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Transfusion-transmitted cytomegalovirus (TT-CMV) is often asymptomatic, but certain patient populations, such as very low birth weight neonates, fetuses requiring intrauterine transfusion, pregnant women, patients with primary immunodeficiencies, transplant recipients, and patients receiving chemotherapy or transplantation for malignant disease, may be at risk of life-threatening CMV infection. It is unclear whether leukoreduction of cellular blood components is sufficient to reduce TT-CMV or whether CMV serological testing adds additional benefit to leukoreduction. The AABB CMV Prevention Work Group commissioned a systematic review to address these issues and subsequently develop clinical practice guidelines. However, the data were of poor quality, and no studies of significant size have been performed for over a decade. Rather than creating guidelines of questionable utility, the Work Group (with approval of the AABB Board of Directors) voted to prepare this Committee Report. There is wide variation in practices of using leukoreduced components alone or combining CMV-serology and leukoreduction to prevent TT-CMV for at-risk patients. Other approaches may also be feasible to prevent TT-CMV, including plasma nucleic acid testing, pathogen inactivation, and patient blood management programs to reduce the frequency of inappropriate transfusions. It is unlikely that future large-scale clinical trials will be performed to determine whether leukoreduction, CMV-serology, or a combination of both is superior. Consequently, alternative strategies including pragmatic randomized controlled trials, registries, and collaborations for electronic data merging, nontraditional approaches to inform evidence, or development of a systematic approach to inform expert opinion may help to address the issue of CMV-safe blood components.

A decade ago, definitions of "transfusionߚrelated acute lung injury (TRALI)" and "possible TRALI" were standardized for research and clinical diagnosis. Since then, evidence has confirmed that TRALI is often due to transfusion of white blood cell antibodies to at-risk patients, and the term "TRALI, antibody mediated" is appropriate for such cases. Other TRALI cases are non-antibody mediated. Because specific, nonantibody transfusion factors have not yet been confirmed to cause TRALI in humans, the general term "TRALI, non-antibody mediated" is appropriate for such cases. In contrast, evidence is against possible TRALI being due to transfusion with the more likely cause of the acute respiratory distress syndrome (ARDS) being the alternative ARDS risk factor present in these patients. We propose to drop the misleading term "possible TRALI" and to rename this category of cases as "transfused ARDS." These nomenclature updates will more accurately categorize ARDS cases that develop after transfusion.

The incidence of human immunodeficiency virus (HIV) in repeat blood donors has been estimated using seven methods. Although incidence is always calculated as cases per person-time, approaches to selecting cases and calculating person-time vary. Incidence estimates have not been compared among methods.The seven methods were compared in a simulation study. Because three methods used information from donations made before an estimation interval, 8 years of donation and infection history were simulated, and Years 7 and 8 were treated as the estimation interval for all methods. An exponential random variate was assigned to each donor to simulate the time to infection. Infection risk was constant over 8 years in one scenario but increased at various rates in seven other scenarios. The infection risk scenarios were combined with four mixes of donation frequency to generate 32 test conditions.Three methods produced biased estimates under all conditions. Three other methods were biased under most conditions. Bias from most methods increased as donation frequency declined. The single method that consistently produced unbiased estimates was the only method that involved the standard epidemiological approach of tabulating all interdonation intervals (IDIs) within the estimation interval. Bias was eliminated from one of the consistently biased methods by a simple modification that involved the average IDI in a sample of donors.The standard epidemiological approach is recommended if required data are available. Otherwise, the modified method involving the estimated average IDI should be considered. Investigators should use caution when comparing incidence estimates among studies that use different estimation methods or donation frequencies.

Background Dengue viruses (DENV-1-4) pose a transfusion-transmission risk. This study estimated the dengue RNA detection period in asymptomatic blood donors and relationships between donor viremia and dengue incidence during a large epidemic. Methods Donor samples from the 2012 dengue transmission season in Rio de Janeiro, Brazil, were tested for DENV RNA by a transcription-mediated amplification (TMA) assay, with DENV types and viral loads determined by polymerase chain reaction. Samples collected during the first and last weeks of enrollment were tested for DENV immunoglobulin (Ig) G and IgM to estimate incidence during the study period, which was analyzed relative to nucleic acid amplification technology (NAT) yield to estimate the duration of NAT-detectable viremia and compared with reported clinical dengue cases in Rio. Results Samples from 16 241 donations were tested; 87 (0.54%) were confirmed as DENV-4 RNA positive. Dengue IgM-positive/IgG-positive reactivity increased from 2.8% to 8.8%, indicating a 6.2% incidence (95% confidence interval [CI], 3.2%-9.1%) during the study period. Based on these data, we estimated a 9.1-day period (95% CI, 4.4-13.9 days) of RNA detectable with TMA. With 100 475 reported cases of clinical dengue, 1 RNA-positive donation was identified per 800 DENV cases. Conclusions These parameters allow projections of dengue incidence from donor NAT yield data and vice versa, and suggest that viremic donations will be rare relative to clinical disease cases.

BACKGROUND: More than 66,000 blood donors are deferred annually in the United States due to travel to malaria-endemic areas of Mexico. Mexico accounts for the largest share of malaria travel deferrals, yet it has extremely low risk for malaria transmission throughout most of its national territory, suggesting a suboptimal balance between blood safety and availability. This study sought to determine whether donor deferral requirements might be relaxed for parts of Mexico without compromising blood safety. STUDY DESIGN AND METHODS: Travel destination was recorded from a representative sample of presenting blood donors deferred for malaria travel from six blood centers during 2006. We imputed to these donors reporting Mexican travel a risk for acquiring malaria equivalent to Mexican residents in the destination location, adjusted for length of stay. We extrapolated these results to the overall US blood donor population. RESULTS: Risk for malaria in Mexico varies significantly across endemic areas and is greatest in areas infrequently visited by study donors. More than 70% of blood donor deferrals were triggered by travel to the state of Quintana Roo on the Yucatan Peninsula, an area of very low malaria transmission. Eliminating the travel deferral requirement for all areas except the state of Oaxaca might result in the recovery of almost 65,000 blood donors annually at risk of approximately one contaminated unit collected every 20 years. CONCLUSION: Deferral requirements should be relaxed for presenting donors who traveled to areas within Mexico that confer exceptionally small risks for malaria, such as Quintana Roo.

Donor-based risk reduction interventions for transfusion-related acute lung injury (TRALI) have been widely adopted in the United States and elsewhere in the past several years.1–5 These strategies are based on data indicating that TRALI has continued to be the leading cause of blood transfusion-related deaths in the United States,6 the consensus that approximately 80% of TRALI cases are mediated by donor human leukocyte antigen (HLA) antibodies,7 and surveillance system findings that TRALI cases are reduced by use of such risk reduction strategies.2,8,9 Thus, as of 2009, almost all US blood centers are transfusing plasma supplied primarily by male or never-pregnant female donors, and many centers are screening previously pregnant platelet (PLT) and/or plasma apheresis donors for HLA antibody.1,9 Most transfused components containing HLA antibody do not result in recipients developing TRALI. Reasons for this include transfusion to a recipient who does not have a cognate HLA antigen profile, as well as less established factors such as the titer and/or other undefined characteristics of the specific transfused HLA antibody or the existence of underlying predisposing recipient risk factors (first hit). Most current theories of TRALI pathogenesis agree that two hits are usually necessary for TRALI to occur: the first is a recipient condition that results in neutrophil priming and the second is the infusion of a biologic response modifier that activates primed neutrophils. The biologic response modifier can be an HLA antibody, an HNA antibody, or several candidate nonantibody substances, such as bioactive lipids.10–12 In terms of this model, HLA antibody–containing components may fail to cause TRALI in the absence of a first hit. At least four studies have assessed outcomes in recipients of previously donated components from HLA antibody–positive donors who were implicated as causing TRALI in an index recipient.13–16 In aggregate, these studies detected five new cases of TRALI that were not reported to the blood bank when records of 171 patients were reviewed (2.9%). In addition, two lookback studies were reported on donors who were HLA antibody positive but had not been implicated in TRALI. In one of these studies, 62 HLA antibody–positive female donors gave a total of 211 blood components, and only one case of TRALI (which had previously been reported to the blood bank) was identified.17 In the second study, no TRALI cases were detected in 167 recipients of transfusions from four HLA antibody–positive donors or in 295 recipients from 12 HLA antibody–negative donors. However, this conclusion appeared to be based solely on review of transfusion service records.18 One additional study did not detect TRALI in any of 265 recipients of either HLA antibody–positive or HLA antibody–negative plateletpheresis units but did not clearly delineate the number of recipients in each group.19 Taken as a group, these lookback studies have significant limitations in that they used differing methods for HLA antibody screening, reviewing recipient outcome data and for diagnosing TRALI; they had small sample sizes considering the low incidence of TRALI; and most did not evaluate TRALI occurrence in recipients of control components using a blinded study design. Since it is well known that TRALI is both underrecognized and underre-ported,20 it is unclear if the findings in these studies can be generalized because methods for ascertainment were not robust. As part of the Retrovirus Epidemiology Donor Study-II (REDS-II), we previously conducted the Leukocyte Antibody Prevalence Study-I (LAPS-I), which identified 1032 whole blood and apheresis donors with HLA antibody.21 Since LAPS-I was conducted before the implementation of TRALI risk reduction policies, donations from these HLA antibody–positive donors were transfused to recipients. Given the limitations of previous studies noted above and the recognition that the recent implementation of TRALI risk reduction strategies will reduce the possibility of conducting future large-scale TRALI lookback studies, we designed a large multicenter retrospective cohort study termed the Leukocyte Antibody Prevalence Study-II (LAPS-II). Based on surveillance data showing a higher TRALI risk from transfused plasma components, LAPS-II was confined to high-plasma-volume components (fresh-frozen plasma and other transfusable plasma manufactured from whole blood or apheresis as well as plateletpheresis components).2,8,9 LAPS-II was designed to evaluate a primary endpoint of combined incidence of TRALI and possible TRALI in study recipients of at least one HLA antibody–positive high-plasma-volume component versus control recipients of at least one HLA antibody–negative high-plasma-volume component. Secondary endpoints were the association of HLA antibody class, HLA antibody specificity, HLA antibody screening test signal strength, and concomitant HNA antibody on TRALI occurrence.

BACKGROUND: Throughout its system of regional centers, Blood Systems implemented culture based bacterial testing with a standardized protocol for both apheresis and whole blood–derived platelets (PLTs). STUDY DESIGN AND METHODS: After a 24-hour hold, 4 mL of PLT product was inoculated into an aerobic bottle (BacT/ALERT, bioMerieux). Cultures were incubated for 24 hours before routine product release to prevent distribution of infected products while minimizing consignee notification, product retrievals, and hospital PLT inventory problems. Initial-positives were further tested (and bacteria identified) by performing cultures from the original component and subcultures from the BacT/ALERT bottle. Results were categorized according to AABB recommended definitions with minor modifications. RESULTS: The rate of true-positive detections from culturing 122,971 apheresis PLTs was 0.017 percent (95% confidence interval [CI], 0.011%-0.026%). All true-positive microorganisms were Gram-positive with a predominance of coagulase-negative Staphylococcus and Bacillus species. Twenty of the 21 true-positive samples (95%) were detected by 24 hours but only 14 (68%) were detected by 18 hours. The false-positive rate due to contamination was 0.1 percent with the majority of isolates being skin or environmental organisms. Results did not differ significantly for whole blood–derived versus apheresis PLTs. CONCLUSION: These data corroborate the fact that the rate of detection of truly contaminated PLT apheresis products in the United States is approximately 1 in 5000 (0.02%); this is lower than the 0.03 to 0.05 percent rates that were generally quoted in the literature before the implementation of prospective bacterial culturing programs.

Monitoring the performance of routinely used infectious disease serologic tests is necessary to evaluate their effectiveness in identifying true-positive units and erroneously disqualifying safe blood donors.With two large screening test data sets collected between 1991 and 1998 and between 1997 and 2000, the impact of changes in screening assays for HIV, HCV, and HBsAg was analyzed with regard to the prevalence of confirmed-positive, indeterminate, and confirmed-negative results and the deferral of donors with an indeterminate or negative results (donor loss).The prevalence of indeterminate results and donors loss increased significantly in the 6 months after introduction of an HIV-1/2 EIA. A second-generation HCV EIA increased the detection of confirmed-positive donations in repeat donors (p0.001) and increased the prevalence of indeterminate donations. Implementation of a third-generation HCV EIA resulted in a significant decrease in indeterminate results in first-time donors. Nonspecific test results increased when HBsAg test kits from a different manufacturer were introduced or different lots of HIV antibody screening test kits from the same manufacturer were used.Introduction of newly licensed versions of assays, switching kit manufacturers, and lot-to-lot variations have an impact on rates of deferrals of safe donors as well as sensitivity of routine screening. Before considering changes in screening tests, blood centers should be aware of, and evaluate, the potential impact on donor loss.

BACKGROUND: The yield of HIV p24 antigen testing implemented in March 1996 has been lower than projected. One possible explanation is that HIV seroconverting donors delay their return because of the recent practice of risk behaviors and/or signs and symptoms associated with primary infection. STUDY DESIGN AND METHODS: From a database of 6.8-million allogeneic donations collected at five U.S. blood centers from 1991 to 1997, 49 HIV, 21 HCV, 32 HTLV, and 44 HBsAg seroconverters with at least three donations were identified. A statistical method was developed to investigate whether the time between a donor's last negative donation and their positive donation was significantly longer than expected based on their previous return history. RESULTS: HIV seroconverters returned on average 42 percent later than expected (p < 0.01). Although not significant, HCV seroconverters donated on average 43 percent earlier than expected. HTLV and HBsAg seroconverters did not appear to change their donation pattern around the time of seroconversion. Sixty-three percent of the HIV seroconverters later acknowledged practicing a high-risk behavior. CONCLUSIONS: HIV seroconverters delay their return around the time of seroconversion and are thus less likely to be recently infected. Unique among HIV seroconverters, this observation provides a possible explanation for the lower than expected yield of HIV p24 antigen testing and suggests that NAT may have a similar low yield.

Background: Blood conservation strategies have been shown to be effective in decreasing red blood cell (RBC) utilization in specific patient groups. However, few data exist describing the extent of RBC transfusion reduction or their impact on transfusion practice and mortality in a diverse inpatient population. Study Design and Methods: We conducted a retrospective cohort study using comprehensive electronic medical record data from 21 medical facilities in Kaiser Permanente Northern California. We examined unadjusted and risk-adjusted RBC transfusion and 30-day mortality coincident with implementation of RBC conservation strategies. Results: The inpatient study cohort included 391,958 patients who experienced 685,753 hospitalizations. From 2009 to 2013, the incidence of RBC transfusion decreased from 14.0% to 10.8% of hospitalizations; this change coincided with a decline in pretransfusion hemoglobin (Hb) levels from 8.1 to 7.6g/dL. Decreased RBC utilization affected broad groups of admission diagnoses and was most pronounced in patients with a nadir Hb level between 8 and 9g/dL (n=73,057; 50.8% to 19.3%). During the study period, the standard deviation of risk-adjusted RBC transfusion incidence across hospitals decreased by 44% (p

Blood conservation strategies effectively decrease red blood cell (RBC) use in specific patient groups.1-3 However, the impact of RBC transfusion reduction on mortality in a diverse inpatient population remains poorly described. We detail the impact of declining RBC use on 30-day mortality within Kaiser Permanente Northern California (KPNC), an integrated health care delivery system serving 3.5 million members at 21 hospitals.

MAJOR GOAL of transfusion medicine is to reduce the risk of transfusion-transmitted infection to as low a level as possible. One method to achieve this is through the use of appropriate donor selection procedures. In the case of transfusiontransmitted diseases for which routine laboratory testing does not exist (ie, Chagas' disease, babesiosis, and malaria as well as Creutzfeldt-Jacob disease [CJD]--a theoretical transfusion risk), these procedures are the only method available for increasing transfusion safety. For infectious diseases for which routine blood donor screening assays are currently performed (human immunodeficiency virus [HIV], human T cell lymphotropic virus [HTLV], hepatitis B and C), the importance of donor screening procedures relates to their ability to identify potentially infectious donors during the infectious seronegative window period.~,2 Since the mid-1980s, the increased awareness of the potential spread of infectious disease by blood transfusion has led to significant changes in the donor interview, implementation of the confidential unit exclusion (CUE) procedure, and a reconsideration of the impact of donor recruitment on recipient safety. This article reviews the issues related to these donor selection procedures and discusses current and future research in this field.

Background Accurate estimates of the risk of transfusion-transmitted infectious disease are essential for monitoring the safety of the blood supply and evaluating the potential effect of new screening tests. We estimated the risk of transmitting the human immunodeficiency virus (HIV), the human T-cell lymphotropic virus (HTLV), the hepatitis C virus (HCV), and the hepatitis B virus (HBV) from screened blood units donated during the window period following a recent, undetected infection. Methods Using data on 586,507 persons who each donated blood more than once between 1991 and 1993 at five blood centers (for a total of 2,318,356 allogeneic blood donations), we calculated the incidence rates of seroconversion among those whose donations passed all the screening tests used. We adjusted these rates for the estimated duration of the infectious window period for each virus. We then estimated the further reductions in risk that would result from the use of new and more sensitive viral-antigen or nucleic acid s...

BY THE SPRING OF 1984, it was clear that AIDS was caused by at least one retrovirus, initially called human T-cell lymphotropic virus, type 111 (HTLV-III), and later called the human immunodeficiency virus (HIV).'.' Shortly after HTLV-111 (HIV) was described, antibody enzyme immunoassays were developed. After these tests were introduced into blood bank practice in March and April of 1985, a significant number of HIV enzyme immunoassay-repeatably reactive results, many later confirmed as true-positive results, were enco~ntered.~ This finding was unexpected and raised serious concern, because blood bankers had believed that most people at high risk for AIDS had voluntarily refrained from donating blood and plasma.4-' In 1985, a second strain of HIV was identified7 and designated HIV-2, with the original virus now called HIV1. A high degree (60-91%) of serologic cross-reactivity was exhibited against the original whole viral lysate enzyme immunoassays for HIV-1 antibodies8 To date, one blood donor infected with HIV-2 has been identified in the United States whose sera reacted with licensed HIV1 antibody screening tests,Y and one blood donor has been identified whose testing patterns suggested reactivity with HIV-2 antigens alone.'" No case of transfusion-transmitted HIV-2 has been reported in the United States.'" US Abbreviations: HIV-1 and -2 = human immunodeficiency virus type 1 and type 2; HTLV-I and -11 = human T-lymphotropic virus type I and type 11; HTLV-111 = HTLV, type 111, now HIV; MCC = medical coordinating center; NHLBI = National Heart, Lung, and Blood Institute; REDS = Retrovirus Epidemiology Donor Study; RFP(s) = request(s) for proposals; WBC(s) = white cell(s).

In the early 1990s, the Department of Health and Human Services (DHHS) asked the Institute of Medicine (IOM) to assess how the government, the private sector, and other stakeholders had responded to the human immunodeficiency virus (HIV) epidemic and its impact on blood safety. In its executive summary published in TRANSFUSION,1 the IOM Committee to Study HIV Transmission Through Blood and Blood Products noted that although stakes were high, decisions had to be made under a cloud of uncertainty and that responses were slowed by imprecise and incomplete knowledge, personal and institutional biases, and ultimately by failures in leadership. Emphasizing that blood safety is a shared responsibility, the IOM Committee issued 14 recommendations related to structure and policy including the designation of a Blood Secretary Director by DHHS, the establishment of a Blood Safety Council by the US Public Health Service (PHS), and several recommendations to the Federal agencies involved in the evaluation of an infectious threat, in particular, the Food and Drug Administration (FDA). Since then, these recommendations have been implemented and the blood safety community (blood collectors, blood safety experts, and relevant Federal agencies) has responded to other emerging infectious disease (EID) threats, such as West Nile virus (WNV) and most recently the xenotropic murine leukemia virus–related virus (XMRV). Responding to any new threat entails assessing the risk to the blood supply and recipients’ health; evaluating how best to manage and/or control each potential risk; and communicating this information to blood donors, recipients, physicians, and the general public. Although the FDA has the regulatory authority to develop guidance documents and new regulations in response to EID threats based on available data, the challenge of generating that data and responding to potential risks requires concerted and coordinated actions by the multiple PHS agencies (Centers for Disease Control and Prevention [CDC], FDA, National Institutes of Health [NIH]) and by the broader transfusion medicine community (AABB and blood providers). It is therefore incumbent upon the transfusion medicine professionals to collect and provide robust data in a timely manner to policymakers to inform their decision process, as well as take an active role in risk communication. All stakeholders must recognize what they can do and provide leadership and timely research and risk assessments. In so doing, they must take a hard look at their responses and learn lessons from history. Such a process does not involve a confirmation or criticism of what has been done in previous responses to potential threats to the blood supply, but an assessment of how responses can be improved for future threats. In the aftermath of the recent XMRV investigation and the inevitable occurrence of future infectious threats, the National Heart, Lung, and Blood Institute (NHLBI) convened an expert task force charged with evaluating how lessons from previous EID blood safety threat assessments could be used to optimize future response strategies. The task force was asked to review and discuss responses to past epidemics and recent EIDs and to consider: What worked? What could have worked better? What data are necessary to assess blood safety risk? Who needs to be engaged in the evaluation of risk; that is, who are the stakeholders? What methods and/or processes need to be in place and when? What resources, infrastructure, and capacity are needed? How best to train future experts? And how can a scientific culture be encouraged that encourages cooperation? In a first session, responses to earlier epidemics were examined, followed by a discussion on responses to recent agents of concern, including an in-depth look at the latest potential threat, XMRV. A general overview of other agents of potential concerns (the horizon) ensued followed by a general discussion on lessons learned and consideration of future strategies. This report summarizes the results of these discussions.

Fingerstick blood samples are used to estimate donor venous hemoglobin (Hb).Fingerstick Hb or hematocrit (Hct) was determined routinely for 2425 selected donors at six blood centers, along with venous Hb. Using sex and measures of iron status including absent iron stores (AIS; ferritin 12 ng/mL), linear regression models were developed to predict venous Hb from fingerstick.Across all subjects, fingerstick Hb was higher than venous Hb in the higher part of the clinical range, but lower in the lower part of the range. The relationship varied by sex and iron status. Across centers, a female donor had on average a venous Hb result 0.5 to 0.8 g/dL lower than a male donor with the same fingerstick Hb and iron status. Similarly, a donor with AIS had on average a venous Hb result 0.3 to 1.1 g/dL lower than an iron-replete donor with the same fingerstick value and sex. An iron-replete male donor with a fingerstick result at the cutoff (Hb 12.5 g/dL) had an acceptable expected venous Hb (12.8 to 13.8 g/dL). A female donor with AIS with a fingerstick result at the cutoff had an expected venous Hb below 12.5 g/dL (11.7 to 12.4 g/dL). Of females with AIS, 40.2% donated blood when their venous Hb was less than 12.5 g/dL.Fingerstick is considered a useful estimator of venous Hb. However, in some donor groups, particularly female donors with AIS, fingerstick overestimates venous Hb at the donation cutoff. This significant limitation should be considered in setting donor fingerstick Hb or Hct requirements.

Most industrialized countries maintain surveillance programs for monitoring transmissible infection in blood donations, revising approaches to methodology and risk assessment as new threats emerge. A comparison of programs in the United States, Canada, France, the UK, and Australia indicates that they have similar function, although the structure of blood programs vary as does the extent and nature of formal ties with public health. The emergence of HIV in the late 1970s and early 1980s was key in recognizing that surveillance systems specific to blood transfusion were essential. Hence, most industrialized countries monitor transfusion-transmissible infections in donors and evaluate the impact of new testing and of predonation screening strategies. Emerging infections since HIV have had different transmission pathways and challenged blood programs to draw upon resources for a rapid and effective response, with recognition that the original focus on sexual/drug-related risk of HIV and hepatitis was inadequate. The focus of surveillance programs on new and emerging pathogens fulfills a key role in risk assessment and policy formulation. The precise nature of such activities varies by country because of the structure of the blood programs and surveillance systems, the strategic focus of the blood programs, and the epidemiology of disease in each country.

There have been no comparisons of the relative sensitivity of the two Food and Drug Administration-licensed multiplex (MPX) nucleic acid test (NAT) systems (Procleix Ultrio [Gen-Probe], TIGRIS platform [Novartis]; and cobas TaqScreen MPX [Roche Molecular Systems], cobas s 201 platform [Roche Instrument Center]) for detecting hepatitis B virus (HBV)-infected donors in minipool sizes (MP) used in the United States.Routine blood samples from Thailand were obtained from plasma units from 129 hepatitis B surface antigen (HBsAg)-negative, HBV NAT-yield donations. Blinded US testing included antibody to hepatitis B core antigen (anti-HBc), NAT using both manufacturers' systems (undiluted-individual donation [ID], in singlet and diluted 1:6 and 1:16 in triplicate), quantitative antibody to hepatitis B surface antigen, HBV DNA viral loads, and HBV genotyping. HBV yields in the United States were estimated using the incidence/window period (WP) model and compared to the calculated assay sensitivities.Eighty samples were classified as occult HBV (anti-HBc reactive) and 49 as WP (anti-HBc nonreactive). For US pool sizes, MPX detected significantly more samples than Ultrio (MPX MP6 vs. Ultrio MP16; p0.0001 for occult and WP). Ultrio MP16 results were not statistically different from Ultrio MP6 (p = 0.68 for occult; p = 0.42 for WP). There was no difference between platforms for MP sizes used in most of the world (MPX MP6 vs. Ultrio ID; p = 0.70 for occult and p = 0.34 for WP). Viral loads were higher in WP samples. Modeled yield estimates were consistent with measured assay sensitivity on the Thai donor samples.As used in the United States, MPX MP6 is more sensitive than Ultrio MP16, but the impact of this difference is mitigated by low numbers of HBV WP infections.

Because the receptor for parvovirus B19 (B19V) is on red blood cells (RBCs), we investigated B19V distribution in blood by in vitro spiking experiments and evaluated viral compartmentalization and persistence in natural infection.Two whole blood (WB) protocols (ultracentrifugation and a rapid RBC lysis and removal protocol) were evaluated using quantitative real-time polymerase chain reaction. WB was spiked with known concentrations of B19V and recovery in various blood fractions was determined. The rapid RBC lysis and removal protocol was then used to compare B19V concentrations in 104 paired WB and plasma samples collected longitudinally from 43 B19V-infected donors with frozen specimens in the REDS Allogeneic Donor and Recipient Repository (RADAR).In B19V spiking experiments, approximately one-third of viral DNA was recovered in plasma and two-thirds was loosely bound to RBCs. In the immunoglobulin (Ig)M-positive stage of infection in blood donors when plasma B19V DNA concentrations were greater than 100 IU/mL, median DNA concentrations were approximately 30-fold higher in WB than in plasma. In contrast, when IgM was absent and when the B19V DNA concentration was lower, the median WB-to-plasma ratio was approximately 1. Analysis of longitudinal samples demonstrated persistent detection of B19V in WB but declining ratios of WB to plasma B19V with declining plasma viral load levels and loss of IgM reactivity.The WB-to-plasma B19V DNA ratio varies by stage of infection, with 30-fold higher concentrations of B19V DNA in WB relative to plasma during the IgM-positive stage of infection followed by comparable levels during persistent infection when only IgG is present. Further study is required to determine if this is related to the presence of circulating DNA-positive RBCs derived from B19V-infected erythroblasts, B19V-specific IgM-mediated binding of virus to cells, or other factors.

To determine the transmissibility of human T-lymphotropic virus types I and II (HTLV-I and HTLV-II) via transfusion, persons who, from 1983 to 1989, received blood components donated by persons who subsequently tested anti-HTLV-I-positive were evaluated. It was found that 16 (30%) of 54 evaluable recipients of transfused cellular components became infected with one of the HTLVs: 8 had HTLV-I and 8 had HTLV-II. Forty percent of platelet recipients and 28 percent of red cell recipients acquired infection. The rate of transmission of HTLV-I and HTLV-II was significantly correlated with storage age of red cell units prior to transfusion: 47 percent for red cells stored 14 days (p < 0.01). Multiple confirmatory serologic tests performed in 46 anti-HTLV-I enzyme immunoassay-negative recipients revealed that HTLV infection could not be excluded in 3 recipients of blood components from HTLV-II-infected donors. Polymerase chain reaction established HTLV-II infection in one recipient, and the other two recipients could not be classified with respect to HTLV infection status. It appears that some HTLV-II-infected transfusion recipients will not be detected by existing HTLV-I antigen-based reagents. If it is deemed necessary to initiate or continue look-back programs to detect transfusion transmission of HTLV-II infection, it is suggested that the current testing algorithm be modified in selected cases.

Transfusion-related acute lung injury (TRALI) is the leading cause of transfusion-related mortality. Blood centers are implementing TRALI risk reduction strategies based on screening apheresis donors for antibodies to human leukocyte antigens (HLA).HLA antibody screening was performed on 7920 blood donors from the Leukocyte Antibody Prevalence Study (LAPS) using Luminex-based normalized background (NBG) cutoff ratios of 10.8 (Class I) and 6.9 (Class II). Single antigen bead (SAB) assay cutoffs of 2500 median fluorescence intensity units (Class I) and 1500 (Class II) were established based on results of two subpopulations of LAPS donors. Antibody frequencies against HLA A, B, C, DR, DQ, and DP antigens were determined for screen-reactive donors with prior pregnancies.SAB reactivity for samples above our multiantigen bead NBG cutoffs was 78% for Class I and 79% for Class II. The SAB-positive rate increased among women with zero to four or more pregnancies (0.3%-15.6% Class I and 0.4%-18% Class II; p0.00001). The highest frequency antibodies were DR11 and B15 (4.4% of women with prior pregnancies). The majority of Class I positives contained more than five specificities. For Class II, antibody-positive women segregated into two groups: a single specificity or more than five specificities.Identification of HLA antigen specificities supports pregnancy associations previously found with screening assays. The significance of particular HLA specificities for inducing TRALI is currently being evaluated in a large lookback study of recipients of high-plasma-volume components from this donor cohort.

A new, multiple-antigen enzyme immunoassay (EIA-2) for hepatitis C virus (HCV) antibodies was evaluated in parallel with the previously available c100-3 HCV EIA (EIA-1) in 14,068 volunteer blood donors as well as in 25 cases of transfusion-associated hepatitis C for which recipient and donor samples were available. When compared to EIA-1, the EIA-2 was more sensitive in detecting HCV-infected blood donors. The EIA-2 detected an additional 1 in 1000 EIA-1-negative, surrogate marker- negative donors who were infected with HCV as demonstrated by polymerase chain reaction (PCR). The specificity of the EIA-2 was comparable to that of the EIA-1, but the two tests appear to detect different populations of false-positive donors. Recombinant immunoblot assay-indeterminate donors were detected five times more frequently by the EIA-2; PCR demonstrated that 21 percent of these donors were infected with HCV. The greater sensitivity of EIA-2 was also found in 25 transfusion recipients with non-A, non-B hepatitis; however, in 16 percent of these cases of posttransfusion HCV infection, the EIA-2 failed to detect an HCV-seropositive donor. These data indicate that EIA-2 testing will significantly reduce, but probably not eliminate, the risk of transfusion-associated HCV infection; we estimate this residual per-unit risk to be 1 in 2000 to 1 in 6000 units transfused. On a national level, it is projected that the replacement of the anti- HCV EIA-1 with the EIA-2 will initially prevent up to 40 additional cases of transfusion-associated hepatitis C per day.

Previously we showed that mononuclear cells from about half of human T- lymphotropic virus (HTLV)-seropositive persons exhibit spontaneous proliferation in vitro. We sought to determine if proliferation was associated with other immunologic changes characteristic of HTLV infection. The parameters assessed were (1) percentages of lymphocytes expressing CD4 and/or CD25 (interleukin-2 receptor), (2) serum levels of soluble CD25, (3) serostatus for other viruses, (4) anti-HTLV antibody levels, and (5) HTLV type determined by polymerase chain reaction or serologic reactivity with type-specific peptides. The proliferation+ HTLV (PROL+) group, proliferation HTLV (PROL-) group, and control group showed similar percentages of CD4+, CD25+, and CD4+CD25+ lymphocytes; serum levels of soluble CD25 were also similar. Antibodies to cytomegalovirus, hepatitis B core, and hepatitis C were present in similar proportions of PROL+ and PROL+ groups. However, a significant association was found between spontaneous proliferation and anti-HTLV antibody levels; sera from 67% of PROL+ persons, but only 18% of PROL- persons, required dilution to yield absorbance values within the linear range of the anti-HTLV antibody assay. In the PROL+ group, persons whose sera required the most dilution had proliferative responses significantly higher than those whose sera required no dilution. The PROL+ and PROL groups were similar with regard to the relative distribution of HTLV-I and HTLV-II infection. These findings indicate that HTLV-related spontaneous lymphocyte proliferation is related to levels of circulating anti-HTLV antibodies, and characterizes both HTLV-I and HTLV-II infection.

BACKGROUND: The routine use of hepatitis C virus (HCV) nucleic acid amplification testing (NAT) donor screening assays has provided an opportunity for revision of the current HCV supplemental testing algorithm, which requires that recombinant immunoblot assay (RIBA) be performed on every HCV enzyme immunoassay (EIA)-repeat-reactive donation. The FDA has approved variance requests to use a new algorithm that eliminates the need to perform RIBA when HCV NAT results are reactive. Data are provided in support of this new algorithm. STUDY DESIGN AND METHODS: HCV EIA (including signal-to-cutoff optical density ratio), RIBA, and NAT data were compiled from 33.2 million donations screened over an approximately 4-year period by the American Red Cross and Blood Systems Laboratories. Further, donations having specific combinations of HCV EIA, RIBA, and minipool (MP) NAT results were evaluated, with more sensitive individual-donation (ID) NAT, to construct improved counseling messages for donors. RESULTS: Of 47,041 EIA-repeat-reactive donations, 49.3 percent were RIBA-positive, 17.1 percent RIBA-indeterminate, and 33.5 percent RIBA-negative. NAT-reactive rates were 79.2, 2.5, and 0.18 percent for RIBA-positive, -indeterminate, and -negative donations, respectively. The new algorithm classified an additional 1 percent of donations as HCV-infected while at the same time detecting all infections classified as HCV-infected under the current algorithm. An additional 2.4 percent of RIBA-positive, MP NAT–nonreactive donations were reactive when a frozen-thawed aliquot was retested by ID NAT. CONCLUSION: Integrating HCV NAT results with RIBA results for purposes of donor notification allows more appropriate counseling messages to be given to EIA-repeat-reactive donors. The new HCV supplemental algorithm is an acceptable alternative to the current algorithm because it provides equivalent or superior accuracy in formulating donor counseling messages and may also result in reduced costs and more timely notification of infected donors.

Studies showing a significant correlation between hepatitis B surface antigen (HBsAg) and hepatitis B virus (HBV) deoxyribonucleic acid (DNA) levels have focused on the HBV seroconversion window period.HBsAg levels relative to HBV DNA results in 200 HBsAg-positive, anti-hepatitis B core antigen (HBc)-reactive blood donations were analyzed using quantitative polymerase chain reaction (PCR) (detection limit 400 copies/mL), two research PCR assays with increasing sensitivities (65 copies/mL and 1.3 copies/mL, respectively), and a quantitative HBsAg assay; HBsAg and HBV DNA levels were correlated with HBV serologic profiles; and the potential for replacing HBsAg screening with nucleic acid testing (NAT) was analyzed.Serologic profiles for over 90 percent of the donor samples were consistent with chronic HBV infection. Correlation between HBsAg and HBV DNA concentrations was weak (correlation coefficient = 0.33). Thirty-six percent (72/200) of donor samples had DNA levels under 400 copies per mL. Retesting of the 72 samples by more sensitive PCR assays showed that 60 out of 200 (30%) were positive by PCR with sensitivity of 65 copies per mL, whereas 6 out of 200 (3%) required PCR sensitivity of 1.3 copies per mL for positivity. Three percent (6/200) were negative by all three NAT assays.HBV DNA levels in HBsAg-positive, anti-HBc-reactive blood donations can be extremely low. About 6 percent of donations would be negative by current minipool HBV NAT methods. About 3 percent of donations would remain undetected by sensitive single-donor NAT. These results indicate caution in any consideration of dropping HBsAg screening.

In 1996, the Ortho HCV Version 3.0 ELISA Test System (HCV 3.0 EIA) was licensed in the United States for donor screening but was neither mandated nor universally implemented. Data from two studies comparing the differential performance of HCV 3.0 EIA and HCV 2.0 EIA are presented. The first study evaluated the differential performance in a cross-section of screened whole-blood donors after implementation of HCV 3.0 EIA; the second study evaluated the differential performance of HCV 3.0 EIA in plasma donors acutely infected with HCV, identified during routine Abbott HCV 2.0 EIA and HCV NAT (using Roche Ampliscreen plate assay) donor screening.The first study evaluated HCV 3.0 EIA repeat-reactive donations from four US blood centers, identified during the first 5 months of HCV 3.0 EIA implementation. HCV EIA repeat-reactive donations confirmed by RIBA HCV 3.0 SIA were retested using both Ortho HCV Version 2.0 ELISA Test System and Abbott HCV 2.0 EIA. All EIA-discordant donations were tested by polymerase chain reaction (PCR). In the second study, Abbott HCV 2.0 EIA-nonreactive, HCV PCR-positive donors were enrolled in a follow-up study in which the index and follow-up samples were re-evaluated by HCV 3.0 EIA.In the first study, of 292,459 donations, 501 (0.17%) confirmed HCV 3.0 EIA-reactive donations were identified; 15 (0.005%) were nonreactive by Ortho HCV 2.0 EIA and were all HCV RNA negative. In the second study, Ortho HCV 3.0 EIA retesting of Abbott HCV 2.0 EIA-nonreactive, RNA-positive index donations identified 16 (23%) as 3.0 EIA reactive. In 42 panels with a discordant time of seroconversion, HCV 3.0 EIA sero-conversion preceded HCV 2.0 EIA in all cases (p0.001). Two donors with HCV 3.0 EIA-reactive index donations never seroconverted by HCV 2.0 EIA during 160 to 180 days of follow-up.These studies demonstrate that HCV 3.0 EIA compared to HCV 2.0 EIA can better detect 1) remote nonviremic HCV infections, 2) acute infection, and 3) HCV antibodies in cases of atypical seroconversion.

Since the recognition that human immunodeficiency virus is transmissible by blood transfusion there has been increasing public and professional support for autologous blood donations before elective surgery. Autologous blood donation is, however, a more expensive process than the donation of allogeneic blood by community volunteers. Furthermore, there have been recent improvements in the safety of the volunteer blood supply.We used a decision-analysis model to assess the cost effectiveness of donating autologous blood for four surgical procedures. Cost data were collected from the observation of transfusion practice at the University of California, Los Angeles, in 1992. Estimates of the risks of transfusion-associated diseases and the costs of treating them came from the medical literature. Cost effectiveness was expressed in dollars per quality-adjusted year of life saved. We performed sensitivity analyses of the variables in our model and examined the effect of strategies suggested to reduce costs.Substituting autologous for allogeneic blood resulted in little expected health benefit (0.0002 to 0.00044 quality-adjusted year of life saved) at considerable additional cost ($68 to $4,783 per unit of blood). The additional cost of autologous blood was primarily a function of the discarding of units that were donated but not transfused and of a more labor-intensive donation process. The cost-effectiveness ratios ranged from $235,000 to over $23 million per quality-adjusted year of life saved.Given the improved safety of allogeneic transfusions today, the increased protection afforded by donating autologous blood is limited and may not justify the increased cost.

Current algorithms for the serologic confirmation of human T-cell lymphotropic virus type I and II (HTLV-I/II) antibody reactivity are complicated. We evaluated the performance of an HTLV-I Western blot (immunoblot) spiked with recombinant p21e protein (p21e WB) as an alternative to current confirmatory methods. These methods include the HTLV-I viral lysate Western blot and either a radioimmunoprecipitation assay or a p21e enzyme-linked immunosorbent assay. Five hundred fifty nine blood donations obtained from five U.S. blood centers and classified as HTLV-I/II seropositive (n = 149) or seroindeterminate (n = 410) by routine testing methods were further evaluated by PCR for proviral DNA and by the p21e WB. On the basis of serologic and PCR testing, 155 donations were classified as HTLV-I/II infected. The sensitivity of the p21e WB was 97.4%, slightly exceeding that of routine confirmatory testing. The specificity of the p21e WB was 97.5%, as determined by testing of 404 seroindeterminate samples that were negative in the PCR. The positive predictive value of the p21e WB was 94%. In contrast, the specificity and positive predictive value of routine confirmatory testing were both 100%. Follow-up sampling of presumptive p21e WB false-positive donors substantiated the absence of HTLV-I/II infection. Although the p21e WB used in this study has high sensitivity and may be useful as a confirmatory assay in epidemiologic research studies, it may not be ideal as a confirmatory test for the notification of blood donors.

To evaluate the relative safety of blood donations given in response to a major disaster, donor demographics and infectious disease test results were compared for donations made during the 10 days following the October 17, 1989, San Francisco Bay Area earthquake and those made during the preceding 6 months. These comparisons were made for donations given to the regional blood center in the area that was immediately affected by the disaster (Irwin Memorial Blood Centers) and for those given in an unaffected region (Los Angeles/Orange Counties Region, American Red Cross Blood Services). The rate of donation increased more than 200 percent during the 5 days following the earthquake in both the disaster-affected and unaffected regions. Both the disaster-affected and unaffected regions observed significant increases in the proportions of donations by first-time donors, by persons aged 20 to 39 years, and by women. The rates of confirmed positivity for infectious disease markers for post-earthquake donations did not differ significantly from rates for homologous donations given during the preceding 6 months, particularly when the rates were adjusted for the increased representation of first-time donors. Approximately 39 percent of post-earthquake first-time donors gave blood again within the following 6-month period. It is concluded that donations given after major disasters are essentially as safe as routine donations and that active efforts to recruit these donors again can be undertaken without reservation.

To assess the incidence of human immunodeficiency virus type 1(HIV-1) transmission by antibody (anti-HIV-1)-positive blood components, and to determine the immunologic and clinical course in HIV-1-infected recipients.We retrospectively tested approximately 200,000 donor blood component specimens stored in late 1984 and 1985 for anti-HIV-1, and we contacted recipients of positive specimens to determine their serologic status. They were compared with both recipients of HIV-1-negative transfusions and healthy (untransfused) controls. Subjects were seen at 3- to 6-month intervals for up to 4 years for clinical and immunologic evaluations.Of 133 recipients, 9 had other possible exposures. Excluding these cases, 111 of 124 (89.5%) were anti-HIV-1-positive (95% CI, 84.1% to 94.5%). The recipient's sex, age, underlying condition, and type of component did not influence infection rates. The cumulative risk for developing the acquired immunodeficiency syndrome (AIDS) within 38 months after transfusion was 13% (CI, 7.5% to 21.6%). At 36 +/- 3 months after the index transfusion, seropositive recipients had lower counts of CD2+CDw26+, CD4+, CD4+CD29+, and CD4+CD45RA+subsets and more CD8+I2+ lymphocytes than did recipients of anti-HIV-1-negative transfusions. The CD4+ and CD2+CDw26+subsets changed the most rapidly. The absolute CD8+ count remained normal.Transfusion of anti-HIV-1-positive blood infected 90% of recipients. The rate of progression to AIDS within the first 38 months after infection was similar to that reported for homosexual men and hemophiliacs. Although most lymphocyte subset counts changed over time, CD8+ counts were constant.

ContextAn understanding of characteristics of blood donors donating in times of crisis may help predict blood supply safety and donor return patterns.ObjectivesTo characterize the volume of donations and prevalence of infectious disease markers in blood donated by US donors responding to the September 11, 2001, terrorist attacks, and to evaluate return rates in those who donated for the first time.DesignCross-sectional survey data from the National Heart, Lung, and Blood Institute Retrovirus Epidemiology Donor Study for 4 weeks before and 4 weeks starting with September 11, 2001, and the corresponding 8-week period in 2000.Setting and ParticipantsA total of 327 065 volunteer blood donors making 373 628 allogeneic donations at 5 large regional US blood centers.Main Outcome MeasuresChanges in number of donations overall and by first-time and repeat status, prevalence of infectious disease markers, estimated risks of transfusion-transmitted viral infections, and first-time donor return rates.ResultsAbout 20 000 allogeneic donations were collected weekly in the 4 weeks preceding September 11, whereas ≈49 000 (2.5-fold increase) and ≈26 000 to 28 000 (1.3-fold to 1.4-fold increases) donations were made per week in the first and in the second through fourth weeks starting with September 11, respectively. All demographic groups donated more than usual after the attacks, and after adjusting for seasonal and annual variation there was a 5.2-fold (95% confidence interval, 5.0-5.4) increase in the number of first-time donations vs a 1.5-fold (1.4-1.5) increase in the number of repeat donations made in the first week starting on September 11 vs the 4 weeks before. The weekly proportion of repeat donors returning after not donating for 10 or more years increased from 2% before September 11 to 6% in the first week starting with September 11. Donations confirmed positive for human immunodeficiency virus (HIV), hepatitis C virus (HCV), and hepatitis B surface antigen nearly tripled between 1 week before September 11 (0.1%) and 1 week after the attacks (0.3%), largely explained by the increase in first-time and lapsed repeat donors. Estimated viral residual risks increased slightly after the attacks (HIV, 1/1.5 million vs 1/1.8 million donations; HCV, 1/1.3 million vs 1/1.6 million; hepatitis B virus, 1/140 000 vs 1/170 000). First-time donor 12-month return rates for 2000 and 2001 were similar, ≈28% (P = .37) for donors in the first week starting with September 11 (or September 12, 2000) and 30% (P = .69) for the second to fourth weeks.ConclusionsThe September 11 events resulted in an influx of first-time donors without substantial increase in absolute risk of transfusion-transmissible viral infections. First-time donor return rates were equally relatively low before and after the attacks, suggesting that those donating in times of crisis have return behaviors similar to those of other first-time donors. Their relatively low return rates reinforce the need for education about the importance of donating regularly.

The Transfusion Safety Study (TSS) and the National Heart, Lung, and Blood Institute (NHLBI) established a repository of approximately 200,000 sera from blood donors in late 1984 and early 1985. Collections were made in the four metropolitan areas with the highest prevalence of AIDS. Retrospective testing showed an overall anti-HIV-1 prevalence of 16 cases per 10,000 donations. In this study, the predictive value of a negative initial enzyme-linked immunoassay was estimated from both quality control specimens and the rescreening of 13,461 sera to be greater than 99.99 percent with respect to technical error. Among anti-HIV-1-positive persons, there was a 1.3- to 1.5-fold excess of first-time donors. The anti-HIV-1 prevalence among donors showed that infection was more common among young men than suggested by national reporting of AIDS cases. Anti-HIV-1 prevalence varied among the four metropolitan areas less than did reported AIDS cases, but, by 1987, the differences in the latter had decreased. Anti-HIV-1 prevalence in collection areas outside of the four major cities differed much more widely than that among the cities themselves. The TSS/NHLBI Donor Repository will remain available for the indefinite future for further evaluation of screening procedures for HIV-1 and other viruses for which transfusion is found to be an important route of transmission.

We investigated the relationship of soluble interleukin 2 receptor (sIL2R) production to cellular IL2R expression and DNA synthesis by mitogen-stimulated mononuclear cells from blood donors seropositive for human immunodeficiency virus (HIV). SIL2R was measured using an enzyme-linked immunosorbent assay which employed 2 anti-IL2R monoclonal antibodies recognizing distinct IL2R epitopes. Decreased phytohemagglutinin-induced DNA synthesis and cellular IL2R expression were accompanied by decreased levels of sIL2R in cell culture supernatants. Similar findings were observed for pokeweed mitogen-induced responses. There was no detectable spontaneous secretion of sIL2R into culture supernatants by unstimulated mononuclear cells from either HIV-seropositive or control seronegative donors. These findings indicate that the in vitro T-cell activation defects which characterize HIV infection include decreased sIL2R production, as well as decreased cellular IL2R expression and DNA synthesis. Further, they show that assessment of supernatant sIL2R levels can be used as a valid, reliable assay for T-cell activation.

Patients infected by the human immunodeficiency virus (HIV) as a result of blood transfusions are unique in that their dates of infection are well defined and their medical conditions befo...

A population of 73 donor samples was assembled on the basis of reactive results in routine screening with three different licensed human T-lymphotrophic virus type III (HTLV-III) antibody enzyme-linked immunosorbent assay (ELISA) procedures. The samples were retested by a number of licensed and developmental tests and by Western blot analysis. Our data indicate that nonspecific results are generated by ELISA tests and that many of these reactions appear to be directed against the cell substrate used to grow the virus. These findings suggest that combinations of currently licensed ELISA tests, based upon HTLV-III grown in H-9 cells, cannot be used to confirm the specificity of reactive samples.

We have estimated the risk of transmitting HIV infection from a unit of HIV seronegative blood collected in Los Angeles and Orange Counties, CA from March 1985 through February 1987. Our method consisted of lookback investigations and anti-HIV testing of living recipients of HIV seronegative units donated by persons who later tested HIV seropositive at the time of a subsequent donation. During these investigations we have documented 3 cases of HIV transmission from HIV seronegative blood; using several assumptions, and extrapolating from this data, we have calculated that the risk of HIV transmission from an HIV seronegative unit was 1 in 51,000 to 1 in 102,000 (with a best guess of 1 in 68,000). We believe that our model can be applied in other geographic regions in an ongoing fashion in order to update our estimates of HIV transmission from HIV seronegative blood.

We performed exchange transfusions, utilizing the technique of automated erythrocytapheresis, for the treatment of patients with sickle cell anemia. In an attempt to determine guidelines for the use of erythrocytapheresis, we studied the use of this procedure in three distinct clinical situations in nine patients with sickle cell disease. Patients with dangerous complications of sickle cell disease such as acute respiratory distress and priapism responded well to erythrocytapheresis, showing marked improvement within 24-48 hours. Patients with prolonged painful vasoocclusive crises showed only variable improvement after erythrocytapheresis therapy, insufficient to justify exposing the patient to the risks of the procedure. Patients treated to decrease the frequency of painful crises demonstrated no prolongation in symptom-free intervals between crises. Therefore, erythrocytapheresis has its main value in the management of acute, dangerous complications of sickle cell disease.

We conducted anti-HIV testing on follow-up samples obtained at a mean interval of 20 weeks from 150 blood donors who had previously tested anti-HIV ELISA positive and Western blot atypical. Of 93 donors who demonstrated reactivity to HIV core protein p24, 4 progressed to positive Western blots. Most of the remaining donors showed a persistent p24 reactivity on Western blot and had no risk factors for HIV infection. Immunofluorescence testing of the initial sample from 93 donors could not definitively separate seroconverters from those with persistent p24 reactivity. Of 57 donors with p18 reactivity, none were positive on follow-up anti-HIV testing. Our findings suggest policies and strategies for notifying donors of atypical anti-HIV Western blot results.