Red Cell Alloantibodies Research Articles

Frequency of red blood cell allo-immunization in transfused patients with sickle cell disease in Africa: a systematic review with meta-analysis

Background and Objectives: Blood transfusion is an effective and proven treatment for some severe complications of sickle cell disease. Recurrent transfusions have put patients with sickle cell disease at risk of developing antibodies against the various antigens they were exposed to. This study aims to investigate the frequency of red blood cell alloimmunization in patients with sickle disease in Africa. Materials and Methods: This is a systematic review of peer-reviewed and published literature. The review was conducted consistent with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses checklist.Data sources for the review include MEDLINE, PubMed, AJOL, CINAHL, Psych-Info and Academic Search Complete. Included in this review are articles that reported the frequency/prevalence of red blood cell alloimmunization in sickle cell disease patients in Africa. Eligible studies were subjected to independent full-text screening and data extraction. Risk of bias assessment was conducted with the aid of the mixed method appraisal tool. We employed a random-effects model of meta-analysis to estimate the pooled prevalence. We computed Cochrane’s Q statistics and I2 and prediction interval to quantify heterogeneity in effect size. Results: The prevalence estimates range from 2.6% to 29%. Pooled prevalence was estimated to be 12.1% (95% CI 8.1 to 17.7), with significant heterogeneity (I2= 91.83; PI = 2 to 54%). Conclusion: The frequency of red cell alloantibody varies considerably in Africa. Keywords: Systematic review; red blood cell; alloimmunization; sickle cell disease; Africa.

ABO-Mismatch Hematopoietic Stem Cell Transplantation with Pre-existing Red Cell Alloantibody Resembling a Case of Post-transplant Autoimmune Hemolytic Anemia

ABO-Mismatch Hematopoietic Stem Cell Transplantation with Pre-existing Red Cell Alloantibody Resembling a Case of Post-transplant Autoimmune Hemolytic Anemia

Prevalence and specificity of clinically significant red blood cell alloantibodies among hospitalized patients attending a tertiary care center in the southern part of India: A retrospective observational study

Abstract: BACKGROUND: Alloimmunization due to red blood cell (RBC) transfusions may occur due to discrepancy between donor and recipient’s antigenic exposure on RBCs. A thorough literature search shows limited data pertaining to the rate of alloimmunization and specificity of alloantibodies in the general patient population. The main aim of our study is to find the prevalence of alloimmunization rate and specificity of RBC alloantibodies among the patients who were admitted under different clinical departments in a tertiary care hospital. MATERIALS AND METHODS: Our study was a retrospective observational study in which the patient data regarding their blood grouping status, alloimmunization status, and other relevant details were collected from the case records that were recorded between 2021 and 2022. Antibody screening of these patients was carried out using Bio-Rad ID DiaCell I, II, III Asia (Mia+), 3-cell panel with the lot number (45330.13.x). The specificity of these alloantibodies was identified using the 11-cell antibody identification panel Bio-Rad (ID-DiaPanel 11 × 4) which belongs to lot number (06171.47.x–06271.47.x). RESULTS: The overall prevalence of RBC alloimmunization in our study was found to be 1.3% (n = 137). The most prevalent alloantibody in our study was considered to be anti-D (30.65%), followed by anti-c (18.24%) and anti-Jkb (16.05%). Females had a more significant association with the development of alloantibodies than males with P = 0.001. Patients with a history of transfusion also had a significant association with alloantibody formation (P = 0.008). CONCLUSION: Since alloimmunization may result in drastic unforeseen responses in patients during transfusions, prior alloantibody screening may provide an additional safety layer in providing safe transfusions to patients. Hence, this study advocates the provision of antigen-matched RBC units for ABO, Rh, and Kell antigens.

The prevalence of erythrocyte alloimmunization in clinical practice: A hospital-based study

Abstract BACKGROUND: One of the complications of blood transfusion is the development of red cell alloimmunization. Little published literature on the prevalence and actual significance of red cell alloantibodies among nonregularly transfused patients and the general population. OBJECTIVES: This study aimed to estimate red cell alloantibodies’ prevalence, specificity, and clinical significance in obstetric and medical practice in Iraq. MATERIALS AND METHODS: A cross-sectional hospital-based study involving internal medicine patients and ladies in obstetric wards of Baghdad Teaching Hospital in Baghdad/Iraq, from January 2022 to May 2022. Demographic data were collected along with detailed medical, obstetric, and transfusion history. Alloantibody screening was performed, and samples with positive results were subjected to antibody titration and identification. RESULTS: A total of 200 patients were enrolled. Indirect antiglobulin test was positive in 15% of patients in internal medicine wards and 23% of ladies in obstetric wards, with most of the identified alloantibodies being clinically significant, against Kidd and Duffy antigen groups. Blood transfusion of more than four units to patients at internal medical wards showed a significant association as a risk for developing red cell alloantibodies (P = 0.025). For ladies in obstetric wards, there was a significant association between pregnancy loss at the time of screening and alloimmunization (P = 0.0164). CONCLUSION: High prevalence of red cell alloantibodies in comparison to what is published worldwide. Transfusion of more than four units of blood and pregnancy loss at the time of screening were statistically significant risks for alloimmunization of the medical and obstetric populations, respectively.

Prevalence of red blood cell alloantibodies in pregnant women with sickle cell disease in Bamako.

Pregnancy in women with sickle cell disease (SCD) is associated with severe complications. Red blood cell (RBC) alloimmunisation is a worrying situation in pregnant women with SCD. This could increase the difficulty in finding a pheno-compatible red blood product. Our study aimed to determine the prevalence of RBC alloantibodies in pregnant women with SCD and to determine the risk factors for alloantibodies formation. We conducted a prospective study at the "Centre National de Transfusion Sanguine de Bamako" from August 2022 to January 2023. For each participant, we collected important information, including obstetrical and transfusion histories. We performed ABO group, Rh and Kell phenotyping, and antibody screening in all study participants. We performed statistical analysis. We recruited 95 pregnant women with SCD. In our study, 62% of our participant had a history of blood transfusion. Only 23% of our pregnant women with SCD had a history of miscarriage. The prevalence of RBC alloantibodies was 14%. The main antibodies detected were anti-E (38%) and pan-agglutinins (23%). Miscarriage history, blood transfusion history, and pregnancy number were the main risk factors for RBC alloimmunisation. The care of pregnant women with SCD is complex and requires collaboration between haematologists, clinicians and gynaecologists. National guidelines should be implemented to make ABO and D typing, Rh and Kell phenotyping and antibody screening routine for all pregnant women. This would facilitate early detection of high-risk situations. Particular attention should be paid to SCD pregnant women with miscarriage and blood transfusion histories.

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.

Characterising the challenges of managing difficult red blood cell alloantibodies in liver transplant recipients

AimsFormation of red blood cell alloantibodies (RBCAs) complicates transfusion support in liver transplantation (LT). Difficult RBCAs (DAs, >3 antibodies or antibodies for which <25% donors are antigen negative) further challenge...

The influence of HLA allele and haplotype on RhE alloimmunization among pregnant females in the Chinese Han population.

Anti-E alloantibody is the most common and important red blood cell(RBC) alloantibody during pregnancy. The study aimed to determine the correlation between RhE alloimmunization and human leukocyte antigen (HLA)allele polymorphism, as well as haplotype diversity, among pregnant individuals in the Chinese Han population. All individuals included in our study were RhE-negative pregnant women of Chinese Han ethnicity, confirmed through serological testing. Pregnancy could be the only potential stimulating factor in RBC alloimmunization. Given the serological testing, the participants were divided into anti-E (responders) and non-anti-E-producing group (non-responders). The class I and II classical HLA genotyping were determined using next-generation sequencing, and the HLA genotype and haplotype frequencies were compared between the responders and non-responders. In total, 76 responders and 94 non-responders were enrolled in this study. Comparison results showed that all HLA class I alleles had no difference between the two groups. For HLA class II phenotypes, responders had higher frequencies of HLA-DRB1*09:01, HLA-DQA1*03:02 and HLA-DQB1*03:03 phenotypes than non-responders, and the differences were statistically significant (pc < 0.05). In addition, the haplotype frequency of HLA-DRB1*09:01-DQA1*03:02-DQB1*03:03 in the RhE responders was significantly higher than in the non-responders (31.58% vs. 12.77%; odds ratio, 3.154; 95% confidence interval, 1.823-5.456; pc value, 1.25 × 10-3). Our findings indicated that HLA-DRB1*09:01, HLA-DQA1*03:02 and HLA-DQB1*03:03 might be susceptible alleles for RhE alloimmunization among Chinese Han pregnant females. These three susceptible alleles constituted the unique three-locus haplotype in the RhE responders and collaborated to RhE alloimmunization.

Incidence of formation of anti-D between patients with and without a history of solid organ transplant.

Solid organ transplant surgeries including liver transplants constitute a substantial risk of bleeding complications and given frequent national blood shortages, supporting D-negative transplant recipients with D-negative red blood cell products perioperatively can be difficult for the transfusion services. This study was designed to compare the incidence of alloimmunization after D-mismatched red cell transfusions between patients with and without a history of solid organ transplant at a single tertiary care hospital. The patients undergoing solid organ transplants are on strong immunosuppressive regimens perioperatively to help reduce the risk of rejection. We hypothesized that the use of these immunosuppressive agents makes these patients very less likely to mount an immune response and form anti-D antibodies when exposed to the D-positive red blood cell products perioperatively. At our center, D-negative patients who received ≥1 unit of D-positive red blood cell products were identified using historical transfusion records. Antibody testing results were examined to determine the incidence of the formation of anti-D and any other red cell alloantibodies after transfusion and these results were compared between patients with and without a history of solid organ transplant. We were able to identify a total of 22 patients over 10 years with D-negative phenotype who had undergone a solid organ transplant and had received D-positive red blood cell products during the transplant surgeries. We also identified a second group of 54 patients with D-negative phenotype who had received D-positive red blood cell products for other indications including medical and surgical. A comparison of the data showed no new anti-D formation among patients with a history of D mismatched transfusion during solid organ transplant surgeries. Among our limited study population, we observed a very low likelihood of D alloimmunization among solid organ transplant recipients. A larger, prospective study could help further evaluate the need for prophylactic D matching for red cell transfusions during solid organ transplant surgeries.

Development of Non-ABO Red Blood Cell Alloantibodies in Patient Undergoing Allogeneic Haematopoietic Stem Cell Transplant

Development of Non-ABO Red Blood Cell Alloantibodies in Patient Undergoing Allogeneic Haematopoietic Stem Cell Transplant

Antibody Screening, Identification and Red Cell Alloimmunisation Analysis in Multi-Transfused Patients at a Tertiary Care Hospital, Amritsar, India

Introduction: Alloimmunisation to red blood cell antigens, resulting from genetic disparities between donors and recipients, is one of the risks associated with blood transfusions. Antibody screening cells are used to detect unexpected antibodies. The risk of alloimmunisation is higher in patients who have undergone multiple blood transfusions. Aim: To estimate the frequency of various Red Blood Cell (RBC) alloantibodies and to determine the types of antibodies present in repeatedly transfused patients. Materials and Methods: This cross-sectional study was conducted on 200 patients with a history of multiple blood transfusions from October 1, 2019, to April 30, 2021, at the blood centre of Sri Guru Ram Das Institute of Medical Sciences and Research (SGRDIMSR), Amritsar, Punjab, India. Antibody detection and identification were performed, and the results were recorded. The data was statistically analysed using the Statistical Package for Social Sciences (SPSS) version 26.0 to draw relevant conclusions. The observations were tabulated in the form of numbers and percentages. Categorical data was analysed using the Chi-square test. The level of significance was determined as p≤0.05. Results: The study included 200 patients who were on multiple transfusions. The most common blood group among the patients was B positive (39%), followed by O positive (26%). The majority of patients (73.50%) had solid malignancies, followed by 28 (14%) thalassemia patients and 25 (12.50%) patients with chronic kidney disease. Solid malignancies included patients with breast cancer, cervical cancer, ovarian cancer, prostate cancer, and liver cancer. Alloantibodies were found in 15 patients (7.50%), of which 11 had solid malignancies and 4 had thalassemia. The most frequent antibody detected was the anti-K antibody (40%). Alloantibody formation was observed in both males and females. However, no statistical significance was found between gender and alloimmunisation (p=0.940). Conclusion: The effect of alloimmunisation can be avoided by routine RBC antibody screening before blood transfusion, especially in patients with a history of multiple blood transfusions. These measures decrease the incidence of red blood cell alloimmunisation and delayed hemolytic transfusion reactions in multi-transfused patients.

Significance of red cell alloantibodies other than anti-D during pregnancy and their effect on the newborn: A case series

Contrary to well-established guidelines in developed countries, awareness regarding red cell alloantibodies in antenatal period are lacking in India. Investigating for indirect antiglobulin test (IAT) is mostly limited to the Rh D negative antenatal cases. This case series revisits this vital aspect of maternal and fetal safety. Instances of alloantibody other than anti-D are reported.Study was done in Transfusion Medicine department of a tertiary care hospital in North India during 2019-2020. IAT was performed not during the 1st or 2nd trimesters of pregnancy but as a routine compatibility test during delivery. Patients with positive IAT were further evaluated for the detection of alloantibody by using identification panel red cells. Result: Eight antenatal cases with irregular antibodies other than anti-D during 2019-2020 are described. Antibodies detected per patient were single (three cases of anti-E, one of anti-Fya, one of anti-M) or multiple (two cases of anti-E plus anti-c, one of anti-E plus anti-K). Direct antiglobulin test of four babies born to these mothers was found to be positive, one of whom was still born and rest recovered with medical management. Two other babies had DAT negative and two mothers presented late after still birth. Alloantibody titer indicated in patient with anti-E during mid-pregnancy had titer was undetectable by standard tube technique.Non anti-D alloantibodies can potentially affect fetus, asserting equal attention as anti-D. IAT should not be missed in pregnancy as it is common to investigations for compatibility as well as for fetal wellbeing assessment.

Prevalence of red blood cell alloantibodies among blood donors in the French Military Blood Institute: A 10-year retrospective study.

Screening for red blood cell alloantibodies (RBC-Ab) is a critical step in ensuring blood transfusion safety performed by blood donation screening laboratories. We aim to evaluate the prevalence of the RBC-Ab among healthy blood donors. Antibody screening of serum of all voluntary blood donors was performed as a routine immune-haematological procedure by a solid-phase method on a fully automated immunohaematology analyser. Positive sera were further investigated to identify the specificity of RBC-Ab by a commercially available red cell panel. Between January 2012 and December 2021, a total of 212,218 donations were screened for the presence of RBC-Ab, 74% from male donors (n = 157,898) and 26% from female donors (n = 54,320). Mean age at donation time was 32 ± 12 years. A total of 1007 donations were screened positive (0.47%), and 131 were confirmed positive for alloantibodies in their serum, yielding a prevalence of 0.06% (95% confidence interval: 0.05-0.07). Most frequent alloantibodies identified were of RH blood group system (64%), followed by anti-MNS (19%), anti-Kidd and Lewis (6% each) and anti-KEL (4%). The results showed a statistically higher prevalence of alloantibodies in women than men. Our results showed a lower prevalence as compared to the available data, which might be related to our study population. The prevalence of positive antibody screening in healthy donors in this study was found to be 0.47%, while the prevalence of alloantibodies was 0.06%. The most common alloantibodies were anti-RH1 (25%) and anti-RH3 (24%).

Quality improvement review of O positive blood in emergency transfusion.

We recently introduced a policy to use O positive red cells in emergency transfusions for males >16 years of age and females >50 years of age. Here, we investigate changes in emergency transfusion practice and rates of red cell alloimmunization with the use of O positive blood for emergency transfusion. State-wide retrospective review of emergency transfusions between June 2020 and June 2021. The laboratory information system and patient medical records were used to collect demographic details, indications for transfusion, usage of O positive and O negative blood and rates of alloimmunization. There were 2354 red cell units transfused to 1013 patients (male = 59%, average age = 53 years) during the 12-month period. O positive units accounted for 46.9% (1103 units) of emergency transfusions. However, 726 (30.8%) O negative units were transfused to patients without a mandatory indication for O negative blood. Twenty-eight patients (2.9%) had a red cell alloantibody prior to transfusion including anti-E (n = 10), anti-D (n = 4), and anti-K (n = 4). One patient with prior anti-D had mild delayed hemolysis. There were 19 patients (4.3%, median follow-up 22 days) who developed a red cell alloantibody after emergency transfusion and include anti-E (n = 10), anti-D (n = 7), and anti-C (n = 5). The use of O positive blood for emergency transfusion has saved 1103 O negative red cell units with no detriment to patient outcome. There remains potential to optimize use of O positive blood in emergency transfusion and to understand red cell alloimmunization rates in a prospective fashion.

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.

Comparison of the conventional tube and erythrocyte-magnetized technology in titration of red blood cell alloantibodies

Erythrocyte alloantibodies are mainly produced after immune stimulation, such as blood transfusion, pregnancy, and transplantation, and are the leading causes of severe hemolytic transfusion reactions and difficulty in blood grouping and matching. Therefore, antibody screening is critical to prevent and improve red cell alloantibodies. Routine tube assay is the primary detection method of antibody screening. Recently, erythrocyte-magnetized technology (EMT) has been increasingly used in clinical practice. This study intends to probe the application and efficacy of the conventional tube and EMT in red blood cell alloantibody titration to provide a reference for clinical blood transfusion. To investigate the application value of conventional tube and EMT in red blood cell alloantibody titration and enhance the safety of blood transfusion practice. A total of 1298 blood samples were harvested from blood donors at the Department of Blood Transfusion of our hospital from March 2021 to December 2022. A 5 mL blood sample was collected in tubing, which was then cut, and the whole blood was put into a test tube for centrifugation to separate the serum. Different red blood cell blood group antibody titers were simultaneously detected using the tube polybrene test, tube antiglobulin test (AGT), and EMT screening irregular antibody methods to determine the best test method. Simultaneous detection was performed through the tube polybrene test, tube AGT and EMT screening irregular antibodies. It was discovered that the EMT screening irregular antibody method could detect all immunoglobulin G (IgG) and immunoglobulin M (IgM) irregular antibodies, and the results of manual tube AGT were satisfactory, but the operation time was lengthy, and the equipment had a large footprint. The EMT screening irregular antibody assay was also conducted to determine its activity against type O Rh (D) red blood cells, and the outcomes were satisfactory. Furthermore, compared to the conventional tube method, the EMT screening irregular antibody method was more cost-effective and had significantly higher detection efficiency. With a higher detection rate, the EMT screening irregular antibody method can detect both IgG and IgM irregular antibodies faster and more effectively than the conventional tube method.

Fetal and neonatal outcome in severe alloimmunization managed with intrauterine transfusion: 18-year experience in a tertiary referral hospital in China.

Hemolytic disease of the fetus and newborn (HDFN) due to red cell alloimmunization, is an important cause of fetal and neonatal morbidity and mortality. However, fetal and neonatal outcome of HDFN managed with intrauterine transfusion (IUT) in China are unknown. In addition, fetal and neonatal outcomes according to the type of maternal red cell alloantibodies involved and outcomes of hydrops fetalis are also unclear. The objective of this study was to evaluate fetal and neonatal outcomes of severe red-cell alloimmunization treated by IUT, to compare the outcomes according to the type of antibody, and to investigate the perinatal and postnatal outcomes of hydrops fetalis due to red cell alloimmunization. A retrospective study of pregnancies affected by HDFN and managed with IUT at a tertiary care university hospital in China between January 2001 and December 2018 was performed. Fetal and neonatal outcomes were investigated, and comparison of outcomes depending on the type of antibody and comparison of outcome between hydrops fetalis and fetuses without hydrops were also conducted. 244 IUTs were performed in 81 fetuses from 80 pregnancies. Anti-RhD was the major etiology of HDFN requiring IUT (71.6%). The fetal survival rate was 90.1%. The survival rate of the hydropic fetuses was significantly lower than those of the non hydropic fetuses (61.2% vs. 95.6%) (P = 0.002**). Compared with non hydropic fetuses, hydropic fetuses had significantly lower gestational age and lower hemoglobin level at first IUT. The neonatal survival rate was 98.6%. Exchange transfusions were required in 26% of the neonates. 30.1% of neonates had late anemia and required top-up transfusions, and hydropic fetuses required more late top-up transfusions than fetuses without hydrops. No significant difference in fetal and neonatal outcomes was found among the four subgroups stratified by the antibody involved. Our study demonstrates that IUT is an effective and safe therapy for severe HDFN at our institution. Early detection and treatment of hydrops is critical for perinatal outcomes. Particular attention should be paid to late postnatal anemia in affected neonates and top-up transfusion is still commonly needed.

Associated Factors of Red Blood Cell Alloimmunization among Solid Cancer Patients in Teaching Hospital in Malaysia

Background: Alloimmunization is a known complication following repeated red blood cell transfusions. However, the associated factors of RBC alloimmunization are different among blood recipient groups. This study aimed to determine the associated factors of red blood cell alloimmunization among solid cancer patients in Hospital USM. Material and Methods: This cross-sectional study involved 322 adult solid cancer patients screened for red cell alloantibodies in our centre from October 2016 until February 2019. The clinical and transfusion data were obtained from the patient’s medical record and laboratory information system (My Transfusi). The multiple logistic regression was used for analysis of potential associated factors of red blood cells alloimmunization, and p-value of less than 0.050 was considered statistically significant. Results: The patient’s mean age was 52.0 years old, with the majority were Malays (91.0%) and females (61.2%). The most common cancers were breast (32.3%) followed by gastrointestinal (16.8%) and head and neck (14.3%). The presence of metastases (adjusted OR=13.53, p=0.017), numbers of packed red cell transfusions (adjusted OR=1.12, p= 0.015), and blood group A (adjusted OR=7.45, p=0.003) were the associated factors of alloimmunization. Conclusions: Solid cancer patients with metastases, received a higher number of packed red cell transfusions, and blood group A were at higher risk for alloimmunization. Strategies to provide phenotype RBC should focus on this type of patient to prevent red blood cells alloimmunization in solid cancer patients. Bangladesh Journal of Medical Science Vol. 22 No. 02 April’23 Page : 379-384

Comparing red cell alloantibody detection and titration by gel microcolumn agglutination method with conventional tube in Rh-negative antenatal cases

BackgroundAlloimmunization to red cell antigens during antenatal period is a serious complication. Antibody titration of maternal blood sample corroborates with severity of disease and helps in planning further management. Conventional Tube Testing (CTT) method is widely accepted for antibody titration in antenatal cases but it can be replaced by Gel Microcolumn Agglutination (GMA) as it offers many advantages. Critical titer levels have been recommended by CTT method, but corresponding levels by GMA are yet to be established due to lack of adequate data. MethodsTotal of 1020 Rh negative antenatal females were evaluated over a period of four years and those found to be positive on antibody screening were further investigated. Antibody titration by CTT and GMA was carried out and the titers were correlated with the outcome of pregnancy. ResultsOut of the 1020 cases screened for antibodies, 112 (10.98%) were detected to be positive by GMA while 40 (3.92%) cases were detected by CTT. Titration was performed by both methods and results were statistically correlated. A moderate correlation was observed where one or more than one antibodies were involved (Pearson’s Coefficient 0.756), while a strong correlation (0.893) was observed between the two methods when single antibody (Anti-D) was involved. Titer values obtained by GMA were also higher than CTT. ConclusionGel microcolumn agglutination (GMA) was found to be more sensitive and precise method for titration. A titer of 512 by GMA (IgG only) mostly corresponded to the values of 16 by CTT and had good correlation with clinical outcome.

Prevalence and specificity of red blood cell antibodies in patients transfused in tertiary hospitals in Burkina Faso.

Sub-Saharan African countries face the challenge of immunological transfusion safety that puts many patients at risk of post-transfusion hemolytic reactions. This is because pre-transfusion testing for irregular/unexpected antibodies that helps to prevent these risks are neither universally available nor accessible. The aim of our study was to determine the prevalence of red blood cell alloantibodies and their specificity in patients transfused in Burkina Faso. This was a cross-sectional study including patients who had received at least one blood transfusion. Indirect antiglobulin testing using LISS-enhanced medium gel column agglutination technique was used for antibodies screening and identification. Enzymatic technique with papain-treated red cell reagent was performed in attempt to solve some difficulties if necessary as well as auto-control test and RH-KEL phenotyping when possible to help antibodies identification. A total of 832 patients were included, 51.6% of whom were female, and the median (IQR) age was 34 (20-49) years. Of these, 43.7% had chronic kidney disease and 20.4% were sickle cell patients. The median (IQR) number of immunisation episodes (blood transfusion and pregnancies) was 3 (2-6) with the median (IQR) number of blood units received per patient of 2 (1-5). The proportion of patients with RBCs antibodies was 6.4% (53/832), with mainly anti-Rh antibodies. A combination of 2 antibodies was found in 7 patients and a combination of 3 antibodies in one patient. Antibodies of unknown specificity (AUS) were encountered in 29%. Independent factors associated with antibody positivity were age (OR=1.02; p=0.026), sickle cell disease (OR=3.23; p=0.017) and receiving more than 10 blood units (OR=7.33; p=0.01). In this study, the proportion of patients with RBC antibodies was quite similar to that observed in Sub-Saharan African countries. However, the availability and accessibility of pre-transfusion compatibility tests as well as the quality of methods used should be improved to ensure the safety of blood transfusions.