Jed B. Gorlin

Pediatric large volume peripheral blood Progenitor cell Collections from patients under 25kg : A primer

Collection of peripheral blood progenitor cells from small pediatric patients provides many social and technical challenges not faced when collecting from adult patients. This paper provides a single institutions experience with 85 collections from 14 patients less than 25 kg of weight over a 2 year period. Specific challenges include obtaining venous access, anticoagulation, volume shifts, and obtaining patient cooperation. A systematic analysts of options for access, alternative modes of anticoagulation, and the effect of large ratios of extra‐corporeal volume to patients blood volume are discussed. Access uniformly required central venous catheters (CVC) ranging from 7–10 Fr Anticoagulation included systemic heparmization titrating dose by activated clotting time in all cases and combined with nitrate at a ratio of 1:25 · 1:30 in most cases. Collections were performed on a COBE. Spectra, after priming with leukoreduced irradiated red cells and omitting both the initial 120cc diversion and rinse back of red cells at the end Social challenges include issues of assent and ability to distract patients for the duration of a prolonged collection. Progenitor yields from collections from 14 patients were quantitiated by CD34+ assay in all cases and C???GM in ten of 14 patients. A median of 4.5 + 106/kg CD34+ cells were obtained for each collection. Complications, including those related to catheter access are enumerated. In summary, large volume peripheral blood progenitor collection can be safely and efficaciously performed in small pediatric patients.

Transmission of Babesia microti in Minnesota through four blood donations from the same donor over a 6‐month period

BACKGROUND : Babesiosis is a tick‐borne zoonosis caused by intraerythrocytic protozoa. More than 40 US cases of Babesia microti infection acquired by blood transfusion have been reported. This report describes the identification of a transfusion‐associated case of babesiosis and the subsequent identification of the infected blood donor and three other infected recipients of cellular blood components from three other donations by this donor.

Evaluation of an automated system for the collection of packed RBCs, platelets, and plasma

BACKGROUND: This study evaluated the quality of WBC‐reduced platelets, RBCs, and plasma collected on a new system (Trima, Gambro BCT) designed to automate the collection of all blood components. The study also evaluated donor safety and suitability of these components for transfusion.

Large-volume leukapheresis in pediatric patients : processing more blood diminishes the apparent magnitude of intra-apheresis recruitment

Background: Recruitment of progenitors during a large‐volume collection, as defined by increasing relative and absolute numbers of progenitors (colony‐forming units‐granulocyte‐macrophage [CFU‐GM] of CD34+ cells), has been reported previously.

Evaluation of a new Trypanosoma cruzi antibody assay for blood donor screening.

BACKGROUND: This multicenter prospective study was designed to evaluate the performance characteristics of a new commercially available enzyme‐linked immunosorbent assay (ELISA) for the detection of antibodies to Trypanosoma cruzi in blood donors, the ORTHO T. cruzi ELISA Test System (Ortho‐Clinical Diagnostics).

Similar donors—similar blood?

Red blood cell (RBC) storage lesions have been suggested as contributing factors to suboptimal clinical outcomes. While undesirable effects of storage are well documented, their clinical relevance is still debated. Focus on storage time as the sole determinant of RBC quality ignores the variability in cell properties that may depend on factors other than age. Mechanical fragility (MF) aggregately reflects many storage‐related functional and structural changes. This study evaluates interdonor versus intradonor variability, throughout storage, of both MF and autohemolysis (AH).

Hemolytic disease of the newborn due to the Scianna antibody, anti-Sc2

BACKGROUND: Alloantibodies to the low‐frequency antigen Scianna 2 (Sc2) are uncommon and not previously reported to cause immune hemolysis. CASE REPORT: A group B, Rh‐negative infant born to a group B, Rh‐ positive mother had a 2+ direct antiglobulin test, as well as modest hyperbilirubinemia and a hematocrit of 45 percent. Ongoing immune hemolysis led to a hematocrit of 17.3 percent on Day 20 of life, and the infant required hospitalization and red cell transfusions. The routine maternal antibody screen was negative, but anti‐Sc2 was detected during work‐up for a low‐frequency red cell antigen, and the fathers red cells typed as Sc:1,2. CONCLUSION: Anti‐Sc2 can cause clinically significant hemolytic disease of the newborn. Although the antibody is uncommon, its frequency and hemolytic potential may be underappreciated, in part because investigations often are not carried out in the infant whose red cells are ABO‐incompatible with maternal blood.

The use and abuse of the full-sibling and half-sibling indices

Increasingly, parentage testing laboratories are called upon to provide documentation of genetic linkage between individuals applying for legal immigration to the United States. Many embassies require that the party who has already obtained legal immigrant status document that the person(s) he or she is trying to bring into the United States is a first-degree relative, for example, establishing that the parties are parent and child. As part of this process, several embassies have started to request not only parent-child calculations, but also statistical tests for other possible relatedness, such as uncle-child or possible sibling status. In that context, Wenk and Chiafari1 demonstrate both the ways in which these indices are used and the fact that paradoxical results are often observed. Specifically, with the use of three highly informative VNTR loci, 4 of 25 examples of proven full-sibling pairs yielded a ratio of greater than 2:1 against full-sibling status. Furthermore, 2 of 25 pairs proven beyond doubt to be half-siblings had ratios exceeding 5:1 in support of full-sibling status. Because of the stringent immigration requirements, we typically test at 5 to 7 pairs of VNTR loci, which yields greater power to distinguish possible relationships. Our concern is with the ways that these indices are used by various US embassies with regard to issues of immigration. Recently, we had a case in which a married couple had legally immigrated to the United States and were trying to bring in their son. We tested the man and the boy at five highly polymorphic VNTR alleles. They (father and son) shared both alleles at three systems, and so the full-sibling index exceeded the father-child index by over 40-fold. Because of this latter calculation, the embassy refused admission of the boy to the country, despite the observation that the man was almost 40 years older than the tested child and hence far more likely to be the boy’s father than a full sibling! We subsequently tested the woman’s blood; this showed that the boy’s results were consistent with the two adults’ being his parents. It is not uncommon for genetic heterogeneity to be less diverse within a small ethnic community than in the entire classification of the race, and this gives an overrated significance to the sharing of more than a single allele. When alleles are common within a tested population, the sharing of two alleles will be correspondingly more common. This occurs even more frequently when less polymorphic systems, such as serial tandem repeats (STRs), are used. For example, alleles are more broadly distributed among all Asians than within the Japanese population alone. Hence, finding parents that share both alleles with children is not a rare event in which certain alleles are common within the tested population. In short, while we appreciate the challenges faced by embassies to follow the rules limiting immigration sponsorship to direct family members, we urge greater dialog between testing centers and the individual embassies, to establish reasonable expectations for additional testing requirements when no exclusions are found. One year after the initial testing was performed, the child in the above example remains abroad and separated from his parents. As the current system stands, families that can ill afford it are required to pay for additional testing and legal and communications costs. Jed B. Gorlin, MD Herbert F. Polesky, MD Memorial Blood Centers of Minnesota 2304 Park Avenue Minneapolis, MN 55404-3789 e-mail: jed@mbcm.org

Iron man pentathlon or “we have met the enemy and they is us!”

T his issue features five independent studies examining aspects of iron status in blood donors from around the developed world. Each adds to the inevitable conclusion that the strongest predictors of iron deficiency (as measured by a ferritin concentration below some cutoff level) are sex and menopausal status (variables that could only be addressed by avoiding recruitment from premenopausal women), donation frequency, and time since last donation, which are direct results of our recruitment strategies. For example, the Danish study of Rigas and colleagues used multiple variable regression analysis of donation frequency, physiologic factors (sex and menstruation status), lifestyle (including alcohol and smoking status), and iron consumption (vitamin or iron supplements and dietary intake). The study included a questionnaire with detailed inquiries about smoking, alcohol, and coffee consumption as well as nutritional supplements and dietary history in more than 14,000 participants with completed questionnaires and measured values for both hemoglobin (Hb) and ferritin. Similar to observations of the US REDS II RISE study, the strongest predictors of a low ferritin (defined as <15 ng/mL ferritin for both sexes) were sex, menopausal status, donation frequency, and time since last donation. Dietary and iron supplementation factors were much weaker predictors confirming the impression that simply recommending additional meat intake in frequent blood donors is unlikely to achieve higher ferritin levels. This observation was independently confirmed by a poster presentation by Steele and coworkers that documented minimal awareness that repeated blood donation leads to iron deficiency. Many repeat donors already take iron-containing supplements but most confused the Hb screening test with a measure of their iron status. Among the most frequent blood donors (nine or more donations in 3 years) iron deficiency was found in approximately one in 10 males, four in 10 premenopausal females, and two in 10 postmenopausal female donors, which were approximately 20-fold higher frequencies than for infrequent male and postmenopausal female donors (not more than three whole blood donations in 3 years) and twofold higher for premenopausal females. In short, iron deficiency is quite uncommon in infrequent male and postmenopausal female blood donors but dramatically more frequent among regular donors. Indeed, the authors observed that “there were almost no irondeficient men unless they had been bled at least seven times in a 3-year period.” While iron deficiency among premenopausal females is common, its frequency and magnitude are significantly exacerbated by frequent donation. Iron deficiency occurred despite the practice of providing iron supplements to premenopausal female Danish donors, one-third of whom confirmed receiving the iron supplements. While meat intake had a modest positive correlation with ferritin levels, the correlation coefficient was low. Relatively few of the participants were vegetarian of whom one-third had low ferritin levels. The Australian study by Booth and colleagues focuses on dietary intake of 184 premenopausal women, 165 regular blood donors, and 19 first-time donors. The study used a validated dietary history tool with an extensive list of iron-containing foods updated for availability in the Australian market. Despite an almost 25% higher mean daily dietary iron intake by regular blood donors, the frequency of depletion of iron stores (ferritin ≤ 15 ng/ mL) was 50% as opposed to 24% among new donors. The median serum ferritin was 73% higher in the new donor group, despite no difference in Hb levels. They also observed a donation frequency–dependent negative correlation with ferritin level. Of note, in Australia, the minimum Hb level for females is 12 g/dL, and current practice for those not meeting this cutoff level is deferral from blood donation for 6 months to allow for regeneration of iron stores. The study by Baart and coworkers uses multivariate logistic regression to validate a predictive model for Hb deferral for both sexes. They use a model developed by Sanquin, using the EU-specific donor cutoffs of 13.5 g/dL for males and 12.5 g/dL for females. The Irish national transfusion service uses the lower cutoffs of 13 and 12 g/dL for males and females, respectively. The variables include sex, age, seasonality, Hb at previous visit, difference in Hb since previous visit, time since previous visit, total number of donations in the previous 2 years, and deferral at the prior visit. It is my understanding that the intent of this model is to have a tool to better predict which donation attempts might end in low Hb deferral with the goal of decreasing deferrals, both for operational efficiency and to prevent donor attrition from repeated deferrals. The article uses various statistical manipulations to improve the predictive value of the models but even the idealized model is only half way between a coin flip and a perfect predictor. While not practical on a realtime basis such models do allow insight into public policies to assist in reducing deferral rates. Perhaps most

Alloimmunisation via previous transfusion places female Kpb-negative recipients at risk for having children with clinically significant hemolytic disease of the newborn.

We report a case of clinically significant hemolytic disease of the newborn due to Kpb alloimmunisation requiring obstetric intervention. This case and a review of the literature are in contrast to reviews of hemolytic disease of the newborn that either ascribe no significance to the Kpb antigen or suggest that it causes only rare or mild disease. Analysis of our Kpb‐negative donor pool suggests that prior transfusion greatly increases the chance of alloimmunisation. The role of frozen rare donor registry cells as a public resource is emphasised.