Fatal hemolytic transfusion reaction resulting from ABO mistyping of a patient with acquired B antigen detectable only by some monoclonal anti-B reagents

Identification of 5 novel feline erythrocyte antigens based on the presence of naturally occurring alloantibodies

Background

Since the discovery of the Mik antigen, several studies have described blood incompatibilities unrelated to the AB system in cats.

Objective

To estimate the prevalence of cats with non‐AB incompatibilities associated with naturally occurring alloantibodies (NOAb), and to begin mapping the corresponding feline erythrocyte antigens (FEA).

Animals

Two hundred and fifty‐eight type A cats.

Methods

Prospectively, cats were evaluated for the presence of NOAb by crossmatching in groups of 4‐6 cats. When NOAb were detected in a cat, its plasma was used as reagent to assess for the presence of the corresponding FEA in all cats included thereafter, and agreement observed between results of this extensive blood typing was evaluated.

Results

The chance of detecting incompatibilities by randomly crossmatching 2 cats was 3.9%, which resulted in at least 7% of type A cats having NOAb. Blood typing and agreement analyses performed with 7 newly detected NOAb allowed the identification of 5 presumably distinct FEA. Feline erythrocyte antigens 1 and 5 were most frequent with prevalence of 84% and 96%, respectively. Only FEA 1‐negative status was associated with a higher risk of presenting NOAb; with 16.7% of 42 FEA 1‐negative cats having NOAb compared to 5.1% of 216 FEA 1‐positive cats.

Conclusions and Clinical Importance

This study represents a first step of FEA identification outside the AB system. Because of its prevalence and association with NOAb, FEA 1 might correspond to the Mik antigen.

[When A is not A anymore: problems and pitfalls with blood group typing]

Correct blood group typing is a prerequisite for transfusion. In most cases blood group determination is without problems; however, in individual cases various factors can complicate blood group determination and sometimes lead to confusing findings. For a better understanding the clinician should have basic knowledge of blood typing. Blood group determination usually covers the AB0 blood groups, Rhesus and Kell systems; in addition, a direct Coombs test and an antibody screening test for the detection of irregular antibodies in the recipient are performed. Confusion of patients, blood samples, results or preparations can lead to severe consequences due to incompatible transfusion and must be prevented. In this context, bedside blood type testing before transfusion is of utmost importance. Problems in laboratory analysis as well as patient-related factors, such as the existence of irregular antibodies against red blood cells can complicate the immunohematology diagnostics. Certain medications, such as daratumumab, lead to a significantly increased complexity in laboratory analyses. Massive transfusions can lead to chimerism with more than one population of circulating red blood cells. Hematopoetic stem cell transplantation can also lead to a change in blood groups as well as chimerism. In addition, there are various other rare causes that can result in difficulties in blood group determination, such as rare blood groups or rare disease-associated phenomena. In the case of problems in blood group determination, early and close cooperation with transfusion medicine is essential for the clinician.

Comparison of gel column, card, and cartridge techniques for dog erythrocyte antigen 1.1 blood typing

OBJECTIVE

To compare accuracy and ease of use of a card agglutination assay, an immunochromatographic cartridge method, and a gel-based method for canine blood typing.

SAMPLE

Blood samples from 52 healthy blood donor dogs, 10 dogs with immune-mediated hemolytic anemia (IMHA), and 29 dogs with other diseases.

PROCEDURES

Blood samples were tested in accordance with manufacturer guidelines. Samples with low PCVs were created by the addition of autologous plasma to separately assess the effects of anemia on test results.

RESULTS

Compared with a composite reference standard of agreement between 2 methods, the gel-based method was found to be 100% accurate. The card agglutination assay was 89% to 91% accurate, depending on test interpretation, and the immunochromatographic cartridge method was 93% accurate but 100% specific. Errors were observed more frequently in samples from diseased dogs, particularly those with IMHA. In the presence of persistent autoagglutination, dog erythrocyte antigen (DEA) 1.1 typing was not possible, except with the immunochromatographic cartridge method.

CONCLUSIONS AND CLINICAL RELEVANCE

The card agglutination assay and immunochromatographic cartridge method, performed by trained personnel, were suitable for in-clinic emergency DEA 1.1 blood typing. There may be errors, particularly for samples from dogs with IMHA, and the immunochromatographic cartridge method may have an advantage of allowing typing of samples with persistent autoagglutination. The laboratory gel-based method would be preferred for routine DEA 1.1 typing of donors and patients if it is available and time permits. Current DEA 1.1 typing techniques appear to be appropriately standardized and easy to use.

Comparison of five blood-typing methods for the feline AB blood group system

Objective-To compare the ease of use and accuracy of 5 feline AB blood-typing methods: card agglutination (CARD), immunochromatographic cartridge (CHROM), gel-based (GEL), and conventional slide (SLIDE) and tube (TUBE) agglutination assays. Sample Population-490 anticoagulated blood samples from sick and healthy cats submitted to the Transfusion or Clinical Laboratory at the Veterinary Hospital of the University of Pennsylvania. Procedures-Sample selection was purposely biased toward those from anemic, type B, or type AB cats or those with autoagglutination. All blood samples were tested by use of GEL, SLIDE, and TUBE methods. Fifty-eight samples were also tested by use of CARD and CHROM methods. The presence of alloantibodies in all cats expressing the B antigen as detected by use of any method was also assessed. Results-Compared with the historical gold-standard TUBE method, good to excellent agreement was achieved with the other typing tests: CARD, 53 of 58 (91% agreement); CHROM, 55 of 58 (95%); GEL, 487 of 490 (99%); and SLIDE, 482 of 487 (99%; 3 samples were excluded because of autoagglutination). Four of the samples with discordant test results originated from cats with FeLV-related anemia. Conclusions and Clinical Relevance-Current laboratory and in-clinic methods provide simple and accurate typing for the feline AB blood group system with few discrepancies. Retyping after in-clinic typing with the GEL or TUBE laboratory methods is recommended to confirm any type B or AB cats.

Blood doping in athletes--detection of allogeneic blood transfusions by flow cytofluorometry

Athletes may undergo blood transfusion to increase their red cell mass and the oxygen carrying capacity of their blood in order to confer a competitive advantage. Allogeneic transfusions are normally mismatched at one or more minor blood group antigens. The most sensitive and accurate method known to detect this form of blood doping is flow cytometry. Low percentages of antigen-positive and antigen-negative red blood cells (RBCs) can be quantitated using suitable specific alloantibodies and careful analysis. By testing blood samples taken at various times, a reduction in the percentage of a minor population of RBCs will indicate transfusion has occurred.

Genomic analysis of clinical samples with serologic ABO blood grouping discrepancies: identification of 15 novel A and B subgroup alleles

Since the cloning in 1990 of complementary DNA corresponding to messenger RNA transcribed at the blood group ABO locus, polymorphisms and phenotype-genotype correlations have been reported by several investigators. Exons 6 and 7, constituting 77% of the gene, have been analyzed previously in samples with variant phenotypes but for many subgroups the molecular basis remains unknown. This study analyzed 324 blood samples involved in ABO grouping discrepancies and determined their ABO genotype. Samples from individuals found to have known subgroup alleles (n = 53), acquired ABO phenotypes associated with different medical conditions (n = 65), probable chimerism (n = 3), and common red blood cell phenotypes (n = 109) were evaluated by ABO genotype screening only. Other samples (n = 94) from apparently healthy donors with weak expression of A or B antigens were considered potential subgroup samples without known molecular background. The full coding region (exons 1-7) and 2 proposed regulatory regions of the ABO gene were sequenced in selected A (n = 22) or B (n = 12) subgroup samples. Fifteen novel ABO subgroup alleles were identified, 2 of which are the first examples of mutations outside exon 7 associated with weak subgroups. Each allele was characterized by a missense or nonsense mutation for which screening by allele-specific primer polymerase chain reaction was performed. The novel mutations were encountered in 28 of the remaining 60 A and B subgroup samples but not among normal donors. As a result of this study, the number of definable alleles associated with weak ABO subgroups has increased from the 14 previously published to 29.

Flow cytometric determination of RBC survival in autoimmune hemolytic anemia

BACKGROUND

In cases of warm autoimmune hemolytic anemia (WAIHA), crossmatch incompatible RBCs are most often used for transfusion. The determination of the in vivo survival of transfused and autologous RBCs in WAIHA is helpful in the assessment of the efficacy of transfusion and other therapeutic interventions.

CASE REPORT

A 38-year-old man presented with acute WAIHA, thrombocytopenia, and neutropenia. Steroids and IVIG therapy were ineffective, and the patient received RBCS: Because of increasing hemolysis and persisting thrombocytopenia, splenectomy was performed, resulting in partial remission. Further improvement was achieved by immunosuppressive therapy.

MATERIALS AND METHODS AND RESULTS

Survival of transfused and autologous RBCs was determined, using a flow cytometric method based on the determination of different blood group antigens of patient and donor RBCS: The survival of autologous and transfused RBCs before splenectomy was determined on two consecutive days. The life span of autologous RBCs remained rather stable at 69 and 64 hours on Days 10 and 11, respectively, whereas the life span of transfused RBCs decreased from 186 hours to 25 hours. After splenectomy, the life span of transfused RBCs almost normalized: 43 days at postsplenectomy Day 3 and 87 days at postsplenectomy Day 69.

CONCLUSION

Flow cytometry was successfully used to determine changing hemolytic activity during the clinical course of WAIHA. Additionally, the survival of transfused RBCs could be measured, which may be helpful to judge for the compatibility of allogeneic RBCS: Thus, we were able to show the therapeutic inefficacy of steroids and immunoglobulins, and quick improvement after splenectomy.