Factors associated with a second deferral among donors eligible for re-entry after a false-positive screening test for syphilis, HCV, HBV and HIV.

BACKGROUND AND OBJECTIVES: Since 25 May 2010, all donors at our blood centre who tested false-positive for HIV, HBV, HCV or syphilis are eligible for re-entry after further testing. Donors who have a second false-positive screening test, either during qualification for or after re-entry, are deferred for life. This study reports on factors associated with the occurrence of such deferrals. MATERIALS AND METHODS: Rates of second false-positive results were compared by year of deferral, transmissible disease marker, gender, age, donor status (new or repeat) and testing platform (same or different) both at qualification for re-entry and afterwards. Chi-square tests were used to compare proportions. Cox regression was used for multivariate analyses. RESULTS: Participation rates in the re-entry programme were 42·1%: 25·6% failed to qualify for re-entry [different platform: 2·7%; same platform: 42·9% (P < 0·0001)]. After re-entry, rates of deferral for second false-positive results were 8·4% after 3 years [different platform: 1·8%; same platform: 21·4% (P < 0·0001)]. Deferral rates were higher for HIV and HCV than for HBV at qualification when tested on the same platform. The risk, when analysed by multivariate analyses, of a second deferral for a false-positive result, both at qualification and 3 years after re-entry, was lower for donors deferred on a different platform; this risk was higher for HIV, HCV and syphilis than for HBV and for new donors if tested on the same platform. CONCLUSION: Re-entry is more often successful when donors are tested on a testing platform different from the one on which they obtained their first false-positive result.

Detection of Epstein-Barr virus in leucoreduced blood products.

This study examined the prevalence of three human herpesviruses (HHV), namely HHV-4 (Epstein-Barr virus/EBV), HHV-6b and HHV-7 in leucoreduced blood products obtained from the Sainte-Justine Hospital blood bank. A total of 100 specimens, including 34 red blood cell concentrates, 33 platelet bags and 33 plasma units, were collected and screened by a sensitive PCR assay using virus-specific primers. Positive units were then retested by quantitative PCR. Of the 100 specimens, one platelet unit tested positive for EBV.

Allowing blood donation from men who had sex with men more than 5 years ago: a model to evaluate the impact on transfusion safety in Canada.

Canada now allows donations from men who had sex with men (MSM) if their last sexual contact with a man was more than 5 years ago. We modelled the impact of this policy on supply and safety. Approximately 4500 new donors will be added and assuming compliance to the new policy remains unchanged, the worst-case scenario predicts the introduction of one HIV-contaminated unit in the inventory every 1072 years. This change will entail negligible additional HIV risk to recipients. A five-year deferral will also protect recipients against the theoretical concern that MSM may represent a group at higher risk of sexually transmitted, emerging blood borne pathogens.

Donors' psychological reactions to deferral following false-positive screening test results.

BACKGROUND AND OBJECTIVES: Being notified of a false-positive infectious disease marker result can cause psychological distress in blood donors. A new notification process, informing donors of the possibility of re-entry, was compared with the previous one in which donors were indefinitely deferred to evaluate the mitigating effect on donors' psychological distress levels. MATERIALS AND METHODS: Two groups of donors, 'deferred donors' (DD) and 'donors eligible for re-entry' (DER), completed a questionnaire involving 5-point scales. Levels of psychological distress, attitude towards blood donation, desire to donate blood in the future and perception of notification process quality were assessed. RESULTS: Attitudes towards blood donation (P = 0·0276) (DD: 3·94 ± 0·11 vs. DER 4·21 ± 0·09) and perceived quality of communication (P = 0·0108) (DD: 2·72 ± 0·12 vs. DER 3·08 ± 0·10) were significantly improved with the new notification process. No significant difference was found between groups in psychological distress levels or desire to donate blood in the future. CONCLUSION: Informing donors of the possibility of re-entry appears to contribute to maintaining a positive predisposition towards future blood donation. It does not, however, appear to alleviate the distress felt after being notified of a false-positive infectious disease marker result, nor does it increase willingness to give blood again in the future.

Blood donation clusters in Québec, Canada (2003-2008): spatial variations according to sex and age.

BACKGROUND AND OBJECTIVES: The detection of spatial clusters of blood donation rate is an important issue, especially for targeting spatial units with significantly low rates, where it could be possible to increase the numbers of donors. The objective of this study is to detect spatial clusters of high or low blood donation rate in Québec according to sex and age of the donors. MATERIALS AND METHODS: Blood donation data were obtained from Héma-Québec over a period of 5 years. We aggregated these data for each of 101 municipalités regionales de comté (i.e. counties) for men, women and four age groups. To detect spatial high/low donation rate areas, we used the Kulldorff's scan statistics. Kappa coefficient was used to assess discordance between clusters obtained for the different groups (18-29, 30-39, 40-49, 50-59, 60-69 years old). T-test analyses were conducted to identify significant associations between spatial clusters and socio-economic variables. RESULTS: The results indicate the presence of several geographical areas with high or low blood donation rates for each group. The size, the location and the socio-demographic profiles of low/high clusters vary according to sex and age categories. CONCLUSION: The Kulldorff's scan statistics are an efficient tool to assess the blood donation performance across a country or even a specific region over a period of several years. In terms of strategic planning and monitoring, it can be used as a fully operational tool to target areas with significantly low rates (for all donors or specific demographic groups) in future blood donation campaigns.

Donation by donors with an atypical pulse rate does not increase the risk of cardiac ischaemic events.

BACKGROUND AND OBJECTIVES: In many jurisdictions, blood donors who have an atypical pulse rate are temporarily deferred. This practice is not supported by evidence. We evaluated whether accepting donors with an atypical pulse rate increases their risk of cardiac ischaemic events. METHODS: We measured the cumulative incidence of hospitalizations and deaths for coronary heart disease within 1 year of follow-up among donors who, between 2002 and 2006, were temporarily deferred because of an atypical pulse (<50 beats/min, >100 beats/min, or irregular). We compared this incidence to that observed among donors who also had an atypical pulse but who were allowed to donate, following a change in our deferral policy in 2007. The occurrence of cardiac events was determined through hospital discharge and death registries. RESULTS: Among 6076 donors who were temporarily deferred for an atypical pulse, the 1-year rate of hospitalization or death for cardiac ischaemic events was 3.5/1000, compared to 2.4 in donors who had an atypical pulse but who were allowed to donate (n =10,671), for an adjusted odds ratio of 1.7 (95% CI, 0.9-3.0, P=0.08). CONCLUSION: Regardless of the clinical significance of an atypical pulse rate, our data show that accepting donors with this condition does not increase the occurrence of serious cardiac ischaemic events. We conclude that pulse rate measurement in prospective donors is not warranted.

The effects of leg crossing and applied tension on blood donor return.

BACKGROUND AND OBJECTIVES: Repeated isometric muscle tension (applied tension) during blood donation reduces vasovagal symptoms in many donors. Experiencing vasovagal symptoms has been found to reduce blood donor return. However, does practicing applied tension improve blood donor return? Follow-up results from a randomized controlled trial are presented. METHODS: Data were collected in mobile clinics held in several colleges and universities. During the baseline donation, participants either (1) practiced 'standard' applied tension consisting of repeated 5 s cycles of whole-body isometric muscle tension in the donation chair (N = 133), (2) practiced tension with legs crossed (N = 131), or (3) gave blood as usual (N = 140). Subsequent blood donations in the following 2 years were determined. RESULTS: Applied tension had no effect on immediate (at the end of the baseline blood donation) rating of intention to give blood or the dichotomous measure of whether or not the participant gave blood again in the following 2 years. However, men asked to practice applied tension with legs crossed gave approximately one unit more during the follow-up period compared with men in the control group (F1,106  = 5·32, P = 0·023). This was associated significantly with adherence - men assigned to the applied tension with legs crossed condition who did not practice as instructed were no more likely to return than controls. CONCLUSION: The results provide modest support for the idea that applied tension may increase subsequent blood donation though the results were limited to men who practiced the technique as instructed.

Allergic transfusion reactions from blood components donated by IgA-deficient donors with and without anti-IgA: a comparative retrospective study.

BACKGROUND AND OBJECTIVES: IgA deficiency is common (1/500) and up to 40% of affected individuals will develop anti-IgA. A few studies suggested that passive transfusion of anti-IgA was not associated with an increased risk of allergic reactions. This study was designed to assess the safety of transfusing blood components containing anti-IgA. MATERIALS AND METHODS: IgA-deficient blood donors with and without anti-IgA were identified from Héma-Québec's (HQ) computerized database. IgA deficiency was confirmed by an ELISA method and the presence of anti-IgA by a passive hemagglutination assay. Blood donations from IgA-deficient donors issued to hospitals between March 1999 and December 2004 were retrieved. Medical charts of recipients were reviewed for the occurrence of a suspected transfusion reaction. Presence and nature of transfusion reactions were assessed blindly by an adjudicating committee. RESULTS: A total of 323 IgA-deficient blood products were issued by HQ to 55 hospitals. Of these, 48 agreed to participate [315 blood products (97.5%)]. A total of 272 products were transfused: 174 contained anti-IgA, and 98 did not. Only two minor allergic reactions occurred in each group. Incidence of allergic reactions was 1.15% in the anti-IgA group and 2.04% in the group without anti-IgA (P = 0.91). There was no anaphylactic reaction in either group. CONCLUSIONS: This study indicates that the proportion of allergic reactions does not appear to be greater in recipients of blood components containing anti-IgA compared to recipients of non-anti-IgA-containing components. Allowing donations from IgA-deficient donors with anti-IgA may therefore be contemplated.

Inventory management.

A critical aspect of blood transfusion is the timely provision of high quality blood products. This task remains a significant challenge for many blood services and blood systems reflecting the difficulty of balancing the recruitment of sufficient donors, the optimal utilization of the donor's gift, the increasing safety related restrictions on blood donation, a growing menu of specialized blood products and an ever-growing imperative to increase the efficiency of blood product provision from a cost perspective. As our industry now faces questions about our standard practices including whether or not the age of blood has a negative impact on recipients, it is timely to take a look at our collective inventory management practices. This International Forum represents an effort to get a snap shot of inventory management practices around the world, and to understand the range of different products provided for patients. In addition to sharing current inventory management practices, this Forum is intended to foster an exchange of ideas around where we see our field moving with respect to various issues including specialty products, new technologies, and reducing recipient risk from blood transfusion products.

Reduced incidence of spontaneous mammary tumors in C3H/He mice after treatment with polyadenylate-polyuridylate.

The effect of treatment with the double-stranded polynucleotide complex polydenylate with polyuridylate [poly(A) with poly(U)] on tumor development in C3H/He mice was evaluated. Poly(A) with poly(U) was injected in newborn females, and mice were observed for 380 days. During this experimental period 42 percent of treated mice developed tumors, while the incidence in the control group was 63 percent. This difference was statistically significant.

Clinical and laboratory practices in investigation of suspected transfusion-transmitted bacterial infection: a survey of Canadian hospitals.

Transfusion of a bacterially contaminated blood product can have serious consequences. We undertook an electronic survey of representative Canadian hospitals to determine current clinical and laboratory practices for investigating such reactions, prior to the development of national guidelines. There was considerable variability in symptoms and signs that would trigger investigation of possible contamination. The most frequent laboratory investigations performed were aerobic blood cultures of recipients and the residual component. If there is no residual product in the component bag, 36% of respondents would use a segment to perform testing. Guidelines could be helpful in improving and standardizing these practices.

Set-up and routine use of a database of 10,555 genotyped blood donors to facilitate the screening of compatible blood components for alloimmunized patients.

BACKGROUND AND OBJECTIVES: Large-scale genotyping of blood donors for red blood cell and platelet antigens has been predicted to replace phenotyping assays in the screening of compatible blood components for alloimmunized patients. Although several genotyping platforms have been described, novel procedures and processes are needed to perform genotyping efficiently and to maximize its benefits for blood banks. MATERIALS AND METHODS: Here we describe the processes and procedures developed to introduce large-scale genotyping in our routine operations. RESULTS: Preliminary cost-benefit analysis indicated that genotyping must target frequent blood donors (> 3 donations/year) to be efficiently used. A custom-designed computer application was developed to manage the whole project. It selects frequent donors among recent donations, prints coded labels to identify blood samples sent to the external genotyping laboratory, and stores genotyping results. It can search for donors compatible for any combination of the 22 genotyped antigens as well as consult the current inventory for the presence of the corresponding blood components. The phenotype of recovered components is confirmed by standard serology techniques prior to shipment to hospitals. CONCLUSION: Since October 2007, 10 555 blood donors have been genotyped. The database is used on a regular basis to find compatible blood components with a genotype-phenotype concordance of 99.6%.

A monoclonal antibody to the double-stranded polyribonucleotide complex poly(A) X poly(U).

A monoclonal antibody to the double-stranded polyribonucleotide complex poly(A) . poly(U) was derived from the fusion of spleen cells from immunized DBA/2 mice and the P3 X X63-Ag8 plasma cytoma. Specificity studies using radioimmunoassays showed that the anti-poly(A) . poly(U) does not cross-react with single-stranded polyribonucleotides. RNA X DNA hybrids or DNAs. In addition to RNA duplexes associating adenine and uracil, it recognizes synthetic poly(I) . poly(C) and naturally occurring reovirus RNA. It is thus directed against a conformational epitope with an absolute requirement for two polyribose phosphate chains. However, the antibody does not cross-react with poly(G) . poly(C) and is therefore able to distinguish between RNA double helices.

Diagnosis of vertical HIV-1 transmission using the polymerase chain reaction and dried blood spot specimens.

We have used the polymerase chain reaction (PCR) to detect HIV proviral sequences in minute amounts of peripheral blood collected onto newborn screening blotters. Forty-three newborns, infants, and children of HIV-infected mothers were serially studied: dried blood spot (DBS) specimens were processed for PCR; serum was assayed for HIV antibodies, p24 antigen, and immunoglobulins; mononuclear cells were cultured and CD4 cells were quantitated by immunofluorescence. There was excellent agreement between the results of blood spot PCR, viral culture, and clinical and immunological indicators of HIV infection. Eighteen of 19 infected children tested positive by both PCR and culture, including six asymptomatic infants who were less than 10 weeks of age. As expected, p24 antigen capture assays were insensitive, detecting only 13 of the 19 infected children. One infected infant tested positive by PCR, but negative by culture and antigen. This infant was seropositive at 27 months and had pronounced hypergammaglobulinemia in association with non-specific symptoms. Twenty-four of the 43 infants were asymptomatic with normal immune profiles, declining antibody levels and no evidence of infection. These children tested repeatedly negative by PCR, culture, and p24 antigen assays. Our results indicate that DBS PCR is a sensitive, specific, and cost-effective alternative to viral culture for the early diagnosis (or exclusion) of perinatal HIV infection. DBS sampling opens the way for large-scale prospective studies to determine the exact rates of vertical HIV transmission in industrialized, as well as, nonindustrialized countries.

Combined active-passive immunization against the hepatitis B virus: five-year follow-up of children born to hepatitis B surface antigen-positive mothers.

In order to evaluate the duration of "protective" concentrations (i.e. > or = 10 IU/liter) of antibody to hepatitis B surface antigen (HBsAg) in children vaccinated against hepatitis B in infancy, we followed 146 children born to HBsAg-positive mothers from birth to age 60 months. Children were seen at yearly intervals and tested for hepatitis B virus serologic markers. Of the children included in the study, 134 were protected against infection with development of antibody to HBsAg, 5 became HBsAg-positive and 6 failed to respond to the vaccine but did not become infected. Antibody concentrations fell progressively with the passage of time. The probability of maintaining a "protective" concentration of antibody in vaccine responders at age 60 months was 86% (95% confidence interval, 80 to 93%). Gender, ethnic origin, HBeAg status of the mother and immunization schedule had no influence on the rate of antibody loss. We conclude that in developed countries, the great majority of children vaccinated in infancy remain protected against infection at least until age 60 months. The need for booster doses of vaccine in this population will be determined by long term follow-up of immunized cohorts.