Kell alloimmunization in pregnancy

BACKGROUND: Kell null (K0 ) individuals can produce anti-Ku, an antibody against many epitopes in the Kell glycoprotein, after transfusion and/or pregnancy. Since sensitized K0 patients are rare, little is known about anti-Ku clinical relevance and in particular about its association to hemolytic disease of the fetus and newborn. CASE REPORT: This work describes a case of neonatal hyperbilirubinemia due to immune-mediated erythrocyte destruction by an alloantibody directed against the Kell glycoprotein...

Irregular antibodies are produced by alloimmunization because of pregnancies or blood transfusions. They are called "irregular" due to target erythrocyte antigens from "rare blood systems," those different from the ABO system. Irregular antibodies have been widely investigated in immunohematology since their presence in blood donors may lead to difficulties in blood typing and in blood cross-matching, or to induce hemolytic transfusion reactions. Nevertheless, their incidence and participation in the physiopathology of autoimmune diseases have not been thoroughly studied...

OBJECTIVE: The goals of this study were to determine the prevalence and relative frequencies of red blood cell antibodies in a Canadian prenatal population, and to evaluate the fetal and neonatal outcomes of affected pregnancies. METHODS: We conducted a retrospective review of pregnancies that screened positive for red cell antibodies between 2006 and 2010. The following antibodies were included: anti-D, -C, -c, -E, -e, -Fya, -Fyb, -Jka, and-Jkb. Cases of anti-Kell as the sole antibody were excluded...

The Kell and Kx blood group systems are expressed as covalently linked molecules on red blood cells (RBCs). The Kell blood group system is very polymorphic, with 35 antigens assigned to the system. The expression of Kell glycoprotein on RBCs is not critical to the erythrocyte function. However, the expression of KX is critical to normal morphology, and null mutations are associated with the McLeod neuroacanthocytosis syndrome. The immunogenicity of the K anigen is second only to the D anigen, and alloantibodies to Kell anigens can cause transfusion reactions and hemolytic disease of the fetus and newborn...

BACKGROUND: KEL1 alloimmunization is a major cause of hemolytic disease of the fetus and newborn (HDFN). While select countries have guidelines for preventing transfusion-associated KEL1 alloimmunization, the United States does not. Beth Israel Deaconess Medical Center instituted a policy in April 2009 whereby women not more than 50 years of age on the obstetric service were transfused KEL1-negative red blood cells (RBCs). We sought to determine compliance and impact for prevention of KEL1 alloimmunization and HDFN...

BACKGROUND: Although the risks of adverse pregnancy outcomes associated with anti-D antibodies are well-recognized, much less is known concerning alloimmunization with other red blood cell antibodies detected during routine maternal screening. To date, most reports of adverse pregnancy outcomes associated with non-anti-D antibodies have been from small case studies. The aim of this study was to examine the associations of maternal alloimmunization with specific red blood cell antibodies and the risks of preterm birth and stillbirth in the Swedish population...

Exposure to nonself red blood cell (RBC) antigens, either from transfusion or pregnancy, may result in alloimmunization and incompatible RBC clearance. First described as a pregnancy complication 80 years ago, hemolytic disease of the fetus and newborn (HDFN) is caused by alloimmunization to paternally derived RBC antigens. Despite the morbidity/mortality of HDFN, women at risk for RBC alloimmunization have few therapeutic options. Given that alloantibodies to antigens in the KEL family are among the most clinically significant, we developed a murine model with RBC-specific expression of the human KEL antigen to evaluate the impact of maternal/fetal KEL incompatibility...

BACKGROUND: Red blood cell (RBC) alloantibodies to nonself antigens may develop after transfusion or pregnancy, leading to morbidity and mortality in the form of hemolytic transfusion reactions or hemolytic disease of the newborn. A better understanding of the mechanisms of RBC alloantibody induction, or strategies to mitigate the consequences of such antibodies, may ultimately improve transfusion safety. However, such studies are inherently difficult in humans. STUDY DESIGN AND METHODS: We recently generated transgenic mice with RBC-specific expression of the human KEL glycoprotein, specifically the KEL2 or KEL1 antigens...

OBJECTIVE: To determine the incidence of clinically significant anti-erythrocyte alloantibodies in pregnant women, which can cause severe hemolytic disease in the fetus and newborn. DESIGN: Retrospective-prospecitive clinical study. SETTING: Transfusion Department, University Hospital Olomouc, Department of Obstetrics and Gynecology, University Hospital Olomouc. SUBJECT AND METHOD: Between the years 2000-2011, a total of 45 435 pregnant women were examined at the Department of Transfusion Medicine at the University Hospital Olomouc...

OBJECTIVES: To evaluate and compare perinatal outcome after intrauterine transfusions (IUT) performed before and after 20 weeks of gestation. To analyse contributing factors. DESIGN: Retrospective analysis. SETTING: The Dutch referral centre for fetal therapy. POPULATION: IUTs for fetal alloimmune anaemia. METHODS: Fetuses were divided into two groups: fetuses requiring the first IUT before 20 weeks of gestation (Group 1) and those in which the IUTs started after 20 weeks (Group 2)...

BACKGROUND: Several irregular red blood cell alloantibodies, produced by alloimmunization of antigens in transfusions or pregnancies, have clinical importance because they cause hemolysis in the fetus and newborn and in transfused patients. OBJECTIVE: a prospective analysis of patients treated by the surgical and clinical emergency services of Hospital de Clínicas of the Universidade Federal do Triângulo Mineiro (HC/UFTM), Brazil was performed to correlate alloimmunization to clinical and epidemiological data...

BACKGROUND: Anemia is highly prevalent in inflammatory bowel disease patients, and red blood cell transfusion is often indicated already at reproductive age. Both transfusion and pregnancy may induce red cell alloantibodies, potentially complicating further transfusions and pregnancies. As recent evidence suggests that inflammation may promote red cell antibody induction, the alloimmunization risk of these patients after allogenic erythrocyte exposure was investigated. METHODS: Red cell alloantibody status and clinical data were analyzed in 193 inflammatory bowel disease patients with a history of transfusion or pregnancy, and compared with transfused controls with noninflammatory diseases (n=357)...

The K blood group remains an important target in hemolytic disease of the newborn (HDN), with no immune prophylaxis available. The aim was to characterize the Th response to K as a key step in designing specific immunotherapy and understanding the immunogenicity of the Ag. PBMCs from K-negative women who had anti-K Abs after incompatible pregnancy, and PBMCs from unimmunized controls, were screened for proliferative responses to peptide panels spanning the K or k single amino acid polymorphism. A dominant K peptide with the polymorphism at the C terminus elicited proliferation in 90% of alloimmunized women, and it was confirmed that responding cells expressed helper CD3(+)CD4(+) and "memory" CD45RO(+) phenotypes, and were MHC class II restricted...

OBJECTIVE: To determine the clinical spectrum of hemolytic disease due to irregular blood subgroup incompatibility in hospitalized neonates. STUDY DESIGN: The medical records of the all hospitalized newborn patients diagnosed with indirect hyperbilirubinemia due to subgroup incompatibility in Kell, C, c, E, and e systems were included in the study. Data from 106 newborns with hemolytic jaundice due to irregular blood subgroups were retrospectively evaluated, and clinical and laboratory findings were compared between patients ...

Large scale red blood cell (RBC) antigen genotyping of donors is currently well developed. There is scarce information, however, to select patients who might benefit from preemptive extended RBC antigen-matched transfusions. Female sex has been proposed as a risk factor for RBC alloimmunization after transfusion. To asses whether females respond differently to RBC alloantigens compared with males, we conducted a literature review on RBC alloimmunization. Clinical studies on RBC alloimmunization incidence were searched for in databases from 1950 through 2011...

We report the case of a 36-year old pregnant woman with a Kell alloimmunization (anti-K1), probably secondary to a previous blood transfusion, and a severe hemolytic disease of the fetus. Once the first fetal blood transfusion by cordocentesis was performed, we started treatment with repeated plasmapheresis to maintain anti-K1 titer below 1:32. With this scheme we did not need to perform a second intrauterine fetal blood transfusion and only mild anemia was found in the newborn. Taking into account that the rate of serious complications with plasmapheresis is lower than that related with intrauterine blood transfusion, this could be an alternative approach to repeated transfusions...

Hemolytic disease of the newborn (HDN) can occur when there are fetomaternal incompatibilities within any number of different erythrocyte antigen systems, including the RhD, Cc, Ee, Kidd and Duffy, and Kell antigen systems. In these disorders, maternal antibodies are developed by alloimmunization of the mother to fetal red blood cells during pregnancy when the fetal cells carry an alloantigen inherited from the father. The maternal antibodies result in the destruction of fetal erythrocytes leading to severe hemolytic anemia and hyperbilirubinemia...

BACKGROUND: The most common cause of anemia remains fetal red cell alloimmunization. Although after the systematization of prophylactic anti-D gamma globulin decreased the number of cases, has not eliminated the problem. OBJECTIVES: To evaluate the role of the fetal middle cerebral artery peak systolic velocity in the management of fetus at risk for anemia due to Rh alloimmunization and analyze the effect in perinatal outcomes. MATERIAL AND METHOD: 68 pregnancies complicated by Rh alloimmunization, in La Paz Hospital (Madrid, Spain) since February 2006 until August 2009, with maternal antibody titers > or = 1:32, affected in previous pregnancies and/or anti-Kell isoimmunization...

UNLABELLED: BHNN is an affection in which life duration of fetus red cells is decreased by means of maternal antibodies opposing certain antigens inherited from the father.The present study will prove the importance of laboratory tests in the diagnosis of alloimmunization through pregnancy and BHNN. MATERIAL AND METHOD: Laboratory determinations were performed between March 2008 and February 2009 on samples from 187 Rh negative pregnant female with incompatible pregnancy and Rh D positive newborns; there was used a certain algorithm for and identifying...

OBJECTIVE: To determine perinatal outcome in pregnancies with early severe red blood cell (RBC) alloimmunization. METHODS: This was a retrospective analysis of 30 patients requiring their first intrauterine transfusion (IUT) at < 22 weeks of gestation. Timing of the first IUT was based on evaluation of either the middle cerebral artery peak systolic velocity (MCA-PSV) or development of ascites. RESULTS: Thirty-three per cent of the patients had experienced a previous intrauterine fetal death as a result of RBC alloimmunization...