A new AQP1 null allele identified in a Gypsy woman who developed an anti-CO3 during her first pregnancy.

BACKGROUND AND OBJECTIVES: The Colton blood group antigens are carried by the AQP1 water channel. AQP1(-/-) individuals, also known as Colton-null since they express no Colton antigens, do not suffer any apparent clinical consequence but may develop a clinically significant alloantibody (anti-CO3) induced by transfusion or pregnancy. Identification and transfusion support of Colton-null patients are highly challenging, not only due to the extreme rarity of this phenotype, the lack of appropriate reagents in most laboratories, as well as the possibility of confusing it with the recently described CO:-1,-2,3,-4 phenotype where AQP1 is present. This study investigated a new Colton-null case and evaluated three commercially available anti-AQP1s to identify Colton-null red blood cell samples. METHODS: The Colton-null phenotype was investigated by standard serological techniques, AQP1 sequencing, immunoblot and flow cytometry analyses. RESULTS: We identified and characterized the Colton-null phenotype in a Gypsy woman who developed an anti-CO3 during her first pregnancy. After developing a simple and robust method to sequence AQP1, we showed that she was apparently homozygous for a new AQP1 null allele, AQP1 601delG, whose product is not expressed in her red blood cells. We also established the Colton specificity of three commercially available anti-AQP1s in immunoblot and/or flow cytometry analyses. CONCLUSION: This Gypsy woman represents the sixth Colton-null case characterized at the serological, genetic and biochemical levels. The validation here of new reagents and methods should facilitate the identification of Colton-null individuals.

[Structural or functional relationship between immunohematology and distribution - Which elements for controlling risks?] / Lien immunohématologie-délivrance structurel ou fonctionnel ­ Quels éléments pour la maîtrise des risques ?

OBJECTIVE: Transfusion safety is based on the availability of safe and compatible blood products at the right time and to the right patient, and requires close monitoring in order to detect possible incidents. The decree of June 20th 2018, which establishes the national blood transfusion's guiding plan, states that the organization that prevails throughout the national territory is built around an inseparable link between the implementation of erythrocyte immunohematology and the labile blood products delivery by authorised structures. METHOD: The article describes the two types of the link's organization, structural or functional, used to develop the comparative risk-benefit analysis. RESULTS: The structural link, which has fewer interfaces, reduces risk situations that lead to delays in release by default of a compatible product. The cases in which a functional link may have a greater benefit than the risks generated are those related to a geographical distance between the delivery site and the patient's place of care. In these cases, a functional link is possible provided that certain organizational points are mastered. CONCLUSION: The comparative analysis shows that the structural link is to be favoured since that the coherence of the patient's care and his care path is ensured. In certain situations, mainly geographical, the functional link can have a benefit that offsets the risks generated by the new interfaces; provided that the system is secured by a real tripartite collaboration between health care institution, biology laboratory and delivery site.

Relevance and costs of RHD genotyping in women with a weak D phenotype.

OBJECTIVES: For pregnant women, the serologic test results of D antigen will determine the frequency of RBC antibody detection as well as the indication for RhIG prophylaxis. RHD genotyping is the only method that may provide clear guidance on prophylaxis for women with a weak D phenotype. This analysis evaluated the economical implications of using RHD genotyping to guide RhIG prophylaxis among pregnant women with a serological weak D phenotype. METHODS: We compared the costs of 2 strategies in a cohort of 273 women with weak D phenotype. In the first strategy, we did not perform genotyping and all women with weak D phenotypes were treated as if they were D-, thus considered to be a risk of RhD alloimmunization. These women all received the prophylactic follow up. In the second strategy, RHD genotyping was performed on all women with a serologic weak D phenotype. Then, the follow-up will be determined by phenotype deduced from genotype. RESULTS: On the studied cohort, the additional expense occurred by genotyping is 26,536 €. RHD Genotyping has highlighted 162 weak D Type 1, 2 3, that could safely be managed as D+ and 111 partial D to consider as D-. By comparing the 2 strategies, the savings generated by genotyping the patients of our cohort are € 12,046 for the follow up of one pregnancy. Knowing that in France, a woman has on average 2 pregnancies and that the genotyping is carried out only once, the savings generated for the following pregnancies would be € 38,581. CONCLUSIONS: Performing RHD genotyping for pregnant women with a weak D phenotype enables to clearly identify weak D type 1, 2 or 3 from the other variants at risk of alloimmunization. This analysis generates savings in terms of follow-up schedule of pregnant women and RhIG prophylaxis. It also allows saving of D- products for patient with a weak D type 1, 2 or 3 in case of a transfusion need.

[Microtitration of anti-RH1 antibodies: interest in the follow-up of pregnant women]. / Intérêt de la technique de microtitrage des anticorps anti-RH1 dans le suivi immunohématologique des femmes enceintes.

UNLABELLED: The proposal for a 300 microg anti-RH1 injection at 28 GW by RH:-1 pregnant women complicates the interpretation of the screening for alloantibodies during pregnancy; to distinguish an alloantibody from a passive one is nevertheless important for the care of the patients. Testing a technique allowing this distinction seems thus necessary. MATERIAL AND METHODS: The technique of microtitration of anti- RH1 antibodies is an indirect antiglobulin test. Two hundred specimens were tested in comparison with a standard prepared from a national anti- RH1 standard. If the anti- RH1 concentration measured is lower or equal to the expected concentration, there is a passive antibody. If the concentration is largely higher, we can suspect an allo-immunization. RESULTS: With this technique, 38 alloanti- RH1 and 112 passive anti- RH1 antibodies were confirmed. Twenty-five diagnosis were modified: seven alloanti- RH1 initially labeled passive and 18 passive anti- RH1 previously considered as alloantibodies. 15 cases can not be concluded, because the blood sample was taking away too early after the injection, and 10 cases are on standby, waiting for a control. DISCUSSION: The microtitration is an important exam in the follow-up of the RH:-1 pregnant women when an anti-RH1 antibody is found. This exam should be offered each time we have no information about the anti-D injection, or when an incoherent reaction compared to the presumed date of injection is observed.

Unreliable patient identification warrants ABO typing at admission to check existing records before transfusion.

BACKGROUND AND OBJECTIVES: This study describes patient identification errors leading to transfusional near-misses in blood issued by the Alps Mediterranean French Blood Establishment (EFSAM) to Marseille Public Hospitals (APHM) over an 18-month period. The EFSAM consolidates 14 blood banks in southeast France. It supplies 149 hospitals and maintains a centralized database on ABO types used at all area hospitals. As an added precaution against incompatible transfusion, the APHM requires ABO testing at each admission regardless of whether the patient has an ABO record. The study goal was to determine if admission testing was warranted. MATERIALS AND METHODS: Discrepancies between ABO type determined by admission testing and records in the centralized database were investigated. The root cause for each discrepancy was classified as specimen collection or patient admission error. Causes of patient admission events were further subclassified as namesake (name similarity) or impersonation (identity fraud). RESULTS: The incidence of ABO discrepancies was 1:2334 including a 1:3329 incidence of patient admission events. Impersonation was the main cause of identity events accounting for 90.3% of cases. The APHM's ABO control policy prevented 19 incompatible transfusions. In relation to the 48,593 packed red cell units transfused, this would have corresponded to a risk of 1:2526. CONCLUSION: Collecting and storing ABO typing results in a centralized database is an essential public health tool. It allows crosschecking of current test results with past records and avoids redundant testing. However, as patient identification remains unreliable, ABO typing at each admission is still warranted to prevent transfusion errors.

[Managing of platelet transfusion refractoriness of haematological malignancies. Experience IPC-EFSAM]. / Prise en charge de l'état réfractaire plaquettaire des hémopathies malignes. L'expérience IPC-EFSAM.

The platelet refractoriness is a complication of transfusion treatments potentially dramatic in onco-haematology. Chemo-treatment of haematological malignancies or packs of allogeneic bone marrow transplants require iterative platelet transfusion requirements. The discovery of a platelet refractoriness along with its support should be the most reactive as possible but also adapted to the cause. In the case of allo-immunization, it may be expected. The purpose of this presentation is to recall the different etiologies and perform a feedback on the support transfusion platelet of onco-haematology adult patients at Institut Paoli-Calmettes (IPC) in partnership with the EFSAM.

[Organization of safe cost-effective blood transfusion: experience APHM-EFSAM]. / Pour une organisation transfusionnelle sécuritaire aux risques et coûts maîtrisés : l'expérience APHM-EFSAM.

INTRODUCTION: Blood transfusion safety depends on strict compliance with each step of a process beginning with the order for labile blood products and related immunohematologic testing and ending with administration and follow-up of the receiver. This process is governed by stringent regulatory texts and guidelines. Despite precautions, processing errors are still reported. Analysis of incident reports shows that the most common cause involves patient identification and that most errors occur at two levels, i.e. the entry of patient information and management of multiple regulatory crosschecks and record-keeping using different systems. METHOD: The purpose of this report is to describe the collaborative approach implemented by the Établissement français du Sang Alpes-Méditerranée (EFSAM) and the Assistance publique des Hôpitaux de Marseille (APHM) to secure the blood transfusion process and protect interfaces while simplifying and facilitating exchanges. RESULTS: Close cooperation has had a threefold impact with simplification of administration, improvement of experience feedback, and better management of test ordering. The organization implemented between the two institutions has minimized document redundancy and interfaces between immunohematologic testing and delivery. Collaboration based on experience feedback has improved the level of quality and cost control. CONCLUSION: In the domain of blood transfusion safety, the threshold of 10(-5) has been reached with regard to the risk of ABO errors in the distribution concentrated red cells (CRC). In addition, this collaborative organization has created further opportunity for improvement by deploying new methods to identify simplification measures and by controlling demand and usage.

[Regional procedure of blood products transport by emergency medical services]. / Procédure régionale de transport des produits sanguins labiles par le samu.

Transfusions are exceptional while patients are rushed to hospital for sanitary reasons. The quality of care requires the collaboration with different partners (samu, blood bank centre, haemovigilance correspondents…). In response to dysfunctions that occurred during transports for sanitary reasons we have drawn up a regional procedure, which specifies how to get and use blood products. This procedure harmonizes our medical practice, states the role of the different participants (traceability of blood samples of immunohaematology tests, etc.), including a part dedicated to identity vigilance. The expected impacts of this procedure are: the decrease of dysfunctions and of destructions of red blood cells, the improvement of security while patients are transfused.

Analysis of ABO discrepancies occurring in 35 French hospitals.

BACKGROUND: The risk of immunohemolytic reaction owing to ABO-mismatched mistransfusion is 100 to 1000 times higher than the risk of viral infection. Like analysis of incident reports, evaluation of near-miss events can provide useful insight into hazardous situations for mis-matched blood transfusion. The aim of this prospective study was to assess the incidence and root causes of all ABO discrepancies, detected by a central hematology laboratory, in blood samples referred from 35 district hospitals. STUDY DESIGN AND METHODS: ABO discrepancies were detected by comparing either two current blood specimens or a current and historical specimen collected over a 5-year study period. Discrepancies were investigated by retyping new samples, checking sample identification, and reviewing previous hospital records. RESULTS: A total of 118 ABO discrepancies were discovered in a series of 407,769 tests carried out during the study period. The incidence of ABO discrepancies was 1 per 3,400. This figure was 10 times higher than the incidence of ABO-mismatched transfusions. Most of these ABO discrepancies were due to phlebotomy errors, that is, collection from wrong patient. The second most common cause involved clerical errors during patient registration or identification. CONCLUSION: ABO discrepancies can result from errors made not only by the medical staff during phlebotomy but also to by the clerical staff during registration and identification. These findings emphasize the need to standardize data transmission between health care personnel.