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Background: The absence of the red cell antigens P, P1 and P k , known as 'p', represents an extremely rare red cell phenotype. Individuals with this phenotype spontaneously form anti-PP1P k isoantibodies, associated with severe haemolytic transfusion reactions, recurrent spontaneous abortion and haemolytic disease of the fetus and newborn (HDFN)., Methods: We report a series of four successful pregnancies in three women with anti-PP1P k isoantibodies, one complicated by HDFN, another by intrauterine growth restriction, all managed supportively. We also review the literature regarding the management of pregnancy involving anti-PP1P k isoimmunization., Results: The literature surrounding anti-PP1P k in pregnancy is limited to a very small number of case reports. The majority report management with therapeutic plasma exchange (TPE) with or without intravenous immunoglobulin. The relationship between titre and risk of pregnancy loss remains unclear, though a history of recurrent pregnancy loss appears important. Although a positive cord blood direct antiglobulin test is frequently noted, clinically significant HDFN appears uncommon, though possible., Conclusion: Early initiation of TPE in high risk patients should be strongly considered. If possible, pregnancies should be managed in a high-risk obstetric or maternal fetal medicine service. The fetus should be monitored closely with interval fetal ultrasound and middle cerebral artery peak systolic volume Doppler to screen for fetal anaemia. Timely sourcing of compatible blood products is likely to be highly challenging, and both directed and autologous donation should be contemplated where appropriate. The International Red Cell Donor Panel may also provide access to compatible products., (© 2020 International Society of Blood Transfusion.)

Purpose of Review: The purpose of this review is to summarize the role of complement in regulating the removal of a target alloantigen following an incompatible red blood cell (RBC) transfusion, the formation of alloantibodies following RBC alloantigen exposure, and the development of hyperhemolysis in patients with sickle cell disease (SCD)., Recent Findings: Recent studies demonstrate that complement can accelerate alloantibody-mediated removal of target alloantigens from the RBC surface following incompatible transfusion. Complement also influences alloantigen availability during developing alloimmune responses and serves as a unique mediator of CD4 T-cell-independent alloantibody formation following RBC alloantigen exposure. Finally, alternative complement pathway activation appears to play a key role in the development of acute hemolytic episodes in patients with SCD, providing a potential druggable target to prevent acute complications in patients with this disease., Summary: Recent studies suggest that complement can regulate a wide variety of processes germane to hematology, from transfusion complications to baseline hemolysis in patients with SCD. As the role of complement in various disease processes becomes more fully understood, the ability to leverage recently developed complement modulating drugs will only continue to enhance providers' ability to favorably intervene in many hematological diseases.

Transfusion of red cell concentrates is an essential lifesaving treatment for patients with massive bleeding or red blood cell disorders. However, correlations between blood transfusion from female donors, especially in sex mismatched transfusions, and a risk of mortality has been reported. A systematic understanding of how sex-mismatched transfusion can contribute to negative outcomes is still lacking. Here, we propose that variations in stored red blood cell products from female and male blood donors may be related to different characteristics of subpopulations of RBCs in units. As very little attention has been paid to this topic, the aim of this review is to investigate biological mechanisms implicated in negative outcomes of sex-mismatched transfusion. This review discusses basic hematology differences in the blood from female and male donors. Also, observational studies that linked donor sex with adverse transfusion outcome are reviewed. We present three physiological mechanisms (oxygen delivery, coagulation and microvesiculation) that could be impacted by sex-mismatched transfusions., (Copyright © 2019 Elsevier Ltd. All rights reserved.)

Background: Accommodation in ABO-incompatible (ABOi) transplantation and subclinical antibody-mediated rejection in HLA-incompatible (HLAi) transplantation share several morphological similarities. Because the clinical long-term outcomes differ, we hypothesized different molecular processes involved in ABOi transplantation and subclinical antibody-mediated rejection., Methods: Using Illumina Human HT-12 v4 Expression BeadChips, the whole transcriptome was evaluated based on 3-month protocol C4d+ biopsies in otherwise stable ABOi and HLAi kidney grafts, as well as in C4d-negative HLA-compatible grafts exhibiting normal histological findings. Top differently regulated genes were further validated using real-time quantitative polymerase chain reaction in another patient cohort and complement regulatory proteins by immunohistochemistry., Results: In the case of genes involved in immune response-related biological processes, ABOi and HLAi cohorts had similar transcriptomic profiles to C4d-negative controls. The majority of deregulated genes in the ABOi and HLAi groups consisted of metallothioneins and epithelial transporter genes. Increased expression of epithelial transporters (SLC4A1, SLC4A9, SLC17A3, SLC12A3, and SLC30A2) and class 1 metallothioneins (MT1F, MT1G, and MT1X) in HLAi transplantation was validated by real-time quantitative polymerase chain reaction. In comparison to controls, both incompatible cohorts were characterized by the upregulation of intrarenal complement regulatory genes. CD46 and CD59 transcripts were increased in the ABOi cohort, whereas CD46 solely in HLAi group, and CD59 protein expression was similar in both incompatible groups., Conclusions: Several epithelial transporters and metallothioneins discriminate subclinical antibody-mediated rejection in HLAi transplantation from accommodation in ABOi transplantation, which suggest different involved downstream mechanisms and increased risk of injury in HLAi settings. Metallothioneins with their antioxidative properties may help to attenuate the inflammation response induced by donor-specific anti-HLA antibody binding.

Screening of fetomaternal hemorrhage (FMH) is essential in management of fetomaternal antigen incompatibilities of blood. The objective in this study was to evaluate the ability of automatic blood analyzer (ABA) to screen FMH, also comparing this method with flow cytometry (FCM). The contents of fetal red blood cells and fetal hemoglobin were evaluated by FCM and ABA, respectively, using both blood samples of male adults laced with umbilical cord blood diluted at 1/10, 1/100, 1/1,000, and 1/10,000, or blood from puerperal women collected within 48 hours following delivery. FCM had better performance (area under curve, AUC = 0.8723) than ABA (AUC = 0.6569) in detecting fetal blood laced with blood from male adults. At a critical level of 0.5%, ABA indicated that 27.5% of puerperal women would have FMH while FCM did not detect FMH. Our results showed that ABA overestimates FMH and disagrees with FCM on indicating puerperal women with FMH. ABA is inadequate for being used to screen for or to measure FMH.

Background: Blood-group typing of donors and patients is essential to avoid incompatible transfusions. Transfusion of incompatible RBCs may result in alloimmunization complicating future transfusions or in the presence of antibodies in adverse reactions. With more than 300 blood group antigens identified, it is difficult to provide fully compatible blood. Currently, standard practice is to match for the most immunogenic antigens. While the current agglutination-based RBC-typing methods are reliable for testing a selected number of antigens, they are not easily adaptable for high-throughput multiplex blood typing beyond the current standard., Study Design and Methods: Surface plasmon resonance (SPR) is a label-free method to follow molecular-and, very recently, also cellular-interactions in real time. Demonstration of binding of RBCs to blood group antigen-specific antibodies by SPR has already been achieved. Here, we demonstrate the generation of an SPR array equipped with clinically relevant blood group antibodies (A, B, and Rh blood groups). To validate this method, we blindly compared typing of 946 blood donors with results of current diagnostic agglutination-based methods., Results: RBC typing was achieved by monitoring RBC binding to blood group-specific antibodies on the sensor simultaneously within 5 minutes per sample. Regeneration of the chip was robust, allowing for typing of at least 100 samples. The typing results gave a 100% match with classical serology with all antibodies tested besides anti-E/e monoclonals, which gave inconsistent results due to low antibody specificity., Conclusion: This study demonstrates that SPR-based RBC typing for multiple antigens can be realized simultaneously with high-quality antibodies, enabling reduced hands-on time and possibly improving cost efficiency., (© 2018 AABB.)

Thromboembolic complications significantly impair the outcome of hemolytic disorders. We hypothesized that red cell adenosine diphosphate (ADP) release results in significant platelet activation in hemolysis and that this prothrombotic state can be prevented by inhibition of the ADP P2Y 12 receptor. In the current study, we therefore sought to investigate the mechanism and inhibition of hemolysis-induced platelet activation. The expression of activated integrin αIIbß3 was determined by flow cytometry, and platelet aggregation was assessed by multiple electrode platelet aggregometry. We demonstrate platelet activation and increased platelet aggregation by adding hemolytic blood (lysates) to whole blood, similarly to that achieved by the platelet agonist ADP. Enhanced platelet activation and reactivity in the presence of hemolytic blood were significantly abolished by apyrase, which catalyzes ADP degradation, and inhibited by blockade of the platelet ADP P2Y 12 receptor with cangrelor. Platelets from patients treated with the ADP P2Y 12 receptor antagonist clopidogrel showed a reduced response to lysates compared to platelets from healthy controls without antiplatelet treatment. Further, in vitro blood group ABO incompatibility induced hemolysis and led to increased platelet activation. Finally, "spontaneous" platelet aggregation seen in patients with cold agglutinin disease was completely abolished by cangrelor. In conclusion, hemolysis is associated with increased platelet activation and aggregation due to red cell derived ADP, which can be prevented by ADP receptor blockade.

The increasing demand for solid organs has necessitated the use of ABO and Rhesus (Rh) D minor mismatched transplants. The passenger lymphocyte syndrome (PLS) occurs when donor lymphocytes produce antibodies that react with host red blood cell (RBC) antigens and result in hemolysis. Our aim was to evaluate prospectively the role of PLS in post transplant anemia and hemolysis in ABO and RhD minor mismatched recipients of liver and kidney grafts and to study the association of PLS with donor lymphocyte microchimerism. We examined 11 liver and 10 kidney recipients at Day +15 for anemia, markers of hemolysis, direct antiglobulin test and eluates, and serum RBC antibodies. Microchimerism was determined in peripheral blood lymphocytes by genotyping of simple sequence length polymorphisms encoding short tandem repeats. Immune hemolytic anemia and anti-recipient RBC antibodies were observed in 2 out of 11 liver (18.2%) and 2 out of 10 kidney (20%) transplants. RBC antibody specificity reflected the donor to recipient transplant, with anti-blood group B antibodies identified in 2 cases of O to B and 1 case of A to AB transplants while anti-D antibodies were detected in 1 case of RhD-negative to RhD-positive transplant. Donor microchimerism was found in only 1 patient. In conclusion, passenger lymphocyte mediated hemolysis is frequent in minor mismatched liver and kidney transplantation. Recognizing PLS as a potential cause of post transplant anemia may allow for early diagnosis and management to decrease the morbidity and mortality in some patients., (Copyright © 2015 American Society for Histocompatibility and Immunogenetics. Published by Elsevier Inc. All rights reserved.)

Antibody-induced hemolytic transfusion reactions were first described over 300 years ago. Indeed, during its early evolution, transfusion medicine focused almost exclusively on issues in immunohematology to prevent such events. However, despite the best of efforts to avoid them, incompatible transfusions still occur, through both error and an inability to obtain compatible red blood cells for patients who are alloimmunized against multiple antigens. Because transfusing units of incompatible blood is potentially lethal, studies on human volunteers are not ethical. Thus, understanding of hemolytic transfusion reactions is generated through clinical cases, animal models, inference from related human pathologies, or studies using small volumes of transfused red blood cells. Over the past several decades, substantial new knowledge has been accumulated regarding the mechanisms of hemolysis, the metabolism of products of hemolysis, and the effects of both on recipient biology. Using these data sources, this article traces the historical generation of this knowledge and describes recent advances.

We report a case of plasma cell-rich rejection accompanied by acute antibody-mediated rejection in a patient with ABO-incompatible kidney transplantation. A 33-year-old man was admitted for an episode biopsy; he had a serum creatinine (S-Cr) level of 5.7 mg/dL 1 year following primary kidney transplantation. Histological features included two distinct entities: (1) a focal, aggressive tubulointerstitial inflammatory cell (predominantly plasma cells) infiltration with moderate tubulitis; and (2) inflammatory cell infiltration (including neutrophils) in peritubular capillaries. Substantial laboratory examination showed that the patient had donor-specific antibodies for DQ4 and DQ6. Considering both the histological and laboratory findings, we diagnosed him with plasma cell-rich rejection accompanied by acute antibody-mediated rejection. We started 3 days of consecutive steroid pulse therapy three times every 2 weeks for the former and plasma exchange with intravenous immunoglobulin (IVIG) for the latter histological feature. One month after treatment, a second allograft biopsy showed excellent responses to treatment for plasma cell-rich rejection, but moderate, acute antibody-mediated rejection remained. Therefore, we added plasma exchange with IVIG again. After treatment, allograft function was stable, with an S-Cr level of 2.8 mg/dL. This case report demonstrates the difficulty of the diagnosis of, and treatment for, plasma cell-rich rejection accompanied by acute antibody-mediated rejection in a patient with ABO-incompatible kidney transplantation. We also include a review of the related literature., (© 2014 Asian Pacific Society of Nephrology.)

Objectives: The full crossmatch is traditionally the final step in compatibility testing, acting as a serologic double check for ABO compatibility and unexpected RBC antibodies. In this review, we discuss the development of electronic crossmatch (EXM), an approach for determining when EXM can be used, and its strengths and weaknesses., Methods: Because EXM relies on highly sensitive screening assays, antibodies are frequently encountered whose clinical significance must be investigated and interpreted. Our approach is to obtain further history, perform enhanced tube testing, and consider tests of immune reactivity or RBC survival., Results: For those without clinically significant antibodies, we found two alternatives: immediate-spin crossmatch (IS XM) and EXM. IS XM is prone to error related to serologic interference, whereas EXM depends on the accuracy of the sample label, accurate data entry, and informatics to avoid errors., Conclusion: EXM is an alternative to the serologic test in patients who have no clinically significant antibodies.

Hemolytic transfusion reactions (HTRs) due to incompatible red blood cell (RBC) transfusions are a leading cause of transfusion associated death. Although many transfused incompatible RBCs are cleared, some remain in circulation despite the presence of RBC-specific antibodies, potentially due to "antigen modulation." With a goal of better understanding incompatible RBC clearance, we generated a murine model with RBC-specific expression of a clinically significant human antigen (KEL2) known to be involved in antigen modulation as well as in HTRs. Wild-type (WT) recipients transfused with transgenic KEL2 RBCs generated anti-KEL glycoprotein alloantibodies, which fixed complement, led to intravascular hemolysis, and resulted in decreased levels of KEL2 antigen detectable on cells remaining in circulation. Antigen modulation did not appear to solely reflect removal of RBCs with higher antigen expression, because cells continued to display antigen modulation in the absence of significant clearance. Recipients genetically lacking complement exhibited lesser degrees of incompatible RBC clearance and antigen modulation in comparison with WT or FcγR knock-out (KO) animals, suggesting a role for complement in RBC clearance. In summary, this HTR model may serve as a platform to test strategies to downmodulate antigen and inhibit incompatible RBC clearance, thus potentially mitigating transfusion dangers.

Haptoglobin, the product of the Hp gene, is a glycoprotein involved in the scavenging of free hemoglobin. Haptoglobin levels increase or decrease in response to various acquired conditions, and they are also influenced by genetic predisposition. There were 2 major alleles, Hp (1) and Hp (2), and 1 minor allele, Hp (del) . Many researchers have attempted to study the haptoglobin types and their association with disease; however, no definitive conclusions have been reached yet. It is reported that patients who are genetically deficient in haptoglobin are at risk of anaphylaxis against blood components containing haptoglobin. Haptoglobin genotypes also affect the reference intervals of haptoglobin levels. Many studies have attempted to establish simple and accurate typing methods. In this paper, we have broadly reviewed several methods for haptoglobin typing-phenotyping, Southern blotting, conventional PCR, real-time PCR, and loop-mediated isothermal amplification. We discuss their characteristics, clinical applications, and limitations. The phenotyping methods are time consuming and labor intensive and not designed to detect patients harboring Hp (del) . The rapid and robust haptoglobin genotyping may help in preventing fatal anaphylactic reactions and in establishing the relationships between the haptoglobin phenotypes and diseases.

Background: Antibody binding to red blood cells (RBCs) can induce potentially fatal outcomes, including hemolytic transfusion reactions (HTRs), hemolytic disease of the fetus and newborn, and autoimmune hemolytic anemia. The mechanism(s) of RBC destruction following antibody binding is typically thought to require complement activation and/or the involvement of Fcγ receptors (FcγRs). In the current report, we analyzed mechanisms of HTRs during incompatible transfusions of murine RBCs expressing human glycophorin A (hGPA) into mice with anti-hGPA., Study Design and Methods: C3 and Fcγ receptor knockout, splenectomized, Fcγ receptor blocking antibody-treated, and clodronate-treated mice were passively immunized with anti-hGPA (10F7 or 6A7) and transfused with RBCs expressing the hGPA antigen. Posttransfusion blood and serum were collected and analyzed via flow cytometry and confocal microscopy., Results: This HTR model results in both rapid clearance and cytokine storm. Neither complement nor FcγRs were required for RBC clearance; in contrast, FcγRs were required for cytokine storm. Circulating aggregates of hGPA RBCs were visible during the HTR. Splenectomy and phagocyte depletion by clodronate had no effect on acute RBC clearance; however, incompatible RBCs reentered over 24 hours in clodronate-treated mice., Conclusion: These data demonstrate a biphasic HTR, the first phase involving sequestration of incompatible hGPA RBCs and the second phase involving phagocytosis of sequestered RBCs. However, the mechanism(s) of phagocytosis in the second phase required neither C3 nor FcγRs. These findings demonstrate novel mechanistic biology of HTRs., (© 2012 American Association of Blood Banks.)

Background: Fetal and neonatal alloimmune thrombocytopenia (FNAIT) is a severe bleeding disorder caused by maternal antibody-mediated destruction of fetal or neonatal platelets (PLTs). Results from our recent large screening study suggest that the pathophysiology of FNAIT is more similar to hemolytic disease of the fetus and newborn (HDFN) than previously thought. Immunization against HPA-1a might therefore be preventable by a prophylactic regimen of inducing antibody-mediated immune suppression (AMIS), which has been documented to be a useful prophylaxis against HDFN. This preclinical proof-of-concept study investigated whether passive administration of anti-β3 integrin could induce AMIS and thereby prevent clinical complications of FNAIT., Study Design and Methods: A murine model of FNAIT using β3 integrin (GPIIIa)-deficient (β3-/-) mice was employed for this study. AMIS in β3-/- mice was induced by intravenous administration of human anti-HPA-1a immunoglobulin G or murine anti-β3 antisera given as prophylaxis after transfusion of HPA-1a-positive human PLTs or murine wild-type PLTs, respectively., Results: AMIS against both human and murine PLT antigens was induced using this prophylactic approach, reducing the amount of maternal PLT antibodies by up to 90%. Neonatal PLT counts were significantly increased and pregnancy outcome was improved in a dose-dependent manner. The incidence of intracranial hemorrhage, miscarriage, and dead-born pups in mice receiving high-dose prophylaxis was reduced to that of normal controls. We also observed that the severity of thrombocytopenia inversely correlated with birth weight., Conclusion: This work conceptually proves that prophylactic administration of PLT antibodies induces AMIS and prevents poor pregnancy outcome in FNAIT., (© 2012 American Association of Blood Banks.)

Prior research has shown that maternal-fetal Rhesus (Rh) and ABO blood incompatibility increase the risk for schizophrenia. In the present study, the relationship between blood incompatibility and volumes of brain structures previously implicated in schizophrenia was assessed in schizophrenia cases and controls from a large birth cohort. Rh/ABO incompatible cases had significantly reduced cortical gray matter volume compared to compatible cases, a finding which appears to be driven by significant volume reductions in the dorsolateral prefrontal cortex and inferior frontal cortex. Larger hippocampal and putamen volumes were also observed in exposed controls compared to unexposed controls. Although the sample size is small and replications are required, these data suggest that maternal-fetal blood incompatibility may increase the risk for altered brain morphology in both schizophrenia and in controls. The findings also suggest that the larger hippocampal volume in exposed controls may indicate a mechanism of adaptive resilience which diminishes the risk that controls will develop schizophrenia., (Copyright © 2011 Elsevier Inc. All rights reserved.)

Background: The aim of this study was to assess the significance of positive C4d capillary immunostaining of endomyocardial biopsies and its correlation to clinical outcome in adult heart transplant recipients., Methods: Nine hundred eighty-five endomyocardial biopsies from 107 heart transplant recipients were evaluated. Immunostaining for detection of intragraft C4d capillary deposition was performed on paraffin-embedded tissue using anti-human C4d polyclonal antibody., Results: Positive staining of C4d was present in 36 patients (34%) and antibody-mediated rejection in eight patients (7%). The patients were subdivided into four groups on the basis of their C4d, circulating antidonor antibodies (donor-specific antibodies [DSAs]), and graft function: group 1=C4d positive, DSA negative, and no graft dysfunction; group 2=C4d positive, DSA positive, and no graft dysfunction; group 3=C4d positive, DSA positive, and signs of graft dysfunction, and group 0 (control)=all negative. An higher mortality risk was found in C4d-positive patients, when compared with negative ones (unadjusted hazard ratios: group 1: 18, group 2: 61, and group 3: 32-fold risk; P<0.0001)., Conclusions: Antibody-mediated rejection is a complex and ongoing phenomenon with different phenotypic features. C4d positive predicts worse prognosis. C4d positive [corrected] and DSA can be used as early mortality predictors in patients without signs of graft dysfunction.

Introduction: Acute humoral rejection is the most important risk factor for early graft loss in ABO-incompatible (ABO-i) renal transplantation (RTx) and is present from the early period after RTx. However, the characteristics of early humoral-mediated graft injury are pathologically uncertain., Objective: To analyze tissue from 10 protocol graft biopsies performed in 10 patients within 30 days post-RTx to clarify the pathologic features of early humoral-mediated graft injuries in ABO-i RTx., Methods: Pathologic findings were examined using light and electron microscopy and immunofluorescence studies for C4d. Protocol biopsies were performed within 30 days after RTx in the absence of an episode of dysfunction (creatinine concentration 1.21-1.81 mg/dL)., Results: The immunofluorescence study demonstrated C4d deposition in peritubular and glomerular capillaries. Acute glomerulitis with infiltration of mononuclear cells and neutrophils was observed in 3 patients. Furthermore, glomerulitis was accompanied by endothelial cell injuries, widening of subendothelial spaces with a double-contoured glomerular basement membrane, and mesangiolysis., Conclusion: In ABO-i RTx, early humoral-mediated graft injuries were observed in approximately 30% of patients despite normal graft function. They were characterized by C4d deposition and glomerular capillary injury. These findings suggest that renal glomeruli are the first site of graft injury by anti-A or anti-B blood type antibody with complement activation in ABO-i RTx.

The Rh (Rhesus) genes encode a family of conserved proteins that share a structural fold of 12 transmembrane helices with members of the major facilitator superfamily. Interest in this family has arisen from the discovery of Rh factor's involvement in hemolytic disease in the fetus and newborn, and of its homologs widely expressed in epithelial tissues. The Rh factor and Rh-associated glycoprotein (RhAG), with epithelial cousins RhBG and RhCG, form four subgroups conferring upon vertebrates a genealogical commonality. The past decade has heralded significant advances in understanding the phylogenetics, allelic diversity, crystal structure, and biological function of Rh proteins. This review describes recent progress on this family and the molecular insights gleaned from its gene evolution, membrane biology, and disease association. The focus is on its long evolutionary history and surprising structural conservation from prokaryotes to humans, pointing to the importance of its functional role, related to but distinct from ammonium transport proteins.

Background: Hemolytic disease of the fetus/newborn due to Jr(a) immunization is very rare and considered to be mild, and only routine obstetrical care is recommended for pregnant women sensitized to the Jr(a) antigen., Case Report: A 20-year-old nulliparous woman was referred to our hospital for perinatal management. Her indirect Coombs test was positive for anti-Jr(a) antibody (1:64). At 33 weeks' gestational age, we observed that fetal growth was mildly restricted and the peak systolic velocity of the fetal middle cerebral artery (PSV-MCA) was above the upper limit of the reference range (1.55 multiples of the median). Amniocentesis was also carried out and the DeltaOD450 value was in the lower mid-zone of the Liley curve. We continued to carefully observe the patient because we observed PSV-MCA values within 1.50-1.60 multiples of the median and no other findings of fetal anemia. She vaginally delivered a female infant weighing 2,136 g at 37 weeks' gestational age. The infant received treatment with both iron and recombinant erythropoietin without developing hyperbilirubinemia and blood transfusion., Conclusion: PSV-MCA should be monitored for the detection of fetal anemia, even in pregnant women sensitized to some antigens for which only routine obstetrical care is recommended., (Copyright (c) 2009 S. Karger AG, Basel.)

ABO-incompatible kidney transplantation is a promising strategy for enlargement of living-donor pools. In recent years, recipient desensitization by blood group antigen-specific immunoadsorption, together with rituximab and intravenous immunoglobulin, has allowed excellent graft performance after ABO-incompatible transplantation. Adopting this protocol, originally described by Tydén and coworkers, we performed four living-donor renal transplants across the ABO barrier (A1-->0, A1-->B, B-->A1, A2-->0) between July 2007 and August 2008. Recipients were aged 25-66 years, donors 49-69 years. A protocol of on-demand immunoadsorption was followed, based on serial post-transplant antibody monitoring. Substantial and sustained decrease of blood group antibody levels was achieved in all four recipients, therefore post-transplant immunoadsorption was not needed. Graft and patient survival after 4-18 months' follow-up was 100%. Current serum creatinine was 1.3-2.0 mg/dl. Two grafts showed C4d deposits in peritubular capillaries in the complete absence of typical morphological features of antibody-mediated rejection. One recipient experienced early graft dysfunction, diagnosed as Banff borderline lesion, which responded well to steroid pulse therapy. The same recipient developed de novo interstitial fibrosis/tubular atrophy and arteriolar hyalinosis, presumably the result of suboptimal control of blood pressure and/or calcineurin inhibitor therapy. Two of the four recipients developed lymphoceles necessitating surgical revision. Apart from urinary tract infection in three patients and subclinical CMV in one, no major infectious complications were reported. Notably, two stable recipients developed polyoma BK viremia without clinical or morphological manifestations of polyomavirus-associated nephropathy. The results obtained in our small series support the earlier reported high efficiency of desensitization based on antigen-specific immunoadsorption. Nevertheless, the lack of long-term data will necessitate continuous and prudent consideration of the benefits and risks of this strategy.

Numerous studies have shown that protocol biopsies have predictive power. We retrospectively examined the histologic findings and C4d staining in 89 protocol biopsies from 48 ABO-incompatible (ABO-I) transplant recipients, and compared the results with those of 250 controls from 133 ABO-compatible (ABO-C) transplant recipients given equivalent maintenance immunosuppression. Others have shown that subclinical rejection (borderline and grade I) in ABO-C grafts decreased gradually after transplantation. In our study, however, subclinical rejection in the ABO-I grafts was detected in 10%, 14% and 28% at 1, 3 and 6-12 months, respectively. At 6-12 months, mild tubular atrophy was more common in the ABO-C grafts whereas the incidence of transplant glomerulopathy did not differ between the two groups (ABO-C: 7%; ABO-I: 15%; p = 0.57). In the ABO-I transplants, risk factors for transplant glomerulopathy in univariate analysis were positive panel reactivity (relative risk, 45.0; p < 0.01) and a prior history of antibody-mediated rejection (relative risk, 17.9; p = 0.01). Furthermore, C4d deposition in the peritubular capillaries was detected in 94%, with diffuse staining in 66%. This deposition, however, was not linked to antibody-mediated rejection. We conclude that, in the ABO-I kidney transplantation setting, detection of C4d alone in protocol biopsies might not have any diagnostic or therapeutic relevance.

In a 12-year-old patient with blood group O, who had received a partial liver graft 10 years ago from his father with blood group A, the levels of anti-A-specific antibodies (Abs) were persistently undetectable after the transplantation, while the levels of anti-B-specific Abs gradually increased and attained a plateau. Peripheral blood mononuclear cells (PBMCs) from this patient were engrafted into NOD/SCID mouse in order to investigate the immune response to donor-type blood group antigens. Even after sensitization with blood group-A erythrocytes, no anti-A Abs were detected in the serum samples of the mouse that received PBMCs from the blood group-O recipient of group-A liver allograft, however, immunoglobulins specific for antigens other than the A antigens were produced. Thus, we provide a possible evidence of immune tolerance to blood group antigens in this ABO-incompatible pediatric liver transplantation.

Recent protocols have allowed successful positive crossmatch (+XM) and ABO incompatible (ABOI) kidney transplantation, although their long-term outcome is not clear. To begin to assess this issue we compared protocol biopsies performed 12 months posttransplant in 37 +XM, 24 ABOI and 198 conventional allografts. Although the majority in all three groups had only minimal histologic changes, transplant glomerulopathy (TG) was significantly increased in +XM (22% vs. 13% ABOI vs. 8% conventional, p = 0.015), and correlated with prior humoral rejection (HR) by multivariate analysis (odds ratio 17.5, p < or = 0.0001). Patients with a prior history of HR also had a significant increase in interstitial fibrosis (No HR 54% vs. HR 86%, p = 0.045). In the absence of HR no difference in histologic changes was seen between groups, although all three groups had a demonstrable mild increase in interstitial fibrosis from biopsies performed at the time of transplant. Thus, although HR is associated with an increase in TG, in its absence allograft histology is similar in +XM, ABOI and conventional allografts 1 year posttransplant.

An 8-year-old boy was diagnosed with precursor B-cell acute lymphoblastic leukemia. After intensified chemotherapy, he underwent sex-mismatched allogeneic cord blood transplantation. Postcord blood transplantation cytogenetic studies revealed engraftment failure evidenced by switching into the recipient type (XY), and, notably, various complex chromosomal aberrations in the recipient cells. Nonclonal and clonal aberrations including deletions of 7q and 20q were persistently observed. Nonetheless, the patient was clinically stable without evidence of marrow dysplasia or leukemic cells. Del(7q) and del(20q), 2 recurrent chromosomal aberrations in myeloid neoplasia, might represent underlying genomic instability in this patient, not the direct culprits of dysplasia or leukemogenesis.

Computer-based systems can detect underreported adverse events. We hypothesized that a system could be designed to detect potential or unreported cases of transfusion-related acute lung injury (TRALI). We developed and tested a computer screening system using retrospective computer blood gas data after transfusions during a 45-day period at a tertiary care academic hospital. The program identified cases of posttransfusion hypoxemia. Medical records of identified cases were reviewed to diagnose TRALI. During the 45-day period, 820 patients received 6,888 blood products. Seven cases of TRALI were diagnosed, whereas only 2 had been reported. The system had 99% accuracy and 26% positive predictive value for detecting potential TRALI. Computer screening finds more cases of TRALI than are reported voluntarily, and a prospective study using this system is feasible and needed to validate this method of detecting this important adverse transfusion reaction.

There have been no reports of severe haemolytic disease of the newborn (HDN) due to Gerbich (Ge) antibodies. Two babies with HDN due to anti-Ge3, both born to the same mother, are described. The anti-Ge appeared in the first pregnancy and was not detectable in the first trimester, the babies' reticulocyte and bilirubin values were not greatly elevated (similar to HDN due to Kell antibodies), and the anaemia in both cases was either not apparent or not severe until 2 to 4 weeks after birth. Ge antigens are found on glycophorins (GPs) C and D; GPC, like Kell, has been shown to be expressed early on erythroid progenitor cells. The maternal anti-Ge3 was shown to promote phagocytosis of Ge+ early erythroid progenitors by monocytes (similar to what has been reported with anti-K and K+ progenitor cells). Thus, anti-Ge3 may cause immune destruction of erythroid progenitors and possibly suppression of erythropoiesis (which would explain the reticulocyte and bilirubin values seen in both cases). Anti-Ge3 appears to be capable of causing severe HDN. We suggest that babies born to mothers with anti-Ge should have their haemoglobin concentrations monitored for signs of anaemia for several weeks after birth. Functional assays may prove useful.

A fatal incident of an ABO incompatible erythrocyte transfusion in a 75-year-old male patient who suffered from dilated cardiomyopathy with cardiac failure is reported. Blood group A red cells were transfused to the unintended recipient who had blood group O. The patient died 45 min after the incompatible erythrocyte transfusion. The way the incident happened remained unclear and the immunohistochemical detection of ABO incompatible erythrocytes in formaldehyde-fixed paraffin-embedded kidney, lung, liver and spleen tissue provided the only material evidence of the transfusion error.

Aim: To determine, in vitro, the effects of blood group ABO mismatching on corneal epithelial cells., Methods: Corneal epithelial cell cultures were established from 32 human cadaver donor eyes. Epithelial cells (100 microl of 4 x 10(2) cells per microl) were incubated for 4 hours with antibodies against blood group antigens A, B, and AB, with and without complement. Cell lysis was assayed by a chemiluminescent assay using Cytolite reagent. Live cells, remaining after incubation, were counted in a scintillation counter. The blood group of the donors was determined retrospectively, in a blinded manner., Results: Retrospective tracing of donor blood groups was possible for 20 donors. In all cases the blood group corresponded with that suggested by the cell lysis assay. Significant cell lysis was observed when known A group cells were incubated with anti-A and anti-AB antibody, B group cells were incubated with anti-B and AB antibody, and AB group cells were incubated with anti-AB antibody. Lysis occurred only in the presence of complement. No lysis of O group cells was observed with any of the antibodies. In all cases, lysis was observed only with neat (serum) antibody concentrations., Conclusions: Blood group ABO mismatching results in significant lysis of corneal epithelial cells. The antibody concentration required for lysis equals that found in serum. Such levels of antibody are unlikely to be achieved in tears and/or aqueous. This may offer an explanation for the conflicting reports of the studies on the effect of blood group matching on corneal grafts. The variability in the outcome may reflect the levels of antibodies gaining access to the corneal cells and not the mismatching alone.

Prenatal thrombocytopenia is a rare event and is generally due to fetal infection. In very rare cases, fetal thrombocytopenia is induced by maternal IgG directed against the fetal platelets. This alloimmunisation could lead to in utero bleeding. We now report such a case, in which fetal thrombocytopenia was complicated by a huge temporal lobe haematoma. Such a prenatal event is rare: only eight cases have been published, with only one pathologically confirmed case. Our patient is the second one in which neuropathological examination demonstrated prenatal intracerebral bleeding.

Background: Transfusion-associated graft-versus-host disease (TA-GVHD) in immunocompetent patients has still been underdiagnosed and underreported. Risk of TA-GVHD caused by transfusion practice in cardiac surgery should be appropriately recognized., Methods: The correlation of TA-GVHD with transfusion practice in cardiac surgery was analyzed from our 17-year clinical experience. We retrospectively reviewed 2,686 consecutive adult patients who underwent cardiac surgery between 1980 and 1996. Classified according to transfusion practice, 847 patients (32%) received nonirradiated fresh homologous whole blood (mean per patient, 5+/-2 units) with or without other blood components; 592 patients (22%) nonirradiated stored RBCs older than 7 days (4+/-2), and 551 patients (21%) received irradiated homologous blood including, fresh whole blood (2+/-1), RBCs (4+/-1), and PCs (8+/-3), respectively. The remaining 696 patients (25%), did not require homologous transfusion., Results: Four of 847 patients who received nonirradiated fresh homologous whole blood (< or =48 hours after donation) developed TA-GVHD. TA-GVHD did not occur in other patients., Conclusions: Our local experience demonstrates the incidence of TA-GVHD in patients who received fresh homologous whole blood in cardiac surgery was much higher, compared with previous reports. This result suggests that the frequency of TA-GVHD is nearly similar to the value calculated from the proportion of HLA haplotypes in the population.

A 41-yr-old patient with non-insulin-dependent diabetes mellitus (NIDDM), before and after ABO-incompatible renal transplant, is reviewed using serial protocol biopsy. Although she recovered from delayed hyperacute rejection (DHAR) immediately post-transplantation, her graft function deteriorated gradually. A mild acute transplant glomerulitis, noted at the 155th day post-transplantation, progressed to pronounced chronic transplant glomerulopathy over 5 yr. In the specimen of the last biopsy, at 5 yr post-transplantation, glomeruli demonstrated an exudative hyaline lesion, which was characteristic of diabetic nephropathy in addition to chronic transplant glomerulopathy. Therefore, we made a diagnosis of this glomerular lesion as chronic transplant glomerulopathy complicated by diabetic glomerulopathy. Considering the result of this case, the protocol biopsy is a useful procedure to diagnose an accurate cause of graft dysfunction in individual cases. It is concluded that the protocol biopsy is apparently useful for the detection of various pathological processes occurring in allograft and may contribute to a strategy for improvement of graft survival.

Two cases of alleged dowry deaths are presented from Haryana State, India. In each case a young lady died after receiving burn injuries. Forensic examination unveiled the mysteries of both deaths and helped in apprehending and prosecuting the culprits. Case 1, allegedly a dowry death, proved to be an accidental burning and Case 2, stated to be a suicidal death, was proved to be homicidal.

To provide evidence of transfusion of incompatible blood in the ABO system in forensic medicine also antigens A and B of the donor must be detected in the body of the recipient. The author presents his own experience with evidence of incompatible red blood cells with group properties A, B or AB by the indirect immunoperoxidase method in paraffin section of the recipient's tissues. A positive reaction makes it possible to detect also occasional incompatible erythrocytes in particular in the periphery. An advantage is in particular the high sensitivity of the method, and as paraffin tissue blocks are used, also the possibility of retrospective evaluation.

Hemolytic transfusion reactions (HTR) are characterized by fever, shock, organ system failure, intravascular coagulation, and possibly death. The same findings may be associated with sepsis. Neutrophils have been implicated in the pathogenesis of HTR, although a mechanism for neutrophil activation has not been shown. In addition, the possible role that cytokines may play in HTR has not been investigated. We show that interleukin-8 (IL-8), a cytokine with chemotactic and neutrophil-activation properties, is produced in whole blood following addition of ABO-incompatible red blood cells, in a dose- and time-dependent manner related to the degree of hemolysis, and is inhibited by inactivation of complement. IL-8 production is accompanied by increased gene expression in the buffy coat. This observation has implications for the understanding of the pathogenesis of and for the treatment of HTR.

In electron microscopic observations on the villous cytotrophoblast in pathologic human placentas we find, besides a general increase of the amount of Langhans cells, significant ultrastructural differences according to the different diseases in pregnancy. Diabetes mellitus: the most striking observations are small, extremely electron dense mitochondria and a lot of intracellular filaments in a hydropic cytoplasm. Rh-incompatibility: according to the stage of placental damage the Langhans cells show a different structure. In light cases we find hydrolic cells with normal mitochondria as well as swollen ones. The plasmalemm shows a lot of foldings and dentations with the syncytium. In serious cases of rh-incompatibility the Langhans cells cover the trophoblastic basal membrane completely. Their electron density is even higher than that of the syncytium. Characteristic lysosomes appear. In the most serious cases the syncytium is completely destroyed and maximal hydropic Langhans cells cover the villi. EPH-gestosis: the Langhans cells show different phases of differentiation, but no other characteristic criteria. The importance of the Langhans cells for the regeneration of the syncytotrophoblast is discussed. Mitochondria and rough endoplasmic reticulum are obviously not formed in the syncytium but they must be regenerated by taking up Langhans cells by syncytial fusion.

Determination of fetal red blood cell Kell antigen is possible on fetal red blood cells obtained at 10 weeks of gestation by chorionic biopsy and may contribute to the management of severe Kell-hemolytic disease.

Monofucosyl type 1 chain A (type 1 Aa) and difucosyl type 1 chain A (ALeb), but not other types of A antigens, have been detected by application of carrier type-specific monoclonal anti-A antibodies (AH21 and HH3) in colonic tumors of blood group O individuals. An A-transferase activity (UDP-Gal-NAc:H-alpha-GalNAc transferase) was demonstrated in the extract of one of the O tumors expressing A antigen. The incidence of A antigen expression in O tumors was found to be two out of 15 cases, based on TLC immunostaining of glycolipid extracts, and five out of 50 cases, based on immunofluorescent staining of tumors with AH21 and HH3 antibodies.

The role of ABO blood group compatibility on graft survival when transplantation is performed between closely related animal species is uncertain. Heart transplants (in the neck) were performed between donor vervet monkeys and recipient baboons; no immunosuppressive therapy was given. Survival in ABO-compatible pairs (group 1, n = 9) was for a mean of 10.3 (+/- 5.2) days, which was not significantly different from that in ABO-incompatible pairs (group 2, n = 9: mean survival 7.3 +/- 5.6 days). In group 2, however, three hearts were rejected hyperacutely within 60 minutes, whereas in group 1 only one heart was rejected within 24 hours (not significant). Preformed anti-vervet monkey antibody was present in only one of 18 baboons, but developed in eight others. ABO-specific antibodies were present in all nine group 2 baboons and increased in titer in six cases. Histopathologic features of vascular (humoral) rejection, sometimes associated with cellular infiltration, were seen in a majority of hearts in both groups. Though the number of animals in this study was small, ABO-incompatibility would not appear to be a major factor in cardiac xenograft survival when transplantation is performed between closely related primate species, though early hyperacute rejection would seem more likely to occur when blood group incompatibility is present.

A patient with blood group O died 8 h after an accidental transfusion of one unit of A1 erythrocytes. The admixture of group A red cells was not detected during postmortem serology. Paraffin-embedded autopsy material was studied by the indirect immunoperoxidase technique using monoclonal antibodies. Group A red cells were easily identified as circulating agglutinates in the larger vessels, in the capillary vessels of all organs examined, and as closely packed cell aggregations in the sinuses of the spleen. However, there was no clear evidence of erythrophagocytosis in the spleen or in liver.

This is a review of the obstetric histories of women with Kell antibodies who delivered between 1964 and 1983. The majority of women with Anti-Kell in their sera have Kell negative husbands and have been sensitised by blood transfusion. In only six mothers was antibody formation the result of isoimmunisation and all cases where the baby was known to be Kell positive ended in fetal death. Amniocentesis is not helpful in managing these cases, and at times might be misleading, so that other techniques, such as ultrasound, might be more helpful. A review of the literature confirms that Kell isoimmunisation is rare, but that when it does occur the outlook for the baby is poor.