Surveillance for Zika, Chikungunya, and Dengue Virus Incidence and RNAemia in Blood Donors at 4 Brazilian Blood Centers During 2016-2019.

BACKGROUND: Except for public health case reports, the incidence of Zika virus (ZIKV), chikungunya virus (CHIKV), and dengue virus (DENV) infection are not available to assess the potential blood transfusion safety threat in Brazil. METHODS: Pools of 6 donation samples (MP6) left over from human immunodeficiency virus, hepatitis B virus, and hepatitis C virus nucleic acid testing were combined to create MP18 pools (3 MP6 pools). Samples were tested using the Grifols triplex ZIKV, CHIKV, and DENV real-time transcription mediated amplification assay to estimate prevalence of RNAemia and incidence, and to compare these results to case reports in São Paulo, Belo Horizonte, Recife, and Rio de Janeiro, from April 2016 through June 2019. RESULTS: ZIKV, CHIKV, and DENV RNAemia were found from donors who donated without overt symptoms of infection that would have led to deferral. The highest RNAemic donation prevalence was 1.2% (95% CI, .8%-1.9%) for DENV in Belo Horizonte in May 2019. Arbovirus infections varied by location and time of year, and were not always aligned with annual arbovirus outbreak seasons in different regions of the country. CONCLUSIONS: Testing donations for arboviruses in Brazil can contribute to public health. Transfusion recipients were likely exposed to ZIKV, CHIKV, and DENV viremic blood components during the study period.

Blood utilization and characteristics of patients treated with chronic transfusion therapy in a large cohort of Brazilian patients with sickle cell disease.

BACKGROUND: Red blood cell (RBC) transfusions are used in sickle cell disease (SCD) to treat acute complications or as chronic transfusion therapy (CTT) to prevent severe manifestations. The objectives of this study were to describe blood utilization and adverse events (AEs) associated with RBCs in the Brazilian SCD population and compare characteristics of patients treated or not with CTT. STUDY DESIGN AND METHODS: A SCD cohort was established at six Brazilian centers. Medical and blood bank records were abstracted for clinical and transfusion history. Two controls not treated with CTT matched on center, SCD genotype, sex, and age were selected for each CTT case within the cohort to compare characteristics between the two groups. RESULTS: Most of the 2794-member cohort had received a transfusion (75.0% of children and 89.2% of adults) with 29.2% of patients receiving transfusion in the prior year. There were 170 (10.6%) children and 115 (9.2%) adults treated with CTT. Children not treated with CTT were more likely to have pain and acute chest hospitalizations in the prior year (25.3% vs. 11.9%, p = 0.0003; and 22.0% vs. 10.7%, p = 0.002, respectively). Both iron overload and alloimmunization were more common in CTT cases compared to controls (65.6% vs. 17.0% and 36.2% vs. 15.9%, respectively). A higher proportion of adults treated with CTT demonstrated oxygen saturation of greater than 95% compared to controls not treated (51.1% vs. 39.2%), while there was no difference in oxygenation between children treated or not. Of 4501 transfusion episodes, 28 (0.62%) AEs were reported. There was no difference in AEs associated with transfusions for acute indications versus CTT. CONCLUSION: Red blood cell transfusion was common in Brazilian SCD patients, with utilization driven by CTT. Transfusion reactions were not common; however, alloimmunization and iron overload were frequent among those on CTT, highlighting the need for novel clinical strategies to mitigate these risks.

Using a motivator and deterrent questionnaire to predict actual donation return behavior among first-time African-origin blood donors.

BACKGROUND: In South Africa, success in recruiting first-time African-origin blood donors at low risk for HIV infection has been tempered by lower-than-anticipated return rates. We studied whether self-reported motivators and deterrents could predict actual donor return among first-time donors. METHODS: We administered a questionnaire on blood donation motivators and deterrents within 2 months after donation to a cohort of first-time African-origin blood donors in 2014 and followed their return behavior for 1 year. Survey responses associated with return within 1 year were assessed using separate multivariate logistic regression models for motivators and deterrents. RESULTS: A total of 2902 first-time African origin donors with median age of 23 years and female predominance (59%) were included. Within 1 year 1574 (54% of donors) attempted at least one additional donation. Donors were more likely to return if they strongly agreed with the statement "Blood donation is an easy way to make a difference" (odds ratio [OR], 2.0; 95% confidence interval [CI], 1.3-2.9) and "I donated in response to advertisements on the radio, TV or newspaper" (OR, 1.6; 95% CI, 1.2-2.1). English language preference and nonstudent employment status were also associated with donor return. Poor customer service (OR, 0.45; 95% CI, 0.28-0.71), geographic region, and nonstudent employment status were associated with donor return in the deterrent model. CONCLUSIONS: Prosocial motivators and marketing communications predicted return, while poor customer experience predicted nonreturn. This novel design allowed us to study the link between donation motivators and deterrents and actual return for donation in the African context.

The impact of recipient factors on the lower-than-expected hemoglobin increment in transfused outpatients with hematologic diseases.

BACKGROUND: Patients with cancer or chronic hematologic disorders frequently receive red blood cell (RBC) transfusions. Based on long-standing assumptions, each RBC unit is thought to increase recipient hemoglobin by 1 g/dL, but smaller increments can occur. A better understanding of recipient factors affecting hemoglobin increments could help providers manage these patients. METHODS: Data were collected as a part of the observational Red Cells in Outpatients Transfusion Outcomes (RETRO) study of outpatients with hematologic or cancer-related diagnoses. Hemoglobin was measured before transfusion and 30 minutes after transfusion. A classification and regression tree (CART) analysis was performed to identify statistically significant associations with clinical variables. A corresponding prediction equation was developed and validated using linear regression. RESULTS: A total of 195 participants had both pre- and posttransfusion hemoglobin values for analysis. The median age was 66 years, and patients received one (73%) or two (27%) RBC units during the transfusion episode. The overall median change in hemoglobin was 0.6 g/dL per RBC unit. Both CART analysis and linear regression identified the following significant predictors of hemoglobin increment: number of units received (positive correlation), patient estimated circulating blood volume (negative correlation), pretransfusion hemoglobin (negative correlation), and patient age (negative correlation). CONCLUSION: In this study of outpatients with hematologic disease, most patients had a hemoglobin increment of less than 1 g/dL/unit. Recipient-specific factors influenced the hemoglobin increment at 30 minutes, and providers should consider circulating blood volume, pretransfusion hemoglobin, and recipient age, when developing patient-specific RBC transfusion plans for this unique cohort.

Association of donor age, body mass index, hemoglobin, and smoking status with in-hospital mortality and length of stay among red blood cell-transfused recipients.

BACKGROUND: Recent publications have reported conflicting findings regarding associations of blood donor demographics and mortality of transfused patients. We hypothesized that the analysis of additional donor characteristics and consideration of alternative outcomes might provide insight into these disparate results. STUDY DESIGN AND METHODS: We analyzed data from a retrospective cohort of transfused patients from the Recipient Epidemiology and Donor Evaluation Study-III (REDS-III). We used stratified Cox regression models to estimate associations between blood donor characteristics and hospital mortality and posttransfusion length of stay among patients transfused red blood cell (RBC) units. Donor characteristics evaluated included age, body mass index, hemoglobin levels, and smoking status. The statistical analyses were adjusted for recipient factors, including total number of transfusions. RESULTS: We studied 93,726 patients in 130,381 hospitalizations during which 428,461 RBC units were transfused. There were no associations between blood donor characteristics and hospital mortality. Receipt of RBC units from donors less than 20 years of age was associated with a shorter hospital length of stay (hazard ratio for discharge per transfused unit, 1.03; 95% confidence interval, 1.02-1.04; p < 0.001) but not for other donor characteristics. CONCLUSION: We found no evidence of associations between blood donor factors and in-hospital mortality. Our finding of shorter hospital length of stay in patients transfused RBCs from younger donors is intriguing but requires confirmation. Future collaborations are needed to develop a framework of appropriate methodologic approaches to be used in linked analyses across large cohorts.

Association of Blood Donor Sex and Prior Pregnancy With Mortality Among Red Blood Cell Transfusion Recipients.

Importance: Evidence regarding associations of blood donor sex with mortality among red blood cell transfusion recipients is conflicting. Objective: To study associations of donor sex and prior pregnancy with mortality of transfusion recipients. Design, Setting, and Participants: Data from 3 retrospective cohorts of transfusion recipients (the Kaiser Permanente Northern California [KPNC] and Recipient Epidemiology and Donor Evaluation Study-III [REDS-III] databases of data from January 2013 to December 2016 and the Scandinavian Donations and Transfusions [SCANDAT] database with data from January 2003 to December 2012) were analyzed. Final dates of follow-up were December 31, 2016, for the KPNC and REDS-III cohorts and December 31, 2012, for the SCANDAT cohort. Stratified Cox regression models were used to estimate associations between donor exposure groups with risk of mortality, adjusting for the number of red blood cell unit transfusions. Exposures: The number of transfused red blood cell units from female donors, previously pregnant donors, and sex-discordant donors (male donor and female recipient or female donor and male recipient). Main Outcomes and Measures: In-hospital mortality. Results: The study population included 34 662 patients (mean age, 69 years; 18 652 [54%] women) from the KPNC cohort, 93 724 patients (mean age, 61 years; 48 348 [52%] women) from the REDS-III cohort, and 918 996 patients (mean age, 72 years; 522 239 [57%] women) from the SCANDAT cohort. The median number of red blood cell transfusions per patient was 3 in the KPNC cohort, 2 in the REDS-III cohort, and 3 in the SCANDAT cohort. The percentage of transfusions from previously pregnant or parous donors was 9% in the KPNC cohort, 18% in the REDS-III cohort, and 25% in the SCANDAT cohort. The percentage of transfusions in the 3 cohorts from female donors ranged from 39% to 43%, from previously pregnant or parous donors ranged from 9% to 25%, and from sex-discordant donors ranged from 44% to 50%. There were 3217 in-hospital deaths in the KPNC cohort, 8519 in the REDS-III cohort, and 198 537 in the SCANDAT cohort. There were no statistically significant associations between any of the 3 donor exposures and in-hospital mortality in the 3 cohorts. Hazard ratios for in-hospital mortality per transfused unit from female donors were 0.99 (95% CI, 0.96-1.03) for the KPNC cohort, 1.00 (95% CI, 0.99-1.01) for the REDS-III cohort, and 1.00 (95% CI, 0.99-1.00) for the SCANDAT cohort. For units from previously pregnant or parous female donors, hazard ratios were 1.00 (95% CI, 1.00-1.01) for the KPNC cohort, 1.01 (95% CI, 0.98-1.03) for the REDS-III cohort, and 1.00 (95% CI, 1.00-1.01) for the SCANDAT cohort. For units from sex-discordant transfusions, hazard ratios were 1.02 (95% CI, 0.99-1.05) for the KPNC cohort, 0.99 (95% CI, 0.98-1.00) for the REDS-III cohort, and 1.00 (95% CI, 0.99-1.00) for the SCANDAT cohort. Conclusions and Relevance: Among red blood cell transfusion recipients, transfusions from female, previously pregnant, or sex-discordant donors were not significantly associated with increased mortality.

Incidence of transfusion reactions: a multicenter study utilizing systematic active surveillance and expert adjudication.

BACKGROUND: Prevalence estimates of the serious hazards of transfusion vary widely. We hypothesized that the current reporting infrastructure in the United States fails to capture many transfusion reactions and undertook a multicenter study using active surveillance, data review, and adjudication to test this hypothesis. STUDY DESIGN AND METHODS: A retrospective record review was completed for a random sample of 17% of all inpatient transfusion episodes over 6 months at four academic tertiary care hospitals, with an episode defined as all blood products released to a patient in 6 hours. Data were recorded by trained clinical research nurses, and serious reactions were adjudicated by a panel of transfusion medicine experts. RESULTS: Of 4857 transfusion episodes investigated, 1.1% were associated with a serious reaction. Transfusion-associated circulatory overload was the most frequent serious reaction noted, being identified in 1% of transfusion episodes. Despite clinical notes describing a potential transfusion association in 59% of these cases, only 5.1% were reported to the transfusion service. Suspected transfusion-related acute lung injury/possible transfusion-related acute lung injury, anaphylactic, and hypotensive reactions were noted in 0.08, 0.02, and 0.02% of transfusion episodes, respectively. Minor reactions, including febrile nonhemolytic and allergic, were noted in 0.62 and 0.29% of transfusion episodes, respectively, with 30 and 50% reported to the transfusion service. CONCLUSION: Underreporting of cardiopulmonary transfusion reactions is striking among academic, tertiary care hospitals. Complete and accurate reporting is essential to identify, define, establish pathogenesis, and mitigate/treat transfusion reactions. A better understanding of the failure to report may improve the accuracy of passive reporting systems.

Downregulation of Cytokines and Chemokines by GB Virus C After Transmission Via Blood Transfusion in HIV-Positive Blood Recipients.

BACKGROUND: An association between GB virus C (GBV-C) and improved outcomes of human immunodeficiency virus (HIV) infection has been reported in HIV-positive individuals with active GBV-C coinfection. This study provides insights into the immune mechanisms underlying the protective role of GBV-C in HIV-infected patients. METHODS: The concentrations of 64 cytokines and chemokines were measured in plasma samples obtained from the Viral Activation Transfusion Study cohort before transfusion and longitudinally from 30 patients positive for both HIV and GBV-C (hereafter, "cases") and 30 patients positive for HIV and negative for GBV-C (hereafter, "controls"). RESULTS: Cases had lower HIV viral loads and higher CD4 T-cell counts than controls after acquisition of GBV-C infection. Most of the modulated cytokines and chemokines were reduced after GBV-C detection, including many proinflammatory cytokines, suggesting an overall antiinflammatory effect of GBV-C in HIV-positive subjects. Most pathways and functions of the measured cytokines were downregulated in cases, except cell death pathways, which were upregulated in various cell subsets in the 3 months after GBV-C detection. CONCLUSIONS: GBV-C has a protective effect, in part through a competition mechanism leading to decreased inflammation and improved HIV disease outcome in cases. Further studies are necessary to establish whether GBV-C may have deleterious effects on the host at the cellular level, including depleting the cells that are the targets of HIV.

Diagnostic Accuracy of Dried Plasma Spot Specimens for HIV-1 Viral Load Testing: A Systematic Review and Meta-analysis.

BACKGROUND: Dried plasma spot specimens may be a viable alternative to traditional liquid plasma in field settings, but the diagnostic accuracy is not well understood. METHODS: Standard databases (PubMed and Medline), conferences, and gray literature were searched until January 2019. The quality of evidence was evaluated using the Standards for Reporting Studies of Diagnostic Accuracy and Quality Assessment of Diagnostic Accuracy Studies-2 criteria. We used univariate and bivariate random effects models to determine misclassification, sensitivity, and specificity across multiple thresholds, overall and for each viral load technology, and to account for between-study variation. RESULTS: We identified 23 studies for inclusion in the systematic review that compared the diagnostic accuracy of dried plasma spots with that of plasma. Primary data from 16 of the 23 studies were shared and included in the meta-analysis, representing 18 countries, totaling 1847 paired dried plasma spot:plasma data points. The mean bias of dried plasma spot specimens compared with that of plasma was 0.28 log10 copies/mL, whereas the difference in median viral load was 2.25 log10 copies/mL. More dried plasma spot values were undetectable compared with plasma values (43.6% vs. 29.8%). Analyzing all technologies together, the sensitivity and specificity of dried plasma spot specimens were >92% across all treatment failure thresholds compared and total misclassification <5.4% across all treatment failure thresholds compared. Some technologies had lower sensitivity or specificity; however, the results were typically consistent across treatment failure thresholds. DISCUSSION: Overall, dried plasma spot specimens performed relatively well compared with plasma with sensitivity and specificity values greater than 90% and misclassification rates less than 10% across all treatment failure thresholds reviewed.

Body mass index, waist circumference and waist to hip ratio and change in sex steroid hormones: the Massachusetts Male Ageing Study.

OBJECTIVE: Cross-sectional data suggest that obesity, particularly central obesity, may be associated with decreased production of sex steroid hormones in men. However, longitudinal hormone data on men in relation to obesity status are limited. Previous studies have not consistently demonstrated whether sex steroids are associated specifically to body mass index or to measures of central obesity. Our objective was to examine the relation of obesity (body mass index > 30 kg/m2), and of central obesity (waist circumference > 100 cm or waist to hip ratio > 0.95) to longitudinal change in sex steroid hormones in men. DESIGN: Prospective follow-up of a population-based sample of men in Boston. PATIENTS: Nine hundred forty-two (942) men in the Massachusetts Male Ageing Study with complete anthropometry and hormone data at baseline (1987-1989, ages 40-70) and follow-up (1995-1997). MEASUREMENTS: Free and total testosterone (FT and TT), dehydroepiandrosterone sulphate (DHEAS), and sex hormone-binding globulin (SHBG) were assessed using standardized methods. Health behaviours and medical history were obtained by structured interview. Repeated measures regression was used to describe trends in steroid hormones and SHBG in relation to obesity status, adjusting for age, smoking, alcohol, comorbidities, and physical activity. RESULTS: Obesity was associated with decreased levels of total and free testosterone, and of SHBG at follow-up relative to baseline. For any given baseline concentration of TT, FT or SHBG, follow-up levels were lowest among men who remained obese or who became obese during follow-up. This was true for all three indices of obesity. Central adiposity was associated with lower DHEAS levels at follow-up, while elevated body mass index was not. CONCLUSIONS: Obesity may predict greater decline in testosterone and SHBG levels with age. Central adiposity may be a more important predictor of decline in DHEAS than is body mass index.

Blinded, multicenter comparison of methods to detect a drug-resistant mutant of human immunodeficiency virus type 1 at low frequency.

We determined the abilities of 10 technologies to detect and quantify a common drug-resistant mutant of human immunodeficiency virus type 1 (lysine to asparagine at codon 103 of the reverse transcriptase) using a blinded test panel containing mutant-wild-type mixtures ranging from 0.01% to 100% mutant. Two technologies, allele-specific reverse transcriptase PCR and a Ty1HRT yeast system, could quantify the mutant down to 0.1 to 0.4%. These technologies should help define the impact of low-frequency drug-resistant mutants on response to antiretroviral therapy.

Effect of long-term transfusion on growth in children with sickle cell anemia: results of the STOP trial.

OBJECTIVE: To determine whether long-term transfusion improves growth in children with sickle cell anemia. STUDY DESIGN: In the Stroke Prevention Trial for Sickle Cell Anemia Study, patients were randomized to receive long-term transfusion (CTX) or standard care (STC). Transfusions were administered every 3 to 5 weeks, and hemoglobin S levels were maintained at 30% pretransfusion for an average of 2 years. Serial height and weight measurements (obtained every 3 months), body mass index (BMI) values, and growth z-scores were analyzed. RESULTS: Children in the CTX (n=53) and STC (n=41) groups were similar at baseline. After 24 months, the z-scores for height, weight, and BMI of those receiving CTX had improved significantly, whereas no changes occurred in the STC group. Patients in the CTX group approached normal height-for-age and weight-for-age z-scores. Patients from a large historical control group had significantly lower weight and height growth velocities than patients in the CTX group. CONCLUSIONS: Patients in the Stroke Prevention Trial for Sickle Cell Anemia Study who received CTX had improved height and weight and BMI over a 2-year period. Higher hemoglobin levels resulting from transfusion may improve growth by lowering energy expenditure. In addition to the prevention of vasoocclusive events, CTX results in significant improvement in the growth of children with sickle cell disease.

Can peak systolic velocities be used for prediction of stroke in sickle cell anemia?

BACKGROUND AND PURPOSE: Ischemic stroke occurs in at least 11% of patients with homozygous sickle cell anemia (SCD) by the time they turn 20 years old. High risk associated with distal intracranial internal carotid (ICA) and proximal middle cerebral artery (MCA) stenosis can be detected by transcranial Doppler (TCD). TCD screening offers the possibility of reducing the risk of first stroke significantly based on a paradigm tested and proven to be effective in a stroke prevention trial in sickle cell anemia (STOP). Children with high flow velocity in the ICA and MCA of 200 cm/s time average mean of the maximum (TAMM) or higher had a 10% per year risk of first stroke that was reduced to <1% with regular red cell transfusion (reduction of hemoglobin S <30%). The clinical application of the STOP results could be enhanced if criteria for treatment could be found that are based on peak systolic velocity (PSV), the measure more commonly used in vascular ultrasound practice. OBJECTIVE: To compare PSV and end diastolic velocity (EDV) with TAMM for prediction of stroke and to derive PSV cutpoints for STOP protocol definitions of conditional and abnormal TCD. Using the STOP TCD and stroke outcome data to compare PSV and TAMM in terms of stroke prediction, PSV cutpoints comparable to those based on TAMM and used in STOP were derived. Because of their familiarity to the vascular ultrasound community, PSV cutpoints should be an important alternative to TAMM and may increase availability of screening and risk stratification for children with this disease. MATERIALS AND METHODS: Data from 1,937 baseline TCD studies from STOP were correlated with stroke outcome in those not treated with transfusion. Stroke prediction was assessed with survival analysis using TAMM, PSV and EDV as continuous variables individually and then pair-wise in the same model, which contained 53 stroke events. RESULTS: PSV and EDV were highly correlated to the TAMM velocity (r=0.94). The multivariate model for prediction indicated that TAMM velocity was a better predictor than EDV, and PSV and TAMM were approximately equivalent. PSV cutpoints defining the two relevant STOP risk categories--"conditional," which should lead to increased TCD surveillance, and "abnormal," which should lead to strong consideration for treatment according to STOP--were derived taking into consideration known differences in measurements between the dedicated Doppler systems (TCD) used in STOP and the transcranial Doppler imaging (TCDI) systems commonly used in clinical practice. The recommended PSV cutpoint for conditional TCD is 200 cm/s, and for abnormal TCD triggering consideration for treatment is 250 cm/s. CONCLUSION: Assuming TCDI equipment is used and the STOP protocol is applied, a PSV cutpoint of 200 cm/s is recommended as the threshold for increased TCD surveillance (comparable to a TCD TAMM of 170 cm/s in STOP); a PSV of 250 cm/s is recommended as the cutpoint at which, if confirmed in a second examination, chronic transfusion should be considered. Assuming the STOP scanning protocol is used, PSV is at least as good as TAMM and can be used to select children with SCD for treatment or increased surveillance to prevent first stroke.

Longitudinal changes in ferritin during chronic transfusion: a report from the Stroke Prevention Trial in Sickle Cell Anemia (STOP).

PURPOSE: Chronic red cell transfusion has been used for prevention of recurrent stroke in patients with sickle cell disease for three decades, and its effectiveness in primary prevention was recently shown. Iron overload, the inevitable result of chronic transfusion, is commonly monitored with serum ferritin concentration. PATIENTS AND METHODS: Sixty-one patients at high risk for stroke received chronic transfusion in a clinical trial of stroke prevention. A serum ferritin level of less than 500 ng/mL was required for study entry. Ferritin levels were obtained quarterly. Fifty patients who had four or more ferritin measurements were included in this analysis. Transfusions were administered as exchange or simple, with washed, reconstituted, or packed red blood cells, at the discretion of the site investigator. RESULTS: Serum ferritin levels increased linearly with cumulative transfusion volume during the first four ferritin measurements, but the rate of increase varied widely among patients. Rates of increase varied similarly among 23 patients who received exclusively simple transfusion with packed red cells and in five patients who received exchange transfusions. Thirty-two patients received a total transfusion volume of more than 250 mL/kg. Ferritin continued to increase linearly after the first four measurements in 14, but the remaining 18 experienced a plateau before the level reached 3,000 ng/mL. Six of those with a linear increase never reached a ferritin level of 3,000 ng/dL. CONCLUSIONS: There was strong intrapatient correlation between serum ferritin levels and volume transfused but wide interpatient variability early during chronic transfusion therapy. Intrapatient correlation declined at transfusion volumes of more than 250 mL/kg. Direct iron store assessment is needed to determine the clinical significance of serum ferritin variability.

Magnetic resonance angiography in children with sickle cell disease and abnormal transcranial Doppler ultrasonography findings enrolled in the STOP study.

The stroke prevention study in sickle cell disease (STOP) demonstrated a 90% reduction in stroke risk with transfusion among patients with time-averaged mean cerebral blood velocity (TAMV) of 200 cm/s or more as measured by transcranial Doppler (TCD). In STOP, 232 brain magnetic resonance angiograms (MRAs) were performed on 100 patients, 47 in the transfusion arm and 53 in the standard care arm. Baseline MRA findings were interpreted as normal in 75 patients and as indicating mild stenosis in 4 patients and severe stenosis in 21 patients. Among 35 patients who underwent magnetic resonance angiography within 30 days of random assignment, the TAMV was significantly higher in 7 patients with severe stenosis compared with 28 patients with normal MRA findings or mild stenosis (276.7 +/- 34 vs 215 +/- 15.6 cm/s; P<.001). In the standard care arm, 4 of 13 patients with abnormal MRA findings had strokes compared with 5 of 40 patients with normal MRA findings (P=.03). In this arm, TAMV became normal (less than 170 cm/s) or conditional (170-199 cm/s) in 26 of 38 patients with normal or mildly abnormal baseline MRA but remained abnormal in 8 of 10 patients with severely abnormal baseline MRA. These results suggest that TCD often detects flow abnormalities indicative of stroke risk before MRA lesions become evident. Furthermore, patients with abnormal MRA findings and higher TCD velocities are at higher risk for stroke, and their cerebral TAMVs are unlikely to decrease without transfusion.

Multicenter evaluation of use of dried blood and plasma spot specimens in quantitative assays for human immunodeficiency virus RNA: measurement, precision, and RNA stability.

Eleven laboratories evaluated the use of dried blood and plasma spots for quantitation of human immunodeficiency virus (HIV) RNA by two commercially available RNA assays, the Roche Amplicor HIV-1 Monitor and the bioMerieux NucliSens HIV-1 QT assays. The recovery of HIV RNA was linear over a dynamic range extending from 4,000 to 500,000 HIV type 1 RNA copies/ml. The Monitor assay appeared to have a broader dynamic range and seemed more sensitive at lower concentrations. However, the NucliSens assay gave more consistent results and could be performed without modification of the kit. HIV RNA was stable in dried whole blood or plasma stored at room temperature or at -70 degrees C for up to 1 year. Dried blood and dried plasma spots can be used as an easy and inexpensive means for the collection and storage of specimens under field conditions for the diagnosis of HIV infection and the monitoring of antiretroviral therapy.