ABO Antibodies Research Articles

Cold autoantibody interference in pretransfusion testing and its resolution: a case report

We report a case of cold autoantibody detected in a 69-year-old gentleman diagnosed with chronic lymphocytic leukemia and cold autoimmune hemolytic anaemia. Pretransfusion testing showed panagglutination in ABO grouping, antibody screening and identification, with positive direct antiglobulin test (DAT) and positive control cells. A cold autoantibody was suspected, however, the test using a prewarm method and washed RBC with warm saline failed to resolve it. Further tests using DTT-treated cells resolved the grouping as AB RhD positive and DAT as positive with anti-C3d only (control negative). Cold autoadsorption was done and repeated antibody screening using cold-autoadsorped plasma was negative, excluding the presence of alloantibody. The cold-agglutinin titer was >1028 having a wide thermal range. Crossmatching using cold autoadsorped plasma with the AB-positive donor blood was compatible and the patient was transfused safely. For such cold autoantibody cases, an extensive immunohematological workup is required to exclude underlying alloantibody for transfusion safety and efficacy. Bangladesh Journal of Medical Science Vol. 23 No. 04 October’24 Page : 1238-1242

Long-term isoagglutinin monitoring after ABO-incompatible kidney transplantation.

This study aimed to evaluate whether a 2-week period of daily isoagglutinin titer testing after ABO-incompatible kidney transplantation (ABOi-KT) is sufficient to ensure successful engraftment and to advocate for an extension of the monitoring duration in specific situations. We reviewed patients from January 2022 to December 2023 at Asan Medical Center who underwent therapeutic plasma exchange (TPE) due to elevated ABO antibody titers and suspected acute antibody-mediated rejection (AMR) after ABOi-KT. Data collected included pre- and posttransplantation laboratory results, clinical and procedural information, imaging studies, and needle biopsy results of the renal graft. We encountered 3 cases of acute AMR 2 weeks after transplantation. All cases exhibited simultaneous increases in anti-ABO antibody isoagglutinin titers, creatinine, and C-reactive protein levels. Clinical signs, including fever, suggested possible infection, and renal graft biopsy, confirmed AMR in all cases. Two cases underwent graftectomy, while the third recovered renal function after conservative treatment, including TPE. Our findings suggest that a 2-week monitoring period for isoagglutinin titers after ABOi-KT may not be sufficient to detect late AMR. Extending the monitoring duration and considering lifelong fresh-frozen plasma transfusion with graft-compatible blood types, along with periodic isoagglutinin titer testing in cases of suspected AMR, may improve long-term graft outcomes.

Whole Blood Program: Implementation in a Rural Trauma Center

BACKGROUND: The balanced transfusion of blood components plays a leading role in traumatic hemostatic resuscitation. Yet, previous whole blood studies have only focused on urban trauma center settings. OBJECTIVE: To compare component vs whole blood therapy on wastage rates and mortality in the rural setting. METHODS: This study was a nonrandomized, retrospective, observational, single-center study on a cold-stored whole blood program implementation for adult massive transfusions from 2020 to 2022 at a Level II trauma center. Trauma registry data determined the facility’s whole blood needs and facilitated sustainable blood supplies. Whole blood use protocols were established, and utilization and laboratory compliance for incompatible ABO antibody hemolysis was monitored and reviewed monthly at stakeholder and trauma services meetings. RESULTS: From 2018 to 2019, the facility initiated component therapy massive transfusions every 9 days (n = 41). Therefore, four units of low-titer, O-positive whole blood delivered fortnightly was determined to provide patient coverage and minimize wastage. Across the study time frame (2020–2022), there were n = 68 hemodynamically unstable patients, consisting of those receiving whole blood, n = 37, and patients receiving component therapy, n = 31. Mortality rates were significantly lower (p = .030) in the whole blood population (n = 3, 8%) compared to those solely receiving component therapy (n = 9, 29%). Wastage rates were constantly evaluated; in 2021, 43.4% was not utilized, and in 2022, this was reduced to 38.7%. Anecdotally, nurses appreciated the ease of administration and documentation of transfusing whole blood, as it negated ratio compliance. CONCLUSION: This evidence-based whole blood program provides vital care to severely injured trauma patients in a vast, rural region.

4-Color Flow Cytometric Crossmatch Using Whole Blood Lysis

BackgroundIn lymphocyte crossmatch using flow cytometry (flow cytometric crossmatch, FCXM), the conventional tricolor FCXM protocol requires a mononuclear cell isolation step. To develop a new, more streamlined protocol, we introduced whole blood lysis (WBL) and CD45 fluorescence-triggered acquisition using 4-color flow cytometry. MethodsA total of 186 donor/recipient pairs for transplantation were classified into donor-specific human leukocyte antigen (HLA) alloantibody-positive (DSA+, n = 78) and DSA-negative (DSA−, n = 108) groups. The latter group was reclassified into blood group ABO-incompatible (ABOi, n = 56) and ABO-compatible (n = 52) subgroups. The WBL FCXM protocol with CD45 V500-C was optimized using a FACSLyric cytometer (BD Biosciences) with 3 lasers. Measurements for T cells or B cells were calculated as a mean fluorescence intensity (MFI) ratio (test divided by control). WBL FCXM was compared with conventional FCXM in each group. ResultsWBL FCXM showed no difference quantitatively compared with conventional FCXM, except for the B cell FCXM in the DSA− group (B cell MFI ratio: 1.06 ± 0.44 and 0.92 ± 0.41, respectively [P = .0001]). There was no ABO antibody interference in the ABOi subgroup. Similar results were observed in the qualitative determinations of FCXM as follows: 1) In the DSA+ group, the sensitivity of B cell WBL FCXM (96.2%) showed no difference compared with that of conventional FCXM (91.0%, P = .2188) and 2) In the DSA− group, the specificity of T cell WBL FCXM (96.3%) showed no difference compared with that of conventional FCXM (98.1%, P = .6250). WBL FCXM reduced the turnaround time by 50 min compared with that by conventional FCXM. ConclusionsWBL FCXM demonstrated comparable assay performance to that of conventional FCXM. Because this new FCXM protocol is simple and does not compromise assay sensitivity, it has the potential to replace the conventional method in histocompatibility laboratory settings.

Akkermansia muciniphila exoglycosidases target extended blood group antigens to generate ABO-universal blood.

Matching donor and recipient blood groups based on red blood cell (RBC) surface ABO glycans and antibodies in plasma is crucial to avoid potentially fatal reactions during transfusions. Enzymatic conversion of RBC glycans to the universal group O is an attractive solution to simplify blood logistics and prevent ABO-mismatched transfusions. The gut symbiont Akkermansia muciniphila can degrade mucin O-glycans including ABO epitopes. Here we biochemically evaluated 23 Akkermansia glycosyl hydrolases and identified exoglycosidase combinations which efficiently transformed both A and B antigens and four of their carbohydrate extensions. Enzymatic removal of canonical and extended ABO antigens on RBCs significantly improved compatibility with group O plasmas, compared to conversion of A or B antigens alone. Finally, structural analyses of two B-converting enzymes identified a previously unknown putative carbohydrate-binding module. This study demonstrates the potential utility of mucin-degrading gut bacteria as valuable sources of enzymes for production of universal blood for transfusions.

In-vitro Dilution of Human Plasma to Reduce ABO Antibody Titer Levels While Preserving Coagulation Factors

In-vitro Dilution of Human Plasma to Reduce ABO Antibody Titer Levels While Preserving Coagulation Factors

Serology and molecular genetic analysis of two unrelated individuals with the same novel CisAB blood type

ObjectiveThis study aims to report two unrelated individuals with the same novel CisAB blood type and confirm this rare blood type using a comprehensive approach that combines serological and molecular biology techniques. MethodsPeripheral blood samples were collected from two patients and their family members. ABO blood typing and antibody detection were performed using conventional tube methods. Molecular biology techniques were employed to amplify and sequence the 6th and 7th exons of the ABO gene, with reference to gene mutation databases provided by NCBI and ISBT. ResultsThe genotypes of the two unrelated individuals were identical and were confirmed as a new genotype through ISBT gene database comparison. Serological testing results showed different antigen reaction patterns, especially in terms of reverse typing. Gene sequencing identified a series of mutation points, and both unrelated individuals and one of their daughters had mutations at 297 A>G, 526 C>G, 657 C>T, 703 G>A, 803 G>C, and 930 G>A. According to the comprehensive results from The Blood Group Antigen Gene Mutation Database provided by NCBI, the genotype was determined as Bw37. However, based on the results from Names for ABO (ISBT 001) blood group alleles v1.1 171023, the sequencing results indicated a novel mutation combination not found in the ISBT database. Considering the serological reactions of all three individuals, the final determination was CisAB. ConclusionsThis study confirmed the novel CisAB blood type in two individuals through the comprehensive application of serology and molecular biology techniques. The identified gene mutation points were not recorded in known databases, emphasizing the uniqueness of CisAB blood types. This research provides important insights into the genetic basis of ABO subtypes and the characteristics of CisAB blood types, and the relevant results have been submitted to the ISBT website for further research.

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 <64 was considered as a low titer, while a titer of >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 <64 was 85.44% (88) and >64 was 14.56% (15), whereas in blood group B, IgM anti-A titers of <64 were 65.5% (93) and >64 were 34.5% (49). In blood group O, the percentage of individuals with <64 and >64 titers of IgM anti-A were 52.60% (81) and 47.40% (73), respectively, whereas for anti-B, <64 and >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 <64 can only be transfused across the ABO barrier. As the majority of group A donors had titers <64, group A platelets may be transfused across the ABO barrier in emergency situations.

Comparison of Column Agglutination Technique and Tube Test for ABO Antibody Titration and Crossmatching

Comparison of Column Agglutination Technique and Tube Test for ABO Antibody Titration and Crossmatching

A study on diagnostic performance of different immunohematological diagnostic tests in assessing the prevalence of ABO Hemolytic Disease of Newborn in the antenatal O group mothers and their neonatal outcome in a tertiary care hospital in Northern India

BackgroundHemolytic disease of the newborn (HDN) results in the decreased lifespan of the red cells. HDN related to ABO incompatibility is mostly unnoticed because routine screening is not being done. This study was done to assess the prevalence of ABO-HDN and to compare different immunohematological tests. Methods-In this study 213 O group mothers and the 122 ABO-incompatible newborns born to them were included. Quantifying the maternal IgG anti-A/anti-B antibody titer was done by Conventional Tube Technique (CTT) using Dithiothreitol (DTT) pretreated maternal serum. Hemolysin test was performed on the mothers having titer > 256. These cases were followed up and, after delivery, were monitored for ABO HDN, along with direct antiglobulin testing and elution studies. The prevalence of ABO-HDN was calculated, and the different diagnostic parameters of the tests were calculated. Results- The prevalence of ABO-HDN in our population was estimated to be 1.7%, 6.1% & 10.6% in our population, O group mothers, and O group mothers with ABOincompatible newborns, respectively. Maternal titer≥ 512 strongly correlated with ABOHDN. DAT positivity is a good predictor of ABO-HDN, especially using sensitive techniques. Maternal IgG titers have the highest sensitivity & Negative Predictive Value, while DAT has the highest specificity & Positive Predictive Value. Conclusion – Maternal ABO antibody titration may be advocated in the centers to identify high-risk groups. It can advocate institutional delivery and dedicated follow-up of newborns with ABO-HDN. Blood grouping & DAT may be performed in all newborns born to O blood group to identify high-risk cases.

High Rate of Passenger Lymphocyte Syndrome after ABO Minor Incompatible Lung Transplantation.

Rationale: Passenger lymphocyte syndrome (PLS) may complicate minor ABO mismatched lung transplantation (LuTX) via donor-derived red cell antibody-induced hemolysis.Objectives: To ascertain the incidence and specificity of PLS-relevant antibodies among the study population as well as the dynamics of hemolysis parameters and the transfusion requirement of patients with or without PLS.Methods: In this cohort study, 1,011 patients who received LuTX between January 2010 and June 2019 were studied retrospectively. Prospectively, 87 LuTX (July 2019 to June 2021) were analyzed. Postoperative ABO antibody and hemolytic marker determinations, transfusion requirement, and duration of postoperative hospital care were analyzed. Retrospectively, blood group A recipients of O grafts with PLS were compared with those without.Measurements and Main Results: PLS affected 18.18% (retrospective) and 30.77% (prospective) of A recipients receiving O grafts, 5.13% of B recipients of O grafts, and 20% of AB patients receiving O transplants. Anti-A and anti-A1 were the predominant PLS-inducing antibodies, followed by anti-B and anti-A,B. Significantly lower hemoglobin values (median, 7.4 vs. 8.3 g/dl; P = 0.0063) and an approximately twice as high percentage of patients requiring blood transfusions were seen in PLS. No significant differences in other laboratory markers, duration of hospital stay, or other complications after LuTX were registered.Conclusions: Minor ABO incompatible LuTX recipients are at considerable risk of developing clinically significant PLS. Post-transplant monitoring combining red cell serology and hemolysis marker determination appears advisable so as not to overlook hemolytic episodes that necessitate antigen-negative transfusion therapy.

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.

Pretransplant immunologic risk assessment in high baseline ABO antibody titers and donor-specific anti-human leukocyte antigen antibodies in ABO incompatible kidney transplantation

Pretransplant immunologic risk assessment in high baseline ABO antibody titers and donor-specific anti-human leukocyte antigen antibodies in ABO incompatible kidney transplantation

P‐CB‐22 | Reduction of Anti‐A and Anti‐B Isoagglutinin Titers of Group O Platelet Units with an ABO Antibody Immune Adsorption Column

P‐CB‐22 | Reduction of Anti‐A and Anti‐B Isoagglutinin Titers of Group O Platelet Units with an ABO Antibody Immune Adsorption Column

A-150 Abo Subgroup Incompatibility Leading to Red Cell Engraftment Failure and Fatal Outcome: A Rare But Preventable Complication in Related Allogeneic HSCT

Abstract Background Pre-allogeneic hematopoietic stem cell transplant (HCST) testing includes, among others, ABO and HLA typing and testing for anti-HLA antibodies. ABO subgroup typing is not routinely performed, as A2 subgroup representes 1% of the total group A population and only 0.4% of A2 individuals have anti-A1 in their serum. ABO antigens are also found on the platelet surface. We describe a case of alloHSCT performed between siblings, the donor A1 and the recipient A2, with a fatal outcome caused by red cell and platelet engraftment failure due to anti-A1 antibodies, and emphasize the need to routinely investigate subgroup incompatibility in the pre-alloHSCT workup. Methods Patient data was collected from hospital and laboratory electronic records. Blood typing and immunohematological investigation was performed at the hospital blood bank using gel cards for ABO typing, DAT and antibody screening panels (Grifols, Barcelona). Tube method was used for A subgroup typing (Fresenius, Germany). Bone marrow analysis and other blood tests were performed at local hospital laboratory. HLA typing and antibody screening (Luminex, USA) were sent to a specialized laboratory. Results A 51 year-old male with Non-Hodgkin lymphoma underwent a full-match ABO compatible allogeneic HSCT, both brother/donor and recipient group A. Pre-transplant anti-HLA or ABO antibodies were negative. WBC recovery was achieved on D + 22. The patient had a catheter infection on D + 15 (Permcath removed), CMV infection on D + 24 (treated with gancyclovir) and received several blood transfusions. On D + 22, he had a hemolytic transfusion reaction with fever (38.5°C), chills and a decline in hemoglobin (7.3 g/dL to 6.6 g/dL in the following day), low haptoglobin and increased indirect bilirrubin levels. Immunohematological investigation revealed a positive DAT with an anti-A antibody in the eluate. Subgroup incompatibility was suspected and the patient was found to be subgroup A2, whereas the donor typed A1. Three days later the DAT became negative and anti-A1 was no longer detected. Other RBC antibodies were also excluded. Only group O RBCs and A / AB platelets were transfused thereafter to prevent further hemolysis. On D + 35 the patient was diagnosed with GI-GVHD, which responded to corticosteroids. He never achieved transfusion independence and received RBC and platelet transfusions on a regular basis. Failure of RBC and platelet engraftment was confirmed by a bone marrow aspirate on D + 45, showing only 20% erythroid lineage and absence of megakaryocytes. Marrow chimerism revealed 83% of donor origin. Sepsis by S. aureus ensued on D + 57 and three days later he had fever (38.2°C) and dyspnea after a platelet transfusion. Despite entubation and mechanical ventilation, he evolved to RCP and died on D + 60. Conclusion ABO subgroup typing is a simple and low-cost technique routinely available in the blood bank. Detection of A subgroup incompatibility impacts on key decisions, such as donor choice (if more than one candidate) and the need for erythrocyte depletion of donor stem cells and recipient plasmapheresis if the anti-A1 titer is high. Since graft failure due to ABO subgroup incompatibility can be hazardous, we recommend routinely ABO subgroup typing in the pre-alloHSCT workup to increase donor safety.

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.

Rituximab administration one week before ABO-incompatible liver transplantation due to drug-induced acute liver failure with hepatic coma: a case report.

In cases of acute liver failure (ALF) with hepatic coma, early liver transplantation, including ABO-incompatible (ABOi) living donor liver transplantation (LDLT), should be considered. The ABO antibody barrier can be reduced using plasma exchange (PE) and the anti-CD20 antibody rituximab. Plasma exchange is also performed for drug-induced ALF and is effective for desensitization. Rituximab treatment usually requires 14days. There is presently no established desensitization protocol for ABOi-LDLT for ALF. Here, we report a case of drug-induced ALF with hepatic coma, which was treated with ABOi-LDLT using PE and rituximab 8days prior to surgery. A 33-year-old female, with a history of headaches for which she was taking analgesics daily, developed drug-induced ALF with hepatic coma. Her ABOi sister desired to become a liver donor. We initiated desensitization using rituximab (500mg) and mycophenolate mofetil (MMF, 2000mg/day), followed by five sessions of PE. Eight days after rituximab administration, ABOi-LDLT with splenectomy was performed. Postoperatively, the patient received local infusion via portal vein for 14days and immunosuppression with tacrolimus, methylprednisolone, and MMF. No episode of cellular or antibody-mediated rejection (AMR) was observed. The patient was discharged uneventfully 56days after ABOi-LDLT with no problems up to 15months after the transplant.

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.