Red Blood Cell Antigens Research Articles

The Incidence of Evanescent Antibodies to Red Blood Cell Antigens in a Tertiary Care Hospital in Northern India

Background and Objectives: The anti-A and anti-B are naturally occurring antibodies in the human body but alloantibodies may be formed in individuals who lacks that corresponding red cell antigen after any sensitising event like blood transfusion or pregnancy. The aim of this study was to find the incidence of evanescenct RBC alloantibodies that may not be detectable at the time of pre-transfusion screening. Methods: This was a retrospective observational study from January 2017 to May 2019 in a tertiary care centre from North India. The data on antibody screening and identification retrieved from the departmental records. The patients were screened for red blood cell antibody and those with a positive screening test were further investigated for antibody identification. Antibody screening was performed by solid phase method using Immucor Capture-R Ready Screen (4 cell). Confirmed positive samples were investigated with advance methods of Antibody ID using Reagent panel Red Blood Cells Capture-R Ready ID (16 Cell) in Automated Analyzer Iris or Neo (Immucor Inc. Nocross, GA, USA). As and when required other advance techniques of adsorption and elution, etc were also performed too. Results: The total number of patient screened during this period were 8071. Amongst them 312 were positive for antibody screening (3.8%), of those 216 (62.9%) cases had alloantibodies and 96 (30.7%) cases had autoantibodies. Among the 216 cases of alloantibody, 147 (68.1%) cases had single alloantibody and 69 (31.9%) cases had multiple alloantibodies. Amongst the patients having single alloantibody, the prevalence was highest for Anti-D 54 (36.7%), followed by Anti-E 27 (18.3%), Anti-C 8 (5.4%), Anti-c 7 (4.7%), Anti-K 9 (6.1%), Anti-Fyb 11 (7.4%), Anti-M 18 (12.2%), Anti-N 4 (2.7%), Anti-Fyb 3 (2%), Anti-Lea 3 (2%), Anti-Cw 2 (1.3%) and Anti-Mia 1 (0.6%). Of the 96 patients with autoantibody 72 had warm autoantibody, 10 had cold autoantibody and there were 8 cases of mixed warm and cold autoantibodies. There were 6 patients with warm autoantibody with underlying alloantibody. Conclusion: In conclusion, the high prevalence of Anti-Rh (Anti-D, E), Anti-M, Anti-Fyb antibodies in patient requiring transfusion reiterates the importance of stringent antibody screening and identification as an essential step in preventing delayed hemolytic transfusion reaction.

Prevalence of alloantibodies associated with haemolytic disease of the fetus and newborn in pregnant women at the Ekiti State University Teaching Hospital, Ado-Ekiti, Southwest Nigeria.

Haemolytic disease of the fetus and newborn (HDFN) is caused by maternal alloimmunization against red blood cell antigens, which could result in fetal anaemia, hyperbilirubinaemia, kernicterus, and death. This study was designed to determine the prevalence of alloantibodies against erythrocyte antigens in blood samples of pregnant women during the first trimester which may cause HDFN. A total of 123 consenting pregnant women attending the antenatal clinic of Ekiti state University Teaching Hospital, Ado Ekiti participated in the study which lasted three months. The participants were within the ages of 16 to 45 years old across the major ethnic group in Nigeria. ABO/Rh typing, screening and identification of red blood cell alloantibodies were carried out using standard protocols. 15 (12.2%) subjects had detectable antibodies known to cause haemolytic disease of the fetus and newborn (HDFN). The specificity of the antibodies was as follows: anti-K (5, 33%), anti-k (3, 20%), anti- Jsa (2, 13%), anti-C. (3, 20%), and anti-E (2, 13 %). Based on ethnicity, the prevalence of Kell antibodies was highly significant among the Yorubas as well as anti-C and anti-E. The observation was similar in the Igbo and Hausa groups. There is a need to determine these antibodies and monitor their titre in pregnant women to manage or prevent the morbidity and mortality associated with HDFN during routine antenatal care.

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.

The development and application of a novel reagent for fixing red blood cells with glutaraldehyde and paraformaldehyde

ABSTRACTObjectiveThe currently employed red blood cell reagents have a short shelf life. Some hospitals with a small number of specimens will be unable to utilize them within the validity period, resulting in a substantial increase in the purchase price. Therefore, the method of developing long-term red blood cell reagents is a problem worthy of further study.MethodsIn this experiment, the type and concentration of the red blood cell reagent treatment solution were evaluated based on the red blood cell antigen concentration 24 h after treatment. In addition, the qualified glutaraldehyde/paraformaldehyde reagent was stored for six months, and five red blood cell indices were measured every month. At the same time, the detection indices of treated red blood cell reagents and untreated red blood cell reagents were compared.ResultsIt was discovered that treated red blood cells containing 0.005% GA and 0.05% PFA were more suitable for the preservation of red blood cells than other treated concentrations, and the preservation time could reach six months. The test tube method (n = 24) and microcolumn gel card (n = 35) were used to determine the accuracy of the treated blood cells containing 0.005% glutaraldehyde +0.05% paraformaldehyde, with an accuracy of 100%.ConclusionThis experiment resulted in the development of a novel reagent for treating red blood cells with glutaraldehyde/paraformaldehyde fixed solution that can effectively prolong its storage time by two to three times that of red blood cell reagents currently on the market.

Extended red blood cell antigens and phenotypes in Burkina Faso: potential issues to design local population-sourced red blood cell reagent panels.

To date, 43 blood group systems with 349 red blood cell (RBC) antigens have been recognized. The study of their distribution is useful for blood services to improve their supply strategies for providing blood of rare phenotypes, but also to design indigenous RBC panels for alloantibody screening and identification. In Burkina Faso, the distribution of extended blood group antigens is not known. This study aimed to investigate the extended profiles of blood group antigens and phenotypes of this population and to raise limitations and potential strategies for the design of local RBC panels. We conducted a cross-sectional study that included group O blood donors. Extended phenotyping for antigens in the Rh, Kell, Kidd, Duffy, Lewis, MNS, and P1PK systems was performed using the conventional serologic tube technique. The prevalence of each antigen and phenotype combination was determined. A total of 763 blood donors were included. The majority were positive for D, c, e, and k and negative for Fya and Fyb. The prevalence of K, Fya, Fyb, and Cw was less than 5 percent. The most frequent Rh phenotype was Dce, and the most common probable haplotype was R0R0 (69.5%). For the other blood group systems, the K-k+ (99.4%), M+N+S+s- (43.4%), and Fy(a-b-) (98.8%) phenotypes were the most frequent. Antigenic polymorphism of blood group systems by ethnicity and geography argues for the design and evaluation of population-sourced RBC panels to meet specific antibody profiles. However, some of the specificities identified in our study, such as the rarity of double-dose antigen profiles for certain antigens and the cost of antigen phenotyping tests, are major challenges to overcome.

Turning universal O into rare Bombay type blood

Red blood cell antigens play critical roles in blood transfusion since donor incompatibilities can be lethal. Recipients with the rare total deficiency in H antigen, the Oh Bombay phenotype, can only be transfused with group Oh blood to avoid serious transfusion reactions. We discover FucOB from the mucin-degrading bacteria Akkermansia muciniphila as an α-1,2-fucosidase able to hydrolyze Type I, Type II, Type III and Type V H antigens to obtain the afucosylated Bombay phenotype in vitro. X-ray crystal structures of FucOB show a three-domain architecture, including a GH95 glycoside hydrolase. The structural data together with site-directed mutagenesis, enzymatic activity and computational methods provide molecular insights into substrate specificity and catalysis. Furthermore, using agglutination tests and flow cytometry-based techniques, we demonstrate the ability of FucOB to convert universal O type into rare Bombay type blood, providing exciting possibilities to facilitate transfusion in recipients/patients with Bombay phenotype.

Live birth prevalence of hemolytic disease of the fetus and newborn in the United States from 1996 to 2010

Hemolytic disease of the fetus and newborn (HDFN) is mediated by maternal alloantibodies, a consequence of immune sensitization during pregnancy with maternal-fetal incompatibility with ABO, Rhesus factor (Rh), and/or other red blood cell antigens. RhD, Kell, and other non-ABO alloantibodies are the primary cause of moderate to severe HDFN, whereas ABO HDFN is typically mild. HDFN live birth prevalence owing to Rh alloimmunization among newborns in the United States was last estimated to be 106 per 100,000 births in 1986. HDFN live birth prevalence owing to all alloantibodies was estimated to be 817 to 840 per 100,000 in Europe. There is a need for updated prevalence estimates in the United States and a better understanding of disease demographics, severity, and treatments. This study aimed to estimate the live birth prevalence of HDFN and the proportion of severe cases of HDFN in the United States, to describe the associated risk factors, and to compare the clinical outcomes and treatments among healthy newborns, newborns with HDFN, and newborns who are sick without HDFN using a nationally representative hospital discharge database. In this retrospective, observational cohort study, we used data from the 1996 to 2010 National Hospital Discharge Survey to identify live births, defined by inpatient visits with the newborn flag, with and without a diagnosis of HDFN across 200 to 500 sampled hospitals (≥6 beds) per year. Patient and hospital characteristics, alloimmunization status, disease severity, treatment, and clinical outcomes were evaluated. Frequencies and weighted percentages were calculated for all variables. Logistic regression was used to compare the characteristics between newborns with HDFN and other newborns using odds ratios. Of 480,245 live births identified, 9810 HDFN cases were recorded. When weighted to the United States population, this corresponded to a live birth prevalence of 1695 per 100,000 live births. Compared with other newborns, newborns with HDFN were more likely to be female, Black, living in the South (vs the Midwest or West), and treated at larger (>100 beds) and government-owned hospitals. ABO and Rh alloimmunization accounted for 78.1% and 4.3% of newborns with HDFN, respectively, whereas HDFN caused by other antigens, such as Kell and Duffy, accounted for 17.6% of the cases. Among newborns with HDFN, 22% received phototherapy, 1% received simple transfusions, and 0.5% received exchange transfusions or intravenous immunoglobulin. Newborns affected by HDFN caused by Rh alloimmunization were more likely to require medical interventions, including simple or exchange transfusions, and more likely to be delivered by cesarean delivery. Overall, HDFN was associated with a longer hospital length of stay in the neonatal intensive care unit when compared with healthy and other sick newborns, a higher rate of cesarean delivery, and a higher rate of nonroutine discharge than healthy newborns. Overall, the live birth prevalence of HDFN was higher than those previously reported, whereas Rh-induced HDFN live birth prevalence was similar to those previously reported. HDFN live birth prevalence owing to Rh alloimmunization decreased over time, likely because of continued Rh immune globulin prophylaxis. Treatment patterns for newborns with HDFN and the comparative clinical outcomes when compared with healthy newborns confirm the continued clinical needs of this population.

Immunostimulatory and Immunorestorative Effects of Leaf Extract and Fractions of Musanga cecropioides on Immunocompetent and Experimentally Immunocompromised Mice

• Musanga cecropioides boosted immune stimulation in immunocompetent animals • M. cecropioides brought about fast rate of restoration of immune status • M. cecropioides stimulated immune response to (sheep red blood cell) SRBC antigen Stimulation of the immune system against disease causing agents and restoration of immune functions in immunodeficiency disease state are essential for maintaining good health. Objective : This study investigated the immunomodulatory effects of the leaf extract and fractions of Musanga cecropioides in immunocompetent and induced immunocompromised animal models. Humoral immune stimulatory effect of the extract and its fractions at 200 and 400 mg∙kg −1 against sheep red blood cells (SRBCs) antigen was determined in both immunocompetent and cyclophosphamide (80 mg∙kg −1 ) immunosuppressed animals. The effect of the most active fraction on leucopoiesis was also determined following high dose cyclophosphamide (300 mg∙kg −1 ) suppression of the immune system. Levamisole at 2.5 mg∙kg −1 was used as the reference drug throughout the study. The extract dose dependently stimulated the humoral immune response to SRBC antigen in immunocompetent animals; however, its stimulatory effect was not significant ( P > 0.05). In the immunosuppressed model, the extract at 400 mg∙kg −1 evoked significant ( P < 0.05) increase in antibody titer value with a corresponding 67% immune-restorative effect. The ethyl acetate fraction (EAF) maintained the most active fraction with significant ( P < 0.05) antibody stimulatory effect in immunocompetent and immunosuppressed animals. Similarly, higher recovery rate was demonstrated by the EAF as shown by steep time recovery curve in high dose immunosuppressed animals. The EAF at 200 and 400 mg∙kg −1 showed above 50% leucopoiesis just like the reference drug (2.5 mg∙kg −1 levamisole) against 33.83% shown by the immune-suppressed control group. M. cecropioides boosted immune stimulation in immunocompetent animals and brought about fast rate of restoration of immune status in immunocompromised animals.

Antigen copy number and antibody dose can determine the outcome of erythrocyte alloimmunization inducing either antibody-mediated immune suppression or enhancement in a murine model.

The administration of anti-D for the prevention of hemolytic disease of the fetus and newborn is one of the most successful clinical uses of the phenomenon of antibody-mediated immune suppression (AMIS). However, despite adequate prophylaxis, failures can still occur in the clinic and are poorly understood. Recently, the copy number of red blood cell (RBC) antigens has been shown to influence immunogenicity in the context of RBC alloimmunization; however, its influence on AMIS remains unexplored. RBCs expressing approximately 3,600 and approximately 12,400 copy numbers of surface-bound hen egg lysozyme (HEL), named respectively HELmed -RBCs and HELhi -RBCs, and selected doses of a polyclonal HEL-specific IgG were transfused into mice. Recipient HEL-specific IgM, IgG, and IgG subclass responses were evaluated by ELISA. Antigen copy number affected the antibody dose required for AMIS induction with higher antigen copy numbers requiring larger doses of antibody. For instance, 5μg of antibody caused AMIS for HELmed -RBCs but not HELhi -RBCs, while 20 μg induced significant suppression for both HEL-RBCs. Overall, increasing amounts of the AMIS-inducing antibody were associated with a more complete AMIS effect. In contrast, the lowest tested doses of the AMIS-inducing IgG led to evidence of enhancement at the IgM and IgG levels. The results demonstrate that the relationship between antigen copy number and antibody dose can influence the outcome of AMIS. Further, this work suggests that the same antibody preparation can induce both AMIS and enhancement but that the outcome may depend on the quantitative interrelationship of antigen-antibody binding.

HLA and red blood cell antigen genotyping in SARS-CoV-2 convalescent plasma donors.

Aim: More data is required regarding the association between HLA allele and red blood cell (RBC) antigen expression in regard to SARS-CoV-2 infection and COVID-19 susceptibility. Methods: ABO, RhD, 37 other RBC antigens and HLA-A, B, C, DRB1, DQB1 and DPB1 were determined using high throughput platforms in 90 Caucasian convalescent plasma donors. Results: The AB group was significantly increased (1.5×, p=0.018) and some HLA alleles were found to be significantly overrepresented (HLA-B*44:02, C*05:01, DPB1*04:01, DRB1*04:01 and DRB1*07:01) or underrepresented (A*01:01, B51:01 and DPB1*04:02) in convalescent individuals compared with the local bone marrow registry population. Conclusion: Our study of infection-susceptible but non-hospitalized Caucasian COVID-19 patients contributes to the global understanding of host genetic factors associated with SARS-CoV-2 infection and severity.

Commentary: Case report: Daratumumab treatment in pre-transplant alloimmunization and severe hemolytic anemia.

Pereda et al. recently reported three cases in which daratumumab was utilized to reduce the 36 burden of red blood cell (RBC) and human leukocyte antigen (HLA) alloantibodies (1). These 37 cases support the need for further investigation into the potential use of daratumumab and related 38 plasma cell depletion therapies for patients with significant alloimmunization. However, the 39 authors' cases, particularly cases 1 and 2 in which the authors describe patients with sickle cell 40 disease (SCD) and multiple RBC antibodies, lack sufficient immunohematology and transfusion 41 details to reliably conclude the effectiveness and safety of daratumumab to reduce and existing alloantibodies can persist despite daratumumab treatment (3-6). Secondly, the 80 authors fail to acknowledge the possibility that the alloantibodies may have disappeared naturally 81 through the phenomenon of evanescence. Numerous studies have shown that many patients' 82 RBC alloantibodies will decline in titer to levels below a detectable threshold without further 83 exposure (7-9). Though the loss of all antibodies due to evanescence may be less likely, not 84 accounting for this potential mechanism of a waning antibody is concerning. 85 86 Furthermore, literature demonstrates that even if these antibodies have become undetectable, 87 these patients may still be at risk for DHTRs (10-13).

Donor variability affects the outcome for the monocyte monolayer assay (MMA)

The monocyte monolayer assay (MMA) is used to predict transfusion outcomes when antibodies to red blood cell (RBC) antigens are present and compatible antigen-negative blood isn’t available. Typically, the monocytes used are peripheral blood mononuclear cells (PBMC) isolated from healthy volunteers. This study aimed to determine the between-volunteer variability in monocyte reactivity in the MMA. PBMCs were isolated (Ficoll density gradient) from freshly collected whole blood from 28 individuals and incubated with RBCs sensitised with anti-D (1 hour, 37oC, 5% CO2; positive control).

Storage differentially impacts alloimmunization to distinct red cell antigens following transfusion in mice.

The impact of blood storage on red blood cell (RBC) alloimmunization remains controversial, with some studies suggesting enhancement of RBC-induced alloantibody production and others failing to observe any impact of storage on alloantibody formation. Since evaluation of storage on RBC alloimmunization in patients has examined antibody formation against a broad range of alloantigens, it remains possible that different clinical outcomes reflect a variable impact of storage on alloimmunization to specific antigens. RBCs expressing two distinct model antigens, HEL-OVA-Duffy (HOD) and KEL, separately or together (HOD × KEL), were stored for 0, 8, or 14 days, followed by detection of antigen levels prior to transfusion. Transfused donor RBC survival was assessed within 24 h of transfusion, while IgM and IgG antibody production were assessed 5 and 14 days after transfusion. Stored HOD or KEL RBCs retained similar HEL or KEL antigen levels, respectively, as fresh RBCs, but did exhibit enhanced RBC clearance with increased storage age. Storage enhanced IgG antibody formation against HOD, while the oppositive outcome occurred following transfusion of stored KEL RBCs. The distinct impact of storage on HOD or KEL alloimmunization did not appear to reflect intrinsic differences between HOD or KEL RBCs, as transfusion of stored HOD × KEL RBCs resulted in increased IgG anti-HOD antibody development and reduced IgG anti-KEL antibody formation. These data demonstrate a dichotomous impact of storage on immunization to distinct RBC antigens, offering a possible explanation for inconsistent clinical experience and the need for additional studies on the relationship between RBC storage and alloimmunization.

The impact of ABO and RhD blood types on Babesia microti infection.

Babesiosis is an emerging infectious disease caused by intraerythrocytic Babesia parasites that can cause severe disease and death. While blood type is known to affect the mortality of Plasmodium falciparum malaria patients, associations between red blood cell (RBC) antigens and Babesia microti infection and disease severity are lacking. We evaluated RhD and ABO blood types of Babesia-infected (18S rRNA reactive) blood donors in 10 endemic states in the Northeastern and northern Midwestern United States. We also assessed possible associations between RhD and ABO blood types and disease severity among hospitalized babesiosis patients in Connecticut. A total of 768 Babesia-infected blood donors were analyzed, of which 750 (97.7%) had detectable B. microti-specific antibodies. B. microti-infected blood donors were more likely to be RhD- (OR of 1.22, p-value 0.024) than RhD+ donors. Hospitalized RhD- babesiosis patients were more likely than RhD+ patients to have high peak parasitemia (p-value 0.017), which is a marker for disease severity. No differences in RhD+ blood type were noted between residents of the Northeast (OR of 0.82, p-value 0.033) and the Midwest (OR of 0.74, p-value 0.23). Overall, ABO blood type was not associated with blood donor B. microti infection, however, B. microti-infected donors in Maine and New Jersey were more likely to be blood type B compared to non-type B (OR 2.49 [p = 0.008] and 2.07 [p = 0.009], respectively), while infected donors from Pennsylvania were less likely to be type B compared to non-type B (OR 0.32 [p = 0.02]). People expressing RhD antigen may have a decreased risk of B. microti infection and babesiosis severity. The association of B antigen with B. microti infection is less clear because the antigen appeared to be less prevalent in infected Pennsylvania blood donors but more prevalent in Maine and New Jersey infected donors. Future studies should quantify associations between B. microti genotypes, RBC antigens, and the frequency and severity of B. microti infection to increase our understanding of human Babesia pathogenesis and improve antibody, vaccine, and RBC exchange transfusion strategies.

Prior immunization against an intracellular antigen enhances subsequent red blood cell alloimmunization in mice

AbstractAntibodies against red blood cell (RBC) alloantigens can increase morbidity and mortality among transfusion recipients. However, alloimmunization rates can vary dramatically, as some patients never generate alloantibodies after transfusion, whereas others not only become alloimmunized but may also be prone to generating additional alloantibodies after subsequent transfusion. Previous studies suggested that CD4 T–cell responses that drive alloantibody formation recognize the same alloantigen engaged by B cells. However, because RBCs express numerous antigens, both internally and externally, it is possible that CD4 T–cell responses directed against intracellular antigens may facilitate subsequent alloimmunization against a surface RBC antigen. Here, we show that B cells can acquire intracellular antigens from RBCs. Using a mouse model of donor RBCs expressing 2 distinct alloantigens, we demonstrate that immune priming to an intracellular antigen, which would not be detected by any currently used RBC compatibility assays, can directly influence alloantibody formation after exposure to a subsequent distinct surface RBC alloantigen. These findings suggest a previously underappreciated mechanism whereby transfusion recipient responders may exhibit an increased rate of alloimmunization because of prior immune priming toward intracellular antigens.

Validation of a flow-cytometry-based red blood cell antigen phenotyping method.

Current manual and automated phenotyping methods are based on visual detection of the antigen-antibody interaction. This approach has several limitations including the use of large volumes of patient and reagent red blood cells (RBCs) and antisera to produce a visually detectable reaction. We sought to determine whether the flow cytometry could be developed and validated to perform RBC phenotyping to enable a high-throughput method of phenotyping using comparatively miniscule reagent volumes via fluorescence-based detection of antibody binding. RBC phenotyping by flow cytometry was performed using monoclonal direct typing antisera (human IgM): anti-C, -E, -c, -e, -K, -Jka , -Jkb and indirect typing antisera (human IgG): anti-k, -Fya , -Fyb , -S, -s that are commercially available and currently utilized in our blood transfusion services (BTS) for agglutination-based phenotyping assays. Seventy samples were tested using both flow-cytometry-based-phenotyping and a manual tube standard agglutination assay. For all the antigens tested, 100% concordance was achieved. The flow-cytometry-based method used minimal reagent volume (0.5-1μl per antigen) compared with the volumes required for manual tube standard agglutination (50μl per antigen) CONCLUSION: This study demonstrates the successful validation of flow-cytometry-based RBC phenotyping. Flow cytometry offers many benefits compared to common conventional RBC phenotyping methods including high degrees of automation, quantitative assessment with automated interpretation of results and extremely low volumes of reagents. This method could be used for high-throughput, low-cost phenotyping for both blood suppliers and hospital BTS.

Type and Screen Method versus Antihuman Globulin Crossmatch in Pretransfusion Testing: A Cross-sectional Study

Introduction: Blood transfusion remains the primary modality of treatment for many serious and common diseases. According to the International Society of Blood Transfusion (ISBT), there are about 349 blood group antigens, out of which only about 25-28 antigens are known to cause acute or delayed type of haemolytic transfusion reactions which could be prevented by Pretransfusion Testing (PTT). Regulated pretransfusion tests include ABO blood grouping, Rh typing, antibody detection, antibody identification and compatibility testing. The purpose of compatibility tests is to demonstrate invitro red cell antigen-antibody reaction. The Antihuman Globulin (AHG) crossmatch testing can assure ABO compatibility between donor and patient blood as well as detect most clinically significant antibodies. Type and Screen (T&amp;S) is a procedure carried out as part of PTT in which the recipient’s blood sample is tested for ABO group, RhD T&amp;S for unexpected antibodies. Aim: To compare T&amp;S method of PTT with AHG crossmatch. Materials and Methods: This cross-sectional study was conducted in the department of Transfusion medicine at Government Royapettah Hospital, Chennai and The Tamil Nadu Dr. MGR Medical University, Chennai, Tamil Nadu, India from June 2012 to December 2013. T&amp;S was performed on 1,040 recipients’ (510 males and 530 females) samples. All these samples were subjected to AHG crossmatch with ABO group and RhD type matched donor samples to assess the compatibility between donor and recipient by using column agglutination technology. Statistical analysis was carried out using Statistical Package for the Social Sciences (SPSS) version 11.0. Results: The prevalence of unexpected antibodies in the recipient population was 1.06%. Among the 1,040 recipients’ blood samples, 11 samples were found to have unexpected antibodies. Out of these 11 samples, 10 showed exact antibodies and the remaining one sample with negative antibody screening was found to be incompatible with AHG crossmatch. The sensitivity and specificity of T&amp;S method in comparison to AHG crossmatch was 87.50% and 99.71%, respectively. Conclusion: The sensitivity and specificity of T&amp;S is as acceptable as AHG crossmatch. However, in view of one sample with false negative antibody screening in the study population, it is imperative to know the phenotyping of Red Blood Cells (RBC) antigens of the native population before getting away with AHG crossmatch.

Prevalence of Rhesus D antigen among patients attending Wudil General Hospital Kano state, Nigeria

The Rhesus blood group system is the second most important red blood cell antigen system after the ABO blood group system. The purpose of this study was to generate basic data on the prevalence of Rhesus D antigen among patients attending Wudil general hospital. Haemagglutination method was used to determine the presence of Rhesus D antigen using commercially available Anti-sera D. Anti-sera A and B were also used to investigate the ABO blood type. It was discovered that Rhesus D positive was the most prevalent with percentage frequency of 90.5% (181) and Rhesus D negative was the lowest with percentage frequency of 9.5% (19). It was observed that Rhesus D positive was higher in males than female (51.5% and 39.0% respectively). Rhesus D negative was also relatively higher in males than in females (6.0% and 3.5% respectively). A prevalent pattern of (B Rh-D +&gt; O Rh-D +&gt; A Rh-D +&gt; AB Rh-D +&gt; B Rh-D -&gt;A Rh-D - &gt; AB Rh-D - &gt;O Rh-D -) was discovered. This study will be useful in studying the susceptibility of diseases with regards to Rhesus factor and may generate a vital information for population genetics and anthropological studies.

Congenital cardiac surgery in a patient with cold agglutinins

Cold agglutinin disease is a type of autoimmune haemolytic anaemia caused by autoantibodies that bind to red blood cell antigens at a cold temperature and causes extravascular haemolysis and sometimes thrombosis also. Due to exposure to a lower temperature during open-heart surgery, the activation of haemolysis may occur in the presence of cold agglutinin antibodies. We present the management of a cyanotic child who has undergone open-heart surgery after the detection of high cold agglutinin titres during routine pre-transfusion screening.

Is Indirect Coombs Test by Pooled Cells Sufficient for Antibody screening? An Eye-Opening Case Series

The ideal way to screen for the presence of alloantibodies is by antibody screening panels which represent all clinically significant antigens in appropriate dosage. Most centers use pooled O-cells for antibody screening as it has antigens of non-ABO blood group systems that are prevalent in a representative population. Pooled O-cells sometimes fail to detect antibodies to less prevalent red blood cell antigens with reduced expression or show a dosage phenomenon. Despite pooling 4 to 5, O-donor segments, sometimes, it is difficult to detect clinically significant antibodies. False-negative indirect Coombs test by pooled O-cells may delay getting a compatible unit for elective cases where type and screen policy is used. Donor units with weak antigenic expression or units showing dosage can come compatible despite being antigen positive and lead to a hemolytic reaction. We report two cases where antibody screening by pooled O-cells was negative; still, cross-match was incompatible. Antibody screening with a three-cell panel was positive. Antibody identification with 11-cell panels confirmed the alloantibody to be anti-E. The present cases emphasize the importance of three-cell panels over pooled O-cells.