International rare donor panels: a review.

International rare blood donor panels or registries are important in the consistent availability of rare blood for patients who need this scarce resource. In countries where it has been possible to commit resources to this effort and often where the need is great, donors have been entered into a registry. The ISBT leadership recognized the importance of this very challenging inventory management activity and created a Working Party to support it. Individual countries support the WHO International Rare Donor Panel by submitting their donors' phenotype or genotype information to be catalogued into the database. It is extremely important that this database be cultivated and grown. The contributing countries keep their list updated and supply the blood product as they can when requested. It is known that some blood types are extremely scarce worldwide and requests for these are particularly difficult to fulfil. Thus, it is important to have a protocol to identify and recruit donors with rare blood types. It is equally or perhaps more important to ensure that the patients who need the rare blood are being managed appropriately in the presence and absence of rare blood products being available.

International society of blood transfusion working party on red cell immunogenetics and terminology: report of the Seoul and London meetings.

The Working Party has met twice since the last report: in Seoul, South Korea 2014, and in London, UK 2015, both in association with the International Society of Blood Transfusion (ISBT) Congress. As in previous meetings, matters pertaining to blood group antigen nomenclature were discussed. Eleven new blood group antigens were added to seven blood group systems. This brings the current total of blood group antigens recognized by the ISBT to 346, of which 308 are clustered within 36 blood groups systems. The remaining 38 antigens are currently unassigned to a known blood group system.

International Society of Blood Transfusion Working Party on red cell immunogenetics and blood group terminology: Cancun report (2012).

The International Society of Blood Transfusion Working Party on red cell immunogenetics and blood group terminology convened during the International congress in Cancun, July 2012. This report details the newly identified antigens in existing blood group systems and presents three new blood group systems.

Hematologic biomarkers in childhood cataracts.

PURPOSE: To date, more than thirty nine genetic loci have been associated with congenital cataracts. Despite this progress, current diagnostic techniques are insufficient for unraveling the underlying genetic defect in sporadic patients and small families. In the present manuscript we demonstrate the contribution of routine laboratory tests in the search for genetic defects of childhood cataracts. METHODS: Two families with congenital cataracts and hematologic findings that included hyperferritinemia and the "ii" blood type underwent detailed ophthalmologic and clinical examinations. Mutation analysis of the ferritin light chain (FTL) and glucosaminyl (N-acetyl) transferase 2, I-branching enzyme (GCNT2) genes was performed in the two families, respectively. RESULTS: In the family with the "ii" blood group we found a novel GCNT2 mutation c.G935A (p.G312D) in the cataract patients, while in the family with hyperferritinemia cataract syndrome we identified a G→C heterozygous mutation at position +32 of FTL. CONCLUSIONS: Hematologic biomarkers may simplify the search for the underlying molecular defect in families with congenital cataract.

The implementation of rapid cooling and overnight hold of whole blood at ambient temperature before processing into components in Israel.

BACKGROUND: The quality of blood components prepared from whole blood (WB) units rapidly cooled to 20 to 24°C and stored for prolonged periods using butane-1,4-diol "cooling plates," and the factors that determine the functional activity of these cooling systems under various temperature conditions were investigated. STUDY DESIGN AND METHODS: Validation of the cooling systems functions, performed in different environmental temperature-time schemes using WB-mock units, were recorded and analyzed in 106 temperature curves, simulating environmental conditions of blood storage at the blood drives and transport to the blood services component laboratory. The quality of red blood cells, fresh-frozen plasma, platelet concentrates, and cryoprecipitate units was studied on components routinely prepared in 2007 to 2009 from WB units collected in citrate-phosphate-dextrose-adenine or citrate-phosphate-dextrose (CPD), rapidly cooled, and stored in ambient temperature for up to 22 hours postdonation using the cooling systems. RESULTS: Quality variables of blood components prepared from WB units rapidly cooled and held overnight for up to 22 hours postcollection, using both cooling systems, met the allowed ranges of American, European, and Israeli standards. Temperature validation of the cooling systems resulted in national standard operating procedures for the proper use in different ambient temperature ranges. CONCLUSION: The rapid cooling of WB and prolonged storage under different environmental conditions using cooling plate systems enabled standardization of blood storage at and transportation from all collection sites. It provided an efficient, reproducible, and cost-effective way to ensure good quality blood components, while utilizing more efficient logistic and administrative means.

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.

Impact of pooling on accuracy of hepatitis B virus surface antigen screening of blood donations.

Expenditure on screening blood donations in developing countries can be reduced by testing donations in pools. This study evaluated serological screening in pools for hepatitis B virus (HBV) at the Israeli national blood bank and a hospital blood bank in Gaza, the Palestinian Authority. The accuracy of HBV surface antigen (HBsAg) enzyme immunoassay performed on pools of 3-24 samples was compared with individual tests. Delay in detecting positive samples due to dilution in pools and the possibility of antibody-antigen neutralization were analyzed. The sensitivity of pooled testing for HBsAg was 93-99%, prolonging the window period by 5 days (8.3%). Neutralization of HBsAg by hepatitis B surface antibodies (anti-HBs) could be minimized by testing immediately after pooling. Serological testing for HBsAg in pools may be performed using manually created pools of up to six samples, with 5% loss in sensitivity and a risk of neutralization by anti-HBs present in the donor population. Pooling can therefore be considered as an option only in countries with a low prevalence of HBV.

Estimation of delay in detecting hepatitis C virus antibodies in pools compared to individual testing on seroconversion panels.

Testing for anti-hepatitis C virus (HCV) antibodies in pools may reduce blood screening costs, making this approach affordable for developing countries, provided that the dilution of infected blood does not significantly increase the number of undetectable viral particles, especially in seroconverters. This study assessed the delay in detection of HCV antibodies in five HCV seroconversion panels, tested in pools of 6-48 samples, and estimated the risk of transfusion-transmitted HCV caused by pooling. The delay in detection of positive samples was 5-12 days for pools of all sizes, adding 7% to the risk of HCV transmission that occurs when blood donors' samples are tested individually.

Rare blood donors: a personal approach.

The National Blood Group Reference Laboratory (NBGRL) in Israel was established in Jerusalem in 1971 and transferred to Magen David Adom (MDA), National Blood Services in 1995. This laboratory was the inspiration of the first author of this article for over 30 years. The realization of this vision was made possible by the cooperation of colleagues and laboratory workers in blood transfusion services throughout the country. The aim of the service was to provide diagnostic help in resolving immunohematologic problems found in the blood banks and clinics in Israel. In the beginning, only a part-time technician performed the work and testing was done using very limited reagents. The service was expanded by personal visits to all of the 22 blood banks in Israel to explain the aim of this new service and to educate them about the importance of resolving each and every case. One major issue was the cost involved in referring problems but it was decided at the outset that these would be covered by the government to ensure that a workup would be performed for all referred cases. The expansion of the service could not have been achieved without the help of the SCARF program. This voluntary service enabled us to identify the first rare donors in Israel, resolve complex cases, and find compatible blood for our patients. To illustrate the importance of the NBGRL in Israel and the rapid resolution of cases referred, several individual stories are described. The purpose of this review is to show the importance of the NBGRL in identifying rare blood groups and in providing and coordinating services and the importance of keeping in close contact with the rare donors to encourage and promote their donations, which may save lives.

H-deficient Bombay and para-Bombay red blood cells are most strongly agglutinated by the galactophilic lectins of Aplysia and Pseudomonas aeruginosa that detect I and P1 antigens.

The galactophilic lectins Aplysia gonad lectin (AGL) and Pseudomonas aeruginosa lectin (PA-IL), which detect human I and P1 RBC antigens, were examined for hemagglutination of H+ (group O and B) and H-deficient (Bombay and para-Bombay phenotype) RBCs. The results were compared with those obtained using two other galactophilic lectins, Maclura pomifera lectin (MPL) and Arachis hypogaea (peanut) agglutinin (PNA), which share T-antigen affinity, and two fucose-binding H-specific lectins, Ulex europaeus (UEA-I) and Pseudomonas aeruginosa lectin (PA-IIL), as well as with those achieved with anti-I serum. The results revealed that, in contrast to UEA-I and PA-IIL, which preferentially agglutinated H+ RBCs, and to MPL and PNA, which similarly agglutinated all examined RBCs, AGL, PA-IL, and the anti-I serum agglutinated the H-deficient RBCs more strongly than did the H+ RBCs. These findings could be attributed to increased levels of I and P1 antigens on those RBCs resulting from the use of the free common H-type 2 precursor for their synthesis. Since both PA-IL and PA-IIL are regarded as potential pathogen adhesins, it would be interesting to statistically compare the sensitivities of individuals of H+ and H-deficient RBC populations to P. aeruginosa infections.

Persistent anti-Dra in two pregnancies.

The Drori (Dr(a)) antigen is one of the ten high-prevalence antigens of the Cromer blood system, which are carried on decayaccelerating factor (DAF, CD55). The Dr(a-) phenotype was first described in a 48-year-old Jewish woman from Bukhara. Her serum contained an antibody to a high-prevalence antigen named anti-Dra. Most known individuals with the Dr(a-) phenotype are Jews from the geographic area of Bukhara, but individuals from Japan have also been described. Antibodies in the Cromer blood group system, including anti-Dra,have never been reported to cause HDN. In most of the cases with anti-Dra examined in Israel, the antibodies have been subtyped as IgG2 and IgG4. This report is of a woman with Dr(a-) phenotype and an anti-Dr(a) titer of 256 to 512 in her serum, observed during two successive pregnancies. At birth, the RBCs of the first- and second-born child were negative and positive in the DAT, respectively, and neither manifested clinical signs of HDN. The disappearance of Cromer system antibodies, including anti-Dra in midpregnancy, has been described in a previous study. In that study, it was theorized that the antibodies in the serum of the women were adsorbed onto placental DAF. The finding of a high anti-Dra titer in two successive pregnancies in this patient, with a positive DAT for the RBCs of one of the two babies at term, differs from published reports, suggesting that a different mechanism might be involved.

Genetic heterogeneity at the glycosyltransferase loci underlying the GLOB blood group system and collection.

The aim of this study was to further explore the molecular genetic bases of the clinically important but rare blood group phenotypes p, P(1) (k) and P(2) (k) by analysis of the 4-alpha-galactosyltransferase (P(k)) and 3-beta-N-acetylgalactosaminyltransferase (P) genes responsible for synthesis of the related P(k) (Gb(3)) and P (Gb(4)) antigens respectively. Lack of these glycolipid moieties is associated with severe transfusion reactions and recurrent spontaneous abortions but also offers immunity against certain infectious agents. Blood samples from 20 p and 11 P(1) (k) or P(2) (k) individuals of different geographic and ethnic origin were investigated. DNA sequencing by capillary electrophoresis was performed following amplification of the coding regions in the P(k) or P genes. In the P(k) gene, nine novel and five previously described mutations were detected. One of the newly found mutations introduced an immediate stop, five shifted the reading frame introducing premature stop codons and three were missense mutations causing amino acid substitutions in conserved regions of the transferase. Four new and two previously described mutations in the P gene were found. Three of the novel alleles reported here carried nonsense mutations whilst the fourth allele had a missense mutation. The finding of 13 novel mutations in 14 alleles emphasizes further the genetic heterogeneity at the glycosyltransferase loci underlying the GLOB blood group system and collection.

Molecular defects underlying the Kell null phenotype.

Expression of the Kell blood group system is dependent on two proteins, Kell and XK, that are linked by a single disulfide bond. Kell, a type II membrane glycoprotein, is a zinc endopeptidase, while XK, which has 10 transmembrane domains, is a putative membrane transporter. A rare phenotype termed Kell null (Ko) is characterized by the absence of Kell protein and Kell antigens from the red cell membrane and diminished amounts of XK protein. We determined the molecular basis of eight unrelated persons with Ko phenotypes by sequencing the coding and the intron-exon splice regions of KEL and, in some cases, analysis of mRNA transcripts and expression of mutants on the cell surface of transfected cells. Six subjects were homozygous: four with premature stop codons, one with a 5' splice site mutation, G to A, in intron 3, and one with an amino acid substitution (S676N) in exon 18. Two Ko persons with premature stop codons had identical mutations in exon 4 (R128Stop), another had a different mutation in exon 4 (C83Stop), and the fourth had a stop codon in exon 9 (Q348Stop). Two Ko persons were heterozygous for two mutations. One had a 5' splice site mutation (G to A) in intron 3 of one allele that caused aberrant splicing and exon skipping, and the other allele had an amino acid substitution in exon 10 (S363N). The other heterozygote had the same amino acid substitution in exon 10 (S363N) in one allele and a premature stop codon in exon 6 (R192Stop) in the other allele. The S363N and S676N mutants, expressed in 293T cells, were retained in a pre-Golgi compartment and were not transported to the cell surface, indicating that these mutations inhibit trafficking. We conclude that several different molecular defects cause the Kell null phenotype.