Kell Systems Research Articles

A 6-month Review of O pRBC Utilization in Non-O Blood Type Patients in a Level 1 Trauma Center

Abstract Introduction/Objective Using O pRBCs for non-O patients for acute events is not unusual in a level 1 trauma hospital. However, we occasionally utilize this blood type to meet the needs of our patients that are not acutely bleeding. In this study, we evaluated the utilization of O units in non-O patients to improve our transfusion practices. Methods/Case Report We reviewed the indications of the O pRBCs transfused to non-O patients from October 2023 to March 2024. We evaluated the number of units used in acute events such as massive transfusion protocol (MTP), acute blood loss, sickle cell disease (SCD) patients in crises, bleeding associated with surgery and in patients with symptomatic anemia. Results (if a Case Study enter NA) There were 258 O pRBCs transfused to non-O blood type from October 2023 to March 2024. 135(52%) of these units were used for bleeding patients, of which 91%(124/135) were used for acute events. Most of the units utilized for acute hemorrhage had activated MTP (92%, 89/124) due to trauma (88%, 78/89). Only 12%(31/258) were used by SCD patients, with a little over half of these units being used acutely and the rest used prophylactically. About 69% of the 16 units used in surgery were due to bleeding. Lastly, 76 units (29%) were used for symptomatic anemia patients with 45% of these units transfused for anemia of prematurity. Conclusion In a level 1 trauma hospital, advocating for conserving O units is crucial to ensure enough units are available for trauma. As anticipated, acute bleeding was found to be the leading cause for patients with non-O blood types to receive O pRBCs. Notably, the prevalence of using O units for acute and prophylactic transfusion is relatively the same for SCD patients and phenotypically matching the Rh and Kell systems likely plays a role.

Frequency of ABO, Rh and Kell Blood Group among Blood Donors in Brazzaville, Republic of the Congo

Introduction: Blood group antigens play an essential role in transfusion safety and in avoiding the risk of alloimmunization. The ABO, Rh and Kell blood group systems are the most clinically important. The aim of this study was to determine the frequency of ABO, Rh and Kell blood groups among blood donors in Brazzaville, Republic of Congo. Methods: This was a cross-sectional study conducted among blood donors in Brazzaville, republic of Congo, from June 2021 to November 2022. The blood samples were tested for ABO, Rh and Kell antigens by standard tube agglutination method. The statistical analysis was done using SPSS version 21.0. Results: A total of 350 participants were included, of which 258(73.7%) of donors were males and 92 (26.3%) females. The antigen frequencies of ABO and Rh(D) blood group system showed that O was the most prevalent blood group 46.8% followed by A (28.9%), B (16.9%), and AB (7.4%). The Rh-positive donors were more prevalent (94.86%) as oppose to the Rh-negative (5.14%). The most common Rh phenotype is the Dccee (64.86%) while the rarest phenotype is the dCcee (0.86%). The prevalence of K and k antigen was 0.9% and 99.1%, respectively. Conclusion: This study determined the phenotypic variability of ABO and Rh blood group antigens with low prevalence of Kell antigen. The extensive phenotypic status of Rh and Kell systems in blood donors is important for the efficient management of blood banks and transfusion services.

PREVALENCE OF KELL BLOOD GROUP SYSTEM IN BLOOD DONORS ATTENDING A TERTIARY CARE CENTRE IN NORTHWESTERN INDIA

Objective: The Kell blood group system is amongst one of the clinically significant blood group system in blood transfusion, consisting of different types of antigens with high immunogenicity which can be a potential cause of serious transfusion reactions and hemolytic disease of fetus and newborn. Knowledge of the antigenic frequency is crucial to assess the risk of alloimmunisation and to guide the probability of finding antigen-negative donor blood, which can be useful for a patient with corresponding or multiple red cell alloantibodies. Methods: This is a retrospective study which was done at Department of Immunohematology and Transfusion medicine, SMS Medical College, Jaipur over a period of one year from 1st Jan to 31st Dec 2020. During the study period, blood both voluntary donors as well as replacement donors were typed for Kell antigens by automated red cell antigen typing by capture-R technology in neo immucor. Results: A Total of 9677(Nine Thousand Six Hundred Seventy Seven) Blood donors were typed for Kell Antigens. Out of these 9677 samples, 288 were Positive for Kell positive (K+) resulting in overall frequency of Kell (K) Antigen as 2.9%. Conclusion: This is the first study that set out to determine the prevalence of Kell antigens among Blood Donors in Northwestern India. These results appear to be useful in providing better care for patients by implementing tests that should become a routine in blood banks. The Kell system is very important in Transfusion medicine practice.

Features of Distribution and Transfusion Significance of Erythrocyte Blood Groups according to ABO, Rh, Kell Systems in the Population of the Baranovichi Region of Belarus

Features of Distribution and Transfusion Significance of Erythrocyte Blood Groups according to ABO, Rh, Kell Systems in the Population of the Baranovichi Region of Belarus

Transfusion in hemoglobinopathies and red blood cell alloimmunization: data from Sicily, Sardinia and Malta.

Hemoglobinopathies are a group of diseases that include those due to globin gene mutations, such as thalassemia major (TM) and thalassemia intermedia (TI) or due to alteration of hemoglobin structure such as sickle cell disease (SCD), as well as a combination of these conditions such as thalasso-drepanocytosis (TD). They constitute the most frequent hereditary anemias requiring blood transfusion. In April 2022, a questionnaire was sent to the Transfusion Services (TS) of Sicily, Sardinia and the Maltese National Blood Transfusion (MNBT) service. The questionnaire was divided into a generic part including the number of patients followed and the type of hemoglobinopathy, and a section relating to transfusion therapy, including the number of units transfused, whether red blood cells (RBC) were washed and, finally, a section relating to the presence or absence of alloantibodies and their identification. Data was retrieved for 2,574 patients: 68.6% TM, 15.4% TI, 10.3% TD, 4.1% SCD, and 1.6% other hemoglobinopathies (OHA). The number of RBC units transfused was 76,974, equivalent to 24.5% of all the RBCU transfused from the total number of patients followed. The number of washed RBCU was 21.1% of all the units used; 337 patients (37%) were diagnosed with alloantibodies, the majority of which were patients with SCD (20.6%). Of the 485 alloantibodies found, 90.3% were identified. The antibodies found most frequently were related to the Kell system (41.7%) followed by antibodies to the Rhesus system (37.9%); 29.7% of patients had more than one antibody. From our study, certain indications can be formulated: complete the National Registry for patients with hemoglobinopathies; create a Registry of alloimmunized patients to ensure transfusion therapy is as safe as possible, considering antibody evanescence; and 3) increase the recruitment of blood donors of diverse ethnicities.

Benign High Prevalence Antibody Yta

Abstract Introduction/Objective The Yt system, also known as the Cartwright system, discovered in 1964, consists of five antigens encoded by the ACHE gene on chromosome 7. Yta and Ytb are antithetical antigens on the GPI – linked red cell glycoprotein, acetylcholinesterase (AChE). About 8-10% of individuals of European ancestry are Yt(b+); Yta is highly prevalent in all populations. The other three high-prevalence antigens, YTEG, YTLI, and YTOT, were added to this system in 2018. Yta is not affected by trypsin but is destroyed by α-chymotrypsin treatment of reagent red cells. Yta and Ytb are sensitive to disulfide bond-reducing agents 2-aminoethylisothiouronium bromide (AET) and dithiothreitol (DTT). Yt antibodies are mostly IgG and require Indirect Antiglobulin Test (IAT) for detection. Yt antibodies are not clinically significant, although anti-Yta may cause accelerated destruction of Yt(a+) transfused red cells. Monocyte Monolayer Assay (MMA) is often used to determine whether the anti-Yta is predicted to cause destruction of transfused Yt(a+) red cells. Methods/Case Report A 50 year old female of Hispanic/Latino descent with a BRCA2 mutationand a history of scoliosis and severe migraineswas admitted for robotic-assisted bilateral salpingo-oophorectomy, cystoscopy, and dilation and curettage. A type and screen was ordered preoperatively, and her antibody screen was positive. In her profile, the origin of anti-Yta was identified from an outside facility since 2008, but written documentation of anti-Yta identification could not be located. On antibody identification, the patient’s plasma was reactive with all cells (1+ AHG in PEG) except the auto control. Rare frozen anti-Yta antisera were used for phenotyping the patient for Yta and she was found to be Yta negative. Yta antigens are sensitive or weakened by DTT, so DTT-treated panel screen cells were used to rule out all clinically significant alloantibodies except for the Kell system. Anti-K and anti-k were ruled out by testing the patient’s plasma against SCARF (Serum, Cells, and Rare Fluid Exchange) Yta negative with homozygous K positive and homozygous k positive cells. Anti-Yta was reconfirmed at our facility. Results (if a Case Study enter NA) NA Conclusion Yta-negative blood is so rare that anti-Yta reacts > 99.8% of most populations. In some cases, autologous transfusion may be recommended for a patient. However, anti-Yta is often benign, and antigen-negative blood may not need to be transfused. The patient had uncomplicated procedures, and blood transfusion was not indicated at that time.

RHCE and Kell genotyping and alloimmunization profile in patients with sickle cell disease in the Federal District of Brazil

IntroductionSickle cell disease (SCD) is the most important hemoglobinopathy worldwide. The treatment often requires phenotype-matched red blood cell (RBC) transfusions, but alloimmunization to non-ABO antigens may occur in a part of the SCD patients. The genotyping has been used for RBC antigen prediction, reducing the possibility of the alloimmunization. Objective and MethodIn this study we performed the genotyping for the Kell and RHCE blood groups in samples from 77 phenotyped Brazilian SCD patients, whose alloimmunization profiles were also assessed. ResultsDiscrepancies between genotyping and phenotyping for the RHCE and Kell blood groups systems were observed in 22.07% (17/77) of the SCD patients. We found C/c and E/e discrepancies in 11.68% and 9.09% of patients, respectively; one SCD patient (1.3%) presented a discrepancy in the Kell group. Two SCD patients with discrepancies between genotype and phenotype were alloimmunized. In total, twenty-eight patients (36.4%) developed alloantibodies, of which 55.17% were directed against antigens in the Rh system, 8.62% were directed against antigens in the Kell system and 36.20%, against other groups. Finally, the frequency of discrepancies is significantly higher in non-alloimmunized patients (30.61%), compared to alloimmunized patients (7.14%) (p = 0.0217). ConclusionIn part, the alloimmunization of the SCD patients may have been triggered by these discrepancies, indicating that the integration of serological and molecular tests in the immunohematology routine could help to increase the transfusion safety. However, the higher number of alloimmunized patients without discrepancies showed that reasons other than the discrepancies appear to have influenced more strongly the alloimmunization in the SCD patients in this study.

Determination of the Risks of Post-Transfusion Allo-Immunization in the Rhesus and Kell Systems: Case of Recipients of the Regional Hospital of Bafoussam

<i>Background</i>: Blood transfusion according to the World Health Organization is the transfer of blood or blood constitute from an individual donor to another transfused. Despite the efforts made in the field of immuno-haematology, the transfusion of packed red blood cells or whole blood brings foreign antigens to the recipients. The risk of occurrence of anti-erythrocyte allo-immunization is therefore greater in polytransfused subjects and increases with the number of bags of packed red blood cells transfused. The main objective was to determine the risks of posttransfusion allo-immunization of the Rhesus and Kell systems in recipients of the HRB blood bank. <i>Methodology</i>: We conducted a descriptive and cross-sectional study by successive recruitment over a period of 10 months including a one-month data collection period during which 145 participants (81 donors and 64 blood recipients) were recruited. A venous blood sample was taken on an EDTA tube and dry. ABO blood groups followed by Rhesus and Kell phenotypes were determined in the tube. <i>Results</i>: Out of the 81 donors, 82.70% (67) were men, the age group [20-30] years was more represented 56.80% (46); the familiar donor status was the most representative at 48.10% (39). Of the 64 recipients, the male sex was the most representative 53.13% (34); the age group [00-10] years was more represented, i.e. 23% (15). Blood group O was more representatives, ie 51.90% (42) /40.60% (26). In the Rhesus system, the Dce (Dccee) phenotype was the most represented, 58.0% (47) in donors and 59.4% (38) in recipients. The K1 antigen was present in 24.7% (20) of donors and 18.8% (12) of recipients. We obtained a risk of allo-immunization of 40.61% in the Rhesus system and 15.62% in the Kell system. Thus the risks of alloimmunization were more represented by the incompatibilities with the antigen E (21.87%), K (15.62%) and C (15.62%). The Chi-square test of independence and linear regression showed that the risk of alloimmunization increases with the number of non-compatible blood bags received with an OR: 0.98, ICOR [3.05-9.26]. <i>Conclusion</i>: In view of the various incompatibilities and high risk of occurrence of alloimmunization, Rhesus/Kell phenotyping is an effective means of preventing post-transfusion alloimmunization and improving transfusion safety and even the transfusion outcome of recipients.

Evaluation of the immuno-hematological qualification of the blood donation at the Avicenne military hospital in Marrakech

Blood transfusion is a therapeutic act that consists of administering blood, or one of its cellular or plasma components, from one or more healthy subjects called "donors" to a sick subject called "recipient. Transfusion safety is ensured by controlling all stages of the transfusion chain, from the collection of blood, its preparation and biological qualification, to the performance of the transfusion act and even the follow-up of the recipients. The basis of immunohematological safety is the compatibility between the erythrocyte characteristics of the donor and those of the recipient. Donation Biological Qualification (DQ) laboratories have a duty and an obligation to ensure maximum reliability and sensitivity of results. They must therefore put in place the human, technical, material, computer and organizational resources, method validation, traceability of operations and risk analysis of all stages of the analysis process, to guarantee reliable results obtained in a timeframe compatible with the optimal use of the blood products. Thus, the work methodology within the immunohematology laboratory must be structured in procedures and operating modes in order to respect the standards of the reference system and to reduce the causes of errors to a minimum. Our work focused on the evaluation of the immunohematological qualification of blood donations within the blood transfusion center (CTS) at the Avicenne military hospital (HMA) in Marrakech, including the state of the premises, personnel and techniques used in the QBD service with the following goals · Review the level of qualification within the CTS of HMA. · To highlight the techniques of immunohematological qualification of blood donation per-formed at the CTS at the Avicenne Military Hospital in Marrakech compared to what is done nationally and internationally. · To draw the phenotypic profile of ABO, RHD and Kell blood groups in a representative population of donors from the city of Marrakech and regions, recruited over a period of 5 years. · The study of the prevalence of phenotypic markers, blood donations collected in the blood transfusion center of the HMA in Marrakech between the years 2016-2017-2017-2018-2019-2020, led to the following results: · For the ABO system, group O is the most frequent (50.47%), followed by group A (30.14%), then group B (15.45%) and lastly group AB (3.93%). · The standard Rhesus system (D); the Rh positive phenotype (D+) predominates largely (89.21%) while the Rh negative (D-) is about 10.79%. · Of the 7713 donations studied, only 3130 were used to study the prevalence of Rh phenotypes. For the remaining 4583 donations, phenotyping was not performed because of a stockout of gel cards. The Ccee phenotype is the most frequent (40.31%). · For the Kell system, the prevalence of K anti-gen was 8.17%. · For the IAT: no IAT was positive in the donors. · In our series, there was no return of the incident report form (IRF) and no traceability of the number of adverse transfusion reactions (ADR). This study allowed us to highlight several shortcomings concerning · The lack of trained personnel · Insufficient techniques in terms of precision, sensitivity and specificity · The lack of high level technical automatons · Occasional reagent stockouts due to supply delays. However, the transfusion system of the Avicenne Military Hospital of Marrakech (HMA) is still lacking in new techniques that have proven their worth in the development of this field; namely · HLA histocompatibility typing. · The research of antiplatelet antibodies: HPA; · Molecular biology: by gene amplification (PCR) from genomic DNA, in particular when hemagglutination shows its limits in the con-text of transfusion medicine. In the light of this work, a list of recommendations has been proposed in order to overcome these dysfunctions and to ensure a better immunohematological safety, in front of the various situations envisaged during the daily practice by reinforcing the operational and technical capacities of the blood transfusion service. Furthermore, the improvement of automation and computerization will reduce the risk of human error, by automatically handling certain phases of the process. However, whatever the degree of automation safety, its quality is strictly linked to the pre-analytical phase of sample collection, sample acceptability and collection information entry, for which particular attention should be paid.

Features of the distribution of the antigens of Kell, Duffy, Kidd, MNS, Lewis, Lutheran blood group systems in blood donors in the Kirov region.

The frequency of occurrence of antigens of the Kell (Kpa, Kpb), Kidd, Duffy, MNS and Lutheran systems in donors of the Kirov region corresponds to the distribution of antigens characteristic of white Europeans. Antigens K (Kell system) and Lea (Lewis system) are detected in the population of the region much less frequently, antigen Leb (Lewis system) - more often than in the population of Europe. The presence of a registry of donors typed according to a wide range of red blood antigens is a prerequisite for the immunohematological safety of blood transfusions.

Prevalence of Kell Ag in Pregnant Women with Thalassemia Minor or Intermedia Beta in Medical Centers Affiliated to Shiraz University of Medical Sciences in 2019-2020

Background: Kell Ag, the main antigen of kell system has the greatest antigenicity after Rh antigen and the associated antibodies are very important. These antibodies are mainly of the Ig G class and can cause side effects like Hemolytic disease of the Fetus and Newborn (HDFN) or Hemolytic Transfusion Reaction (HTR), especially in patients with chronic blood transfusions such as thalassemia patients. The aim of this study was to evaluate Kell antigen in pregnant women with thalassemia minor and intermedia and to determine the appropriate strategy for transfusion in this group of patients Methods: This study is a cross-sectional study on pregnant women with thalassemia minor or intermedia. The samples were taken from patients of Shahid Motahari clinic and those with positive antigen were selected and statistically analyzed. Results: The results showed that from the 64 patients who entered this study, the results of kell ag of 58 patients were negative and 6 were positive. Therefore, 91% of the pregnant women with beta thalassemia minor or intermedia were negative for ag kell and 9% were positive. Conclusion: In summary, the results of this study indicated that a large percentage of pregnant women with beta-thalassemia minor or intermediate are Kell-negative, and due to the complications of alloimmunization, screening of pack cells and pregnant patients is very important.

English

A variant is an alternative nucleotide located at a specific region of a gene. 48 genes encode for human red cell blood group systems. Variants within these genes encode for alleles, which can be highly polymorphic. The blood group gene loci jointly display all types of inherited variants to include single nucleotide variants (SNVs), insertions/deletions (indels), and structural variants. In Africa, there is limited information on the red cell variants. The aim of the study was to determine the incidence of Kell red blood cell variants among the Kenyans. Blood donor&rsquo;s samples that were used for routine grouping process were identified for this study. Next generation sequencing method was employed to predict the Kell red cell variants in blood donor samples. Descriptive statistics was applied and the result was presented in form of tables. The study reveals that Kell system has six variants with two major phenotypes and genotpes. The most common phenotype genotyped was KEL2 (KEL*02/KEL*02) 79% (85/108) followed by KEL2 KEL6 KEL7 (KEL*02.06/KEL*02) 16.7% (18/108). The rest were found to be of low frequency and all were associated with KEL2. The study recommends an extended study with a large sample size and introduction of extended phenotyping to aid Kell antigens identification in the donor population. &nbsp; Key words: Kell, variant, allele, KEL, KEL*02/KEL*02, molecular, genome, gene, next generation sequencing.

Molecular methods in identifying the true grouping of erythrocytes in patients with blood system diseases before transplantation of hematopoietic stem cells and their donors

Background. when transplantation of hematopoietic stem cells (HSC) is performing, it is necessary to take into account the incompatibility of the donor and recipient in terms of erythrocyte antigens in order to assess the possibility of immunological complications during HSC transfusion and/or graft engraftment (acute hemolysis, delayed hemolysis, etc.). The results of serological research methods do not always allow identifying the true group affiliation due to posttransfusion chimerism in patients and/or the presence of antigen allelic polymorphism.Aim. To establish the frequency of ABO-incompatible allo-HSC transplantations in the National Research Center for Hematology, to determine by molecular methods the group affiliation of patients with a weakened expression of antigens and/or after multiple blood transfusions before HSC transplantation, to clarify the blood type of HSC donors with a weakened expression of antigens.Materials and methods. The blood of 270 HSC donor-recipient couples was examined. The blood group of the ABO, Rhesus, MNS, Kell systems was determined in a plane agglutination test using the corresponding IgM class Tsoliclones and in gel cards. Genotyping was performed by polymerase chain reaction with primers to identify the genes of the ABO, Rhesus, Kell, and MNS systems.Results. In 2018-2020 270 HSC transplantations were performed at the National Research Center for Hematology. In 141 (52.22 %) couples, incompatibility of the donor and recipient according to the ABO system was revealed: major - 23.33 %, minor - 20 %; bidirectional - 8.89 %. problems in assessing of serological results were observed in 97 (36.3 %) patients: in 78 patients with post-transfusion chimerism and 19 patients with weakened antigen expression; in 15 (5.56 %) HSC donors: in 4 due to the lack of information about the blood group of cryopreserved cells, in 10 due to weakened antigen expression, in 1 to search for informative markers for monitoring HSC engraftment. The results of the study demonstrated that the percentage of agglutinated erythrocytes in post-transfusion chimerism cannot be a reliable criterion for establishing the true phenotype of a patient. In donors and patients with weakened expression of antigens, the presence of ABO*O1, -A1, -A2, -B1, RHD weak type 1, RHD weak type 2, RHD weak type 3, RHCE*Cw genes was confirmed. for the first time in Russia gene RHCE*01.38 was found.Conclusion. The prevalence of ABO-incompatible HSC transplants was noted. problems with serological determination of the blood group in a third of patients before HSC transplantation arose due to the presence of post-transfusion chimerism and weakened expression of antigens. Determining of the genotypes of HSC donors is necessary when the expression of antigens is weakened and cryopreserved cells are received. The percentage of agglutinated erythrocytes in post-transfusion chimerism cannot be a reliable criterion for establishing the true phenotype of a patient. Detection of mixed chimerism in the determination of group factors by serological methods is an indication for genotyping, especially in the context of the predominance of incompatible HSC transplantations.

Rare Blood Groups in ABO, Rh, Kell Systems - Biological and Clinical Significance.

Background: The frequency of ABO, Rh and Kell blood group antigens differs among populations of different ethnic ancestry. There are low-frequency antigens (<1%) and high-frequency antigens (>90%). A rare blood group is defined as the absence of a high-frequency antigen in the general population, as well as absence of multiple frequent antigens within a single or multiple blood group systems. Aim: To perform red blood cell typing and to calculate the antigen and phenotype frequencies, in order to identify rare blood group donors within the clinically most important АВО, Rh and Kell systems. Material and Methods: АВО, Rh (D, C, E, c, e) and Kell (K) antigen typing was performed using specific monoclonal sera and microplate technique, while Cellano (k) typing was performed with a monoclonal anti-k, antihuman globulin and column agglutination technique. Weak ABO subgroups were determined using the absorption elution method or molecular genotyping (PCR-SSP). Results: ABO antigen frequency is: A (40.89%), O (34.22%), B (16.97%), AB (7.92%) and weak ABO subgroups (0, 009 %). The established genotypes were AxO1 (0, 0026%) and AxB (0, 001%). Rh antigen frequency is: D (85.79%), C (71.7%), c (76.0%), E (26.0%) and е (97.95%). The most common Rh pheno-type is the DCcee (32.7%) while the rarest phenotype is the DCCEE phenotype (0. 003%). The prevalence of K and k antigen is 7.5% and 99.94%, respectively. The frequency of the rare phenotype K+k- is 0.06%. Conclusion: Large scale phenotyping of blood group antigens enables the identification of blood donors with rare blood groups for patients with rare phenotypes or with antibodies to high-frequency antigens and to frequent antigens within one or more blood group systems.

P1387: MONITORING OF DONOR CHIMERISM ON RED BLOOD CELLS ANTIGENS AFTER HEMATOPOIETIC STEM CELL TRANSPLANTATION

Background: Allogeneic hematopoietic stem cell transplantation (HSCT) is an effective treatment for diseases of the blood system. One of the indicators reflecting the functioning of donor hematopoietic tissue is posttransplant chimerism. Aims: To evaluate the effect of ABO belonging of the donor and recipient on the timing of the formation of red blood cells (RBS) donor chimerism after HSCT. Methods: The study included 57 patients who underwent HSCT in 2013-2021. Patient age ranged from 3 to 60 years (median - 34). Diagnosis of the patients: acute leukemia - 42 persons, Hodgkin’s lymphoma - 6, aplastic anemia - 4 and other blood diseases - 5. Before HSCT, the study of RBC antigens of the ABO, Rh, Kell systems in donors and recipients was performed by gel agglutination using reagents and equipment BioRad (USA). Antigens identified in the recipient’s phenotype and absent in the donor’s phenotype were considered informative, or vice versa. For statistical data processing, the nonparametric Kruskal-Wallis test was used. Results: Thirty-two (56.1%) of 57 pairs differed in ABO system antigens. Of these, 16 pairs (28.1%) had a major ABO incompatibility, 16 pairs (28.1%) had a minor incompatibility. The time of appearance of donor’s RBS in patients with ABO incompatibility had a wider range (from 14 to 201 days) and occurred significantly later (Me - 28 days) than in recipients ABO identical with donors (Me - 20 days), and from minor ABO incompatibility (Me - 19 days) (Table 1). The periods of occurrence of 50% and 100% donor chimerism did not differ significantly in all groups. In the group of recipients with major ABO incompatibility a case of pure red cell aplasia was revealed. The first appearance of RBC carrying donor antigens was recorded on day 201. 100% donor chimerism was formed on day 278. Antibodies of the ABO system (anti-A) IgG were present in the recipient’s blood for 189 days, IgM - for 230 days. Table 1. - The emergence of chimerism depending on ABO compatibility of donor-recipient pairs ABO identical Minor ABO incompatibility Major ABO incompatibility р (n=25) (n=16) (n=16) First appearance of donor chimerism 20 (12-54) 19 (11-41) 28 (14-201) р<0.05 Ме (Min-Max days) 50% donor chimerism 41 (19-142) 41 (26-74) 54 (34-227) p>0.05 Ме (Min-Max days) 100% donor chimerism 138 (40-316) 110 (70-150) 141 (90-278) p>0.05 Ме (Min-Max days) Summary/Conclusion: In recipients with a major ABO incompatibility the first appearance of donor’s RBS after HSCT occurs significantly later than in couples ABO identical and couples with a minor ABO incompatibility.

P1628: ALLOIMMUNIZATION DURING ASSISTED REPRODUCTIVE TECNOLOGY: CASE REPORT OF A PREGNANCY WITH IRREGULAR ANTIBODIES PROBABILY RELATED TO EGG DONOR ANTIGEN.

Background: Alloimmunization is a well known complication during pregnancy. It consists in an immune response of the mother against non-self antigens expressed by the fetus, which derive from the male partner, and its manifestation is an hemolytic disease of the fetus and newborn (HDFN). The most common antigen involved in alloimmunization came from the AB0 group and affect 15% to 25% of all pregnancies. However, the response caused by AB0 incompatibly is modest most likely due to the expression of AB0 blood type antigen in several organs. Other red cell antigens have been implicated in the HDFN; the Rh(D) antigen is the most immunogenic and the main cause of HDFN because the antigen is well expressed on the surface of the erythrocytes in the fetus. Previously, HDFN was known to cause fetal death in 1% of all pregnancies; with the advent of immunoprophylactic therapies, HDFN is currently well managed with fewer complications. In Italy, RBC iantibody screenings are typically performed at first and third trimester of pregnancy. Affected women are followed up to ensure the timely identification of those antibodies who require therapeutic interventions to prevent perinatal morbidity and mortality. The italian guidelines aim to direct these women to third-level centers where management protocols are shared by Immuno-hematology and Obstetrics Units in order to monitor the pregnancy with laboratory tests and clinical interventions. Aims: Identification of risk factor for alloimmunization during pregnancy Methods: Blood group, undirect and direct antiglobulin test during prregnancy mounthly based. After delivery blood group and DAT on Newborn Results: We report a case of alloimmunization during pregnancy of a woman that underwent a medically assisted procreation with egg donation. The subject, in apparently good health, had no chronic pathologies and was not taking medications. Her blood group was B Neg ccdee kk and the partner was 0 Pos CcDee Kk During the last triemster of the pregnancy, the woman developed alloimmunization towards many antigens of different blood systems,Rh (anti-D, antiC, anti-E), and the Kell (anti-Kell) systems. at low titers At week 37 of the pregnancy, she was admitted to the hospital for obstetrical problems and delivery was induced without clinical complications, neither for her nor for the fetus. Newborn blood group was 0 Pos CcDee Kk and Direct antiglobulin test was positive (++++). Anti-RHD and Kell antibodies were identified after elution. Additional studies are underway to characterize the egg donor RBC Phenotype to verify the presence of E antigen Summary/Conclusion: Alloimmunization during pregnancy is a condition caused by a response of the mother to paternal antigenes exhibited by the fetus and can be monitored with standard laboratory and clinical approaches However, the possibility to carry out pregnancies with egg donor that has a different RBC antigen profile of the mother open a new immuno-hematological scenarios previously not pointed. This could lead to potentially increased risk for the mother and the newborn.

Charakterystyka serologiczna populacji wsi Wielkie Drogi w pobliżu Krakowa

Serological characteristic of the population of Wielkie Drogi village near Cracow was made on the material of 83 persons of both sexes. The ABO, Rh(D) and Kell systems were examined. The frequencies of genes and phenotypes were evalusted and then the genetic intervals were computed for the investigated group in relation to other populations from Poland, Ukraine and Moravia.

Prevalence and specificity of red blood cell alloantibodies and autoantibodies in transfused Iranian β-thalassemia patients: A systematic review and meta-analysis.

BACKGROUND:Repeated allogeneic blood transfusions in thalassemia major patients stimulate the patient's immune system to generate antibodies against foreign erythrocyte antigens. This study was carried out to systematically review the findings of available studies about the prevalence of alloantibodies and autoantibodies, as well as the type of causative antigens among transfusion-dependent thalassemia patients in Iran.METHODS:Electronic search was conducted on Medline, PubMed, Cochrane, EMBASE, ScienceDirect, and Persians databases. All relevant articles published from January 1990 to July 2018 were included. s of conference booklets which that been published in the last 5 years were also included in the meta-analysis. The search language was restricted to English and Persian. The quality of studies was evaluated according to a checklist developed by authors, and Cochrane Risk of Bias Assessment Tool was used to evaluate the risk of bias.RESULTS:Twenty-three relevant articles met all the inclusion criteria. The prevalence of alloimmunization was 13%. Our study showed that anti-D (25%) and anti-K (25%) were most prevalent among Iranian β-thalassemia patients. Data analysis shows the autoantibody prevalence to be 1% among 3787 patients. Meta-regression revealed that the prevalence of alloantibodies increases with each year as the average age of the study population increases.CONCLUSION:The prevalence of red blood cell (RBC) alloantibodies in transfused Iranian β-thalassemia patients was high. Appropriate preventive strategies such as RBC phenotyping for patients before beginning transfusion and using extended RBC donor–recipient matching, specifically for Rh and Kell system, could be implemented to avoid complications in thalassemia patients.

Retrospective Analysis of Serological Characteristics and Distribution of Patients with Mimicking Antibodies

To understand the characteristics of patients with mimicking specificity autoantibodies through the analysis of the causes of autoantibodies, specificity of antibodies, strategy of blood transfusion, effect of transfusion and distribution of antibodies in China and abroad. A total of 23 patients who applied for blood in our hospital from January 2017 to June 2019 were identified as mimicking specificity autoantibodies by antibody identification or absorption-elution test. The causes of mimicking specificity autoantibodies, antibody specificity, blood transfusion strategy and blood transfusion effect were analyzed. The relevant articles on antibodies published in China and abroad were summarized and sorted out, and the distribution of antibodies was analyzed. All the 23 patients with mimicking specificity autoantibodies were Rh blood group system antibodies, of which mimicking anti-Ce autoantibodies were the most common (34.8%), followed by mimicking anti-e autoantibodies (26.1%), mimicking anti-D autoantibodies (21.7%), mimicking anti-C autoantibodies (8.7%) and mimicking anti-E autoantibodies (8.7%). Except for 2 cases with suspected history of blood transfusion, the other 21 cases had a history of blood transfusion / pregnancy. The most common cause of mimicking autoantibodies was drug, followed by infection and autoimmune diseases. The hemoglobin (Hb) of pretransfusion in the blood transfusion group was (48.4±23.9) g/L, which was significantly lower than (86.0±38.9) g/L in the non-transfusion group (P<0.01). Except for 2 cases who could not evaluate the effect of blood transfusion, the effective rate of transfusion was 100%. According to the retrospective statistics of 32 related articles published in China and abroad, the most type of mimicking antibodies were in Rh blood group system, accounting for 79.28%, among which anti-E was the main part of all mimicking autoantibodies, accounting for 21.95%. The following ones were in Kidd system MNSs system, and Kell system. Combined with the clinical symptoms and the degree of difficulty of blood matching, the best strategy of blood transfusion should be selected to ensure the safety of blood transfusion.

Red-cell alloimmunization profile in multi transfused patients: Findings and insights of a blood transfusion service.

Blood transfusion is a key intervention for decreasing morbidity and mortality in many cases and, besides its importance, potentially fatal consequences of incompatible transfusion are a great risk to patients. This study evaluated the incidence and specificity of erythrocyte alloantibodies in multi-transfused patients enrolled at an important Regional Blood Center. This was a single-center retrospective cohort study that eveluated patients enrolled at a Regional Blood Center in a period of four years. A total of 29,128 patient samples were screened, out of which 79 (0.27%) were multiple-transfused patients with alloantibodies identified. The most common alloantibody found was anti-E (22.55%) followed by anti-D (14.71%), anti-C (5.88%), anti-c (5.88%), anti-e (1.96%) and anti-Cw (0.98%). We also identified combinations of alloantibodies (25.32%), 5.88% of which showed an IgG autoantibody isolated or combined with alloantibodies. The most frequent reason for the need of blood transfusion included cases of surgery, emergency and urgency (36.71%). A low rate of development of alloantibodies in multi-transfused patients was found, which could be a consequence of the implementation of red blood cell phenotyping for patients who may receive frequent transfusions, as in the case of some hematological neoplasms and hemoglobinopathies. However, the most common alloantibodies identified were against the Rh and/or Kell systems, with high clinical significance since both can cause delayed hemolytic transfusion reactions. Thus, the implementation of reliable antibody screening tests and the transfusion of phenotyped units for selected patients in all transfusion services represent important measures to increase transfusion safety.