Monoclonal Antisera Research Articles

The Distribution Patterns of Rhesus (Rh) Antigens.

The determination of one's blood group is dictated by the inheritance-based diversity in the presence or absence of RBC antigens on the surface. Extended Rhesus (Rh) antigens are the most clinically relevant antigens of blood group systems after the ABO blood group system in transfusion medicine. The aim of this study was to serologically assess the prevalence of extended Rh antigens across diverse blood group systems. A total of 2043 samples were tested for the ABO blood group and Rh typing with monoclonal antisera. The Rh phenotyping (C, c, E, e ) was performed on all the samples. The most frequently observed ABO blood group was O (36.5%), while AB (13.6%) was identified as the least prevalent. Positive Rh D antigen was found in 91.6% of tested samples, while 8.4% were Rh D-negative. The most frequently encountered antigen was e, followed by D, while the least prevalent was E. Establishing a Rh phenotype repository for blood donors and conducting Rh phenotype assessments as part of pretransfusion testing before initiating the initial blood transfusion for each patient could significantly lower the patients' incidence of alloimmunization.

Haemoglobin Variants, ABO/Rh Blood Groups and their Associa-tions with Levels of Malaria Parasitaemia amongst Infected Subjects at Rivers State University, Port Harcourt, Nigeria

The aim of the study was to associate haemoglobin variants, ABO/Rh blood groups with levels of malaria parasitaemia amongst infected subjects at Rivers State University, Port Harcourt, Nigeria. ABO/Rh D blood groups were analyzed using monoclonal antisera, and haemoglobin electrophoresis was analyzed using the alkaline cellulose acetate electrophoresis method, while malaria parasites were identified by microscopic examination of stained blood films. Graph Pad Prism version 8.0 was used to statistically analyze odd ratios, confidence intervals, likelihood ratios and relative risks. All 147 subjects (87 females, 60 males) were positive for malaria (Plasmodium falciparum). For 3+ falciparum malaria, the order of infection for haemoglobin genotype was AA > AS/SS; ABO blood group was B > A > O > AB; Rh blood group was Rh D+ > Rh D-; gender was females > males at p > 0.05. At p > 0.05, for 2+ falciparum malaria: haemoglobin genotype was SS >AA > AS; ABO blood group was B > A > O > AB; Rh blood group was Rh D- > Rh D+; and gender was females > Males. At p > 0.05, for 1+ falciparum malaria infection: haemoglobin genotype was AS >AA > SS; ABO blood group was AB > O > A > B; Rh blood group was Rh D+ > Rh D-; and gender was males > females. Conclusively, 3+ Plasmodium falciparum malaria infection is common amongst individuals with: AA haemoglobin genotype, blood group B, Rh D+, and females; 2+ P. falciparum infection is common amongst individuals with: haemoglobin genotype AA, blood group B, Rh D-, and females; while 1+ P. falciparum malaria infection is common amongst individuals with: AS haemogobin genotype, blood group AB, Rh D+, and amongst males than females.

Distribution of ABO-Rh Blood Group System Among the Students at Shah Abdul Latif University Khairpur, Pakistan

Background: The distribution of ABO and Rh blood groups significantly varies across different populations and is crucial for effective blood bank management and transfusion services. Previous studies have shown diverse patterns in blood group distribution globally, influenced by regional, ethnic, and demographic factors. Objective: This study aimed to analyze the distribution of ABO and Rh blood groups among the student population at Shah Abdul Latif University (SALU), Sindh, Pakistan, and to understand its implications for local healthcare services. Methods: A cross-sectional study was conducted involving 253 students (133 males and 120 females) aged 18 to 24 years. Informed consent was obtained from all participants. The study employed a sterile lancet for blood sample collection via a finger prick. Blood group phenotyping was done using the slide method with monoclonal antiserum A, B, and D. Agglutination results were recorded to determine the ABO blood group and Rh factor. Data analysis was conducted using the Statistical Package for the Social Sciences (SPSS) version 25. Results: The study found that 21.7% of students belonged to blood group A (49.1% Rh positive and 5.5% Rh negative in males, 40% Rh positive and 5.5% Rh negative in females), 35.2% to blood group B (38.2% Rh positive and 6.7% Rh negative in males, 52.8% Rh positive and 2.3% Rh negative in females), 11.1% to blood group AB (57.1% Rh positive in males, 39.3% Rh positive in females), and 32.0% to blood group O (54.3% Rh positive and 2.5% Rh negative in males, 38.3% Rh positive and 4.9% Rh negative in females). Conclusion: The distribution of ABO and Rh blood groups in the student population at SALU exhibits a distinct pattern, emphasizing the importance of regional studies in blood group distribution. These findings have significant implications for blood bank management, transfusion services, and healthcare planning in the region.

Phenotypic Frequency of Clinically Significant Blood Group Antigens (Rh, Kell, Kidd, and Duffy) in Blood Donors of the Blood Center at a Tertiary Care Referral Teaching Hospital in Tirupati, Andhra Pradesh, South India

ABSTRACT Background and Objectives: The knowledge of various blood group antigen and phenotype frequencies in a population is important in selecting compatible blood in alloimmunized patients. Such information in Indian population is very limited. Hence this study was carried out to determine the frequency of clinically significant antigens. Such information in Indian population is very limited. Methods: This study was carried out to determine the frequencies of the D, C, c, E, e, K, k, Fya, Fyb, Jka, and Jkb antigens in 1024 blood donors at our department. Samples were collected for extended antigen typing during March 2016–February 2017 for D, C, c, E, e, K, k, Fya, Fyb, Jka, and Jkb antigens using monoclonal antisera by column agglutination technology. Antigenic and phenotypic frequencies were expressed as percentages. Results: Among the Rh system, “e” antigen was found in 98.6% of donors, followed by D (92%), C (89%), c (56%), and E (17%) with DCe/DCe (R1 R1, 41.4%) as the most common phenotype. “k” was found to be positive in 97% of donors, and K+k− phenotype was found in 0.1% of donors. For Kidd and Duffy blood group system, Jk(a+b+) and Fy(a+b+) were the most common phenotypes with frequency of 56.2% and 47.5%, respectively. MNS antigens were not included on account of financial constraints. Conclusion: Database for antigen frequency of various blood group systems in native donors helps provide antigen-negative compatible blood units to patients with multiple antibodies in order to formulate in-house red cells for antibody detection and identification and for preparing donor registry for rare blood groups.

Naturally occurring clinically significant anti-M alloantibodies with wide thermal range: A series of three cases

Abstract: Anti-M antibodies are usually of the immunoglobulin (Ig)-M type and have a cold thermal range, which is generally considered clinically insignificant. However, in some cases, there may also be an IgG component present exclusively. In addition to the discrepancy in blood grouping (attributable to the IgM component), the presence of an IgG component reacting at 37°C can interfere with pretransfusion testing, making it difficult to find fully compatible blood within a short time. In this report, we discuss three children: two boys aged five and 1½ years, respectively, and a female toddler aged 1 year who were all successfully treated using M-antigen negative packed red blood cells along with the standard treatment plan of the hospital. This was made possible by an established institutional blood donor registry comprising O-typed blood donors (n = 374), who were phenotyped for 21 erythrocyte antigens using commercially available monoclonal antisera (Ortho Clinical Diagnostics, Pvt Ltd., Mumbai, India).

Seroprevalence of Transfusion-Transmissible Infections among Family Replacement Donors and Voluntary Non-Remunerated Blood Donors During the COVID-19 Pandemic in Sub Saharan Africa.

Introduction : According to WHO, regular, voluntary, unpaid blood donors are the safest group of donors, as they have the lowest prevalence of blood transmitted infections. However, family/replacement blood donors is widely used in sub Saharan Africa and this practice was exacerbated during the COVID 19 pandemic. This study aimed to compare the seroprevalence of infectious markers in family replacement blood donors and voluntary non-remunerated blood donors during the COVID 19 pandemic in a country of sub Saharan Africa. 
 Materials and Methods
 Blood donors received at the National Centre of Blood Transfusion (NBTC) of Dakar from August 1st to October 31th 2021, were included in this study. All donors completed a pre-donation questionnaire. Donors identity, epidemiological parameters, reasons for donation and laboratory results were collected in the Inlog® software of the NBTC. The serological tests for HBV, HIV and HCV were performed with chemiluminescence technology. The Rapid Plasma Reagent test was used to find out treponemal antibodies. The determination of ABO and Rh blood groups was performed using monoclonal antisera following classical hemagglutination test on a plate.
 Results
 A total of 5002 donors were collected during this COVID-19 pandemic period. Blood family/replacement donors represented 54.0% and new voluntary donors represented 52.6%. Comparison of HIV, HCV and syphilis markers seroprevalence showed no statistically significant difference between new voluntary donors and new family replacement donors (p>0.05). However, for HBV the seroprevalence was significantly higher in new family replacement donors (p=0,002).
 Conclusion 
 The proper supply of blood was impacted by the COVID-19 pandemic meanwhile replacement donations had contributed to limiting the damage observed with blood shortages. However, the significant differences noted on the seroprevalences of transfusion-transmissible infections between voluntary non-paid donors and family/replacement donors strengthens WHO recommendations for the selection of volunteer non-paid donors to lower transfusion-transmissible HBV in sub Saharan Africa.
 
 
 
 
 
 
 
 

Genotype analysis to clarify RhD variants in discrepant samples of Chilean population.

The D antigen variants are classified as weak, partial, and extremely weak (DEL) and can be differentiated using molecular tests. In Chile, the laboratories of local blood centers do not identify variants of the D antigen, referring them for study to the Reference Laboratory of the Public Health Institute of Chile. So, our aim was to talk about the results of the molecular analysis of variants of the D antigen in samples that had different results in the serological classification. In the D antigen classification of the Rh system, 479 samples with serological discrepant results were sent for molecular analysis. The Rh phenotype was performed with monoclonal anti-C, anti-c, anti-E, and anti-e antisera by direct agglutination. To find the D antigen, researchers used direct agglutination with monoclonal antisera and indirect antiglobulin testing with the column (gel) agglutination method. Molecular analysis was performed with a polymerase chain reaction with sequence-specific primers (SSP-PCR) and sequencing. The presence of D antigen variants was confirmed in 332 samples (69.3%), with an initial discrepancy in serological classification. In this group of discrepant samples, the frequency of weak RhD variants was 66% (219/332), that of extremely weak RhD was 28% (93/332), and that of partial RhD was 6% (20/332). The weak variants type 2 (27.4%), type 3 (8.4%), type 48 (8.4%), and type 1 (8.1%) were the next most prevalent variants after RHD*DEL43 (28%). The ccEe (R2r) phenotype was the most frequently detected (38.4%) and is present in 87% of the RHD*DEL43 samples. The E antigen is associated with the presence of this variant. Our analyses give the first description of D antigen variants in Chile. The most common variants are DEL type (RHD*DEL43) and weak (weak type 2), which are linked to the ccDEe (R2r) phenotype. These findings allow us to characterize the variants of the D antigen in Chile and, according to the obtained data, to design strategies for the management of donors, patients, and pregnant women.

Clinically significant minor blood group antigens amongst South Indian donor population

Background and objectives: Distribution of blood group antigen varies among different races. It is important to know the distribution of these antigens so as to provide a donor database that aid in providing compatible blood units for patients with multiple alloantibodies. The present study was conducted to determine the distribution of clinically significant minor blood group antigens amongst the South Indian blood donors. Materials and methods: Blood samples were collected from healthy regular repeat voluntary blood donors of same ethnicity attending a tertiary care hospital in South Kerala. Clinically significant blood antigens of the ABO, Rh (D, C, c, E, and e), Kell, Duffy and Kidd blood group systems were determined. The ABO and Rh(D) grouping were performed by tube technique using monoclonal antisera. Column agglutination technique was used to phenotype Rh, Kell, Duffy and Kidd antigens. Results: Total 200 healthy repeat voluntary blood donors were enrolled in the study. Out of 200 donors, 92% were RhD positive. Among the Rh antigens, the e antigen was positive in 97.8 % and 100% among the Rh(D) positive and Rh(D) negative donors respectively. No E antigen was detected in RhD negative donors. Total 6 and 2 Rh phenotypes were observed among the Rh(D) positive and negative donors respectively. R1R1 and Rr were the most frequent phenotypes among the RhD positive and negative donors (47.28% and 93.75%) respectively. Among the Kell blood group antigens, K and Kpb antigens were present in 100% of our donors while in Duffy and Kidd system Fya and Jka were most predominant (89% and 87%) respectively. Conclusions: The findings of the present study would be helpful in developing in-house panel cells. Moreover, a rare donor registry of donors typed negative for a high-frequency antigen can be formulated. IMC J Med Sci. 2024; 18(1):004. DOI: https://doi.org/10.55010/imcjms.18.004 *Correspondence: Soonam John, Department of Transfusion Medicine, Government Medical College, Parippally, Kollam, Kerala,India. Email: johnsoonam@gmail.com

Hematological Abnormalities Among Malaria Infected Adult Patients in Association with ABO Blood Groups at Jinella Health Center, Harar, Eastern Ethiopia.

Hematological abnormalities are a common complication of malaria infection. However, there is a paucity of evidence regarding it among malaria-infected adult patients in association with the ABO blood group in Ethiopia, particularly in the Harari Region. Therefore, this study aimed to assess the hematological abnormalities among malaria-infected adult patients in association with ABO blood groups at Jinella Health Center, Harar, Eastern Ethiopia. An institutional-based cross-sectional study was conducted from July 10, 2022, to January 10, 2023. Four milliliters of venous blood were collected from each study participant. Drops of blood were used for blood film preparation. ABO blood group was determined by agglutination test using monoclonal anti-sera (Agape Diagnostics Ltd., India). A complete blood count was done using the DxH 800 (Beckman Coulter, Inc, Miami, FL) hematology analyzer. The data were analyzed using SPSS version 26. Bivariable and multivariable logistic regression models were fitted. The level of significance was declared at a p-value of <0.05. The study revealed that 47.2% (95% CI: 41.0 53.6) of the participants were anemic. Being female (AOR = 3.18, 95% CI = 1.67, 6.04), having the A blood group (AOR = 2.75, CI = 1.20, 6.31), and being infected with P. falciparum (AOR = 2.64, CI = 1.26, 5.53) were all significantly associated with malaria anemia. The overall prevalence of thrombocytopenia was also 67.7% (95% CI: 61.7-73.4%). It was significantly associated with P. falciparum infection (AOR = 8.03, CI = 3.53, 18.25) and high parasitemia levels (AOR = 4.40, CI = 1.57, 12.32). Patients with malaria who belonged to the "A" blood group in the study area had anemia as a serious health problem. Hence, frequently checking for anemia in patients with malaria who have blood group "A" can help with early detection and better management of anemia.

Establishing a Regional Rare Blood Donor Registry in Uttarakhand, India

Background and Objectives: Uttarakhand, a state in northern India, is home to various local communities, including the Garhwali, Kumaoni, and Jaunsari. In addition, individuals from neighboring countries such as Nepal and Tibet reside in Uttarakhand for many years, resulting in a diverse population. However, currently, there is no regional registry for rare blood donors in this state. The aim of this study was to develop a rare donor registry in Uttarakhand which could in future become a part of the national rare blood donor registry. Methods: During the routine donation process, samples were taken from randomly selected O-typed blood donors who are residents of Uttarakhand. Seventeen monoclonal antisera included Rh (anti-D, anti-C, anti-c, anti-E, and anti-e), Duffy (anti-Fya and anti-Fyb), Kell (anti-K and anti-k), Kidd (anti-Jka and anti-Jkb), Lewis (anti-Lea and anti-Leb), M, N, S, and s (Ortho Diagnostics Pvt Ltd, Mumbai, India). Furthermore, four polyclonal antisera from our serum repository, Diego (anti-Dia), Indian (anti-Ina), Rh (anti-Cw), and anti-Gp-Mur were used for phenotyping. The study was financially aided by the Uttarakhand State Council of Science and Technology (UCOST), Dehradun, Uttarakhand, Government of India. Results: Over a period of 16 months (November 2021–February 2023), out of a total of 17,004 blood donations, O blood type donors accounted for 29.9% (5085/17,004) of the donors screened. Among these, 7.3% (374/5085) of the donors were from the interior and plain areas of Uttarakhand. Our study revealed a high prevalence of k and e antigens, with 96.7% and 92.5%, respectively. The least prevalent antigen was Rh (Cw), observed in only 0.5% of cases. We also identified rare blood antigens such as Diego, Indian, and Gp-Mur and compared our findings with other studies. Furthermore, we identified a donor with an H-deficient phenotype, specifically the Bombay blood group (Oho). Conclusion: We have successfully established a regional registry for rare blood donors in Uttarakhand, which will be valuable for managing complex transfusion scenarios in the future. Further, given Uttarakhand's proximity to China and Nepal, the presence of individuals from these countries aptly connects the fields of anthropology and transfusion medicine.

Prevalence of blood group antigens among regular blood donors: A single center study from South India with a review of national literature

Background and objectivesThe antigen frequencies vary across different regions and ethnic groups. Hence, we aimed to study the prevalence of blood group antigens in our population and to systemize the zone-wise prevalence of the same across India. Materials and methodsRegular voluntary O group blood donors were screened for 21 blood group antigens; C, c, E, e, K, k, Kpa, Kpb, Jka, Jkb, Fya, Fyb, Lea, Leb, Lua, Lub, P1, M, N, S, s, using commercially available monoclonal antisera by column agglutination technology. A literature search was performed to identify all the studies that reported blood group antigens prevalence to estimate the zone-wise prevalence of these antigens in the country. ResultsA total of 521 participants of 9248 O group donors meeting all the inclusion criteria were included. Among the study group, the male-to-female ratio was 9:1 with a mean age of 32.6 years (±10.01) ranging from 18-60 years. The majority of the donors 446 (85.6%) were D positive. The most common phenotypes among Rh, Lewis, Kell, Duffy, Kidd, Lutheran and MNSs were CcDee (34.93%), Le(a-b+) (61.80%), K-k+(98.27%), Fy(a+b-) 43.19%, Jk(a+b+) 42.61%, Lu(a-b+) ( 99.61%), M+N+ (48.17%), S-s+ (45.29%) respectively. The prevalence of D and E antigens was significantly lower in the South zone compared to other zones of India. ConclusionSignificant difference in the prevalence of blood group antigens is observed between the South and other zones of India. Zone-wise prevalence of blood group phenotypes is essential in the timely management of alloimmunized patients.

Extended blood group phenotyping of donors from the lower and middle Himalayan region of Uttarakhand India: A pilot study.

The state of Uttarakhand, bordering countries such as Tibet and Nepal, is a multi-ethnic region. Further, erythrocyte alloimmunization may arise from the incompatibility of major and/or minor blood groups between ethnically diverse donors and recipients. We aimed to screen Uttarakhand blood donors (UBDs) for extended phenotyping of their erythrocytes serologically. This prospective cross-sectional analysis involved all UBD samples collected at the blood centre of our tertiary-care hospital. Samples were obtained over 9months (Mar'22 to Nov'22). Donors who were O-typed, DAT-negative and non-reactive for TTI markers were processed further for serological testing using the column agglutination technique utilizing 21 different monoclonal antisera (Ortho diagnostics Pvt ltd, Mumbai India). The research was financially aided by UCOST, Uttarakhand, Government of India. Of the 5,407 blood samples collected, the total number of O-typed samples collected was 1622. Of these 1622, 329 (20.2%) O-typed samples were selected based on our inclusion criteria and hence further phenotyped. Amongst these 329 UBDs, the average age was 32.7±9.32 (18-52) years and the male-to-female ratio was (M: F=12:1). The prevalence of high- and low-frequency blood antigens in our study was Rh (D 96.6%, C 84.8%, c 63.5%, E 27.9% and e 92%), Lewis (Lea 6.3%, Leb 31.9%), Kidd (Jka 87.8%, Jkb 63.2%), Kell (K 1.8%, k 96.3%) and Duffy (Fya 63.5%, Fyb 10.6%). And in the MNS system we received 21.2% as M, 10.9% N, 37% S and 51.3% as s respectively. We also identified some very rare minor antigens such as Dia 1.8%, Ina 1.8%, Cw 0.6% and, 1.2% Mur positive donors, which are not common in our population, as per the published literature. Moreover, we also identified one Bombay blood phenotype (Oh) in one of our UBD recruits. To sum up, practically with the outcome of this research, we were also able to identify rare phenotypes among the local people and a rare blood donor registry was created. This repository shall also come in use for our multi-transfused patients having different oncological and haematological ailments.

Characterization of Shigella flexneri Serotype 6 Strains Isolated from Bangladesh and Identification of a New Phylogenetic Cluster.

A significant cause of shigellosis in Bangladesh and other developing countries is Shigella flexneri serotype 6. This serotype has been subtyped, on the basis of the absence or presence of a group-specific antigen, E1037, into S. flexneri 6a and 6b, respectively. Here, we provided rationales for the subclassification, using several phenotypic and molecular tools. A set of S. flexneri 6a and 6b strains isolated between 1997 and 2015 were characterized by analyzing their biochemical properties, plasmid profiles, virulence markers, pulsed-field gel electrophoresis (PFGE) results, and ribotype. Additionally, the genomic relatedness of these subserotypes was investigated with global isolates of serotype 6 using publicly available genomes. Both subserotypes of S. flexneri 6 agglutinated with monoclonal antiserum against S. flexneri (MASF) B and type VI-specific antiserum (MASF VI) and were PCR positive for O-antigen flippase-specific genes and virulence markers (ipaH, ial, sen, and sigA). Unlike S. flexneri 6a strains, S. flexneri 6b strains seroagglutinated with anti-E1037 antibodies, MASF IV-I. Notably, these two antigenically distinct subserotypes were clonally diverse, showing two distinct PFGE patterns following the digestion of chromosomal DNA with either XbaI or IceuI. In addition, hybridization of a 16S rRNA gene probe with HindIII-digested genomic DNA yielded two distinguishing ribotypes. Genomic comparison of S. flexneri subserotype 6a and 6b strains from Bangladesh indicated that, although these strains were in genomic synteny, the majority of them formed a unique phylogroup (PG-4) that was missing for the global isolates. This study supports the subserotyping and emphasizes the need for global monitoring of the S. flexneri subserotypes 6a and 6b. IMPORTANCE Shigella flexneri serotype 6 is one of the predominant serotypes among shigellosis cases in Bangladesh. Characterization of a novel subserotype of S. flexneri 6 (VI:E1037), agglutinated with type 6-specific antibody and anti-E1037, indicates a unique evolutionary ancestry. PFGE genotyping supports the finding that these two antigenically distinct subserotypes are clonally diverse. A phylogenetic study based on single-nucleotide polymorphism (SNP) data revealed that these two subserotypes were in genomic synteny, although their genomes were reduced. Interestingly, a majority of the S. flexneri 6 strains isolated from Bangladesh form a novel phylogenetic cluster. Therefore, this report underpins the global monitoring and tracking of the novel subserotype.

Extended Phenotyping to Identify Blood Donors for an Institutional Rare Donor Registry

Abstract Background: Alloantibody formation to red cell antigens, sometimes seen in patients receiving multiple transfusions, are capable of causing hemolytic transfusion reactions when transfused with blood cells that are positive for the corresponding antigens. Providing them with red cells negative to these antigens becomes imperative. There is a need to have a pool of donors known to be negative for such antigens to provide blood units to such patients. Aim: The aim of the study is to identify rare donors in our population and register them for need-based blood unit collection for patients when phenotype-specific blood units are required. Methodology: Regular blood donors after consent were included for extended phenotyping for antigens c, C, e, E, K, k, Lea, Leb, Lua, Lub, P1, Kpa, Kpb, Jka, JKb, M, N, S, s, Fya, and Fyb by serological testing using monoclonal antisera. The phenotypes that were either negative for high-frequency antigens such as H, k, or multiple common antigen negative phenotypes were identified and enrolled as rare blood donors. Results: A total of 202 donors were completely phenotyped for the said 21 antigens. We identified 14 such donors, 7 of whom were high-frequency antigen-negative and 7 were multiple common antigen-negative phenotypes. The turnaround time for providing blood for patients requiring such units has drastically reduced with this initiative. A unit of such a rare phenotype was collected and shipped to Pune for a patient who required it within 24 h. Conclusion: Our findings highlight the need for a countrywide rare donor registry to coalesce the data from all centers with the facility for phenotyping. This will reduce the turnaround time of searching for donors for a particular phenotype, contributing to better patient care, and emergency management.

ANTIGEN FREQUENCY OF KELL, DUFFY, KIDD, MNS AND LUTHERAN BLOOD GROUP SYSTEM IN POPULATION OF NORTH MACEDONIA – TOWARDS RARE BLOOD GROUP REGISTRY

The aim of this study is to perform RBC antigen typing of: Kell, Duffy, Kidd, MNS and Lutheran systems and to calculate antigen and phenotype frequency In 920 blood donors, RBC typing of K, k, Kpa, Kpb, Fya, Fyb, Jka, Jkb, S, s, Lua and Lub antigens was performed using specific monoclonal antisera, antihuman globulin and column agglutination technique with gel cards (BioRad). Antigen and phenotype frequencies were calculated from the statistics module of the donor information system (database for blood donors). The prevalence of Kell antigens is 7.5% for K and 99.94% for k. The phenotype (K+k-) is present in 21 (0.06%) blood donors. The frequency of other clinically significant antigens is as follows: 1.1% (Kpa), 100.0% (Kpb), 60.3% (Jka), 76.2% (Jkb), 65.5% (Fya), 79.5% (Fyb), 59.8% (S), 86.5 (s), 7.2% (Lua) and 92.8% (Lub). The most frequent phenotypes are Jk(a+b+) with 41.5%, Fy(a+b+) with 48.5%, (S+ s+) with 46.3% and Lu(a-b+) with 92.8%. Fy(a-b-) phenotype was detected in 0.21% of blood donors. The estimated RBC antigen frequency in our blood donor population differs from the antigen frequency in different populations. Because of that extended RBC typing is necessary for identifying rare blood group donors within the local population. This strategy enables to meet the needs for RBC transfusion in patients with rare phenotypes and with antibodies against high frequency antigens or multiple antibodies, as well as to prevent RBC alloimmunization in polytransfused patients providing antigen matched RBC.

Relationship between ABO Blood Group Phenotypes and Some Cardiovascular Risk Factors among Undergraduate Students in Kano Nigeria

Background: Studies have linked ABO phenotypes to cardiovascular diseases (CVDs); however, data on the relationship between ABO phenotypes and CDV risk factors among healthy adults are lacking. Aim: To determine the relationship between ABO phenotypes and CVD risk factors among undergraduate students in Kano, Nigeria. Materials and Methods: This cross-sectional descriptive study recruited 150 participants. ABO phenotypes were determined using monoclonal antisera. Serum total cholesterol (TC), triglycerides (TG), and high-density lipoprotein cholesterolwere determined enzymatically, while low-density lipoprotein cholesterol (LDL-c) was calculated using the Friedewald equation. Blood pressure and anthropometric measurements were by standard protocols. Data were analyzed using SPSS version 23.0; P ≤ 0.05 was considered statistically significant. Results: Mean age of the participants was 23.12 ± 2.97 (17–31) years. The frequency of ABO phenotypes among the participants was: O (39.3%), B (26.0%), A (23.3%), and AB (11.3%). Non-O phenotypes had significantly lower systolic blood pressure (P = 0.050), higher TC (P = 0.023), TG (P = 0.003), and LDL-c (P = 0.050) compared to O phenotypes. Of the non-O phenotypes, A had significantly higher TC compared to B (P = 0.004) and O (P = 0.001); higher TG compared to O (P = 0.001); higher LDL-c compared to B (P = 0.001), AB (P = 0.042), and O (P = 0.006); heavier compared to B (P = 0.012) and O (P = 0.033); and higher hip circumference compared to B (P = 0.022). Conclusion: Non-O phenotypes, especially A phenotypes, had significantly higher mean serum lipids compared to O. ABO phenotypes should be considered in CVD risk stratification.

Distribution and frequency of principal Rh blood group antigens (D, C, c, E, and e) and their phenotypes in the blood donors attending blood bank in a tertiary care hospital in Barpeta district of Assam.

The ABO and Rhesus grouping system antigens have been found to have the highest immunogenicity and propensity to produce alloantibodies that cause most of the transfusion reactions. The Rhesus antigens that produce most of the immunogenic transfusion reactions are D, C, c, E, and e. Knowledge of the distribution of these Rh antigens in a population helps to render compatible blood in alloimmunized patients. The aim was to study the distribution and frequency of principal Rh blood group antigens (D, C, c, E, and e) and their phenotypes in the blood donors attending blood bank in a tertiary care hospital in Barpeta district of Assam. The study was conducted in 315 voluntary blood donors in the blood bank of a tertiary care center. Rh-D typing was done by conventional tube method. Specific monoclonal antisera, i.e., anti-C, anti-c, anti-E, and anti-e, were used and tests were performed by conventional tube method for detection of the presence of rest of the major Rh antigens. The samples were analyzed for the five major Rhesus antigens. "D" antigen was found to be the most common antigen (99.05%), followed by e (97.14%), C (92.38%), c (51.43%), and E (20.95%). In order of descending frequency, the most common phenotypes were DCCee - 45.71%, DCcee - 30.48%, DCcEe - 11.43%, DccEe - 4.76%, DCcEE - 1.90%, DCCEe - 1.90%, Dccee - 1.90%, DCCEE - 0.95%, and dccee - 0.95%. D antigen is the most common antigen in our study population, whereas "e" antigen is the most common in most of the studies done from other parts of India. Data on frequencies of major Rh antigens in the local donor population will help in transfusing alloimmunized patients with corresponding antibody-negative blood ensuring blood safety.

Alloimmunization in Egyptian Children with Sickle Cell Disease

Abstract Background Transfusion is critical in the management of sickle cell disease (SCD) complications. The resultant alloimmunization to RBC group antigens is a major complication of allogeneic blood transfusion and generally presents significant challenges in the management of SCD patients. Aim To measure the frequency of the occurrence of the alloimmune markers in sickle cell disease and to investigate its predicators. Subjects and methods This cross-sectional study included 50 children and young adults with SCD, all patients were subjected to detailed medical history thorough clinical examination. Laboratory investigations included complete blood count, markers of hemolysis and serum ferritin. The D, C, c, E, e, M, NJKa and JKb antigens were typed using monoclonal antisera. Fya, Fyb, Jka, Jkb, S, s and Anti Lua antigens were typed by commercially prepared polyclonal anti- human sera. Antibody screening was performed using Ortho screening panel. Results The study Sickle SS was the most common type of SCD representing more than half of the recruited patients. Frequency of antibody positive screening among SCD was 16%. Comparison between SCD patients with positive and those with negative antibody screening showed that higher frequency of positive antibody screening in those with SB+ than those SS and SB0. Patient with positive antibodies screening were significantly older when they received their first blood transfusion and had lower transfusion index (p = 0.037) than those with negative antibodies screening (p=0.013). There were no significant difference between patients with positive and those with negative antibodies screening as regards age, gender, transfusion frequency and as regards comorbidities; painful crisis (p=0.117), stroke (p=0.398), ACS (p=0.363). Conclusion The distribution of the blood group antigens in patients with SCD has important clinical significance especially those who often require regular blood transfusion and who may have developed multiple antibodies. The resultant alloimmunization is serious necessitates early recognition and management.

Association of Falciparum Malaria and ABO Blood Group in Awka, Anambra State, Nigeria

A cross-sectional randomized study was carried out to evaluate the association of falciparum malaria and ABO Blood group in Awka, Anambra State, Nigeria from the months of June to August 2018. Blood samples were collected from all study participants. Thick films were made from each blood sample, stained with 10% Giemsa using standard parasitological techniques. Agglutination technique using monoclonal Anti-sera A, B, and D were used to determine the ABO blood groups. Data generated were statistically analyzed using ANOVA test and the significance level was set at P&lt;0.05. An overall malaria prevalence of 62% was observed among study participants. Blood groups O positive and A positive had higher malaria prevalence of 48.38% and 19.35% respectively of the total population size of patients infected, while blood groups B negative and AB negative had a lower prevalence of 0% respectively. There was no statistical significance (P&gt; 0.05). The findings of this study showed that individuals with blood group O were susceptible to contracting uncomplicated malaria but had a higher resistance to developing severe malaria compared to non-O blood groups (A and B). To this end, therefore, malaria interventions and control strategies should be directed equally among individuals irrespective of their blood groups.

Implementation of a regional rare donor registry in India

BackgroundIn an ethnically diverse country like India, establishing a national rare donor registry is a massive challenge. We aimed to establish a regional rare donor registry at our center by screening the local donor population for rare phenotypes. MethodsSerological testing of O blood group donors was done using monoclonal antisera from Bio-Rad for 23 different blood group antigens, which include Rh subgroups (C,cE,e), Kell (K,k, Kpa, Kpb), P1, Duffy (Fya, Fyb), Kidd (Jka, Jkb), Lewis (Lea, Leb), Lutheran (Lua, Lub), H, M, N, S and s. We categorized the donors with rare blood phenotypes into two categories. Category-I: High-frequency antigen-negative phenotypes with a prevalence of less than 1% in our study population. Category-II: Multiple common antigen-negative phenotypes with a prevalence of less than 1% in our study population. ResultsA total of 521 donors with blood group O, meeting the inclusion criteria among a total of 23567 were phenotyped for minor blood group antigens. Out of these, 85.6% (n = 446) were Rh D positive, and 14.4% (n = 75) were Rh D negative. The male-to-female ratio was 9:1. We had identified eight rare phenotypes in category-I and 18 rare phenotypes in Category-II according to the definition adopted in our study. We have noticed a significant decrease in turnaround time in providing rare blood to patients after implementing the registry. ConclusionThis is a first-of-its-kind rare donor registry established in South India. Establishing a national rare donor registry is the need of the hour in India.