 adult survivors of childhood cancer (mean age, 35 years [standard deviation, 7.4 years]; time since diagnosis, 29 years [standard deviation, 6.2 years]) who received blood products before universal HCV screening. No differences were observed between confirmed HCV-seropositive survivors (n = 79) and HCV-seronegative survivors (n = 757) in the primary diagnosis or neurotoxic therapies. Multivariate regression models were used to compare functional outcomes between seropositive and seronegative survivors.

RESULTS

Compared with seronegative survivors, seropositive survivors demonstrated lower performance on measures of attention (P < .001), processing speed (P = .008), long-term verbal memory (P = .01), and executive function (P = .001). After adjustments for sex, age at diagnosis, and treatment exposures, seropositive survivors had a higher prevalence of impairment in processing speed (prevalence ratio [PR], 1.3; 95% confidence interval [CI], 1.1-1.6) and executive functioning (PR, 1.3; 95% CI, 1.1-1.6). Differences were not associated with the treatment of HCV or the presence of liver cirrhosis. Seropositive survivors reported worse general HRQOL (PR, 1.6; 95% CI, 1.2-2.1), which was associated with the presence of liver cirrhosis (P = .001).

CONCLUSIONS

Survivors of childhood cancer with a history of HCV infection are at risk for neurocognitive impairment and reduced HRQOL beyond the known risks associated with neurotoxic cancer therapies. Cancer 2017;123:4498-505. © 2017 American Cancer Society.

Occult Hepatitis Infection in Transfusion Medicine: Screening Policy and Assessment of Current Use of Anti-HBc Testing

HBV still represents a global risk factor in transfusion medicine. The residual risk of HBV is not limited to pre-seroconversion window period but it extends to donors with occult HBV infection (OBI) characterized by the presence of HBV DNA in liver and by the absence of the virus surface antigen. Each country developed an appropriate blood screening policy according to local HBV prevalence, yields of infectious units per different screening methods and cost-effectiveness. We underline the need of maintaining a high level of attention for OBI carrier identification in all blood banks worldwide where the screening procedures are generally based on a combination of both serological markers and nucleic acid amplification test. In this context, markers such as hepatitis B surface antibodies and hepatitis B core antibodies (anti-HBc) might be useful, although the use of this latter is highly debated and still controversial. Our aim is to give an overview on the relevant diagnostic approaches for the routine screening for HBV focusing on the feasibility of anti-HBc testing as precautionary measure in preventing OBI transmission worldwide. In our tailored algorithm, the loss of about 1% of 'anti-HBc only' donors, does not significantly affect the blood supply while improving recipient safety.

Use of an HBV-DNA Hybridization Assay in the Evaluation of Equivocal Hepatitis B Virus Tests in Solid Organ Donors

Context

Serological markers for the hepatitis B virus are routinely used in the evaluation of potential organ donors. However, serological tests can be associated with significant false or equivocal results and may not be indicative of the true risk of hepatitis B infection. Studies have recently questioned the significance of an isolated hepatitis B core antibody test in evaluating the suitability of solid organs for transplantation. The ability to detect hepatitis B virus DNA may prove useful when the diagnosis of hepatitis B infection is in doubt.

Design

Serum samples from 16 donors with equivocal or positive hepatitis B core antibody and/or hepatitis B surface antigen serological screening tests were retrospectively tested for the presence of hepatitis B DNA. Any available follow-up data on the placement of organs from these donors was obtained.

Results

One of the 16 (6.3%) donors tested positive for the presence of hepatitis B DNA, but organs from this donor were not recovered or transplanted. Follow-up on 14 organs recovered and transplanted from 6 donors in this group did not show clinical and/or laboratory evidence of hepatitis B infection in the recipients.

Conclusions

In our donor population, there was a low incidence (6.3%) of donors with equivocal or positive hepatitis B core antibody and/or hepatitis B surface antigen serological screening tests who subsequently demonstrated the presence of detectable hepatitis B DNA. Posttransplantation follow-up of the recipients of 14 recovered organs failed to demonstrate any cases of posttransplant hepatitis B infection.

Transfusion-associated hepatitis before the screening of blood for hepatitis risk factors

BACKGROUND

The true incidence of transfusion-associated hepatitis (TAH) before blood screening is unknown. Our aims were to reevaluate blood recipients receiving unscreened blood and analyze hepatitis viruses circulating more than 45 years ago.

STUDY DESIGN AND METHODS

Cryopreserved serum samples from 66 patients undergoing open heart surgery in the 1960s were reevaluated with modern diagnostic tests to determine the incidence of TAH and its virologic causes.

RESULTS

In this heavily transfused population receiving a mean of 20 units per patient of predominantly paid-donor blood, 30 of 66 (45%) developed biochemical evidence of hepatitis; of these, 20 (67%) were infected with hepatitis C virus (HCV) alone, four (13%) with hepatitis B virus (HBV) alone, and six (20%) with both viruses. Among the 36 patients who did not develop hepatitis, four (11%) were newly infected with HCV alone, nine (25%) with HBV alone, and one (3%) with both viruses. Overall, 100% of patients with hepatitis and 39% of those without hepatitis were infected with HBV and/or HCV; one patient was also infected with hepatitis E virus. The donor carrier rate for HBV and/or HCV was estimated to be more than 6%; contemporaneously prepared pooled normal human plasma was also contaminated with multiple hepatitis viruses.

CONCLUSION

TAH virus infections were a larger problem than perceived 50 years ago and HCV was the predominant agent transmitted. All hepatitis cases could be attributed to HCV and/or HBV and hence there was no evidence to suggest that an additional hepatitis agent existed undetected in the blood supply.

Paul Holland: contributions to transfusion medicine

Paul Holland began his career in transfusion medicine in 1963 as an assistant to Dr. Paul Schmidt in the Blood Bank at the National Institutes of Health (NIH). He served at the NIH for 20 years and retired in 1983 with the rank of Captain in the Public Health Service. He subsequently became the Medical Director/CEO of the Sacramento Medical Foundation Blood Center, now Blood Source, a position he held for the next 21 years. Paul Holland has authored/co-authored 265 articles, chapters and monographs, mostly concerning issues relating to either viral hepatitis or HIV. In addition to his research career, Paul was a very active educator, having contributed importantly to the development of many current thought leaders in transfusion medicine. His distinguished career also included important administrative roles in national and international organizations relevant to transfusion medicine. He also was the recipient of many honors and awards which has won him wide-spread renown and the respect of his many colleagues.

Profibrogenic chemokines and viral evolution predict rapid progression of hepatitis C to cirrhosis

Chronic hepatitis C may follow a mild and stable disease course or progress rapidly to cirrhosis and liver-related death. The mechanisms underlying the different rates of disease progression are unknown. Using serial, prospectively collected samples from cases of transfusion-associated hepatitis C, we identified outcome-specific features that predict long-term disease severity. Slowly progressing disease correlated with an early alanine aminotransferase peak and antibody seroconversion, transient control of viremia, and significant induction of IFN-γ and MIP-1β, all indicative of an effective, albeit insufficient, adaptive immune response. By contrast, rapidly progressive disease correlated with persistent and significant elevations of alanine aminotransferase and the profibrogenic chemokine MCP-1 (CCL-2), greater viral diversity and divergence, and a higher rate of synonymous substitution. This study suggests that the long-term course of chronic hepatitis C is determined early in infection and that disease severity is predicted by the evolutionary dynamics of hepatitis C virus and the level of MCP-1, a chemokine that appears critical to the induction of progressive fibrogenesis and, ultimately, the ominous complications of cirrhosis.

Prevalence of Hepatitis C virus antibody in patients with sexually transmitted diseases attending a Harrisburg, PA, STD clinic

OBJECTIVE

The prevalence of hepatitis B and hepatitis C in a sexually transmitted disease (STD) clinic population was studied, along with the prevalence of various STD agents, in an attempt to identify possible STD markers for the hepatitis C virus and help delineate the role of hepatitis C as an STD. The hepatitis C antibody rates found in the STD clinic were also compared with those found among patients attending a local OB/GYN clinic and those enrolled in a blood donor program, all from the same geographical area.

METHODS

A total of 150 women attending an STD clinc were examined for each of the following agents: Chlamyadia trachomatis, Neisseria gonorrhoeae, syphilis, hepatitis B surface antigen, hepatitis B core antibody, hepatitis B surface antibody, and hepatitis C virus antibody. Additionally, several patients who signed informed consent to be evaluated for human immunodeficiency virus (HIV) antibody were tested by an enzyme immunoassay (EIA) screen method. The prevalence of each agent was then compared with the other agents.

RESULTS

The overall prevalence rates detected were as follows: hepatitis B 16%, hepatitis C 4%, chlamydia 18.7%, gonorrhea 7.4%, syphilis 0.7%, and HIV 0%. Hepatitis C antibody was detected in 4% of patients in the STD clinic, 0.76% of volunteer blood donors from central Pennsylvania, and 0% of patiants studied from the Harrisburg Hospital (Harrisburg, PA) prentatal population.

CONCLUSIONS

This screening study reveals an association between attending a Harrisburg, PA, area STD clinic and having an increased prevalence of hepatitis C antibody, but larger matched control studies will be needed to help clarify sexual transmission as a mode of transmission for the hepatitis C virus.

The hazards of blood transfusion in historical perspective

The beginning of the modern era of blood transfusion coincided with World War II and the resultant need for massive blood replacement. Soon thereafter, the hazards of transfusion, particularly hepatitis and hemolytic transfusion reactions, became increasingly evident. The past half century has seen the near eradication of transfusion-associated hepatitis as well as the emergence of multiple new pathogens, most notably HIV. Specific donor screening assays and other interventions have minimized, but not eliminated, infectious disease transmission. Other transfusion hazards persist, including human error resulting in the inadvertent transfusion of incompatible blood, acute and delayed transfusion reactions, transfusion-related acute lung injury (TRALI), transfusion-associated graft-versus-host disease (TA-GVHD), and transfusion-induced immunomodulation. These infectious and noninfectious hazards are reviewed briefly in the context of their historical evolution.

A study-screening of blood donors for blood transmissible diseases

AIMS

Blood donors are of voluntary and replacement type. All donors, especially voluntary, are considered as slow risk for seropositive status for Hepatitis B and C, HIV and syphilis. The present study endeavors to screen blood donors-a slow risk group and evaluate the resultant data.

METHODOLOGY

We screened 23,068 donors serologically over 2 years for the above blood transmissible diseases. Serum alanine aminotranferase (ALT) and bilirubin were evaluated as surrogate markers in hepatitis B and C positive donors.

RESULTS

Seroprevalence rates were found to be HIV (1.96 %), syphilis (2.15 %), hepatitis B (1.98 %) and hepatitis C (0.9 %). Majority donors were voluntary (70.37 %) and male (96.2 %). However seroprevalence rates showed no significant difference: voluntary (7.02 %), replacement (6.67 %) male (6.85 %) and female (6.95 %). HCV and HIV showed highest (29.6 %) while HBV and HCV (2.5 %) showed lowest concomitance. Serum ALT and bilirubin were not effective surrogate markers. No demographic or behavioral variable was found as a significant risk factor.

CONCLUSION

Thus, all donors need adequate privacy, information, counseling and motivation in order to reduce the seropositive rates in donors. Advent of sensitive tests renders surrogate markers redundant.

Detection and characterization of hepatitis B virus of anti-hepatitis B core antigen-reactive blood donors in Quebec with an in-house nucleic acid testing assay

BACKGROUND

Hepatitis B virus (HBV) infection can be detected in blood donations by many serologic markers. Since the introduction of routine anti-hepatitis B core antigen (HBc) donor screening at Héma-Québec in April 2003, a large number of donors have been deferred on the basis of reactive anti-HBc test results. The objective of this study was to evaluate the correlation between the anti-HBc-reactive donations and the detection of HBV DNA with an in-house nucleic acid testing (NAT) assay.

STUDY DESIGN AND METHODS

The in-house HBV NAT assay is a conventional polymerase chain reaction amplifying part of the viral S gene. From October 2004 to November 2005, a total of 1169 anti-HBc-reactive donations were tested with this in-house assay. The results were correlated with hepatitis B surface antigen (HBsAg) and anti-HBs markers. HBV DNA-positive samples were further investigated by DNA sequencing.

RESULTS

All HBsAg-positive samples were detected by the NAT assay. Overall, 38 (3.25%) of anti-HBc-positive samples were found to be positive for the presence of HBV DNA. Of these 38, a total of 12 donations with a low level of HBV DNA were HBsAg-negative. The sequencing results clearly showed various genotypes and subtypes within a same genotype.

CONCLUSION

The 3.25 percent HBV DNA positivity rate among the anti-HBc-reactive donations and more particularly the low level of HBV DNA observed in occult donations underline the importance of the use of a sensitive assay to detect HBV DNA in conjunction with other markers. The HBV genetic diversity found in our donor population reflects the province demographics, particularly in the Montreal area where most of the positive donors were from.

Anti-hepatits B core antigen testing, viral markers, and occult hepatitis B virus infection in Pakistani blood donors: implications for transfusion practice

BACKGROUND

The purpose of this study was to determine the seroprevalence of anti-hepatitis B core antigen (HBc) and the impact of its testing along with other markers of hepatitis B, hepatitis B virus (HBV) DNA, hepatitis C virus antibody (anti-HCV), and syphilis in Pakistani blood donors.

STUDY DESIGN AND METHODS

The study design was cross-sectional. A total of 966 donors were selected randomly for testing of anti-HBc and HBV markers, including HBV DNA, of 94,177 blood donors who were routinely screened for hepatitis B surface antigen (HBsAg), anti-HCV, human immunodeficiency virus antibody (anti-HIV), Treponema pallidum hemagglutination assay (TPHA), and malarial parasites from 2003 to October 2005.

RESULTS

The seroprevalence of various infectious markers was as follows: HBsAg, 2.16 percent; anti-HCV, 4.16 percent; anti-HIV, 0.004 percent; TPHA, 0.75 percent; and malaria, 0.002 percent. Anti-HBc prevalence in HBsAg-negative, HBV DNA-negative blood donors was 167 of 966 (17.28%), with 76 percent demonstrating anti-HBs positivity. Younger donors with mean age of 25 years were exposed to HBV to a lesser extent compared to those with a mean age of 29 years. Anti-HBc positivity was significantly higher in anti-HCV-reactive individuals. HBV DNA was detectable in 5 blood donors who were HBsAg-, anti-HBc-positive and were categorized as having occult HBV infection.

CONCLUSIONS

The study shows that more than 17 percent of healthy, young blood donors in Pakistan are already exposed to HBV, with two-thirds showing anti-HBs levels of greater than 100 mIU per mL. One in 200 blood donors who are HBsAg-, anti-HBc-positive, however, have occult HBV infection, with likelihood of transmission of hepatitis B in recipients of blood components derived from them. HBsAg-negative individuals who are anti-HBc-negative and those who are anti-HBc-positive, anti-HBs-positive, and HBV DNA-negative should be selected as regular blood donors to minimize transmission due to occult hepatitis B infection.

Effectiveness of autologous fibrin tissue adhesive in reducing postoperative blood loss during total hip arthroplasty: a prospective randomised study of 100 cases

PURPOSE

To evaluate the effectiveness of autologous fibrin tissue adhesive (auto-FTA) in reducing blood loss during cementless total hip arthroplasty (THA).

METHODS

From September 2000 to August 2001, 100 patients who predonated 400 ml of autologous blood were randomised to undergo either standard treatment with auto-FTA (auto-FTA group) or standard treatment alone (control group). The volume of postoperative blood loss and the decrease in haemoglobin level were measured. All patients were followed up for 3 years to evaluate the rate of bone ingrowth and heterotopic ossification.

RESULTS

The mean postoperative blood loss was 580 ml (standard deviation [SD], 240 ml) in the auto-FTA group and 810 ml (SD, 341 ml) in the control group; the difference was significant (230 ml, p<0.001). The decrease in haemoglobin concentration was 17 g/l (SD, 11 g/l) in the auto-FTA group and 22 g/l (SD, 12 g/l) in the control group. The difference was significant (5 g/l, p=0.03). The percentage of total blood loss of >1200 ml in any single patient was significantly lower in the auto-FTA group (4%) than in the control group (20%) [p=0.01].

CONCLUSION

Auto-FTA is a safe and effective means of reducing perioperative blood loss in THA.

Evaluation of five hepatitis C virus screening tests and two supplemental assays: performance when testing sera from sexually transmitted diseases clinic attendees in the USA

The performances of five screening tests (recombinant peptide-based first and second generation tests from Abbott and Ortho, and a synthetic peptide-based test from Biochem Immunosystems) and two supplemental tests: recombinant peptide- based, Abbott neutralization test and Chiron second generation recombinant immunoblot assay (RIBA 2), were evaluated for their ability to detect hepatitis C virus (HCV) antibodies in a population of 276 individuals attending a sexually transmitted diseases (STD) clinic in the USA. Although the five screening tests produced a variable number (35-62) of repeatedly reactive samples, only 13% (36/276) were classified as true positives by the supplemental tests. Thirty-four of the 36 were reactive by all screening tests and 32 of the true positives were reactive by both supplemental tests, while 2 did not neutralize but were reactive in the RIBA 2 test. Of the remaining 2 of the true positives which were discordant by several of the screening assays, 1 was confirmed by both supplemental assays but the other required a chemiluminescent enhancement technique to show positivity in RIBA 2. The sensitivities of the first and second generation Abbott and Ortho tests ranged from 97% to 100% and that of the Biochem test was 94%. The specificities of these tests ranged from 89.2% to 99.6%. The second generation Ortho test presented 9.4% (26/276) false positives. The use of second generation Ortho as a screening test would lead to an excessive number of confirmatory false positives. the positive predictive values of the screening tests ranged from 58.1% to 97.1%. Although the synthetic peptide based Biochem test exhibited the best overall indices, the presence of 2 false negative results would prevent its use as a singular screening test. Nevertheless its high specificity may lend itself to be used as a second screening test before confirmatory testing with RIBA 2.

Occult hepatitis B virus infection: implications in transfusion

Hepatitis B virus (HBV) presents a higher residual risk of transmission by transfusion than hepatitis C virus (HCV) or human immunodeficiency virus (HIV). While most infectious blood units are removed by screening for hepatitis B surface antigen (HBsAg), there is clear evidence that transmission by HBsAg-negative components occurs, in part, during the serologically negative window period, but more so during the late stages of infection. Donations negative for HBsAg, but positive for HBV DNA, with or without the presence of HBV antibodies, correspond to 'occult' HBV infection (OBI). The frequency of OBI depends on the relative sensitivity of both HBsAg and HBV DNA assays. It also depends on the prevalence of HBV infection in the population. OBI may follow recovery from infection, displaying antibody to hepatitis B surface antigen (anti-HBs) and persistent low-level viraemia, escape mutants undetected by the HBsAg assays, or healthy carriage with antibodies to hepatitis B e antigen (anti-HBe) and to hepatitis B core antigen (anti-HBc). Over time, in the latter situation, anti-HBe and, later, anti-HBc may become undetectable. The critical question is whether or not OBI is infectious by transfusion. All forms have been shown to be infectious in immunocompromised individuals, such as organ- or bone marrow-transplant recipients. In immunocompetent recipients, there is no evidence that anti-HBs-containing components (even at low titre) are infectious. Anti-HBc only, with HBV DNA, can be associated with infectivity, as can rare cases of HBV DNA without any serological HBV marker. If HBV nucleic acid amplification technology (NAT) is considered, the OBI viral load would usually be < 500 IU/ml, making testing of plasma pools unsuitable unless the sensitivity of NAT significantly increases by genome enrichment or test improvement.

Identifying Patients at Risk of Intraoperative and Postoperative Transfusion in Isolated CABG: Toward Selective Conservation Strategies

BACKGROUND

Allogeneic blood product use during cardiac operation is often reported to exceed 40% despite published guidelines and costly blood conservation strategies. We developed a predictive model, based on eight preoperative risk factors, of allogeneic blood product transfusion rates in patients undergoing a cardiac procedure.

METHODS

All 3,046 consecutive, isolated coronary artery bypass graft (CABG) procedures at a university hospital from 1995 to 1998 were included. A logistic regression model was created to identify independent predictors of allogeneic blood product transfusion. This model was validated using a prospective patient sample.

RESULTS

Overall use of allogeneic blood products was 23% with a crude operative mortality of 2.1%. In isolated, elective, first-time CABG cases, 16.9% received allogeneic blood products. Independent predictors of blood product usage in CABG patients were preoperative hemoglobin 12.0 or less, emergent operation, renal failure, female sex, age 70 years or older, left ventricular ejection fraction 0.40 or less, redo procedure, and low body surface area. Prospective validation of this model on 2,117 consecutive isolated CABG patients demonstrated an observed-to-expected allogeneic blood product transfusion rate ratio of 1.06.

CONCLUSIONS

This internally validated logistic regression risk model is a sensitive and specific predictor of allogeneic blood product use in patients undergoing isolated CABG. Utilization of this model allows for preoperative risk stratification and may allow for more rational resource allocation of costly blood conservation strategies and blood bank resources.

Occult hepatitis B virus infection

The detection of HBV DNA without HBsAg with or without the presence of HBV antibodies outside the acute phase window period defines occult HBV infection. This condition has been described in hepatocellular carcinoma (HCC), chronic hepatitis B, healthy HBV carriage and recovered infection, chronic hepatitis C and individuals without serological markers of HBV. The frequency of the diagnosis depends on the relative sensitivity of both HBsAg and HBV DNA assays. It also depends on the prevalence of HBV infection in the population. Occult HBV in blood donors has a wide range of potential origins within the natural history of the infection. It may originate from recovered infections with anti-HBs and persistent, low-level, viral replication, escape mutants undetected by the HBsAg assays or healthy chronic carriage. The last situation is mostly found with anti-HBc only. Over time, antibody markers may become undetectable leaving HBV DNA as the only marker of the infection. In all cases, the viral load is low, mostly below 10(4) IU/ml, often below 100 IU/ml. At these levels, nucleic acid testing (NAT) in pools is likely to be largely ineffective. Is occult HBV transmissible by transfusion? Carriers of anti-HBs or anti-HBc only were shown infectious in immunosuppressed organ or bone marrow transplant recipients. In immunocompetent recipients, there is no evidence that anti-HBs-containing components are infectious, even in low titre. Donations carrying anti-HBc only and HBV DNA can be infectious and this is a threat where anti-HBc is not screened. Anti-HBc screening identifies most occult HBV infection but not all. HBV NAT needs either extreme sensitivity or to be performed on individual donations to eliminate HBV DNA-containing units.

Use of hepatitis B core antibody-positive donors in recipients without evidence of hepatitis B infection: a survey of current practice in the United States

Because of the current organ shortage, some liver transplant programs have begun to accept marginal organs that previously would have been rejected. An example is the use of donors with evidence of past hepatitis B virus (HBV) infection. To gain insight into the use of hepatitis B core antibody-positive (anti-HBc(+)) donor livers in recipients without evidence of HBV infection, we conducted a survey. Surveys consisting of 12 multiple-choice questions were sent to all 110 liver transplant programs across the United States in mid-2001, and 56 of 110 surveys (51%) could be evaluated. Overall, 32 of 56 programs (57%) indicated they would transplant an anti-HBc(+) liver into a recipient without serological evidence of HBV infection. Of those who would accept an anti-HBc(+) liver, 16 of 27 respondents (59%) indicated knowledge of HBV DNA status would change their protocol; 46% of these respondents would decrease prophylaxis if HBV DNA was negative, 27% would increase prophylaxis if HBV DNA was positive, and 27% would not accept the liver if HBV DNA was positive. Conversely, 9 of 28 respondents (32%) who would not accept an anti-HBc(+) liver stated that knowing HBV DNA status would change their protocol in that they might consider accepting livers if HBV DNA was negative. In conclusion, as of mid-2001, of transplant medical directors in the United States who responded to our survey, 57% would accept an anti-HBc(+) donor liver for an HBV-naïve recipient. Treatment protocols for using these organs varied. Knowledge about HBV DNA status of the donor and/or liver would greatly influence prophylaxis for those accepting anti-HBc(+) donor livers.

Low-positive anti-hepatitis C virus enzyme immunoassay results: an important predictor of low likelihood of hepatitis C infection

BACKGROUND

Tests for hepatitis C antibodies (anti-HCV enzyme immunoassays) are usually described as positive or negative. Several studies, mainly in blood donors, have found that specimens with low signal/cutoff (S/C) ratios are commonly negative when tested with a recombinant immunoblot assay (RIBA) or for HCV RNA.

METHODS

We retrospectively reviewed 17 418 consecutive anti-HCV results from a screening program for high-risk veterans; 2986 (17.1%) samples were anti-HCV-positive, and 490 (16.4%) had S/C ratios <or=3.7 (low positive). Additional tests were performed in 1814 anti-HCV-positive individuals.

RESULTS

RIBA was performed in 263 patients with low-positive anti-HCV; results were negative in 86%, indeterminate in 12%, and positive in 2%. Only 16 of 140 individuals (11%) with low-positive anti-HCV values were HCV RNA-positive, whereas HCV RNA was positive in 90% of 1435 individuals with high-positive anti-HCV values (P <0.0001). Compared with those with high-positive anti-HCV, individuals with low-positive anti-HCV values were older (P <0.0001) and were less likely to have risk factors for HCV (P <0.0001 for most), multiple increased alanine aminotransferase (ALT) activity values (30% vs 81%; P <0.0001), or positive anti-hepatitis B core antigen (19% vs 59%; P <0.0002). Among 634 individuals with high anti-HCV titers and multiple increased ALT activity values, 95% were HCV RNA-positive.

CONCLUSIONS

The S/C ratio is important even in high-risk individuals; laboratories should report the S/C ratio along with anti-HCV EIA results and perform supplemental RIBA testing in those with low-positive values to avoid reporting false-positive results.

Low prevalence of HCV, HIV, and HTLV-I/II infection markers in northwestern Greece: results of a 3-year prospective donor study (1995-1997)

Background: The risk of infection with transfusion-transmitted viruses has been reduced remarkably. A zero-risk blood supply, however, remains a popular goal. A 3-year prospective donor study was conducted in the Epirus region of Greece to determine the prevalence of human immunodeficiency virus (HIV), human T-lymphotropic virus (HTLV), hepatitis B virus, and hepatitis C virus (HCV). Herein, we report the prevalence of HIV, HTLV, and HCV infection markers in this area. Methodology: Between January 1, 1995 and December 31, 1997, 6696 donors were investigated for the presence of anti-HIV, anti-HTLV, and anti-HCV antibodies using standard enzyme immunoassays (EIA). Every sample with anti-HCV reactivity by third-generation EIA was further investigated using a third-generation recombinant immunoblot assay (RIBA 3.0) and HCV-RNA by a combination of polymerase chain reaction (PCR) and DNA EIA. Results: None of the donors tested positive for anti-HIV or anti-HTLV antibodies. In contrast, anti-HCV was detected in 41 donors (0.61%). Using a RIBA 3.0 test, eight donors tested positive and eight had indeterminate results, while 25 tested negative. Seven of the eight donors with both EIA and RIBA 3.0 reactivity had increased levels of aminotransferases and detectable serum HCV-RNA. The remaining 34 donors had repeatedly normal aminotransferases and three times negative HCV-RNA. Liver biopsy was performed in anti-HCV/HCV-RNA-positive donors (7/41). The lesions were compatible with chronic hepatitis C in all of them. Conclusion: A zero prevalence of HIV and HTLV infection markers was found. Although the number of annual donations in this study was relatively low, the negative data for HIV and HTLV clearly indicate that rates of these infections are low in our region and that infected donors will be seen infrequently. HCV infection in blood donors remains very low in our region and is similar to the data reported in other industrialized countries. In fact, the prevalence of definite HCV infection seems to be very low (7/6696; 0.1%). However, a significant proportion of anti-HCV-reactive donors by third-generation EIA (33/41) had indeterminate or negative results by the RIBA 3.0. The latter donors were repeatedly negative for HCV-RNA. This finding may indicate that some donors tested false-positive for anti-HCV, although the possibility of true HCV infection contracted in the distant past cannot be excluded. In our opinion, close attention to mandatory principles of transfusion medicine, along with the screening of plasma donors using nucleic acid amplification technology, are the only methods that can further ensure the safety of our blood supply.

Impact of allogenic packed red blood cell transfusion on nosocomial infection rates in the critically ill patient

OBJECTIVE

To determine whether critically ill patients who receive allogenic packed red blood cell transfusions are at increased risk of developing nosocomial infections during hospitalization.

DESIGN

Retrospective database study utilizing Project IMPACT.

SETTING

A 40-bed medical-surgical-trauma intensive care unit in an 825-bed tertiary referral teaching hospital.

PATIENTS

One thousand seven hundred and seventeen patients admitted to the medical-surgical-trauma intensive care unit.

MEASUREMENTS AND MAIN RESULTS

Data were collected by using the Project IMPACT database. Nosocomial infection rates were compared among three groups: the entire cohort, the transfusion group, and the nontransfusion group. We determined the nosocomial infection rates in these groups while adjusting for probability of survival by using Mortality Prediction Model (MPM-0) scores, age, gender, and number of units of packed red blood cells transfused. The average number of units transfused per patient was 4.0. The nosocomial infection rate for the entire cohort was 5.94%. The nosocomial infection rates for the transfusion group (n = 416) and the nontransfusion group (n = 1301) were 15.38% and 2.92%, respectively (p <.005 chi-square). Transfusion of packed red blood cells was related to the occurrence of nosocomial infection, and there was a dose-response pattern (the more units of packed red blood cells transfused, the greater the chance of nosocomial infection; p< 0.0001 chi-square). The transfusion group was six times more likely to develop nosocomial infection compared with the nontransfusion group. In addition, for each unit of packed red blood cells transfused, the odds of developing nosocomial infection were increased by a factor of 1.5. A subgroup analysis of nosocomial infection rates adjusted for probability of survival by using MPM-0 scores showed nosocomial infection to occur at consistently higher rates in transfused patients vs. nontransfused patients. A second subgroup analysis adjusted for patient age showed a statistically significant increase in rates of nosocomial infection for transfused patients regardless of age.

CONCLUSIONS

Transfusion of packed red blood cells is associated with nosocomial infection. This association continues to exist when adjusted for probability of survival and age. In addition, mortality rates and length of intensive care unit and hospital stay are significantly increased in transfused patients.

Hepatitis B core antibodies in Danish blood donors: a surrogate marker of risk behaviour

BACKGROUND AND OBJECTIVES

The aim of this work was to determine the prevalence of antibodies to hepatitis B core antigen (anti-HBc) among Danish blood donors and to correlate this with risk factors for blood-borne and sexually transmitted diseases.

MATERIALS AND METHODS

During a 5-month period, 10 862 consecutive donors in the County of Funen were screened for anti-HBc, and repeat-reactive samples were confirmed by supplementary testing. Information on risk factors was assessed by questionnaire in 585 consecutive anti-HBc-negative blood donors and compared with information obtained from confirmed positive donors.

RESULTS

The prevalence of confirmed positive anti-HBc among donors was 0.70% (76/10 862, 95% confidence interval [CI]: 0.55-0.87). One donor was positive for anti-HBc immunoglobulin M (IgM); none tested positive for hepatitis B virus (HBV) DNA. In a logistic regression analysis, age, female gender, tattoos and commercial sexual relations, were independent predictive factors for the presence of anti-HBc.

CONCLUSION

Anti-HBc is a surrogate marker for previous risk behaviour in the Danish blood donor population. We suggest that screening for anti-HBc may be used among new donors to supplement interviews on risk behaviour.

Hepatitis C virus. The importance of viral heterogeneity

Although recent evidence indicates that the quasispecies nature of HCV constitutes a critical strategy for the virus to survive in the host, the mechanisms of viral persistence remain unknown. Similarly, the correlates of immune protection in a limited proportion of individuals who succeed in clearing HCV are still largely undefined. Understanding the mechanisms of sterilizing immunity is essential for devising preventive measures against HCV and unraveling how the virus eludes such immunity. As in other viral infections, the complex interactions between the virus and the host early in the course of HCV infection probably determine the outcome of the disease (i.e., resolution or persistence). The evidence now accumulated on HCV and other models of viral infection is compatible with the hypothesis that both cellular and humoral components are needed for definitive viral clearance. Nevertheless, detailed studies of the specific cellular and humoral immune responses during the incubation period and the acute phase of hepatitis C, in relation to the viral quasispecies evolution and the clinical outcome, are still lacking both in humans and in the chimpanzee model. Until such studies are performed, most ideas of viral clearance mechanisms remain hypothetical, and the immunologic basis of HCV clearance will continue to be inferred from associations rather than from causal relationships.

Value of anti-HBc screening of blood donors for prevention of HBV infection: results of a 3-year prospective study in Northwestern Greece

BACKGROUND

The risk of infection with transfusion-transmitted viruses has been reduced remarkably. However, a zero-risk blood supply remains a popular goal. Some authorities have introduced the screening for antibody to HBc (anti-HBc) as a surrogate test for the presence of several infectious agents. A 3-year prospective study was conducted in the Epirus region of Greece to determine the prevalence of several blood-borne viruses. One component of the study was the prevalence of HBV infection markers and the potential value of anti-HBc testing of donors in this area.

STUDY DESIGN AND METHODS

Between January 1, 1995, and December 31, 1997, some 6696 donors were investigated for the presence of HBV infection markers by standard EIAS: Every sample that tested HBsAg-negative but anti-HBc-reactive alone or in combination with either or both antibodies to HBV e antigen (anti-HBe) and low-titered antibodies to HBsAg (anti-HBs <20 mIU/mL) was further investigated for the presence of HBV DNA by a combination of PCR and DNA EIA.

RESULTS

Of these 6696 donors, 15.8 percent tested positive for at least one serologic marker of HBV infection (HBsAg prevalence, 0.85%). Anti-HBc reactivity alone or in combination with either or both anti-HBe and low-titered anti-HBs was found in 282 donors (4.2%). None tested HBV-DNA positive. No transfusion-associated HBV infections were recorded in the recipients of the above 282 blood units.

CONCLUSION

A moderate prevalence of HBV infection markers was found. However, taking into account previous studies from this region, it appears that the HBsAg prevalence has declined. In addition, the present study cannot recommend the introduction of anti-HBc screening as a surrogate marker of occult HBV infection. The adoption of this exclusion criterion in this region would result in unacceptably high rejection rates among otherwise healthy donors. The absence of any case of transfusion-associated HBV infection after the transfusion of all HBsAg-negative, anti-HBc-positive units appears to provide further support for the negative HBV DNA results. Before a consideration of screening donors, efforts must be focused on reducing the number of false-positive anti-HBc results.

Will genome detection replace serology in blood screening for microbial agents?

The residual risk of transfusion-transmitted viral infection in developed countries is considered minimal or negligible. However, zero risk remains a strong political objective. Genomic screening for HCV, HIV and HBV represents a major advance, eliminating infectious blood donations collected during the pre-seroconversion window period, rare cases of immunosilent infections and, possibly, a large spectrum of viral variants. In Western countries, HCV RNA genomic screening started on pools of 16-400 plasma samples from individual donations. Pooling may produce false-positive and false-negative results. Individual donation testing is more suitable to blood screening but requires multiplexing, automation, and affordable cost. Because donations from individuals who are HBV DNA-negative/serologically positive, or those apparently recovered from HCV infection, may remain infectious, it is unlikely that HBsAg, anti-HCV, and anti-HIV will be discontinued when genomic screening is extended to all three viruses. HIV-1 p24 antigen may prove redundant with HIV RNA screening. Anti-HTLV-I and HTLV-II will remain more effective than genomic testing.