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Biomedical subjects

Steven H Kleinman

Publications and source records attributed to Steven H Kleinman.

9 recordsLinked to original sources
PubMed2003

Dynamics of HIV viremia and antibody seroconversion in plasma donors: implications for diagnosis and staging of primary HIV infection.

OBJECTIVES: The characterization of primary HIV infection by the analysis of serial plasma samples from newly infected persons using multiple standard viral assays. DESIGN: A retrospective study involving two sets of archived samples from HIV-infected plasma donors. (A) 435 samples from 51 donors detected by anti-HIV enzyme immunoassays donated during 1984-1994; (B) 145 specimens from 44 donors detected by p24 antigen screening donated during 1996-1998. SETTING: Two US plasma products companies. MAIN OUTCOME MEASURES: The timepoints of appearance of HIV-1 markers and viral load concentrations during primary HIV infection. RESULTS: The pattern of sequential emergence of viral markers in the 'A' panels was highly consistent, allowing the definition and estimation of the duration of six sequential stages. From the 'B' panels, the viral load at p24 antigen seroconversion was estimated by regression analysis at 10 000 copies/ml (95% CI 2000-93 000) and the HIV replication rate at 0.35 log copies/ml/day, corresponding to a doubling time in the preseroconversion phase of 20.5 h (95% CI 18.2-23.4 h). Consequently, an RNA test with 50 copies/ml sensitivity would detect HIV infection approximately 7 days before a p24 antigen test, and 12 days before a sensitive anti-HIV test. CONCLUSION: The sequential emergence of assay reactivity allows the classification of primary HIV-1 infection into distinct laboratory stages, which may facilitate the diagnosis of recent infection and stratification of patients enrolled in clinical trials. Quantitative analysis of preseroconversion replication rates of HIV is useful for projecting the yield and predictive value of assays targeting primary HIV infection.

Biomarkers↗
PubMed2003

Effect of a national disaster on blood supply and safety: the September 11 experience.

CONTEXT: An understanding of characteristics of blood donors donating in times of crisis may help predict blood supply safety and donor return patterns. OBJECTIVES: To 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. DESIGN: Cross-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 PARTICIPANTS: A total of 327065 volunteer blood donors making 373628 allogeneic donations at 5 large regional US blood centers. MAIN OUTCOME MEASURES: Changes 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. RESULTS: About 20000 allogeneic donations were collected weekly in the 4 weeks preceding September 11, whereas approximately 49 000 (2.5-fold increase) and approximately 26000 to 28000 (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, 1/140000 vs 1/170000). First-time donor 12-month return rates for 2000 and 2001 were similar, approximately 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. CONCLUSIONS: The 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.

Blood Banks↗
PubMed2003

Attitudes toward blood donation incentives in the United States: implications for donor recruitment.

BACKGROUND: The potential effectiveness of various donation incentive programs may vary by demographics, first-time or repeat status, and collection site. STUDY DESIGN AND METHODS: Attitudes toward future incentives were obtained from a 1998 anonymous survey sent to 92,581 US blood donors. Responses (encouraged, discouraged, no difference) to incentives were compared within demographic groups, donations sites, and between first-time and repeat community whole-blood (WB) donors using chi-square tests and logistic regressions adjusted for sample design. RESULTS: Incentives most likely to encourage donation return among all 45,588 WB respondents were blood credits (61%), cholesterol screening (61%), and prostate-specific antigen (PSA) screening (73% of men). Younger donors (< or = 25 years old) were 4 to 5 times more likely to be encouraged to donate if offered compensatory incentives (tickets to events, discounts or lottery and/or raffle tickets), gifts, or a token of appreciation than were those donors older than 55. This age effect influenced positive attitudes toward incentives in first-time donors and in donors giving at schools, universities, or military sites. Among all donors, up to 7 to 9 percent reported they would be discouraged to return if offered compensatory incentives. CONCLUSIONS: Blood credits and cholesterol and PSA screening would be well received at all donation sites. Gifts, compensatory incentives, and tokens of appreciation appeal more to younger donors. These data may allow blood centers to optimize recruitment by tailoring limited incentive resources more effectively.

Adult↗
PubMed2003

Impact of changes in viral marker screening assays.

BACKGROUND: 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. METHODS: 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). RESULTS: 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 (p < 0.001) 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. CONCLUSION: 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.

Antigens, Viral↗
PubMed2003

Frequency of HBV DNA detection in US blood donors testing positive for the presence of anti-HBc: implications for transfusion transmission and donor screening.

BACKGROUND: An estimate of the rate of HBV DNA-positive, anti-HBc-positive units is important for evaluating the need for anti-HBc donor screening, especially in the context of HBV NAT. STUDY DESIGN AND METHODS: HBsAg EIA-nonreactive, anti-HBc-reactive (Corzyme, Abbott Laboratories) specimens were retrieved from a repository and were retested for anti-HBc (with PRISM HBcore, Abbott Laboratories, currently under FDA review) and anti-HBs (with PRISM Ausab, Abbott Laboratories, research assay). HBV DNA testing using a PCR assay with a greater than 95 percent detection rate of less than 50 copies per mL was performed on a subset of specimens that were PRISM HBcore-reactive and were anti-HBs- negative or reactive at less than 100 IU per L. RESULTS: A total of 395 of 1231 specimens eligible by our serologic criteria were tested by PCR. Four anti-HBs-negative specimens were PCR-positive with estimated HBV DNA copy numbers of 10 per 30 copies per mL in two specimens and 50 to 100 copies per mL in two others. The HBV DNA detection rate in anti-HBs-negative specimens was 3.7 percent, and the projected rate among all Corzyme-reactive specimens was 0.24 percent, leading to an estimated yield of 1 HBV DNA-positive, anti-HBc-positive unit in 49,000 units that were otherwise eligible for transfusion (95% CI, 1 in 16,600-1 in 152,600). CONCLUSIONS: Anti-HBc screening detects HBsAg EIA-negative, HBV-infected donors at a rate comparable to the estimated residual risk for HBV window-period infections. The low viral load in the HBV DNA-positive samples suggests that minipool NAT will not detect most potentially infectious units from anti-HBc-positive donors.

Blood Donors↗
PubMed2002

HIV seroconverting donors delay their return: screening test implications.

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.

Blood Donors↗
PubMed2002

Motivations to donate blood: demographic comparisons.

BACKGROUND: Understanding blood donor motivations is crucial to improving effectiveness of donor recruitment and retention programs. STUDY DESIGN AND METHODS: Data from a 1998 survey of 92,581 U.S. blood donors were used to evaluate factors influencing the decision to donate in various demographic groups. Data were weighted to adjust for response and sample design. RESULTS: Of 52,650 respondents, 45,588 gave whole-blood (WB) donations. Among all demographic groups, the major reasons to donate were altruism (75-87%) and awareness of the need for blood (34-43%). Except for first-time donors and those <or=25 years old, blood drive organizers and/or recruiters were more important than family and/or peers in encouraging donors (13-19% vs. 1-8%). Although 59 to 63 percent of donors said they would be encouraged to donate by reminders originating from the blood bank, for some, the contact would have a negative effect and discourage donation. Discouragement would be higher if they were reminded by a telephone call (14%) rather than by a letter or e-mail (4%) or an appeal (2%) from the blood bank. CONCLUSION: WB donations appear to be made primarily for altruistic reasons and in response to appeals for blood. Ways to build on this humanitarianism and take advantage of new communication routes, such as e-mail, need to be developed.

Altruism↗