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Maedica Dec 2021RhD alloimmunization remains a severe problem worldwide, but its management has been revolutionized by two important discoveries: the possibility to establish fetal Rh...
RhD alloimmunization remains a severe problem worldwide, but its management has been revolutionized by two important discoveries: the possibility to establish fetal Rh genotype non-invasively by using a maternal blood sample, and using of Doppler velocimetry to monitor early signs of affected fetuses. We performed a literature review by searching PubMed for relevant information about diagnosis, prognosis, and management of secondary affected Rh alloimmunized pregnancies. The risk to develop fetal anemia and hydrops seems to increase with increasing concentrations of Rh antibodies, and studies show it is higher for subsequent pregnancies. Individuals presenting the DEL phenotype with the types 1, 2 or 3 can be considered RhD positive and anti-D immune globulin is not indicated. Medical algorithm involves previous pregnancy history together with serum parameters. Follow-up in a department of maternal fetal medicine is desired and encouraged in these cases. Depending on the severity and woman's previous pregnancy history, especially condition prior to 24 weeks of gestation, several therapies such as plasmaphereses, intravenous immune globulin or intrauterine transfusions can be conducted. Intrauterine transfusions have a better prognosis when performed earlier and on fetuses without hydrops. Although the incidence of hemolytic disease of the fetus and newborn has decreased and is no longer a major cause of perinatal mortality, vigilance is still required. There is a strong argument for reunite the management of these cases in dedicated maternal fetal medicine centers that perform invasive procedures in order to improve knowledge, gain skills and enhance clinical management.
PubMed: 35261671
DOI: 10.26574/maedica.2020.16.4.681 -
American Journal of Transplantation :... May 2018Alloimmunization occurs during pregnancy when tissue antigens derived from the fetus and/or placenta prime maternal immune cells to divide and differentiate. For many... (Review)
Review
Alloimmunization occurs during pregnancy when tissue antigens derived from the fetus and/or placenta prime maternal immune cells to divide and differentiate. For many women, the result of pregnancy alloimmunization is the formation of anti-HLA antibody that can endure for decades and preclude transplantation by limiting donor compatibility. Pregnancy alloimmunization may also generate memory B cells that can rapidly produce anti-HLA antibody after transplantation as well as pathogenic memory T cells, which pose a threat to graft survival. However, emerging data suggest that pregnancy also programs the differentiation of anergic, dysfunctional, and regulatory T cell populations, which may not mediate accelerated graft rejection. Hence, some of the immune mechanisms responsible for maternal immunologic tolerance of the fetus may persist into postpartum life and affect the response to an allograft. This review discusses these emerging data as well as the persistent knowledge gaps that affect women at multiple stages of their transplant care.
Topics: Female; Fetus; Graft Rejection; HLA Antigens; Humans; Immunologic Memory; Isoantibodies; Isoantigens; Organ Transplantation; Pregnancy; Pregnancy Complications; T-Lymphocytes, Regulatory
PubMed: 29369525
DOI: 10.1111/ajt.14673 -
Immunity May 2016The ultimate outcome of alloreactivity versus tolerance following transplantation is potently influenced by the constellation of cosignaling molecules expressed by... (Review)
Review
The ultimate outcome of alloreactivity versus tolerance following transplantation is potently influenced by the constellation of cosignaling molecules expressed by immune cells during priming with alloantigen, and the net sum of costimulatory and coinhibitory signals transmitted via ligation of these molecules. Intense investigation over the last two decades has yielded a detailed understanding of the kinetics, cellular distribution, and intracellular signaling networks of cosignaling molecules such as the CD28, TNF, and TIM families of receptors in alloimmunity. More recent work has better defined the cellular and molecular mechanisms by which engagement of cosignaling networks serve to either dampen or augment alloimmunity. These findings will likely aid in the rational development of novel immunomodulatory strategies to prolong graft survival and improve outcomes following transplantation.
Topics: Animals; CD28 Antigens; Cell Cycle Proteins; Graft Rejection; Humans; Immunotherapy; Intracellular Signaling Peptides and Proteins; Lymphocyte Activation; Organ Transplantation; Receptor Cross-Talk; Signal Transduction; T-Lymphocytes; Transplantation Immunology; Transplantation Tolerance; Transplantation, Homologous; Tumor Necrosis Factor-alpha
PubMed: 27192567
DOI: 10.1016/j.immuni.2016.04.012 -
Nature Reviews. Nephrology Aug 2016The development of post-transplantation antibodies against non-HLA autoantigens is associated with rejection and decreased long-term graft survival. Although our... (Review)
Review
The development of post-transplantation antibodies against non-HLA autoantigens is associated with rejection and decreased long-term graft survival. Although our knowledge of non-HLA antibodies is incomplete, compelling experimental and clinical findings demonstrate that antibodies directed against autoantigens such as angiotensin type 1 receptor, perlecan and collagen, contribute to the process of antibody-mediated acute and chronic rejection. The mechanisms that underlie the production of autoantibodies in the setting of organ transplantation is an important area of ongoing investigation. Ischaemia-reperfusion injury, surgical trauma and/or alloimmune responses can result in the release of organ-derived autoantigens (such as soluble antigens, extracellular vesicles or apoptotic bodies) that are presented to B cells in the context of the transplant recipient's antigen presenting cells and stimulate autoantibody production. Type 17 T helper cells orchestrate autoantibody production by supporting the proliferation and maturation of autoreactive B cells within ectopic tertiary lymphoid tissue. Conversely, autoantibody-mediated graft damage can trigger alloimmunity and the development of donor-specific HLA antibodies that can act in synergy to promote allograft rejection. Identification of the immunologic phenotypes of transplant recipients at risk of non-HLA antibody-mediated rejection, and the development of targeted therapies to treat such rejection, are sorely needed to improve both graft and patient survival.
Topics: Autoantibodies; Autoantigens; Collagen; Heparan Sulfate Proteoglycans; Humans; Kidney Transplantation; Receptor, Angiotensin, Type 1; Transplantation Immunology
PubMed: 27345243
DOI: 10.1038/nrneph.2016.88 -
Journal of Immunological Methods Feb 2022Antibody-mediated rejection is a major cause of graft failure in organ transplantation. For this reason, B cell responses are of particular interest to transplantation...
Antibody-mediated rejection is a major cause of graft failure in organ transplantation. For this reason, B cell responses are of particular interest to transplantation research. Rats are important model organisms for transplant studies, but B cell alloimmune assays and B cell subset markers are poorly established in rats. We alloimmunized rats by donor blood injection using the high responder rat strain combination Brown Norway (donor) and Lewis (recipient) rats. Using splenocytes from alloimmunized and control rats, we established assays to assess allospecific B cell proliferation and the capacity to generate allospecific B memory cells and alloantibody-secreting cells after antigenic rechallenge in vitro using a mixed lymphocyte reaction. Furthermore, we defined a simple gating and sorting strategy for pre- and post-germinal center follicular B cells, as well as non-switched and switched plasmablasts. Our protocols for assessing B cell alloresponses and B cell subsets in rats may help to accelerate research into the role of B cells and manipulation of humoral alloresponses in transplant research.
Topics: Animals; B-Lymphocytes; Cell Proliferation; Cells, Cultured; Graft Rejection; Immunity, Humoral; Immunologic Memory; Isoantibodies; Isoantigens; Lymphocyte Activation; Male; Memory B Cells; Phenotype; Rats, Inbred BN; Rats, Inbred Lew; Rats
PubMed: 34971633
DOI: 10.1016/j.jim.2021.113212 -
Transfusion Medicine Reviews Jan 2023RBC alloimmunization remains a significant barrier to ongoing transfusion therapy leading to morbidity, and in extreme cases mortality, due to delayed or insufficient... (Review)
Review
RBC alloimmunization remains a significant barrier to ongoing transfusion therapy leading to morbidity, and in extreme cases mortality, due to delayed or insufficient units of compatible RBCs. In addition, the monitoring and characterization of alloantibodies, often with multiple specificities in a single patient, consumes substantial health care resources. Extended phenotypic matching has mitigated, but not eliminated, RBC alloimmunization and is only logistically available for specialized populations. Thus, RBC alloimmunization remains a substantial problem. In recent decades it has become clear that mechanisms of RBC alloimmunization are distinct from other antigens and lack of mechanistic understanding likely contributes to the fact that there are no approved interventions to prevent RBC alloimmunization from transfusion. The combination of human studies and murine modeling have identified several key factors in RBC alloimmunization. In both humans and mice, immunogenicity is a function of alloantigen copy number on RBCs. Murine studies have further shown that copy number not only changes rates of immunization but the mechanisms of antibody formation. This review summarizes the current understanding of quantitative and qualitative effects of alloantigen copy number on RBC alloimmunization.
Topics: Humans; Mice; Animals; Isoantigens; DNA Copy Number Variations; Erythrocytes; Blood Transfusion; Isoantibodies
PubMed: 36725483
DOI: 10.1016/j.tmrv.2022.12.009 -
Asian Journal of Transfusion Science 2020Alloimmunization is an immune response against foreign antigens which introduced into the body through transfusion, pregnancy, or transplantation. This phenomenon is a... (Review)
Review
BACKGROUND
Alloimmunization is an immune response against foreign antigens which introduced into the body through transfusion, pregnancy, or transplantation. This phenomenon is a big challenge in patients, which require regular transfusions. In the current study, we tried to have a comprehensive review on the status of alloimmunization in Iran. For this purpose, we searched for papers investigating alloimmunization in transfusion-dependent patients and also in patients with no regular transfusions who are candidate for surgery or who need blood.
METHODS
We searched PubMed, Google Scholar, SID, and MAGIRAN databases using the following keywords: "blood transfusion," "alloimmunization," "alloantibodies," "irregular antibodies," "red cell antibodies," and "Iran." No limitation for the date of publication and language of the papers was defined. All the identified records were then screened for the relevance and duplication.
RESULTS
A total of 22 papers were included in this study. All of the studies were conducted from 1999 to 2016 and providing alloimmunization data from different cities all over of Iran. In general, the results showed that the most prevalent alloantibodies are anti-Kell (anti-K antigen) and anti-Rh system, mainly anti-E, anti-D, anti-C, and anti-c.
CONCLUSION
Anti-Kell and anti-Rh antibodies are the most prevalent antibodies responsible for alloimmunization in Iranian population.
PubMed: 33162697
DOI: 10.4103/ajts.AJTS_137_17 -
Transfusion and Apheresis Science :... Feb 2020Non-invasive fetal HPA-1a typing is a valuable tool to identify the pregnancies at risk of fetal and neonatal alloimmune thrombocytopenia (FNAIT). At present, prenatal... (Review)
Review
Non-invasive fetal HPA-1a typing is a valuable tool to identify the pregnancies at risk of fetal and neonatal alloimmune thrombocytopenia (FNAIT). At present, prenatal determination of the fetus HPA-1a type is performed for diagnostic purposes in pregnancies of HPA-1 alloimmunized women with history of a previous fetus or child with FNAIT. Different approaches have been used to determine the fetal HPA-1a genotype from cell-free fetal DNA (cffDNA) in the mother's plasma, mainly based on real-time PCR. Due to the single nucleotide polymorphism (SNP) between the HPA-1a and HPA-1b allelic sequences, a robust and accurate detection of the fetal genotype is challenging, and the sensitivity of most assays is still limited early in pregnancy. Nowadays, the availability of technologies such as next generation sequencing (NGS) or digital PCR offers unprecedented possibilities of analyzing cell-free DNA (cfDNA)-amplified sequences with very high coverage and high sensitivity. In addition, other interesting approaches using variant sequence enrichment strategies have been recently described. In particular, coamplification at lower denaturation temperature PCR (COLD-PCR) offers a simple and sensitive strategy for noninvasive fetal HPA-1 typing. These novel approaches are explained in more detail in this review. Despite no population-based FNAIT screening programs have so far been implemented, the perspectives in terms of treatment and prevention are changing and less costly high-throughput maternal HPA-1a typing methods have been developed. Altogether, this may lead to the implementation of fetal HPA-1a typing with a broader scope in the future, playing a critical role within FNAIT screening programs.
Topics: Antigens, Human Platelet; Female; Fetus; Humans; Integrin beta3; Pregnancy; Thrombocytopenia, Neonatal Alloimmune
PubMed: 31953107
DOI: 10.1016/j.transci.2019.102708 -
Journal of Clinical Medicine May 2020: Incompatibilities between the mother and unborn baby can cause complications that must be identified early to initiate the appropriate treatment. For example, neonatal... (Review)
Review
: Incompatibilities between the mother and unborn baby can cause complications that must be identified early to initiate the appropriate treatment. For example, neonatal alloimmune thrombocytopenia (NAIT), neonatal alloimmune neutropenia (NAIN), and morbus hemolyticus neonatorum affect children worldwide. : This literature review aims to depict the similarities and differences between these three disorders from a clinical and mechanistic point of view. : The current literature review entailed conducting a systematic search to locate articles on the three conditions. Different electronic databases, including PsycINFO, PubMed, Web of Science, and CINAHL, were searched using the search terms "neonatal alloimmune thrombocytopenia", "neonatal alloimmune neutropenia", "morbus hemolyticus neonatorum", "NAIT", "FNAIT", "fetal", "NAIN", and "hemolytic disease of the newborn". : This review shows that these three diseases are caused by incompatibilities between the maternal and fetal immune systems. Furthermore, these conditions can lead to severe complications that hinder fetal development and cause death if not well managed. Discussion: The current literature review shows that NAIT, NAIN, and morbus hemolyticus neonatorum are rare conditions that occur when the mother produces antibodies against the fetal immune system. Thus, there is a need for the early detection of these conditions to initiate appropriate treatment before the child experiences adverse effects. : The development of NAIT, NAIN, and morbus hemolyticus neonatorum is linked to the production of antibodies against the fetal immune system and fetal antigens. Further studies are required to determine potential interventions to reduce the risk of developing these three conditions.
PubMed: 32422924
DOI: 10.3390/jcm9051470 -
Journal of Immunology (Baltimore, Md. :... May 2016Corneal transplantation is one of the most prevalent and successful forms of solid tissue transplantation. Despite favorable outcomes, immune-mediated graft rejection... (Review)
Review
Corneal transplantation is one of the most prevalent and successful forms of solid tissue transplantation. Despite favorable outcomes, immune-mediated graft rejection remains the major cause of corneal allograft failure. Although low-risk graft recipients with uninflamed graft beds enjoy a success rate ∼90%, the rejection rates in inflamed graft beds or high-risk recipients often exceed 50%, despite maximal immune suppression. In this review, we discuss the critical facets of corneal alloimmunity, including immune and angiogenic privilege, mechanisms of allosensitization, cellular and molecular mediators of graft rejection, and allotolerance induction.
Topics: Angiogenesis Inducing Agents; Animals; Corneal Transplantation; Graft Rejection; Humans; Immune Tolerance; Immunity, Cellular; Immunosuppression Therapy; Inflammation; Isoantigens; Risk; Transplantation Immunology
PubMed: 27183635
DOI: 10.4049/jimmunol.1600251