Acute Hemolytic Transfusion Reaction in a Patient with Bombay Phenotype: Implications for ABO Grouping

Challenges in the transfusion management of a 15-month-old pediatric patient with Bombay blood group phenotype

Bombay blood group phenotype is often mistyped as O group which can lead to hemolytic transfusion reactions. There are a very few case reports of Bombay blood group phenotype in pediatric age group. Herein, we report an interesting case of Bombay blood group phenotype in a fifteen-month-old pediatric patient who presented with features of raised intracranial pressure and required an emergency surgery. The Bombay blood group was detected on detailed immunohematology work up which was further confirmed by molecular genotyping. The challenges faced in developing countries for transfusion management of such a case have been discussed.

Host Synthesized Carbohydrate Antigens on Viral Glycoproteins as "Achilles' Heel" of Viruses Contributing to Anti-Viral Immune Protection

The glycans on enveloped viruses are synthesized by host-cell machinery. Some of these glycans on zoonotic viruses of mammalian reservoirs are recognized by human natural antibodies that may protect against such viruses. These antibodies are produced mostly against carbohydrate antigens on gastrointestinal bacteria and fortuitously, they bind to carbohydrate antigens synthesized in other mammals, neutralize and destroy viruses presenting these antigens. Two such antibodies are: anti-Gal binding to α-gal epitopes synthesized in non-primate mammals, lemurs, and New World monkeys, and anti-N-glycolyl neuraminic acid (anti-Neu5Gc) binding to N-glycolyl-neuraminic acid (Neu5Gc) synthesized in apes, Old World monkeys, and many non-primate mammals. Anti-Gal appeared in Old World primates following accidental inactivation of the α1,3galactosyltransferase gene 20–30 million years ago. Anti-Neu5Gc appeared in hominins following the inactivation of the cytidine-monophosphate-N-acetyl-neuraminic acid hydroxylase gene, which led to the loss of Neu5Gc <6 million-years-ago. It is suggested that an epidemic of a lethal virus eliminated ancestral Old World-primates synthesizing α-gal epitopes, whereas few mutated offspring lacking α-gal epitopes and producing anti-Gal survived because anti-Gal destroyed viruses presenting α-gal epitopes, following replication in parental populations. Similarly, anti-Neu5Gc protected few mutated hominins lacking Neu5Gc in lethal virus epidemics that eliminated parental hominins synthesizing Neu5Gc. Since α-gal epitopes are presented on many zoonotic viruses it is suggested that vaccines elevating anti-Gal titers may be of protective significance in areas endemic for such zoonotic viruses. This protection would be during the non-primate mammal to human virus transmission, but not in subsequent human to human transmission where the virus presents human glycans. In addition, production of viral vaccines presenting multiple α-gal epitopes increases their immunogenicity because of effective anti-Gal-mediated targeting of vaccines to antigen presenting cells for extensive uptake of the vaccine by these cells.

Human Natural Antibodies to Mammalian Carbohydrate Antigens as Unsung Heroes Protecting against Past, Present, and Future Viral Infections

Human natural antibodies to mammalian carbohydrate antigens (MCA) bind to carbohydrate-antigens synthesized in other mammalian species and protect against zoonotic virus infections. Three such anti-MCA antibodies are: (1) anti-Gal, also produced in Old-World monkeys and apes, binds to α-gal epitopes synthesized in non-primate mammals, lemurs, and New-World monkeys; (2) anti-Neu5Gc binds to Neu5Gc (N-glycolyl-neuraminic acid) synthesized in apes, Old-World monkeys, and many non-primate mammals; and (3) anti-Forssman binds to Forssman-antigen synthesized in various mammals. Anti-viral protection by anti-MCA antibodies is feasible because carbohydrate chains of virus envelopes are synthesized by host glycosylation machinery and thus are similar to those of their mammalian hosts. Analysis of MCA glycosyltransferase genes suggests that anti-Gal appeared in ancestral Old-World primates following catastrophic selection processes in which parental populations synthesizing α-gal epitopes were eliminated in enveloped virus epidemics. However, few mutated offspring in which the α1,3galactosyltransferase gene was accidentally inactivated produced natural anti-Gal that destroyed viruses presenting α-gal epitopes, thereby preventing extinction of mutated offspring. Similarly, few mutated hominin offspring that ceased to synthesize Neu5Gc produced anti-Neu5Gc, which destroyed viruses presenting Neu5Gc synthesized in parental hominin populations. A present-day example for few humans having mutations that prevent synthesis of a common carbohydrate antigen (produced in >99.99% of humans) is blood-group Bombay individuals with mutations inactivating H-transferase; thus, they cannot synthesize blood-group O (H-antigen) but produce anti-H antibody. Anti-MCA antibodies prevented past extinctions mediated by enveloped virus epidemics, presently protect against zoonotic-viruses, and may protect in future epidemics. Travelers to regions with endemic zoonotic viruses may benefit from vaccinations elevating protective anti-MCA antibody titers.

A Very Rare Case with Particular H-deficient Phenotypes

Bombay phenotype, H partially deficient non secretor phenotype and Para-Bombay phenotype are rare blood groups with deficiency or absence of H antigen. A 52-year-old female with Chronic suppurative otitis media was referred to our hospital. The primary serologic results of ABO blood typing were discrepant in forward and reverse grouping. Further, the saliva secretion tests, the pedigree studies and the sequence analysis were performed to confirm the rare phenotype. The patient was diagnosed as a variant H-deficient phenotype, secretor (para-bombay). Red cells of the patient have no H antigens, and it's a very interesting thing that there were two opposite results in the saliva test by using different anti-H. The test showed that H substances were present in the saliva by using anti-H from Libo Biotechnology Co, while which were absent by using anti-H from Shanghai blood center. The patient's Lewis phenotype was Le (a-b+). Anti-HI was present in the sera of her. The sequence of the ABO gene of the patient was 261delG and 467C>T heterozygote by direct DNA sequencing and was assigned as A102/O01. There were two mutations of the patient's FUT1, 328G/A and 658C/T, which were identified by DNA sequencing compared with the reference sequence (GenBank, NG_007510.2). In this case, we report a patient with particular H-deficient phenotype, secretor, which showed opposite results in the saliva test by using anti-H from different sources. We suspect that it is a variant of para-Bombay phenotype.

Bombay phenotype (Oh ) and high-titer anti-H in pregnancy: two case reports and a review of the literature

BACKGROUND

Antenatal cases of Bombay-phenotype (O_h ) individuals and hemolytic disease of the fetus and newborn (HDFN) are not well described in the literature. We present two case reports of high-titer anti-H in pregnant O_h individuals and their serologic investigation, clinical management, and subsequent outcomes. We describe current published cases detailing pregnancy in O_h individuals, to add to the evidence base for clinical decision making and management of pregnancy.

STUDY DESIGN AND METHODS

We describe two case reports of high-titer anti-H in pregnancy in O_h individuals. We summarize published cases to date, to inform clinical decision making and antenatal management in individuals with the Bombay phenotype.

RESULTS

Of the case reports described, neither were affected by HDFN due to anti-H. Antibody titers were high in both cases (immunoglobulin G titer scores, 512 and 4000, respectively) and would be expected to cause some degree of HDFN, a surprising finding. Regular mean cerebral artery Doppler ultrasound was normal. Patient blood management (PBM) techniques ensured that the patient's hemoglobin (Hb) levels were monitored and maintained. Transfusion intervention was not required, with minimal blood loss recorded at birth in both cases.

CONCLUSION

High-titer anti-H in O_h pregnancies may, in rare cases, cause HDFN, but evidence suggests that this may not be the case in all pregnancies. We recommend a multidisciplinary approach, with prompt referral to a fetomaternal medicine unit, combined with PBM strategies, and a planned delivery with the provision of rare-phenotype units (if available and if indicated) on standby.

Transfusion Medicine and Molecular Genetic Methods

Transfusion procedures are always complicated by potential genetic mismatching between donor and recipient. Compatibility is determined by several major antigens, such as the ABO and Rhesus blood groups. Matching for other blood groups (Kell, Kidd, Duffy, and MNS), human platelet antigens, and human leukocyte antigens (HLAs) also contributes toward the successful transfusion outcomes, especially in multitransfused or highly immunized patients. All these antigens of tissue identity are highly polymorphic and thus present great challenges for finding suitable donors for transfusion patients. The ABO blood group and HLA markers are also the determinants of transplant compatibility, and mismatched antigens will cause graft rejection or graft-versus-host disease. Thus, a single and comprehensive registry covering all of the significant transfusion and transplantation antigens is expected to become an important tool in providing an efficient service capable of delivering safe blood and quickly locating matching organs/stem cells. This review article is intended as an accessible guide for physicians who care for transfusion-dependent patients. In particular, it serves to introduce the new molecular screening methods together with the biology of these systems, which underlies the tests.

Longtime soaking of high concentration tranexamic acid in total hip arthroplasty: A prospective randomized controlled trial in 224 patients

Objectives:

To evaluate the efficacy and safety of intra-articular Soaking of high concentration Tranexamic Acid (TXA) in total hip arthroplasty.

Methods:

From March 2013 to March 2014, 224 patients who underwent unilateral primary THA in our hospital was enrolled in this randomized, prospective double-blinded study. The patients were allocated into two groups according to intra-articular solution received: Intra-articular soaking of TXA group, Control group (physiologic saline). The solution was injected from intermuscular space following fixation of the implants and closure of articular capsule, short external rotators. Total blood loss, total volume of drainage and transfusion were recorded. Postoperative deep vein thrombosis and other complications was also measured.

Results:

The mean total blood loss was 730±296 ml in intra-articular soaking of TXA group compared with 1048±295ml in control group (P<0.05). The postoperative mean total volume of drainage was 93±50 mL in intra-articular soaking of TXA group versus 312±136 mL in control group.22 patients (19.8%, control) and 6 patients (5.3%, Intra-articular soaking of TXA) required transfusion (P=0.001). Postoperative deep vein thrombosis and other complications were no statistical significance between the two groups.

Conclusions:

Intra-articular soaking of high concentration TXA with 2-hour clamping drain can reduce the total blood loss and transfusion rates in primary THA without significant increase in postoperative thrombotic complications.

Strategies to overcome the ABO barrier in kidney transplantation

Kidney transplantation across the ABO blood group barrier was long considered a contraindication for transplantation, but in an effort to increase donor pools, specific regimens for ABO-incompatible (ABOi) transplantation have been developed. These regimens are now widely used as an integral part of the available treatment options. Various desensitization protocols, commonly based on transient depletion of preformed anti-A and/or anti-B antibodies and modulation of B-cell immunity, enable excellent transplant outcomes, even in the long-term. Nevertheless, the molecular mechanisms behind transplant acceptance facilitated by a short course of anti-humoral treatment are still incompletely understood. With the evolution of efficient clinical programmes, tailoring of recipient preconditioning based on individual donor-recipient blood type combinations and the levels of pretransplant anti-A/B antibodies has become possible. In the context of low antibody titres and/or donor A2 phenotype, immunomodulation and/or apheresis might be dispensable. A concern still exists, however, that ABOi kidney transplantation is associated with an increased risk of surgical and infectious complications, partly owing to the effects of extracorporeal treatment and intensified immunosuppression. Nevertheless, a continuous improvement in desensitization strategies, with the aim of minimizing the immunosuppressive burden, might pave the way to clinical outcomes that are comparable to those achieved in ABO-compatible transplantation.

Pediatric patient with Bombay blood group: A rare case report

Bombay blood group is a rare blood group in which there is the absence of H antigen and presence of anti-H antibodies. At the time of blood grouping, this blood group mimics O blood group due to the absence of H antigen, but it shows incompatibility with O group blood during cross matching. Serum grouping or reverse grouping are essential for confirmation of the diagnosis. Patients carrying this blood group can receive blood only from a person with this blood group. Reported cases of anesthesia in the pediatric patient with Bombay blood group are relatively rare. Here, we present successful anesthetic management along with intraoperative blood transfusion in a pediatric patient with Bombay blood group posted for ovarian cystectomy.