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)

The healthy mother of a child with transient immune neutropenia was found to be "NA-null." The mother's neutrophils did not react with anti-NA1 and anti-NA2 antibodies (polyclonal human alloantibodies and mouse monoclonal antibodies). A healthy donor was discovered during routine neutrophil antigen typing whose neutrophils were also "NA-null." This NA-phenotype was due to the absence of FcRIII (CD16 antigen) on neutrophils as demonstrated with anti-FcRIII monoclonal antibodies. The neutrophils of these two individuals were not able to bind dimeric immunoglobulin G. However, their cells had a normal expression of other phosphatidylinositol (PI)-linked membrane glycoprotein (CD24, CD67, and CLB gran/5 antigens), ruling out the existence of a PI-linkage defect, such as paroxysmal nocturnal hemoglobinuria. The mother (propsitus) had isoantibodies in her blood against neutrophil-FcRIII without allospecificity, apparently produced during pregnancy and responsible for the neutropenia of her child. The expression of FcRIII on natural killer lymphocytes of both individuals was normal. FcRIII is encoded by two separate genes, one (FcRIII-1) for the neutrophil-PI-linked receptor, another (FcRIII-2) for the natural killer cell and macrophage-transmembrane receptor. By messenger RNA and DNA analysis (with an FcRIII-cDNA probe and restriction endonucleases) the neutrophil-FcRIII deficiency appeared to be due to deletion of the FcRIII-1 gene in both individuals, while the FcRIII-2 gene was normally present. The parents of the propositus were found to be heterozygous for this defect. Thus, FcRIII-1 gene deficiency of the mother may be a cause of (iso)immune neutropenia of the newborn. Whether this deficiency may have other clinical consequences has to be studied.
 ...
PMID:Maternal genomic neutrophil FcRIII deficiency leading to neonatal isoimmune neutropenia. 183 May 1

The initiation of hemodialysis using cuprophane membranes is followed by a rapid fall in the circulating neutrophil count. This neutropenia is caused by a transient sequestration of neutrophils in the lung due to homotypic aggregation, largely in response to generation of C5a by contact of plasma with the dialyzer. The transient nature of hemodialysis neutropenia is due to desensitization of neutrophils to stimulation by C5a, thus demonstrating desensitization in vivo. To examine the in vivo effects on surface phenotype of continuous exposure of neutrophils to C5a over 3 h, the surface expression of 22 antigens was examined by flow cytometry in patients undergoing dialysis. Neutropenia was prominent at 15 min and absent at 60 and 180 min of dialysis. CD10, CD11b, CD11c, CD13, CD18, CD35, CD45, CD66acde, and CD66b were upregulated at 15 min and remained upregulated at 180 min. CD61 and CD63 increased slightly at 15 min and returned to baseline by 180 min. CD16 and CD62L were down regulated at 15 min and normalized by 180 min. CD15s, CDw17, CD32, and CD44 were slightly down regulated at 15 min and then returned to baseline by 180 min. CD11a, CD15, CD24, CD31, and CDw65 did not change during dialysis. This study demonstrates the changes in surface phenotype of neutrophils during prolonged in vivo exposure to C5a over 3 h, during which time neutrophils become desensitized to subsequent stimulation by similar concentrations of C5a but maintain responsiveness to other chemotactic stimuli.
 ...
PMID:Changes in neutrophil surface phenotype during hemodialysis. 982 71

Transfer of drug resistance genes to hematopoietic cells is being studied as a means to protect against the myelosuppression associated with cancer chemotherapy and as a strategy for the in vivo selection and amplification of genetically modified cells. The goal of this study was to test if retroviral-mediated gene transfer of a dihydrofolate reductase (DHFR) variant (L22Y) could be used for in vivo selection of transduced myeloid cells and to determine what proportion of transduced cells was required for protection from myelosuppression. Based on previous work suggesting that selection with antifolates may also require inhibition of nucleoside transport mechanisms, mice transplanted with DHFR-transduced bone marrow cells were treated with trimetrexate and the nucleoside transport inhibitor prodrug nitrobenzylmercaptopurine riboside phosphate. In vivo selection of transduced myeloid progenitors was seen in the bone marrow and in circulating mature peripheral blood cells following drug treatment. These results show that the novel combination of the L22Y-DHFR cDNA, trimetrexate and nitrobenzylmercaptopurine riboside phosphate can be used to select for transduced myeloid cells, and that this approach warrants further study in large animal models. A bicistronic vector containing a human CD24 reporter gene was used to determine the number of modified cells needed for chemoprotection. Partial protection from neutropenia was seen when greater than 10% of myeloid cells expressed the vector, and high levels of protection were obtained when the proportion exceeded 30%. These results suggest that gene transfer may be useful for myeloprotection in certain pediatric cancers, but that more efficient gene transfer will be required to apply this approach to adult cancer patients.
 ...
PMID:Retroviral vectors containing a variant dihydrofolate reductase gene for drug protection and in vivo selection of hematopoietic cells. 1101 66