Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0027947 (neutropenia)
 17,527 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Alloimmunization of a mother against granulocytes causing alloimmune neonatal neutropenia (ANN) in her newborn was found likely to be attributed to previous intradermal injections of paternal lymphocytes. Immunotherapy with leukocytes which was performed for recurrent spontaneous abortions hence provides the possibility of granulocyte alloimmunization and increases the risk of the occurrence of ANN.
 ...
PMID:Alloimmune neonatal neutropenia is a potential side effect of immunization with leukocytes in women with recurrent spontaneous abortions. 145 93

Neutrophil-specific alloantibodies and the antigens they recognize are important in clinical medicine but little is known about the structure of these antigens. Alloimmunization to the antigen NB1 is a clinically important cause of neonatal neutropenia and leukocyte-mediated transfusion reactions. A novel mechanism of protein attachment to cell membranes involving the covalent linkage of the protein through an oligosaccharide to phosphatidylinositol has recently been defined. Many proteins which are anchored to the cell membrane by this mechanism can be released by treatment with phosphatidylinositol-specific phospholipase C (PI-PLC). The 58-64-kDa human neutrophil surface protein which contains the NB1 antigen was labeled with 125I by using lactoperoxidase and examined for PI-PLC sensitivity. The 58-64-kDa protein was specifically released from the cell by treatment with PI-PLC, and the mobility of the protein under non-denaturing conditions using non-ionic detergent was increased by treatment with PI-PLC. Surface expression of the NB1 antigen was slightly up-regulated by treatment with the chemotactic peptide f-met-leu-phe. Removal of N-linked carbohydrates with endoglycosidase-F decreased the apparent molecular weight of the protein to approximately 45-kDa. The data suggest that most of the 58-64-kDa protein bearing the neutrophil-specific antigen NB1 is anchored to the membrane through a glycosyl-phosphatidylinositol linkage.
 ...
PMID:Neutrophil-specific antigen NB1 is anchored via a glycosyl-phosphatidylinositol linkage. 182 10

Neutrophil-specific alloantibodies and the antigens they recognize are important in clinical medicine, but little is known about the structure of these antigens. Alloimmunization to the antigen NB1 is a clinically important cause of neonatal neutropenia and febrile transfusion reactions. To study the immunochemistry of the NB1 antigen, we prepared neutrophil plasma membranes and granules by nitrogen cavitation and differential centrifugation and then analyzed them by sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and immunoblotting with alloantibodies to several neutrophil-specific antigens. Two different antisera to the neutrophil-specific antigen NB1 identified an approximately 55-Kd protein by immunoblotting on neutrophil membranes from four NB1-positive donors but not on neutrophil membranes from five NB1-negative donors. Four anti-NB1 antisera immunoprecipitated a 58- to 64-Kd protein from extracts of NB1-positive neutrophils surface-labeled with 125I using lactoperoxidase, but not from similarly treated NB1-negative neutrophils. Normal human serum did not immunoprecipitate or immunoblot any proteins from these same neutrophil preparations. The NB1 antigen was detected by immunoblotting in secondary granules but was not found in primary granules. The electrophoretic mobility of the antigen was decreased slightly by reduction, suggesting that intrachain disulfide bonds were present. After reduction, the antigen could no longer be recognized by anti-NB1 antisera, but treatment of the antigen with periodate had no effect on the ability of anti-NB1 antisera to recognize the antigen, suggesting that it is not a carbohydrate. The data suggest that the neutrophil-specific antigen NB1 is present on a 58- to 64-Kd surface glycoprotein that is also present in secondary granules, and that the NB1 epitope is not a carbohydrate but probably resides in the tertiary structure of the protein backbone.
 ...
PMID:Biochemical characterization of the neutrophil-specific antigen NB1. 215 25

Alloimmunization to the neutrophil antigen NB1 (HNA-2a, CD177) can result in immune neutropenia and transfusion-related acute lung injury. Recently, we were able to elucidate the primary structure of NB1. To shed light also on the molecular basis of the NB1-negative phenotype, we studied the neutrophils of 2 women with NB1-specific alloantibodies for intracellular and extracellular NB1 expression, NB1-specific mRNA production, and the presence of the NB1 gene. No antibody binding to neutrophils was observed by immunofluorescence and immunoblot using a variety of human and monoclonal NB1-specific antibodies. By reverse transcription-polymerase chain reaction with NB1-specific primers we could not detect NB1 cDNAs without accessory sequences, which were found to be introns. The NB1 gene was present in the genome of both patients. Our data indicate that the NB1-negative phenotype is the result of different off-frame insertions on RNA level, resulting in NB1 deficiency on neutrophils.
 ...
PMID:Molecular basis of NB1 (HNA-2a, CD177) deficiency. 1201 Aug 33

Alloimmunization to granulocyte-specific antigens can occur during pregnancy. Maternal IgG can cross the placenta and result in neonatal neutropenia. The clinical course of alloimmune neonatal neutropenia is usually self-limiting with only mild infection. However, in severe cases complicated with bacterial sepsis it is a potentially life-threatening disorder. The effect of intravenous (IV) immunoglobulin, prophylactic antibiotic therapy, and recombinant human granulocyte-colony stimulating factor is variable and may prove useful in some cases. Two cases of alloimmune neonatal neutropenia due to anti HNA-2a alloimmunization in two siblings are reported. The first neonate was administered IV gammaglobulins to increase the blood neutrophil count, at a standard dosage (0.4 g/kg body weight) for 5 days without response. The second neonate did not receive specific therapy for blood neutrophil count increase. Neutropenia persisted for 2 and 6 months, respectively. The choice and efficacy of specific therapy for neutrophil count increase in the management of alloimmune neonatal neutropenia have not yet been fully defined and require additional evaluation in the majority of cases.
 ...
PMID:Alloimmune neonatal neutropenia due to anti-HNA-2a alloimmunization with severe and prolonged neutropenia but mild clinical course: two case reports. 1784 1

Alloimmunization to granulocyte-specific antigens can occur during pregnancy. Maternal antibodies of IgG class can cross the placenta to result in alloimmune neonatal neutropenia. Antibodies to human neutrophil antigens anti-HNA-1a, HNA-1b, and HNA-2a have been most commonly reported to cause alloimmune neonatal neutropenia. Isoantibodies to Fc gamma RIIIb (CD16) if mother is a HNA-null phenotype are rarely involved in neonatal neutropenia. We report on a case of severe neutropenia (440 neutrophils/muL) due to anti-Fc gamma RIIIb (CD16) isoimmunization. On day 14 severe omphalitis developed, which was treated for 7 days by an antibiotic (ceftriaxone in a dose of 80 mg/kg/d) according to umbilical swab finding. Omphalitis persisted for 10 days in spite of antibiotic therapy and only resolved upon the introduction of rhG-CSF therapy. Therapy with rh-GCSF proved efficient and led to neutrophil count increase to 1970/muL and cure of omphalitis. However, therapeutic effect on granulocyte count was of transient nature, as granulocyte count fell to 760 n/muL on day 4 of therapy discontinuation. Neutropenia persisted for 2 months. The newborn was discharged from the hospital on day 26 with normal clinical status with clinical and laboratory control examinations at 2-week intervals. No additional infections were observed during the course of neutropenia.
 ...
PMID:A Case of Neonatal Neutropenia Due to Anti-Fc Gamma Receptor IIIb Isoantibodies Treated with Recombinant Human Granulocyte Colony Stimulating Factor. 1973 Jul 45