anti-B Titers Research Articles

Pediatric safety profile of low titer O whole blood with increasing Anti-A and Anti-B titers

Abstract Objectives To add additional evidence to the safety of using low-titer O whole blood (LTOWB) in the massively hemorrhaging pediatric population, even with increasing allowance of anti-A and anti-B titers, up to 200. Methods A retrospective review from December 2021 to March 2023 of the blood bank and surgical massive transfusion protocols was performed with IRB approval to identify patients less than 18 years old who had received LTOWB as part of trauma resuscitation. In addition to patient characteristics, volume of LTOWB and other components were assessed, as well as Day 1-3 of serum potassium, creatinine, and total bilirubin. Wilcoxon rank-sum tests were performed to compare continuous variables and Fisher’s exact tests were performed to compare categorical variables between group O blood groups patients and non-O blood group patients. Results Only ten patients were identified under 18 years of age who had received LTOWB during trauma resuscitation, with five being blood group O and five non-O. Patient characteristics were similar between the two groups; however, only 10% were female and 10% self-reported as Black or African American. Age in the non-O group was 15 +/- 3.0 and 16.2 +/- 1.3 in the O group, p=0.75. Weight was 56.16 kg +/- 7.17 in the non-O group and 64.02+/- 14.23 in the O group, p=0.35. LTOWB transfused was 10.46 mL/kg +/- 2.42 in the non-O group and 10.32 +/- 6.53 in the O group, p=0.25. Potassium, creatinine, and total bilirubin were similar on Days 1-3 in both groups, except a single high total bilirubin in the non-O group, and this value normalized on Day 3. Conclusion A small data set was extracted from the available massive transfusion protocol data, reflecting the small amount of pediatric patients requiring massive transfusion for trauma compared to adults. Moreover, the predominance of males requiring massive transfusion for trauma corresponds with general trauma trends in the United States. These data reflect and are similar to previous safety reviews of pediatric trauma patients receiving LTOWB. This retrospective review records, however, a time period when the titer of anti-A and anti-B had been relaxed to 200 (rather than 50 in previous studies). This study, although small, reflects an additional Level I trauma site delivering LTOWB at potentially higher titers without negative sequelae in potassium, creatinine, or total bilirubin. With upcoming randomized controlled trials, such as Massive Transfusion in Children (MATIC-2), these data continue to reassure that the practice of using LTOWB is likely safe during the resuscitation period.

Relative Quantification for Obtaining the IgG Blood Group Antibodies in Plasma by the Absorption and Elution Test

To establish the absorption and elution test for relatively quantitive obtaining anti-A and anti-B blood group IgG antibodies in the plasma of O-type RhD-positive pregnant women. 95 cases of the O-type RhD-positive pregnant women plasma samples were randomly selected for obtaining the IgG antibodies of anti-A and anti-B blood group, with absorption test under 37 ℃ and elution test under 56 ℃, and the IgG anti-A and anti-B antibody titers of plasma and elution were determined by the microcolumn gel anti-human globulin test. The differences and correlation between the titers of IgG antibodies in the eluent and plasma were compared and analyzed. After a logarithmic transformation (Log2), there was no statistically difference between IgG antibody anti-A difference value and anti-B difference value in the eluent and plasma (P >0.05). The titer of IgG antibody in the eluent was positively correlated with the titer of IgG antibody in the plasma (r =0.914). The linear equation for IgG antibody titers fitted by a scatter plot between the eluent and plasma was Y=-3.55+0.96X. The absorption and elution test can be used to obtain the anti-A and anti-B IgG antibodies in the plasma of O-type RhD-positive pregnant women, whose plasma origin IgG titer is greater than 8. Meanwhile, the acquisition of anti-A antibodies was as effective as anti-B antibodies at the same time, and the antibodies obtained are positive proportional to their respective concentrations in the plasma.

Anti-A and anti-B titers in A, B and O whole blood donors: Beyond “dangerous O”

Background and ObjectivesHemolytic transfusion reactions (HTRs) pose significant risks in transfused patients, with anti-A and anti-B antibodies in donor plasma being potential contributing factors. Despite advancements in component preparation, HTRs remain a concern, particularly with apheresis-derived platelets. This study aimed to determine the prevalence of high anti-A and anti-B titers among A, B, and O blood group donors and to explore factors associated with high titers. Materials and MethodsA cross-sectional observational study was conducted over 18 months, enrolling 978 participants from a tertiary care teaching hospital in Western India. Anti-A and anti-B titers were determined using the Conventional Tube Technique (CTT). Statistical analysis assessed correlations between high titers and demographic factors. ResultsThe majority of participants were young males (98.8%). Prevalence of high titers for IgM anti-A was 12.2% and IgG anti-A was 2.5%. For anti-B, IgM titers were 2.3% and IgG titers were 0.2%. The prevalence of dangerous O was found to be 14.1%, while 3.52% and 10.5% of A and B blood group donors were found to have high titers, respectively. Factors associated with high titers included female gender, vegetarian diet, age <30 years, and O blood group. ConclusionThe study sheds additional light and provides supplementary information regarding the prevalence and correlation of high anti-A and anti-B titers among O, A and B blood donors. Understanding these factors is crucial for optimizing transfusion safety protocols, including selective screening of platelet units and tailored transfusion strategies based on donor characteristics.

Feasibility Analysis of Establishing Combat Readiness Blood Bank Based on Low Titer Group O Whole Blood and Group A Plasma

To explore the feasibility of establishing combat readiness blood bank with low titer group O whole blood and group A plasma. The Galileo automatic blood analyzer was used to detect the titers of IgM anti-A and anti-B antibodies in the samples of group O blood donors and IgM anti-B titer in the samples of group A blood donors. Group O blood donors with antibody titers below 128 were selected and included in the mobile blood bank for combat readiness, group A plasma with anti-B titer lower than 128 and group O whole blood with antibody titers below 128 were included in the combat readiness entity blood bank. A total of 1 452 group O blood donors were selected, and the anti-A/B antibody titers were detected. Both antibody titers were distributed below 512, and both peak values of sample distribution were at titer 4. The proportion of samples with titers>128 for both antibodies was relatively low. There was a significant positive correlation between the titers of the two antibodies (r =0.383), and the proportion of samples with IgM anti-A titer higher than IgM anti-B titer was relatively high. 1 335(91.94%) group O blood donors with IgM anti-A and anti-B antibody titers <128 could be included in the mobile blood bank. The anti-B titer of group A blood was detected in 512 cases and the results showed that as the antibody titer increased, the proportion of blood donors gradually decreased. 99.8% of group A blood donors had anti-B antibody titer less than 128, and only one case did not meet the inclusion criteria. The proportion of group O blood donors whose whole blood meet the low antibody titer standard is high, and almost all plasma of group A blood donors meet the low titer standard, which improves the blood supply rate in emergencies.

Comparative Analysis of AB vs. ABO-specific Plasma for Desensitization in Blood Group O Recipients: An In Vitro Study.

Neutralizing capacity measurement (NCM) of soluble ABH substances (SAS) in plasma was assessed to guide the selection of the appropriate ABO group of fresh-frozen plasma (FFP) for plasma exchange (PE) in blood group O recipients with ABO-incompatible transplantations. Neutralizing capacity was assessed by measuring anti-A and/or anti-B titers in samples comprising one unit of O FFP and 10 O EDTA plasma samples and subtracting the binary logarithm of the titer in each group with a saline dilution. Ten EDTA plasma samples with Lewis b (Leb) antigen positivity and 10 sets of pooled FFP from each blood group were used as diluents. In O FFP, the NCM values (mean±SD) were 3.4±0.52 (2.6±0.52) and 2.6±0.52 (1.5±0.3) in B and AB for IgM (total antibody) anti-B (both P<0.001), and in the 10 O EDTA plasma samples, they were 3.9±0.88 (3.1±0.88) and 3.2±0.79 (2.4±0.97) for IgM (P=0.0013) and total anti-B (P=0.025), respectively. In vitro analysis revealed that B FFP is more effective than AB FFP in reducing IgM and total anti-B antibody titers in O recipients, regardless of Leb antigen positivity.

Estimation of ABO Anti-A and Anti-B Agglutinin Titers among Blood Donors at a Tertiary Care Referral Teaching Hospital Blood Centre in Southern India: A Cross-sectional Study

Introduction: Transfusion of blood Group O and its components with high ABO antibody titers to non O recipients has been shown to cause acute transfusion reactions, especially in platelet transfusions, as platelets contain significant amounts of ABO antigen on their surface as well as Anti-ABO alloisogglutinins in plasma. Aim: To estimate the ABO Anti-A and Anti-B agglutinin titers among blood donors at a tertiary care referral teaching hospital blood centre. Materials and Methods: This cross-sectional observational study was conducted at the Immunohaematology laboratory of the Department of Transfusion Medicine, Sri Venkateswara Institute of Medical Sciences, Tirupati, Andhra Pradesh, India, from March 2021 to June 2022. All blood donors presenting to the blood centre were screened for eligibility for blood donation. Donors who fulfilled the eligibility criteria as per the Drugs and Cosmetics Act, 1940, and Rules, 1945 were included. Anti-A and Anti-B titers were determined by the conventional tube method with dilutions of 1 in 2, 1 in 4, 1 in 8, 1 in 16, 1 in 32, 1 in 64, 1 in 128, 1 in 256, 1 in 512, and 1 in 1024. A titer of &lt;64 was considered as a low titer, while a titer of &gt;64 was considered as a high titer. Results: A total of 399 donors were included in the study, with 393 (98.5%) being males and 6 (1.5%) being females. The mean age of the study population was 28.49 years. Among blood group A, the percentage of individuals with an IgM anti-B titer of &lt;64 was 85.44% (88) and &gt;64 was 14.56% (15), whereas in blood group B, IgM anti-A titers of &lt;64 were 65.5% (93) and &gt;64 were 34.5% (49). In blood group O, the percentage of individuals with &lt;64 and &gt;64 titers of IgM anti-A were 52.60% (81) and 47.40% (73), respectively, whereas for anti-B, &lt;64 and &gt;64 titers were 77.92% (120) and 22.08% (34), respectively. Conclusion: It is recommended that a database be maintained in all institutes by estimating antibody titers for every A, B, O blood group donors. Whole blood or platelets from group O donors with IgM Anti-A and Anti-B antibody titers &lt;64 can only be transfused across the ABO barrier. As the majority of group A donors had titers &lt;64, group A platelets may be transfused across the ABO barrier in emergency situations.

Anti-A and anti-B titers, age, gender, biochemical parameters, and body mass index in Japanese blood donors.

It has been reported that anti-A and anti-B (ABO antibody) titers decrease with age, but little is known about the association between ABO antibody titers and physiologic/biochemical parameters such as body mass index (BMI), gamma-glutamyl transpeptidase (GGT), and total cholesterol (T-Cho). We investigated the present situation of ABO antibody titers among healthy blood donors in Japan and the physiologic/biochemical factors that may be associated with changes in ABO antibody titers. Plasma from 7450 Japanese blood donors was tested for ABO antibody titers using ABO reverse typing reagents by an automated microplate system; donor samples were classified into low, middle, and high titers according to the agglutination results obtained with diluted plasma samples. Multivariate regression analysis was performed to analyze the association between ABO antibody titers and age, gender, biochemical parameters (alanine transaminase [ALT], GGT, globulin, T-Cho, and glycosylated albumin [GA]), and BMI according to the ABO blood groups. A significant correlation between ABO antibody titers and age/gender, except for gender in anti-A of blood group B donors, was observed. BMI showed significant but negative correlations with anti-A and anti-B (β = -0.085 and -0.062, respectively; p < 0.01) in blood group O donors. In addition, significant but negative correlations between GGT and T-Cho with anti-B of blood group A donors (β = -0.055 and -0.047, respectively; p < 0.05) were observed. Although differences existed among the ABO blood groups, ABO antibody titers seem to be associated with physiologic and biochemical parameters of healthy individuals.

An in vitro comparison of intra-operative isohemagglutinin and human leukocyte antigen removal techniques in pediatric heart transplantation

Background: Highly sensitized pediatric patients awaiting heart transplantation experience longer wait times and thus higher waitlist mortality. Similarly, children less than 2 years of age have increased waitlist times and mortality when compared to their older peers. To improve the likelihood of successful transplantation in these patients, various strategies have been utilized, including peri-operative plasmapheresis. However, limited data exists comparing plasmapheresis techniques for antibody reduction. This study’s aim was to compare the in vitro magnitude of isohemagglutinin titers (IT) and human leukocyte antigen (HLA) antibody removal and the time required between membrane-based plasmapheresis (MP) and centrifuge-based plasmapheresis (CP) incorporated into the extracorporeal (EC) circuit. Methods: Two MP (Prismaflex) and two CP (Spectra Optia, Terumo BCT) circuits were incorporated into four separate EC circuits primed with high titer, highly sensitized type O donor whole blood. Assays were performed to determine baseline IT and anti-HLA antibodies and then at 30-minute increments until completion of the run (two plasma volume exchanges) at two hours. Results: There was a decrease in anti-A and anti-B IgM and IgG titers with both MP and CP. Mean anti-A and anti-B titer reduction was by 4.625 titers (93.7% change) and 4.375 titers (93.8% change) using MP and CP, respectively. At 2 h of apheresis, CP reduced 62.5% of all ITs to ≤ 1:4, while MP reduced 50% of ITs to ≤ 1:4. Additionally, reduction of anti-HLA class II antibody to mean fluorescence intensity (MFI) &lt;3000 was achieved with both MP and CP. At 2 h of apheresis, CP reduced MFI by 2–3.5 fold and MP reduced MFI by 1.7–2.5 fold. Both demonstrated similar hemolytic and thrombotic profiles. Conclusions: In this in vitro plasmapheresis model of IT and anti-HLA antibody reduction, both MP and CP incorporated into the EC circuit can be used quickly and effectively to reduce circulating antibodies. While CP may have some greater efficiency, further study is necessary to verify this in vivo.

Decreased rate of blood donors with high ABO antibody titers in Japan and the underlying factors: Comparisons between 2010 and 2021

Background and ObjectivesPreviously (2007), it was reported that ABO antibody titers in Japanese blood donors had decreased significantly compared to 20 years before. Here we evaluated whether further decrease of antibody titers had occurred in recent years, and the potential factors associated with changes in antibody titers. Materials and MethodsSerum/plasma from random blood donors in 2010 and 2021 (2010: 3369, 2021: 5796 donors) was classified into low, middle, and high ABO antibody titers according to the reactivity of diluted serum/plasma (2.5-fold and 20-fold) by an automated microplate system. The rates of low/high titer in the two periods were compared. Logistic regression and age-gender-BMI subgroup analyses were conducted to identify the factors that contributed to changes in antibody titers. ResultsCompared to 2010, the rate of donors with high ABO antibody titers was decreased in 2021 for both anti-A and anti-B (anti-A, 2010: 23.8%, 2021: 19.3%; anti-B, 2010: 23.8%, 2021: 16.4%). In logistic regression analysis, age was found to significantly affect both anti-A and anti-B antibody titers (anti-A, adjusted odds ratio 0.36, 95% CI 0.31–0.41; anti-B, 0.42, 0.37–0.47), and BMI (0.82, 0.73–0.92) and other time-related factors (0.79, 0.71–0.88) significantly affect anti-B antibody titers. Subgroup analysis revealed decreased rate of high anti-B titers in the higher age group in 2021. ConclusionThe rate of high ABO antibody titers, especially high anti-B titers, was significantly decreased in 2021, and our results suggested an association with aging and obesity of blood donors as well as other time-related factors.

Characteristics of ABO Antibodies in Group O Malaysian Blood Donors.

Haemolytic transfusion reactions (HTRs) due to anti-A and anti-B antibodies in Group O blood products are rare but potentially fatal. This study aimed to identify the prevalence of high ABO antibody titre and the immunoglobulin (Ig) classes (IgM only or with IgG) and the prevalence of haemolysin antibodies in Group O blood donors. Plasma from Group O blood donors was tested by using antibody titration at room temperature. Titres ≥ 64 were considered high. The plasma was treated with 0.01 M dithiothreitol (DTT) to determine the presence of IgG antibodies and titre. IgG titres ≥ 64 were considered high. Tests for haemolysis were conducted by mixing the plasma with 3% fresh A1 and B cell suspensions and incubating at 37 °C. The haemolysis was observed macroscopically. Of 311 donors, 238 (76.5%) showed high anti-A and/or anti-B antibody titres. The highest antibody titre obtained was 256. Female and younger donors (< 40 years old) had higher anti-A and anti-B titres. The anti-B titre showed an association with gender (P < 0.001), and was high in female donors (77.8%). Males aged over 50 years old were found to have low mean titre antibodies. Most donors had both IgM and IgG ABO antibodies. The prevalence of haemolysins in our population was 3.5%. Most of our O blood donors had a high ABO antibody titre but a low prevalence of haemolysins. Males aged over 50 years old are the best O donors for preventing HTRs, particularly when mismatch transfusion is required. We recommend a transfusion unit screen for ABO antibody titre in younger female donors (< 40 years old), to prevent the transfusion of high titre O blood products into non-O recipients.

Platelet Additive Solutions as an Alternative Storage Medium of Apheresis Platelets to Reduce ABO Antibody Titer for ABO-Incompatibility Platelet Transfusion.

Introduction Platelet additive solutions (PASs) are nutrient media commonly used to replace and reduce the need for storage plasma. They are an alternative medium to maintain high-quality platelets lasting longer on the shelf for about seven days. Platelets with high titer of ABO antibody can pose a hemolytic transfusion reaction (HTR) risk if units are given across the ABO barrier. The risk of complication is greater when group O platelet is released to non-group O patients. The PAS has been known as a safe medium, where the titer of ABO antibodies is expected to be diluted. In this study, we compared the anti-A and anti-B antibody titers of apheresis platelets in PAS and non-PAS (plasma) as the suspending media. Methods A total of 20apheresis platelet donors were selected, with seven from blood group A, eight from blood group B, and five from blood group O. The platelets were collectedusing an Amicus cell separator. They were suspended in PAS and plasma before being stored at a temperature range of 22-24ºC. Anti-A (blood group B and O)and Anti-B(blood group A and O) antibody titers were measured and compared between the two suspending media. Wilcoxon signed-rank test is used for statistical analysis, and a p-value <0.05 is considered significant. Results The median titer of the anti-A antibody of apheresis platelets showed a significant difference between suspended in PAS (2.50) and plasma (4.00), p=0.002. Similar findings were also seen with the median titer of the anti-B antibody of apheresis platelet, in which it showed a significant difference between suspended in PAS (2.00) and plasma (4.00), p=0.004. It was observed that there was a significant reduction in both anti-A and anti-B antibody titers in the PAS as compared to the plasma group. Conclusion The decrease in ABO antibody titer in apheresis platelets stored with PAS can be beneficial for patients. This reduces the risk of HTRs if ABO-incompatible platelet units need to be issued. Thus, using PAS as a storage medium significantly improves platelet inventory management without compromising patient safety.

An assessment of the safety, hemostatic efficacy, and clinical impact of low-titer group O whole blood in children and adolescents.

Low-titer group O whole blood (LTOWB) use has been associated with improved survival and less blood transfusions in adult trauma patients. Its use in pediatric trauma has been shown to be safe when using leukoreduced, LTOWB with anti-A, anti-B antibody titers of <1:50. We set out to evaluate the safety, hemostatic potential, and impact on pediatric outcomes at a center using non-leukoreduced, LTOWB with anti-A, anti-B antibody titers of <1:200. Patients younger than 18 years, who received emergency-release, uncrossed matched blood, and presented to our trauma center from November 2017 to April 2021 were included. Patients were divided into those receiving any LTOWB and those receiving only RBC and or plasma (COMP). Primary outcome was 30-day survival. One hundred sixty-four patients received emergency release blood products. Of these, 73 received at least one unit of LTOWB. The LTOWB group were younger (14 years vs. 13 years), more likely to be male (87% vs. 49%), and to have sustained penetrating trauma (44% vs. 23%); all p < 0.05. Low-titer group O whole blood patients received more blood than their COMP counterparts prior to arrival. Serial hemolysis panels (K+, bilirubin, LDH, haptoglobin) obtained at 24 hours, 48 hours, and 72 hours were similar between groups; all p > 0.05. There was no difference in survival by univariate analysis but after adjusting for inverse probability of treatment weights there was an observed association between WB administration and improved survival, with an odds ratio of 2.48 (1.15-5.47). Non-leukoreduced, LTOWB in anti-A/anti-B antibody titers of <1:200 appear safe in children and adolescents. While patients receiving LTOWB had more evidence of shock, higher torso injury severity, and received more prehospital blood products, there may be a mortality benefit with whole blood. Larger, multicenter studies are needed. Therapeutic/Care Management; Level IV.

Role of antibody screening in high titre group O donors

Red Cells, Fresh Frozen Plasma (FFP) and Platelets (RDP/SDP) prepared from donors with group O may have high titers of anti-A, anti-B and/or anti-A,B antibodies. When such components given to non-group O patients, this high titre can result in haemolytic transfusion reactions (HTRs). Such group O donors are generally termed ‘high-titer group O donors. Significant amounts of ABO antigen being present on the platelet surface and anti-ABO iso-agglutinins being present in the donor’s plasma, Platelet transfusions need to take into account the issues. Although relatively rare, but acute intravascular haemolytic transfusion reaction has been caused by passive transfer of anti-A and anti-B antibodies, present in group O donors. This study aimed to identify the prevalence of high titre antibodies in group O donors. Thus, titre are performed in randomly selected group O donors from different gender and age group to identify best available source of products for Platelet and follow up transfusions.: Randomly selected 100 O blood group donors were included in the study. Samples from these donors were tested for ABO antibody (both IgM and IgG) titres using conventional tube technique at RT and 37°C at Indirect Antiglobulin phase. Statistical analysis was performed using two sample t-test and anova test.Donors included in the present study were mainly male (85%) donors. ABO antibody titres ranged from 0 to 2048. In the present study, Anti-B (IgG) titer is significantly higher than other antibodies in both genders.There are a large proportion of group O donors having high titres of antibodies and hence a routine pretransfusion screening for such antibodies can prevent the development of hemolytic transfusion reaction by issuing only low titre components for out of group transfusions.Each Blood Transfusion Service should establish a policy for testing and issue of group O platelets to non-O group recipient to avoid chances of development of adverse transfusion reaction.

Reduced susceptibility to COVID-19 associated with ABO blood group and pre-existing anti-A and anti-B antibodies

BackgroundSusceptibility to severe acute respiratory syndrome coronavirus 2 shows individual variability in un-vaccinated and previously un-exposed individuals. We investigated the impact of ABO blood group, titers of anti-A and anti-B, other blood group antigens, and the extracellular deposition of ABH antigens as controlled by secretor fucosyltransferase 2 (FUT2) status. Study design and methodsWe studied incidents in three different hospitals between April to September 2020, where un-diagnosed coronavirus disease 2019 (COVID-19) patients were cared for by health care workers without use of personal protection and with close contact while delivering therapy. We recruited 108 exposed staff, of whom 34 were diagnosed with COVID-19. ABO blood type, titer of anti-A and -B, blood group specific alleles, and secretor status were determined. ResultsBlood group O was associated with lower risk of COVID-19 (OR 0.39, 95 %CI (0.16–0.92), p = 0.03) compared to non-O, i.e., blood groups A, B and AB. High titer anti-A immunoglobulin G (IgG) compared to low titer was associated with lower risk of COVID-19 (OR 0.24 95 %CI (0.07–0.78), p = 0.017). High titer of anti-B immunoglobulin M (IgM) compared to no anti-B (IgM) was associated with lower risk of COVID-19 (OR 0.16, 95 %CI (0.039–0.608), p = 0.006) and the same applies to low titer anti-B (IgM) compared to no titer (OR 0.23, 95 %CI (0.07–0.72), p = 0.012).The 33Pro variant in Integrin beta-3, that is part of human platelet antigen 1b (HPA-1b), was associated with lower risk of COVID-19 (OR 0.23, 95 %CI (0.034–0.86), p = 0.028). ConclusionOur data showed that blood group O, anti-A (IgG) titer, anti-B (IgM) titer as well as HPA-1b are associated with lower risk for COVID-19.

Reduction of anti-A and anti-B isoagglutinin titers of group O whole blood units employing an ABO antibody immune adsorption column

BackgroundMassive hemorrhage is a leading cause of death from trauma. There is growing interest in group O whole blood transfusions to mitigate coagulopathy and hemorrhagic shock. Insufficient availability of low-titer group O whole blood is a barrier to routine use. We tested the efficacy of the Glycosorb® ABO immunoadsorption column to reduce anti-A/B titers in group O whole blood. MethodsSix group O whole blood units were collected from healthy volunteers, and centrifuged to separate platelet poor plasma. Platelet-poor plasma was filtered through a Glycosorb® ABO antibody immunoabsorption column, then reconstituted to prepare post-filtration whole blood. Anti-A/B titers, CBC, free hemoglobin, and thromboelastography (TEG) assays were performed on pre-and post-filtration whole blood. ResultsMean( ± SEM) anti-A (224 ± 65 pre vs 13 ± 4 post) and anti-B (138 ± 38 pre vs 11 ± 4 post) titers were significantly reduced (p = 0.004) in post-filtration whole blood. No significant changes were detected in CBC, free hemoglobin, and TEG parameters on day 0. Free hemoglobin increased throughout storage (48 mg/dl ± 24 Day 0 vs 73 ± 35 Day 7 vs 96 ± 44 Day 14; p = 0.14). ConclusionsThe Glycosorb® ABO column can significantly reduce anti-A/B isoagglutinin titers of group O whole blood units. Glycosorb® ABO could be employed to provide whole blood with lower risk of hemolysis and other consequences of infusing ABO incompatible plasma. Preparation of group O whole blood with substantially reduced anti-A/B would also increase the supply of low-titer group O whole blood for transfusion.

Acute hemolytic transfusion reaction following ABO-mismatched platelet transfusion: Two case reports

Acute hemolytic transfusion reaction following ABO-incompatible platelet transfusion: two case reportsAn ideal platelet transfusion should provide ABO identical platelet concentrate, and cross match compatibility is not routinely performed in the standard practices. However, ABO non identical platelet transfusions are not uncommon with the limited resources and short shelf life of platelet concentrate. Though rare, acute hemolytic transfusion reaction (AHTR) may occur following minor ABO-incompatible platelet transfusion. Here, we report two cases of thrombocytopenic patients (one child and one adult) type as Group B RhD positive and received Group O RhD positive platelet transfusions. Both patients experienced an AHTR evidenced by a drop in hemoglobin level, spherocytosis and small agglutinations on the blood film, and positive direct Coombs test. They were treated symptomatically, recovered and discharged well post-event without any morbidity. No anti-B isohemagglutinins titer were done to confirm the high titer of the antibody in the platelet donors. Our cases highlighted the importance of ABO-compatible platelet transfusion, especially to children and those vigilant groups of patients.

A prospective observational study to evaluate effect of heat inactivation on ABO titers performed by column agglutination technology and conventional tube technique.

When determining ABO antibody titers, immunoglobulin G (IgG) antibodies can be masked by immunoglobulin M (IgM) antibodies. Hence, the measurement of actual concentration of IgG requires methods like heat inactivation (HI) of plasma. This study was aimed at determining the effects of HI on IgM and IgG titers performed by conventional tube technique (CTT) and column agglutination technique (CAT). This was a prospective, observational study conducted from October 2019 to March 2020. All consecutive A, B, and O group donors who gave consent for participation were included. All samples were consecutively tested by CTT and CAT, before and after HI (pCTT, pCAT). A total of 300 donors were included. IgG titers were found to be more than IgM titers. For group O, IgG titer results were higher for both anti-A and anti-B compared to group A and B. For group A, B, and O, pretreatment results were higher than posttreatment IgG titer results. Median anti-A titers were similar to median anti-B titers across all categories. Median IgM and IgG titers were higher for group O individuals than nongroup O individuals. There was reduction in IgG and IgM titers after HI of plasma. One log reduction in median titers was observed when ABO titers were performed by CAT and CTT. There is one log difference between median antibody titers estimated using heat inactivated and nonheat inactivated plasma. The use of HI for ABO isoagglutinin titer estimation can be considered in low resource settings.

Analisis Titer dan Subtipe Antibodi pada Inkompatibilitas ABO yang Menyebabkan Hemolytic Disease of Fetus and Newborn

Background: Hemolytic disease of the fetus and newborn (HDFN) is a type of anemia in the fetus or newborn. Clinical features of HDFN such as hepatosplenomegaly, liver failure, ascites, at birth die from heart failure to brain damage. One of the most common causes is incompatibility of blood groups such as ABO. Differences in clinical manifestations that occur in HDFN are caused by differences in antibody titers and IgG subtypes.Objective: The aim of this study was to determine the anti-A and anti-B antibody titers and the types of immunoglobulins that affect HDFN due to ABO incompatibility.Methods: The sample used in this study was blood and umbilical cord blood from 30 pairs of mother-babies who had different blood groups. Titration examination by tube method and IgG subtype by ELISA method were performed on maternal samples.Results: The correlation of total bilirubin levels with maternal Anti-A and Anti-B titers are p= 0.023 and p= 0.001, in addition there are significant increase in OD of Anti-A IgG1 and Anti-B IgG1 againts elevated infant bilirubin levels.Conclusion: IgG titers &gt;8 causing hyperbilirubinemia, but no jaundice and IgG titers &gt;16 causing hyperbilirubinemia to jaundice. The IgG subtype that plays a more role in causing clinical problems is IgG1.

Comparative evaluation of titer estimation of ABO isoagglutinins using three different methods

Background and Aims: While automation has the advantage of objectivity, ease of use, and reproducibility with well-defined end points of agglutination reaction, standardization of these methods has still not been possible. The aim of the present study was to compare results obtained by manual conventional test tube technique (CTT) with semi-automated, column agglutination technique (CAT), and fully automated hemagglutination/solid-phase red cell adherence (HA/SPRCA) by calculating and comparing correlation and median immunoglobulin M (IgM) and immunoglobulin G (IgG) titer. Materials and Methods: This was a prospective, observational study conducted from October 2019 to March 2020. All consecutive A, B, and O group donors who consented to participate were included in the study. All samples were consecutively tested by CTT, CAT, and HA/SPRCA. Results: A total of 300 (100 each from A, B, and O blood groups) donors were included. IgG titers were higher than IgM titers in most group O individuals. This difference was more evident with the use of CAT. The correlation between CTT and CAT was found to be strong, whereas the correlation between CTT and HA/SPRCA was found to be variable for anti-A and anti-B IgG and IgM titers. When measured by CTT and CAT, median anti-A and anti-B titer results for group O individuals were similar. Anti-A and anti-B median titer results obtained by CTT and CAT for group A and B individuals were also similar. Conclusion: Semi-automated method (CAT) shows higher ability in detecting ABO isoagglutinins than the manual method (CTT) and automated method (HA/SPRCA). These methods cannot be used interchangeably.

A prospective observational study to compare abo isoagglutinin titer by conventional test tube and column agglutination technique after heat inactivation of plasma in O blood group individuals

Background and Aims: When determining ABO antibody titers, IgG antibodies can be masked by immunoglobulin M (IgM) antibodies. Hence, the measurement of actual concentration of IgG requires methods such as heat inactivation (HI) of plasma. This study was aimed at determining the effects of HI on IgM and IgG titers performed by conventional test tube (CTT) technique and column agglutination technique (CAT). Materials and Methods: This was a prospective, observational study conducted from October 2018 to March 2020. All consecutive O group donors who gave consent for participation were included in the study. All samples were consecutively tested by CTT and CAT, before and after HI (pCTT and pCAT). Results: A total of 2005 donors were included. IgG titers were found to be more than IgM titers. pCTT IgG results are similar or lower when compared to results obtained by solid-phase red cell adherence (SPRCA), whereas pCAT IgG titers were higher with pCAT when compared to hemagglutination (HA)/SPRCA. The results of titers obtained by pCTT were lower as compared to pCAT and HA/SPRCA, with majority giving results <64. The median IgG and IgM titers for both anti-A and anti-B were highest in pCAT, whereas the median IgG and IgM anti-A and anti-B titers were similar to HA and pCTT. Conclusion: Results obtained by HA/SPRCA were closer to results obtained by pCTT, with the advantage of less time consumption, automation requiring less expertise, and no interobserver variation. Titers obtained by pCAT were higher in comparison to HA/SPRCA and pCTT results, due to high sensitivity.