Reducing the incidence of non-A,non-B post-transfusion hepatitis by testing donor blood for alanine aminotransferase: economic considerations

Epidemiology of Hepatitis C Virus: A Battle on New Frontiers

The hepatitis C virus (HCV) is a leading cause of liver-related morbidity and mortality in the United States and other parts of the world. The epidemiology of the disease is highly variable between and within countries, and strategies to deal with HCV identification and treatment must be tailored to the geographic location and the political and economic environment of the region. Although great strides have been made in improving HCV transmission risk in blood supply products, new challenges related to changing patterns of disease incidence continue to require fresh evaluation and new approaches to disease prevention.

Economic analyses of blood safety and transfusion medicine interventions: a systematic review

Economic evaluations are increasingly common in blood safety and transfusion medicine. We sought to summarize and review economic evaluations of donated blood interventions conducted in the United States. By using computer database searches, we identified 19 studies that reported both cost and health benefit results, and relative to each other, we rated the quality of their design and reporting. We classified 6 of the studies as having high quality, 10 as having fair quality, and 3 as having poor quality. Several strengths and limitations in economic evaluations of blood safety and transfusion medicine interventions were identified. Four key improvements can increase the quality of literature in this discipline. We believe researchers should (1) provide more explicit detail on cost parameters in each study and the methods used to obtain them; (2) adopt a clear analysis perspective relevant to decision makers that captures all key costs and consequences, such as the societal perspective; (3) use a consistent approach to reporting sensitivity analyses; and (4) place greater reliance on graphical presentation of results including sensitivity analyses because a large amount of information can be conveyed in relatively simple figures, leaving space to discuss the impact of important analysis assumptions and applicability of the results to other settings.

Blood transfusion and blood conservation: cost and utilization issues

Approximately 12 million red blood cell units are transfused to nearly 4 million patients annually in the United States (1). The conservation of blood has historically arisen from awareness that the inventory of this resource is limited (2), as well as the knowledge that blood transfusion carries a risk (3). Estimates of current blood transfusion risks (4-12), and the costs of transfusion complications (13-17), are summarized in Table 1. In addition, emphasis on the costs of health care has raised issues related to the costs of blood transfusion (18, 19). Finally, recent guidelines have emphasized that in the elective transfusion setting, no blood transfusion is a desirable outcome (20, 21). Furthermore, these guidelines along with consensus conference recommendations (22) have emphasized that if blood is to be transfused, autologous (the patient's own) blood is preferable to allogeneic (from an anonymous, volunteer donor) blood. Thus, the costs of blood conservation, for which an increasing array of technologic procedures and products have become available (Table 2), have also become an issue (23). The purpose of this review is to provide an overview of emerging data on the cost-effectiveness of blood and blood conservation interventions in order to help identify areas important for future investigation.

Serum alanine aminotransferase measurement as a guide to selective testing for hepatitis C during medical checkup

The efficiency of elevated serum alanine aminotransferase values for selecting subjects to be tested for hepatitis B or C infections in a large French population undergoing a medical checkup was investigated. For 5 consecutive weeks, serum alanine aminotransferase values were controlled in 9044 subjects; 308 subjects (202 males) were selected with alanine aminotransferase levels 1.2-fold above the normal value (58 iu/l for men, 34 iu/l for women). For each selected case, an age- and sex-cross-matched control was included. Of the 308 subjects with elevated alanine aminotransferase values, one was HBsAg positive and 15 (seven males) were anti-HCV positive. All anti-HCV sera tested by enzyme immunoassay were also positive by three immunoblots and 11/15 (73%) were HCV-RNA positive by reverse transcription-polymerase chain reaction. Of the 308 control subjects, two were HBsAg positive and four (two males) were weakly anti-HCV positive by enzyme immunoassay. Only one weakly anti-HCV positive serum was reactive by one immunoblot and all were HCV-RNA negative. This study shows the usefulness of alanine aminotransferase screening to detect hepatitis C virus infection in the general French population. Many of the anti-HCV positive subjects detected in this study were not aware of their hepatitis C virus seropositivity (12/15) or that they were viremic (11/15). Use of this low-cost assay will considerably reduce the number of subjects to be tested for hepatitis C virus serological status and therefore the cost. It may make possible the investigation of large populations by setting up public health programs to detect and treat hepatitis C virus. Hepatitis C virus infected subjects detected in these programs could benefit from medical follow up, including antiviral therapy.

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.

A lambda gt11-cDNA clone specific for chronic hepatitis C generated from pooled serum presumably infected by hepatitis C virus

A lambda gt11-random-primed-cDNA clone specific for chronic hepatitis C was isolated from pooled serum presumably infected by hepatitis C virus. The translation product of the clone detect 50% of patients with chronic hepatitis C in 4 test panels but none of the patients with acute hepatitis C, other liver diseases or normal controls was positive for the peptide. The nucleotide sequence of the cDNA clone, the size of which is 66 bp, has no homology to the complete sequences of known human viruses such as adenovirus, coxsackievirus, rhinovirus, immunodeficiency virus type 1, Epstein-Barr virus, polioma virus, poliovirus, papilloma virus, parvovirus, papovavirus, varicella-zoster virus, yellow fever virus, endogenous retrovirus, T-cell lymphotropic virus types I, II, and III Japanese encephalitis virus, and hepatitis A, B, and D viruses. Probably only one or two epitopes are present on the molecule encoded by the clone as the peptide consists of only 22 amino acid residues.

[Significance of alanine aminotransferase and reduction of post-transfusion non-A, non-B hepatitis]

To appreciate the test based on the activity of sera alanine aminotransferase (ALT) in the reduction of non-A non-B post-transfusional hepatitis, a study of the variation of this enzyme's activity was done versus several parameters: sex, age and acquired diseases. The population which included 25,813 Parisian blood donors (41.2% of men and 58.8% of women) was divided into two groups: the first was constituted of 25,585 subjects (40.9% of men and 59.1% of women) without clinical etiology and biological diseases, it will be the reference population; the second group was composed of 173 subjects (68.2% of men and 31.8% of women) who had acquired biological markers or clinical diseases during the life. The study within the reference population showed a sexual dimorphism. The study by dispersion diagrams in the population with high seric activity of ALT could explain the causes of blood donors' elimination.

Rationale for surrogate testing to detect non-A, non-B hepatitis

NANB hepatitis was initially recognized in 1975 and 13 years later, the exact etiology of this presumed viral disease remains uncertain. The acute illness is relatively mild with only about 25% of patients becoming icteric. Nevertheless, at least one half of the patients have evidence of chronic infection, and, as recently recognized, 10% to 20% develop severe liver disease. Because approximately 2% of patients who receive transfusions and whose underlying medical condition permits long term follow-up develop posttransfusion hepatitis, procedures for reducing this risk are considered prudent. Unfortunately specific tests for detecting NANB hepatitis are not available, and it is unlikely that such tests will be available in the near future. Hence, testing by surrogate or nonspecific tests (ALT and anti-HBc) were recommended because evidence from two studies conducted during the 1970s showed these tests identify some donors thought to transmit the infection. However, randomized, controlled prospective studies to determine whether these tests will, in fact, reduce NANB posttransfusion hepatitis were not performed. By the mid-1980s it was apparent these studies would not be performed nor were studies to determine the incidence of NANB posttransfusion hepatitis in the post-AIDS screening era likely to be initiated. Therefore, surrogate testing, as the best available method for reducing posttransfusion hepatitis, was implemented in the United States in 1986-87.

Screening blood donors for human immunodeficiency virus antibody: cost-benefit analysis

The costs and benefits of screening blood donors for antibody to human immunodeficiency virus (HIV) are assessed. Total costs, including testing, discarding processed blood, marginal donor recruiting, notifying and evaluating positive donors, are $36,234,000 annually for 10 million donors in 1986. Screening these donors will prevent 292 cases of transfusion-transmitted acquired immune deficiency syndrome (TT-AIDS), saving the costs of therapy and loss of earnings for total benefits of $43,490,480, a benefit:cost ratio of 1.2:1. Net economic benefits of $0.73 per donor will arise from the program. Calculated benefits will rise as increased numbers of infected recipients are diagnosed with longer follow-up or as partially effective therapy increases the cost of caring for patients with AIDS. Changes in test sensitivity, follow-up procedures, estimated value of life, and testing costs will also alter these projections, but none as dramatically as a change in the overall specificity of the screening process. The cost per case of TT-AIDS prevented, $124,089, and cost per year of life extended, $10,885, are comparable to costs of other screening programs.

The usefulness of surrogate markers anti-HBc and ALT for post-transfusion non-A, non-B hepatitis prevention

Non-A, non-B hepatitis represents an important problem for public health throughout the world. For several years, Transfusion Centers have been looking into improvements for more efficiently preventing post-transfusion non-A, non-B hepatitis. The viruses involved in such a pathology have not yet been isolated and no specific marker is available for direct screening and prevention. Surrogate markers, alanine aminotransferase and anti-HBc antibody have been evaluated by different teams, however, for this purpose. Fifty or 60% of transfusion-related non-A, non-B hepatitis could be prevented thanks to these markers, but such a strategy would induce a high loss of blood products. Therefore, a compromise must be found between quality objectives and economical costs, generated by this procedure. The social and financial costs of chronic hepatitis for the public health would be balanced by costs involved in such a screening policy and therefore Transfusion Centers should probably initiate this quality improvement using one or both tests in the near future.

A multicenter, prospective study of posttransfusion hepatitis in Milan

We studied the risk of posttransfusion hepatitis in recipients of blood collected from volunteer donors who tested negative for HBsAg and had serum ALT levels less than 1.5 times the upper limit of the normal range. Between October, 1983 and September, 1984, 676 consecutive patients who needed blood or plasma transfusions during or after elective surgery, who had no history of liver disease and had never received blood previously, were studied. The patients were given a total of 4,813 (mean = 7) units. Ninety-six patients developed posttransfusion hepatitis, which yielded a hepatic incidence of 20 cases per 1,000 units of transfused blood. Ninety-two patients had non-A, non-B hepatitis, 3 had hepatitis B and 1 had cytomegalovirus infection. The incubation periods for non-A, non-B hepatitis ranged from 2 to 26 (mean = 9.5 +/- 4) weeks. In 68 (73%) patients, the hepatitis was completely asymptomatic; only 24 (27%) patients developed symptoms, including jaundice and hepatomegaly. There were no cases of fulminant hepatitis. Sixty per cent of the patients still had elevated serum ALT levels 1 year after the onset of hepatitis. The 96 patients with hepatitis had received a mean of 9.6 blood units, as compared to a mean of 6.7 units for the unaffected patients (p less than 0.001). This study demonstrated that non-A, non-B hepatitis remains a common and important complication of blood transfusion despite screening of blood donors for HBsAg and elevated serum ALT levels.

Hepatitis in clinical practice. 2. Non-A non-B and delta hepatitis

Non-A non-B (NANB) hepatitis has at least two distinct causative agents. NANB hepatitis can lead to chronic liver disease, cirrhosis, and hepatocellular carcinoma. No definitive policy exists to exclude this disease as a cause of posttransfusion hepatitis. Delta agent is epidemiologically linked to hepatitis B virus (HBV) infection, either as a coinfection or as a superinfection in chronic hepatitis B surface antigen carriers. Recognition of hepatitis due to delta agent will probably increase as testing for this agent becomes more available and its presence becomes more generally well known throughout the medical profession.