Hepatitis B, hepatitis C and HIV transfusion-transmitted infections in the 21st century.

In the past, transfusion-transmitted virus (TTV) infections were not uncommon. In recent years with advanced technologies and improved donor screening, the risk of viral transfusion transmission has been markedly reduced. Hepatitis B virus (HBV), hepatitis C virus (HCV) and human immunodeficiency virus (HIV) have all shown marked reduction in transmission rates. However, the newer technologies, including nucleic acid technology (NAT) testing, have affected the residual rates differently for these virally transmitted diseases. Zero risk, which has been the goal, has yet to be achieved. False negatives still persist, and transmissions of these viruses still occur, although rarely. It is known that HBV serological testing misses some infected units; likewise, HBV NAT-negative units have also been known to transmit the virus. Similarly, HIV minipool NAT-negative units have transmitted HIV, as recently as 2007; likely, these transmissions would have been prevented with single-unit NAT testing. Newer technologies, such as pathogen inactivation (PI), will (ideally) eliminate these falsely test negative components, regardless of the original testing method used for detecting the viruses.

Does donating blood for the first time during a national emergency create a better commitment to donating again?

BACKGROUND AND OBJECTIVES: Emergency situations often elicit a generous response from the public. This occurred after attacks on the US on September 11, 2001 when many new blood donors lined up to donate. This study was performed to compare return rates for first time donors (FTD) after September 11th, 2001 to FTD during a comparable period in 2000. MATERIALS AND METHODS: A total of 3315 allogeneic whole blood donations from FTD at a regional blood centre were collected between September 11th and 30th, 2001. Subsequent donations by the FTD before March 31, 2002 were reviewed. This (test) group was compared to 1279 FTD (control group) donating during the same time period in September 2000 and to their return rate in the subsequent 6 months. RESULTS: Following September 11, 2001, 1087/3315 (32.8%) FTD returned by March 31, 2002. This return rate was similar to the control group [427/1279 (33.4%)]. The deferral rate during the donor screening process for the control group was significantly higher than the deferral rate for the September 11-30, 2001 group (P < 0.01). The odds of an individual FTD returning increased with age, and the chance of a female donor returning was 1.13 times higher than a male (P = 0.06). There was a carryover effect after September 11, 2001 too. CONCLUSION: A national emergency, September 11, 2001, inspired people to donate blood for the first time. However, the proportion of return donations amongst them was not increased. Females and males in certain age groups were more likely to become repeat donors due to the residual effect of September 11, 2001. Additional efforts are needed to retain eligible FTD in donor pools.

TRALI is due to pulmonary venule damage from leucocytes with cholesterol crystal formation.

BACKGROUND: There are two presumed mechanisms for the pulmonary oedema in transfusion-related acute lung injury (TRALI). One is antibodies to leucocytes while the other is biologically active lipids. We evaluated the vascular injury due to the former. METHODS: The pulmonary vasculature was studied by light microscopy (LM) and scanning electron microscopy (SEM) in three fatal cases of TRALI and compared with that of two autopsied control patients. Lung tissue from two of the TRALI cases and both controls was studied by gas chromatography-mass spectroscopy (GC-MS) to identify crystals present in the former. RESULTS: All three TRALI cases exhibited massive pulmonary oedema by weight and light microscopy and extensive defects by SEM in the endothelium of venules of the lungs. Such endothelial defects were absent in controls. Thrombi, composed of crystals, were present in venules and small veins diffusely throughout the lungs in Case 1. Similar crystals were identified in Case 2. The crystals in the lung vessels were identified morphologically as cholesterol and were proximate to the cytoplasmic defects of the endothelial surfaces. By GC-MS, there were markedly elevated levels of cholesterol and fatty acids in the two TRALI lungs tested compared with the lungs of the two controls. CONCLUSIONS: Pulmonary damage in TRALI is related to formation of cholesterol crystals that appear to pierce endothelial membranes of venules. The endothelial defects lead to plasma extravasation into the alveoli causing TRALI.

Transfusion-associated graft-versus-host disease.

Transfusion-associated graft-versus-host disease (TA-GvHD) is a rare complication of transfusion of cellular blood components producing a graft-versus-host clinical picture with concomitant bone marrow aplasia. The disease is fulminant and rapidly fatal in the majority of patients. TA-GvHD is caused by transfused blood-derived, alloreactive T lymphocytes that attack host tissue, including bone marrow with resultant bone marrow failure. Human leucocyte antigen similarity between the transfused lymphocytes and the host, often in conjunction with host immunosuppression, allows tolerance of the grafted lymphocytes to survive the host immunological response. Any blood component containing viable T lymphocytes can cause TA-GvHD, with fresher components more likely to have intact cells and, thus, able to cause disease. Treatment is generally not helpful, while prevention, usually via irradiation of blood components given to susceptible recipients, is the key to obviating TA-GvHD. Newer methods, such as pathogen inactivation, may play an important role in the future.

Replacement therapy of alpha 1-antitrypsin deficiency. Reversal of protease-antiprotease imbalance within the alveolar structures of PiZ subjects.

The emphysema associated with the inherited serum deficiency of alpha 1-antitrypsin appears to result from an imbalance between neutrophil elastase and its major inhibitor within the alveolar structures. In the present study we assessed the feasibility of reversing this biochemical defect within the lung via parenteral replacement therapy with an alpha 1-antitrypsin concentrate of normal plasma. A 20--40% polyethylene glycol precipitate of pooled human donor plasma was used to obtain an enriched alpha 1-antitrypsin concentrate devoid of hepatitis B antigen and immunoglobulins. Using this material, five individuals with severe serum alpha 1-antitrypsin deficiency (PiZ phenotype) and advanced emphysema received 4 g of alpha 1-antitrypsin intravenously at weekly intervals for four doses. During this period of weekly replacement therapy alpha 1-antitrypsin serum levels were maintained at greater than or equal to 70 mg/dl, the level likely required for effective antielastase protection of the lung. In addition, assessment of lower respiratory tract antielastase activity by bronchoalveolar lavage demonstrated that parenteral replacement of alpha 1-antitrypsin resulted in establishment of effective antielastase activity within the alveolar structures. There were no untoward side effects consequent to this approach to the replacement therapy of alpha 1-antitrypsin. These results demonstrate that the parenteral replacement of alpha 1-antitrypsin provides a means of obtaining elastase-antielastase balance within the lung of individuals with this serum protease inhibitor deficiency.

Improved survival with plasma exchange in patients with thrombotic thrombocytopenic purpura-hemolytic uremic syndrome.

PURPOSE: Thrombotic thrombocytopenic purpura and hemolytic uremic syndrome are uncommon disorders that are generally fatal if left untreated. Plasma exchange therapy is associated with high response rates and improved short-term survival, but most previous studies have been limited by small numbers of patients or short duration of follow-up. METHODS: We performed a retrospective cohort analysis in 126 consecutive patients with thrombotic thrombocytopenic purpura/hemolytic uremic syndrome, most of whom were treated principally with plasma exchange at the Sacramento Medical Foundation Blood (Center and the University of California Davis Medical Center between 1978 and 1998. We measured the effect of therapeutic plasma exchange on 30-day mortality, response rate, and overall survival, and determined which factors were associated with 30-day mortality and relapse. RESULTS: The overall 30-day mortality was 10% of the 122 patients who received plasma exchange as their principal treatment (a median of 9 exchanges and a mean cumulative infused volume of 43 +/- 77 L fresh frozen plasma); 56% were complete responders and 21% were partial responders. The relapse rate was 13%. The estimated 2-year survival was about 60%; among patients without serious underlying comorbid conditions, the estimated 2-year survival was about 80%. Each unit increase in clinical severity score (on a 0 to 8 scale) was associated with a 2.2-fold (95% confidence interval [CI]: 1.3 to 3.9) increase in the odds of 30-day mortality. Patients who were febrile at presentation were substantially less likely to suffer a relapse (odds ratio = 0.2; 95% CI: 0.03 to 0.9). CONCLUSION: Plasma exchange therapy produced high response and survival rates in this large cohort of patients with thrombotic thrombocytopenic purpura/hemolytic uremic syndrome. The Clinical Severity Score may be useful in predicting 30-day mortality, whereas fever at onset was associated with a lesser risk of relapse. Prospective studies should stratify patients according to these prognostic factors.

The disappearance of transfusion-transmitted hepatitis C virus infections in the United States.

Because of anti-HCV testing, rates of transfusion-transmitted HCV infections have dropped from a high level (approximately 1 per 200 units, even using volunteer, repeat donors) to an extremely low one (approximately 1 per 125,000 units). Moreover, preliminary data indicate that pooled- (and perhaps, eventually, single-) specimen NAT for HCV-RNA or EIA for HCV core antigen may reduce this risk even further. It is anticipated that implementation of one or more of these methods, coupled with one or more pathogen-inactivation steps, may functionally eliminate the risk of transmitting HCV by transfusions.

Donor cell induced CD69 expression and intracellular IL-2 and IL-4 production by peripheral blood lymphocytes isolated from kidney transplant recipients.

Flow cytometry assays, which measure CD69 activation and intracellular cytokine production, have been used to measure peripheral blood lymphocyte (PBL) responses to in vitro antigen exposure. In the present study, we show that, in healthy individuals and immunosuppressed kidney transplant recipients, CD69 expression and intracellular cytokine production by peripheral blood T cells compare favorably to thymidine uptake as a measure of PBL response to alloantigen in mixed leukocyte culture (MLC). Heparinized whole blood from 23 healthy individuals was incubated for 24-48 h with 3rd party allogeneic monocytes; blood from twelve kidney transplant recipients was incubated with monocytes from their kidney donor and with monocytes from unrelated individuals. The percentage of T cells expressing surface CD69 or intracellular IL-2 or IL-4 was determined by 3-color flow cytometry. We identified 5 donor-specific response patterns in our kidney transplant group. One transplant recipient was hyporesponsive; his cells did not express CD69 or produce IL-2 in response to either donor or 3rd party allogeneic cells. All other transplant recipients expressed CD69 and IL-2 in response to 3rd party allogeneic cells. Two had no response to donor cells (donor-specific hyporesponsiveness), three had donor-specific anergy (CD69 expression without cytokine production in response to donor cells), five had a donor-specific Thl response (CD69 expression and IL-2 production in response to donor cells), and one had a donor-specific Th2 response (CD69 expression and IL-4 but not IL-2 production in response to donor cells). Rapid measures of donor-specific hyporesponsiveness such as CD69 activation antigen expression and intracellular cytokine production may prove valuable in monitoring lymphocyte function and aid in the long-term management of kidney transplant recipients.

Non-A, non-B viral hepatitis.

Non-A, non-B hepatitis is a newly recognized disease entity. Although initially described as a transfusion related viral infection, the disease can occur in sporadic, endemic, and epidemic settings. There are no confirmed, reproducible serologic tests for associated antigens or antibodies, but electron microscopy has revealed virus-like particles of different sizes. Nonspecific laboratory tests of hepatic dysfunction, especially alanine aminotransferase, are currently utilized to diagnose non-A, non-B hepatitis in patients and may be used to implicate blood donor carriers of this virus. The existence of an infectious non-A, non-B hepatitis agent and proof of a chronic carrier state in humans have been documented by transmission studies in chimpanzees. Cross challenge studies in chimpanzees, as well as some epidemiologic data, suggest that more than one agent causes non-A, non-B hepatitis.

HIV transmissions from a window-period platelet donation.

Recently, blood centers began investigational testing for HIV RNA by pooled nucleic acid testing (NAT). A 35-year-old frequent platelet donor tested HIV p24 antigen positive, antibody negative before implementation of NAT. He made 2 platelet donations (day -4 and -11) immediately before testing positive for HIV. The donor's HIV seroconversion was monitored, and stored samples were tested retrospectively for HIV RNA. Platelet recipients were tested for HIV infection. The day -4 sample tested positive for HIV RNA by pooled and individual sample NAT. The day -11 sample tested negative for HIV RNA by both NAT tests. The 2 recipients of the day -4 platelets tested HIV RNA and p24 antigen positive. The recipient of the day -11 platelets could not be tested because he had died. HIV NAT would have prevented transmission of HIV had it been available at the time of this donor's HIV seroconversion.

Consent for transfusion: is it informed?

Informed consent for transfusions presumes that the patient has been "informed," meaning they have been given sufficient information to make an intelligent choice, and that they "consent," meaning that the patient is competent and free to consent. Although this may be oral or written, the latter is preferable for documentation and legal proof. This may either be as a chart note, or form. In any case, the informed transfusion recipient should be given a description of the procedure in lay terms, told of the expected benefit, including the outcome without the transfusion, and what reasonably foreseeable adverse consequences may occur. The individual should have the opportunity to ask questions of the physician performing the informed consent process. There should be time to provide the information and a discussion; and the patient must be able to comprehend all of this. If this process is performed by the physician talking to his/her patient, then, the patient is likely to be informed about, and consent to, elective transfusions. Once obtained and documented, that consent should be presumed to be valid with a course of therapy for transfusions. If some event significantly changes some aspects of the information on which the patient relied in consenting and now should be aware of, then, the patient should again give consent for transfusion, after being informed of this new information.

Comprehensive reimbursement model: an alternative to fee-for-service reimbursement by blood centers.

"If we could first know where we are, and whither we are tending, we could then better judge what to do and how to do it." This quote from Abraham Lincoln epitomizes where SMF and its CRM hospital customers are today. The CRM has been received by SMF's hospital customers as a step in the right direction. Currently, it seems to be the best way to partner with hospitals by sharing risk in the current health care delivery system milieu. The CRM focus on patient outcomes will provide hospitals and blood centers a common goal. Modifications to the CRM will most certainly be necessary. With input from customers and the community over time, and flexibility from SMF, a revised model will evolve that will be even more mutually beneficial.

The Duffy blood group phenotype in American blacks infected with Plasmodium vivax in Vietnam.

We determined blood group phenotypes of 13 blacks who were infected with Plasmodium vivax in Vietnam. All were Duffy blood group positive as compared to 40--50% Duffy positive in surveys of black blood donors in the United States. The probability that 13 of 13 were Duffy positive by chance alone was P less than 0.001. All other blood groups occurred at the expected frequency. This study is further support for the hypothesis that the Duffy negative genotype (FyFy) is the basis for resistance of blacks to P. vivax.

Differentiation of hepatitis B virus genotypes D and E by ELISA using monoclonal antibodies to epitopes on the preS2-region product.

An enzyme-linked immunosorbent assay (ELISA) has been described for serological determination of hepatitis B virus genotypes, using monoclonal antibodies (mAb) against seven distinct epitopes (b, m, k, s, u, f and g) on the preS2-region products of hepatitis B surface antigen (HBsAg). The usefulness of this method for serological detection of genotype E, however, was theoretical, because no HBsAg samples of this genotype were included in the original test panel. Moreover, the predicted serotype of genotype E (bksufg) closely resembled that of genotype D (bksu, bksuf or bksug). Four HBsAg samples of genotype E were tested by the original described ELISA. The epitope g, predicted to be present in these samples by amino acid sequences, was not detected when HBsAg of genotype E was captured on a solid phase by mAb to the common determinant 'a' of HBsAg and then reacted with mAb to g (5156) labeled with horseradish peroxidase. However, the four examples of HBsAg of genotype E were captured by mAb 5156 to g on a solid phase; they were then detected by labeled mAb to the common determinant 'a'. Since epitopes f and g co-occurred on HBsAg of genotype E, HBsAg samples of this genotype were also detected, by 'sandwiching' them between immobilized mAb to g and labeled mAb to f. By contrast, HBsAg of genotype D in 90 sera was not reactive when sandwiched between mAb to f and g. Thus, this modified ELISA enables the serological determination of all six genotypes of HBsAg and, by inference, of hepatitis B virus.

A second-generation method of genotyping hepatitis C virus by the polymerase chain reaction with sense and antisense primers deduced from the core gene.

A second-generation method of genotyping hepatitis C virus (HCV) was developed by the polymerase chain reaction (PCR) with sense as well as antisense primers deduced from the core gene. HCV RNA specimens extracted from sera were reverse-transcribed and amplified with universal primers in the first round of PCR to obtain fragments of 433 base pairs representing nucleotides 319-751. In the second round of PCR, portions of PCR products were amplified separately with sense and antisense primers specific for each of the five common genotypes prevailing across the world, i.e., I/1a, II/1b, III/2a, IV/2b and V/3a. The specificity of the method was verified by a panel of 177 HCV isolates of various genotypes in the genetic groups 1-9. It allowed clear differentiation of genotype I/1a from II/1b which was not always accomplished by the previous method. When 501 sera from blood donors and hepatitis patients with HCV viremia from various countries were genotyped by the second-generation method, 478 (95.4%) were classified into the five genotypes. HCV RNA samples from 23 (4.6%) sera were not classifiable into any of the five common genotypes and, by sequence analysis, 22 were found to be of four genotypes in group 4 and one of genotype 1c in Simmond's classification.

The clinical significance of hepatitis B virus antigens and antibodies.

There are two well-characterized antigen-antibody systems which relate specificially to viral hepatitis B. Tests for HBsAg and anti-HBs are readily available and of great benefit to the diagnosis, prevention and understanding of hepatitis B. Tests for HBcAg and anti-HBc are still research techniques which requires further development before they can be used at the level of everyday medical practice. HBsAg in an individual indicates that he harbors the virus of hepatitis B; it may be present in the absence of liver disease or be found in association with both acute and chronic type B hepatitis. The presence of HBsAg also suggests that HBV may be causally related to some cases of periarteritis nodosa, chronic glomerulonephritis, and hepatoma. Although HBV is readily transmitted in blood, the major portion of post-transfusion hepatitis now appears to be serologically unrelated to either the hepatitis B virus ("serum") or the hepatitis A virus ("infectious"); the etiology of these cases is currently undetermined. There is increasing evidence that HBV may be transmitted by modes other than blood, but the exact mechanisms of such transmission is not established. The combined transmission of HBV by blood and other routes has resulted in a large number of persistent carriers of HBsAg in the world. There is no current method to alter this carrier state. The hepatitis risk of such persistent carriers to their personal and professional contacts is under investigation.

A study of street heroin lots for the presence of the hepatitis B surface antigen.

Hepatitis B surface antigen (HBsAg) of subtype ay predominates among narcotic addicts infected with hepatitis B virus (HBV) in Europe, Australia and the United States. However, the ad subtype predominates among the non-addict carriers of HBsAg. We investigated the possibility that heroin lots were contaminated with HBV at a source of opium production, the Middle East, a geographical region where HBsAg/ay predominates in the general population. One hundred and nine lots of street heroin were assayed for HBsAg by radioimmunoassay. None of the lots tested was reproduceably HBsAg positive. These results suggest that the heroin itself is not responsible for the high incidence of HBV infection or for the predominance of HBsAg/ay in the addict population. The predominance of HBsAg/ay among addicts in Europe and Australia as well as the United States might be due to extensive needle sharing among a mobile population of drug abusers, although such worldwide dissemination of one subtype by these means is unlikely.

Overview: diagnostic tests for viral infections transmitted by blood.

The risk of transmitting viral infections by transfusion today is quite remote. The many, sensitive, diagnostic tests in place, when applied to the blood of volunteer, unpaid (unremunerated), unpressured donors who are also carefully evaluated at the time of donation, make blood and blood component transfusions very safe. A number of sensitive laboratory tests are performed on each unit of donated blood and plasma to reduce the risk of transmission of hepatitis viruses and retroviruses from asymptomatic donors to transfusion recipients. With the tests, we hope to catch otherwise undetectable individuals who may be carrying these viruses yet appear healthy and deny risk factors for their carriage. However, the laboratory tests in use in blood banks were designed to aid in the diagnosis of patients with viral diseases. Therefore, a reactive test, even if reproducible, on a sample from a healthy blood donor is more apt to be falsely than truly positive. An ideal microbiologic test is one which is one hundred percent sensitive, i.e., it will identify every person with an infectious disease (including asymptomatic carriers). In addition, a perfect test would have one hundred percent specificity, i.e., it would not be reactive in anyone without the infectious agent. The decision point or "cutoff" for an ideal test would be above the (negative) results for all normal and uninfected samples, but below that for all (positive) infectious ones. In reality, there is an overlap between some of the results on normals and those on diseased individuals, including persons who are carrying an infectious agent. When we try to obtain maximal sensitivity, e.g., to detect all asymptomatic carriers of a virus, the assay cutoff is set very low for tests applied to blood donors; but this approach will compromise the specificity of a test. The net effect is that many normal people donating blood are said to have "abnormal" test results which, among other things, necessitates the loss of their blood and plasma. In addition, we must follow up the reactive results by enzyme linked immunoassays (EIA or ELISA) or radioimmunoassays (RIA) used to screen or preliminarily test blood from donors with supplemental or confirmatory tests to verify whether the initial test is a true positive or a false positive one. Trying to explain the significance of a false positive test for AIDS or hepatitis to a healthy donor often causes fear, concern and/or anger. Thus, the use of very sensitive tests on blood donors will increase the safety of transfusion for recipients but result in loss of some donors and discard of many blood components unnecessarily. Despite the problems in applying sensitive tests to asymptomatic individuals who are not patients, the assays in place in blood banks have, nonetheless, resulted in remarkably small risks of virus transmission by transfusions. Currently, the risk of HCV infection following a transfusion is about 1 in 3,300 per unit transfused. This is an enormous improvement compared to the risks of what was called non-A, non-B hepatitis in the 1970s and 1980s before the use of the test for antibodies to HCV. For HTLV-1 (and, potentially, HTLV-II) the risk of transfusion transmission is about 1 in 50,000 per unit of screened blood. Using blood which is anti-HIV-1/2 non-reactive, the risk is about 1 in 225,000 units of transmitting HIV. The risk of transfusion associated AIDS is thus quite remote in 1993. For hepatitis B virus, only about 1 in 200,000 units of blood transmit this virus now. In sum, only about 3 units of blood per 10,000 of those collected from acceptable, volunteer donors are currently likely to transmit a serious or fatal transfusion-transmitted viral infection. In contrast, in America, about 6 out of every 1,000 patients hospitalized will die from an accidental or preventable cause other than the underlying disease for which he/she was hospitalized. (ABSTRACT TRUNCATED)

Hepatitis B antigen subtypes-history, significance and immunogenicity.

Initial work showed that all hepatitis B surface antigens (HBs Ag) were identical. Subsequent, additional studies revealed that hepatitis B surface antigens have a group reactive determinant, a, plus additional specificities which are not universally present on all antigens. Four well-defindd subtypes of HBs Ag exist (HBs Ag/adw, HBs Ag/ayw, HBs Ag/adr, HBs Ag/ayr) but additional subtypes will be forthcoming as newly described determinants are confirmed. The subtype specificities are determined by the hepatitis B virus and not the host. Subtypes of HBs Ag are already of great use in the epidemiology of hepatitis B virus infections; yet they may have additional significance. Current work on HBs Ag subtypes is limited by the ability to find or produce antibodies to other than the a or group reactive determinant. The other determinants appear to be less immunogenic than a.

The emerging pattern of post-transfusion hepatitis.

The exclusion of commercial and hepatitis B surface antigen (HBs Ag)-positive donors, as measured by counterelectrophoresis, has markedly reduced the frequency of post-transfusion hepatitis (PTH). A further, significant reduction in type-B PTH can be achieved by prescreening donors for HBs Ag by solid-phase radioimmunoassay (RIA); When a voluntary donor population, pretreated by RIA, is used, approximately 90 per cent of residual hepatitis is serologically unrelated to either the type-A or type-B hepatitis viruses. Similarly, cytomegalovirus and the Epstein-Barr virus are not serologically implicated in "non-A, non-B" hepatitis. Additional human hepatitis virus(es) may exist.