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Organ transplantation from ABOblood group–incompatible (ABOi) donors requires accurate detection, effective removal and subsequent surveillance of antidonor antibodies. Because ABHantigen subtypes are expressed differently in various cells and organs, measurement of antibodies specific for the antigen subtypes in the graft is essential. Erythrocyte agglutination, the century‐old assay used clinically, does not discriminate subtype‐specific ABOantibodies and provides limited information on antibody isotypes. We designed and created an ABO‐glycan microarray and demonstrated the precise assessment of both the presence and, importantly, the absence of donor‐specific antibodies in an international study of pediatric heart transplant patients. Specific IgM, IgG, and IgA isotype antibodies to nonself ABHsubtypes were detected in control participants and recipients of ABO‐compatible transplants. Conversely, in children who received ABOi transplants, antibodies specific for A subtype IIand/or B subtype IIantigens—the only ABHantigen subtypes expressed in heart tissue—were absent, demonstrating the fine specificity of B cell tolerance to donor/graft blood group antigens. In contrast to the hemagglutination assay, the ABO‐glycan microarray allows detailed characterization of donor‐specific antibodies necessary for effective transplant management, representing a major step forward in precise ABOantibody detection. The authors design a novel ABH‐glycan microarray and demonstrate its effectiveness and accuracy in confirming donor‐specific B cell tolerance in a cohort of ABO‐incompatible pediatric heart transplant patients.

Tricalcium phosphate ceramics (TCP) has been widely investigated. The main advantage of this bioceramic is its bioresorbable behavior. The factor that still limits the application of these materials as temporary implants is the low strength resistance of the TCP sintered material. The tricalcium phosphate presents an allotropic transformation b to a phase around 1250 degC that degrades its resistance, limiting the sintering temperature of the compacted samples. The objective of this work is to study the physical and mechanical properties of hot-pressed tricalcium phosphate with MgO additions. The results obtained have shown that the hot-pressed process increases significantly the mechanical properties of TCP materials. The addition of MgO has not improved the sintering process and the properties of hot-pressed tricalcium phosphate.