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Journal of AAPOS : the Official... Jun 2024Hyphema is rarely seen in neonates. Although most cases are secondary to instrument-assisted delivery, neonatal hyphema can occur spontaneously or result from an...
Hyphema is rarely seen in neonates. Although most cases are secondary to instrument-assisted delivery, neonatal hyphema can occur spontaneously or result from an underlying coagulopathy. We report the case of an infant who was born with unilateral hyphema and was subsequently found to have gestational alloimmune liver disease-a condition where maternal antibodies attack the infant's liver, leading to a hypocoagulable state. Our patient was treated with topical prednisolone and cyclopentolate/phenylephrine, with subsequent resolution of the hyphema.
PubMed: 38876158
DOI: 10.1016/j.jaapos.2024.103957 -
Cureus May 2024This review paper provides an overview of the risk factors and laboratory testing for red blood cell (RBC) alloimmunization in pregnancy. RBC alloimmunization is a... (Review)
Review
This review paper provides an overview of the risk factors and laboratory testing for red blood cell (RBC) alloimmunization in pregnancy. RBC alloimmunization is a significant medical issue that can cause haemolytic disease of the fetus and newborn (HDFN), leading to neonatal morbidity and mortality. Current HDFN prophylaxis targets only Rhesus D (RhD) alloimmunization, with no effective measures to prevent alloimmunization to other RBC antigen groups. Several factors can increase the risk of developing RBC alloimmunization during pregnancy, including fetomaternal haemorrhage, RBC and maternal genetic status, and previous transfusions. Identifying these risk factors is essential to execute the appropriate management strategies to minimize the risk of HDFN. The review also discusses the laboratory methods and overview of pregnancy management. The paper highlights the importance of identifying and managing the risk factors for RBC alloimmunization in pregnancy to minimize the risk of HDFN and improve neonatal outcomes.
PubMed: 38868295
DOI: 10.7759/cureus.60158 -
Transfusion Medicine and Hemotherapy :... Jun 2024Human leukocyte antigen (HLA)-DPB1 mismatches during hematopoietic stem cell transplantation (HSCT) with an unrelated donor result in an increased risk for the...
INTRODUCTION
Human leukocyte antigen (HLA)-DPB1 mismatches during hematopoietic stem cell transplantation (HSCT) with an unrelated donor result in an increased risk for the development of graft-versus-host disease (GvHD). The number of CD8 T-cell epitopes available for indirect allorecognition as predicted by the PIRCHE algorithm has been shown to be associated with GvHD development. As a proof of principle, PIRCHE-I predictions for HLA-DPB1 mismatches were validated in vitro and in vivo.
METHODS
PIRCHE-I analysis was performed to identify HLA-DPB1-derived peptides that could theoretically bind to HLA-A*02:01. PIRCHE-I predictions for HLA-DPB1 mismatches were validated in vitro by investigating binding affinities of HLA-DPB1-derived peptides to the HLA-A*02:01 in a competition-based binding assay. To investigate the capacity of HLA-DPB1-derived peptides to elicit a T-cell response in vivo, mice were immunized with these peptides. T-cell alloreactivity was subsequently evaluated using an interferon-gamma ELISpot assay.
RESULTS
The PIRCHE-I algorithm identified five HLA-DPB1-derived peptides (RMCRHNYEL, YIYNREEFV, YIYNREELV, YIYNREEYA, and YIYNRQEYA) to be presented by HLA-A*02:01. Binding of these peptides to HLA-A*02:01 was confirmed in a competition-based peptide binding assay, all showing an IC value of 21 μm or lower. The peptides elicited an interferon-gamma response in vivo.
CONCLUSION
Our results indicate that the PIRCHE-I algorithm can identify potential immunogenic HLA-DPB1-derived peptides present in recipients of an HLA-DPB1-mismatched donor. These combined in vitro and in vivo observations strengthen the validity of the PIRCHE-I algorithm to identify HLA-DPB1 mismatch-related GvHD development upon HSCT.
PubMed: 38867810
DOI: 10.1159/000537789 -
Transplantation Jun 2024The observation decades ago that inflammatory injuries because of an alloimmune response might be present even in the absence of concomitant clinical impairment in...
The observation decades ago that inflammatory injuries because of an alloimmune response might be present even in the absence of concomitant clinical impairment in allograft function conduced to the later definition of subclinical rejection. Many studies have investigated the different subclinical rejections defined according to the Banff classification (subclinical T cell-mediated rejection and antibody-mediated rejection), overall concluding that these episodes worsened long-term allograft function and survival. These observations led several transplant teams to perform systematic protocolar biopsies to anticipate treatment of rejection episodes and possibly prevent allograft loss. Paradoxically, the invasive characteristics and associated logistics of such procedures paved the way to investigate noninvasive biomarkers (urine and blood) of subclinical rejection. Among them, several research teams proposed a blood gene signature developed from cohort studies, most of which achieved excellent predictive values for the occurrence of subclinical rejection, mainly antibody-mediated rejection. Interestingly, although all identified genes relate to immune subsets and pathways involved in rejection pathophysiology, very few transcripts are shared among these sets of genes, highlighting the heterogenicity of such episodes and the difficult but mandatory need for external validation of such tools. Beyond this, their application and value in clinical practice remain to be definitively demonstrated in both biopsy avoidance and prevention of clinical rejection episodes. Their combination with other biomarkers, either epidemiological or biological, could contribute to a more accurate picture of a patient's risk of rejection and guide clinicians in the follow-up of kidney transplant recipients.
PubMed: 38867352
DOI: 10.1097/TP.0000000000005105 -
Journal of Pediatric Hematology/oncology Jul 2024Sickle cell disease (SCD) is a common hereditary hemoglobin disorder worldwide. One of the main treatments for patients with SCD is the requirement for blood...
OBJECTIVE
Sickle cell disease (SCD) is a common hereditary hemoglobin disorder worldwide. One of the main treatments for patients with SCD is the requirement for blood transfusions. Posttransfusion alloimmunization with red blood cell (RBC) antigens continues to be a major risk factor for SCD. The objective of this study was to determine the rate, nature, and risk factors of red cell alloimmunization among pediatric patients with SCD in our center and compare our results with published reports from Saudia Arabia SA, regional countries, and some international countries.
MATERIALS AND METHODS
A retrospective chart review of patients with SCD at King Abdulaziz Medical City-Jeddah, between 2008 and 2019 was performed. Demographic characteristics and transfusion histories were recorded. Blood samples were analyzed for alloimmunization using immunohematologic techniques.
RESULTS
In total, 121 patients were analyzed. Alloantibodies were detected in 21 patients (17.4%) and were mostly single in 15 patients (71.4%), anti-K (23.7%), anti-E (19.0%), and anti-S (9.5%). The other 6 patients (28.6%) had multiple alloantibodies, especially the combination of anti-C and anti-K (9.5%) and the combination of anti-C and anti-E (9.5%). Alloantibody levels were significantly higher in patients with frequent hospital admissions (>5 times annually), those who had an exchange blood transfusion, those younger than 3 years old, and those who received a larger number of blood units ( P ≤0.05).
CONCLUSION
The rate of RBC alloimmunization is determined and considered relatively low compared with that in other nations. Matching for extended RBC antigens to include ABO, RH (D, C, c, E, e), K, Fy a , Fy b , Jk a , and Jk b antigens in the screening panel for donors and recipients is highly recommended to ensure better transfusion practices and avoid transfusion-related complications.
Topics: Humans; Anemia, Sickle Cell; Saudi Arabia; Child; Male; Retrospective Studies; Female; Isoantibodies; Child, Preschool; Adolescent; Prevalence; Erythrocytes; Infant; Blood Group Incompatibility; Blood Group Antigens; Risk Factors; Blood Transfusion
PubMed: 38857199
DOI: 10.1097/MPH.0000000000002889 -
Case Reports in Women's Health Jun 2024Fetal hemolysis is caused by maternal antibodies that cross the placenta. Anti-M antibodies can rarely cause severe forms of alloimmunization in the fetus and newborn....
Fetal hemolysis is caused by maternal antibodies that cross the placenta. Anti-M antibodies can rarely cause severe forms of alloimmunization in the fetus and newborn. We present a case of severe anti-M alloimmunization requiring a total of 8 intrauterine transfusions, in a patient with a prior poor obstetrical history. A 35-year-old Iranian pregnant woman with a prior obstetrical history of one abortion and two stillbirths was found to have had anti-M antibody titers 1:8 and accompanying elevated middle cerebral artery peak systolic velocity (MCA-PSV) of 1.9 MoM suggestive of severe fetal anemia at 17 weeks of gestation. Persistently elevated fetal MCA-PSV was noted despite intraperitoneal transfusion at 17, 19, and 22 weeks. Fetal blood sampling at 27 weeks confirmed severe fetal anemia (3 g/dL), which required additional intravascular and intraperitoneal blood transfusion. At 37 weeks, elective cesarean section was performed. Neonatal hemoglobin immediately after delivery was 10.1 g/dL. In addition to standard supportive care, the neonate required two additional transfusions and remained in the neonatal intensive care unit (NICU) for 23 days. Anti-M antibodies are a rare cause of severe alloimmunization. We present a case in order to improve management.
PubMed: 38855719
DOI: 10.1016/j.crwh.2024.e00620 -
The Veterinary Clinics of North... Jun 2024Alloimmune disorders occur in foals when pregnant mares produce antibodies against antigens on the foal's cells or tissues, and concentrate them within colostrum. Once... (Review)
Review
Alloimmune disorders occur in foals when pregnant mares produce antibodies against antigens on the foal's cells or tissues, and concentrate them within colostrum. Once foals nurse and absorb colostral antibodies, they can develop hematologic or cutaneous manifestations that can occur individually or in combination. These include neonatal isoerythrolysis, a hemolytic anemia directed against factors on the foal's erythrocytes, alloimmune thrombocytopenia when the antibodies are directed against platelet antigens, alloimmune neutropenia when they are directed against neutrophil antigens, and a combination of suspected alloimmune ulcerative dermatitis, neutropenia and thrombocytopenia. Foals can also develop neutrophilic dermatitis which is suspected to be alloimmune.
PubMed: 38852013
DOI: 10.1016/j.cveq.2024.05.001 -
Cell Metabolism Jun 2024Glucagon-like peptide-1 receptor (GLP-1R) is a key regulator of glucose metabolism known to be expressed by pancreatic β cells. We herein investigated the role of...
Glucagon-like peptide-1 receptor (GLP-1R) is a key regulator of glucose metabolism known to be expressed by pancreatic β cells. We herein investigated the role of GLP-1R on T lymphocytes during immune response. Our data showed that a subset of T lymphocytes expresses GLP-1R, which is upregulated during alloimmune response, similarly to PD-1. When mice received islet or cardiac allotransplantation, an expansion of GLP-1R T cells occurred in the spleen and was found to infiltrate the graft. Additional single-cell RNA sequencing (scRNA-seq) analysis conducted on GLP-1R and GLP-1R CD3 T cells unveiled the existence of molecular and functional dissimilarities between both subpopulations, as the GLP-1R are mainly composed of exhausted CD8 T cells. GLP-1R acts as a T cell-negative costimulatory molecule, and GLP-1R signaling prolongs allograft survival, mitigates alloimmune response, and reduces T lymphocyte graft infiltration. Notably, GLP-1R antagonism triggered anti-tumor immunity when tested in a preclinical mouse model of colorectal cancer.
Topics: Animals; Glucagon-Like Peptide-1 Receptor; Mice; Mice, Inbred C57BL; Islets of Langerhans Transplantation; T-Lymphocytes; Male; Heart Transplantation; Mice, Inbred BALB C; CD8-Positive T-Lymphocytes; Graft Survival
PubMed: 38838642
DOI: 10.1016/j.cmet.2024.05.001