1/12. Leukocyte adhesion deficiency II syndrome, a generalized defect in fucose metabolism.Leukocyte adhesion deficiency II has been described in only 2 patients; herein we report extensive investigation of another patient. The physical stigmata were detected during prenatal ultrasonographic investigation. Sialyl-Lewis X (sLex) was absent from the surface of polymorphonuclear neutrophils, and cell binding to E- and p-selectin was severely impaired, causing an immunodeficiency. The elevation of peripheral neutrophil counts occurred within several days after birth. A severe hypofucosylation of glycoconjugates bearing fucose in different glycosidic links was present in all cell types investigated, demonstrating that leukocyte adhesion deficiency II is not only a disorder of leukocytes but a generalized inherited metabolic disease affecting the metabolism of fucose.- - - - - - - - - - ranking = 1keywords = leukocytes (Clic here for more details about this article) |
2/12. Leukocyte adhesion deficiency in a Norwegian boy.A Norwegian boy suffering from recurrent urinary and respiratory tract infections was examined. It was found that granulocyte random migration, respiratory burst activity and the proportions of CD11/CD18 receptor positive leukocytes were reduced, consistent with a diagnosis of leukocyte adhesion deficiency. An increased proportion of Fc gammaI-receptor-bearing granulocytes did not compensate for the CR3 deficiency.- - - - - - - - - - ranking = 1keywords = leukocytes (Clic here for more details about this article) |
3/12. Leukocyte adhesion deficiency disorder: report of one case.In this paper, a case of leukocyte adhesion deficiency disorder confirmed by flow cytometry and leukocyte chemotaxis assays is reported. The 32-day-old female infant was admitted to our ward on account of delayed umbilical cord detachment and omphalitis. After admission, hemogram revealed severe leukocytosis (white blood cell (WBC) counts: 86,800/cumm), and there was poor clinical response to several kinds of antibiotics. The above history indicated that the patient might be a case of leukocyte adhesion deficiency disorder. A definite absence of CD11b/CD18 adhesion molecule on the patient's granulocytes and severe defects of leukocyte function demonstrated by chemotaxis, chemokinesis and zymosan-induced respiratory burst assays confirmed this diagnosis.- - - - - - - - - - ranking = 0.033295270854282keywords = blood cell (Clic here for more details about this article) |
4/12. A novel form of integrin dysfunction involving beta1, beta2, and beta3 integrins.The adhesion receptors known as integrins perform key functions for hematopoietic cells. The platelet integrin alphaIIbbeta3 is critical in hemostasis, and the beta1 and beta2 integrins on leukocytes have many roles in cell-mediated immunity. Mutations in the beta2 subunit lead to integrin nonexpression and to an immune deficiency, leukocyte adhesion deficiency-1. Mutations in either the alpha or beta subunit of alphaIIbbeta3 usually lead to integrin nonexpression and a bleeding tendency termed Glanzmann thrombasthenia. Here we describe a unique patient with clinical features of both Glanzmann thrombasthenia and leukocyte adhesion deficiency-1. The patient has normal expression of beta1, beta2, and beta3 integrins, but all are dysfunctional. The key findings are that "inside-out" signaling pathways leading to integrin activation are defective and that this is associated with abnormal integrin clustering. The integrins themselves are intact and capable of function following extracellular stimulation. T cell motility is normal, as are the expression levels and electrophoretic characteristics of all cytoskeletal and signaling proteins tested, except PKC-alpha, which has enhanced expression in the patient's cells. To our knowledge, this is the first description of a dysfunction affecting three classes of integrins. We propose that it is caused by a lesion in an intracellular factor or signaling pathway essential for integrin activation in hematopoietic cells and results in lack of regulation of clustering, an essential component of integrin-mediated adhesion.- - - - - - - - - - ranking = 1keywords = leukocytes (Clic here for more details about this article) |
5/12. A novel genetic leukocyte adhesion deficiency in subsecond triggering of integrin avidity by endothelial chemokines results in impaired leukocyte arrest on vascular endothelium under shear flow.Leukocyte arrest on vascular endothelium under disruptive shear flow is a multistep process that requires in situ integrin activation on the leukocyte surface by endothelium-displayed chemoattractants, primarily chemokines. A genetic deficiency of leukocyte adhesion to endothelium associated with defective beta2 integrin expression or function (LAD-1) has been described. We now report a novel severe genetic disorder in this multistep process associated with functional defects in multiple leukocyte integrins, reflected in recurrent infections, profound leukocytosis, and a bleeding tendency. This syndrome is associated with an impaired ability of neutrophil and lymphocyte beta1 and beta2 integrins to generate high avidity to their endothelial ligands and arrest cells on vascular endothelium in response to endothelial chemoattractant signals. Patient leukocytes roll normally on endothelial selectins, express intact integrins and G protein-coupled chemokine receptors (GPCR), spread on integrin ligands, and migrate normally along a chemotactic gradient. Activation of beta2 integrins in response to GPCR signals and intrinsic soluble ligand binding properties of the very late activation antigen-4 (VLA-4) integrin are also retained in patient leukocytes. Nevertheless, all integrins fail to generate firm adhesion to immobilized ligands in response to in situ GPCR-mediated activation by chemokines or chemoattractants, a result of a primary defect in integrin rearrangement at ligand-bearing contacts. This syndrome is the first example of a human integrin-activation deficiency associated with defective GPCR stimulation of integrin avidity at subsecond contacts, a key step in leukocyte arrest on vascular endothelium under shear flow.- - - - - - - - - - ranking = 2keywords = leukocytes (Clic here for more details about this article) |
6/12. chemotaxis of non-compressed blood polymorphonuclear leukocytes from an adolescent with severe leukocyte adhesion deficiency.We have defined the defect in a child with severe leukocyte adhesion deficiency-1 (LAD) as resulting from a single amino acid shift in CD18 (from a C to T mutation at position 533) that prevents heterodimerization with the CD11 antigens to produce beta(2) integrins-the first reported patient homozygous for this defect. Although beset by frequent infections, the patient has survived to adolescence despite the lack of these important adhesion molecules. Consistent with his clinical course is the ability of his PMN to respond chemotactically in slide preparations, albeit with difficulty because of their poor purchase on substrate. The operant adhesins are unknown; his polymorphonuclear leukocytes (PMN) remain chemotactically responsive in the presence of antibodies to alphavbeta(3) and beta(1) integrins and to integrin-associated protein (IAP). These findings indicate that not all patients with severe LAD are candidates for early bone marrow transplantation.- - - - - - - - - - ranking = 5keywords = leukocytes (Clic here for more details about this article) |
7/12. Genetic and immunological assessment of a bone marrow transplantation in a patient with a primary immune defect: leukocyte adhesion deficiency.Leukocyte adhesion deficiency (LAD) was suspected in a three weeks old girl from a family with an established history of LAD with a lack (less then 1%) of the beta 2 integrins CD 11a, b/CD 18 expression at the leukocytes surface, was engrafted with her mother HLA identical bone marrow at the age of 14 months. Repeated post transplantation (up to 22 months). Immunological assessments showed a good engraftment with 97% of the lymphocytes expressing CD11a/CD18. Cells proliferated normally in response to PHA and to tetanus toxoid after revaccination. The level of serum immunoglobulins was normal. Investigation of the CD18 intragenic polymorphic marker Avall before and after bone marrow transplantation (BMT) showed a transition from the Avall / genotype to the mother's Avall /- genotype. Similarly dna fingerprints obtained with the patient genomic dna, prepared from PBMC, prior and after transplantation, showed that the patient's dna fingerprints pattern matched the mother's one. These findings are consistent with the good engraftment observed clinically. This study emphasizes the usefulness of the molecular techniques to evaluate the degree of chimerism in monitoring the outcome of bon marrow transplantation.- - - - - - - - - - ranking = 1keywords = leukocytes (Clic here for more details about this article) |
8/12. prenatal diagnosis of Rambam-Hasharon syndrome.Rambam-Hasharon syndrome (RHS) is a newly recognized autosomal recessive inborn error in fucose metabolism. Mental retardation, short stature, coarse facies, and recurrent infections are the main clinical findings. Several fucosilated proteoglycans are deficient in these patients. Leukocyte adhesion deficiency type 2 is associated with lack of the membrane glycoprotein sialyl-Lewisx (CD15s). In the red blood cells (RBCs), lack of the membrane glycoprotein H is manifested as a Bombay (Oh) blood type. Two consecutive pregnancies it risk for RHS were monitored during mid-trimester by cordocentesis. One fetus expressed H substance and her blood phenotype was O Rh . The second fetus, a female, was 2 weeks smaller than expected by dates and had the Bombay blood type. The placenta of the affected fetus was small and irregular. This is the first prenatal diagnosis of this syndrome and the first case found in a female. The documentation of the syndrome in patients of both sexes and the parental consanguinity support an autosomal recessive inheritance. Two apparent recombinations between fucosyl-transferase 1 (FUT1, the H gene) and fucosyl-transferase 2 (secretor) are suggestive of non-allelic heterogeneity. We believe that the Bombay phenotype in this family is caused by a mutated gene, other than FUT1, which is causing multiple deficiencies of fucosilated proteoglycans.- - - - - - - - - - ranking = 0.033295270854282keywords = blood cell (Clic here for more details about this article) |
9/12. Successful HLA-identical sibling cord blood transplantation in a 6-year-old boy with leukocyte adhesion deficiency syndrome.A 6-year-old boy with the severe form of the leukocyte adhesion deficiency syndrome (LAD) received a transplant of cord blood (CBT) from his HLA-identical brother. The donor was proved healthy by successful prenatal diagnosis. CBT was performed after conditioning with etoposide, busulfan and cyclophosphamide. After hematopoietic recovery complete chimerism was proved as well as the normal expression of CD11x/CD18 complex on circulating leukocytes. The only post-transplant complication was a mild pneumonitis resolving on the corticosteroid therapy. Thirteen months after CBT the boy is in good health and shows no signs of immunodeficiency. As far as we know this is the first report of successful CBT in a patient with LAD syndrome.- - - - - - - - - - ranking = 1keywords = leukocytes (Clic here for more details about this article) |
10/12. Leukocyte adhesion deficiency type 1 (LAD-1)/variant. A novel immunodeficiency syndrome characterized by dysfunctional beta2 integrins.Leukocyte adhesion deficiency (LAD) is characterized by the inability of leukocytes, in particular neutrophilic granulocytes, to emigrate from the bloodstream towards sites of inflammation. Infectious foci are nonpurulent and may eventually become necrotic because of abnormal wound healing. LAD-1 is characterized by the absence of the beta2 integrins (CD11/CD18) on leukocytes. When expression is completely absent, patients often die within the first year. However, low levels of beta2 expression may result in a milder clinical picture of recurrent infection, which offers a better prognosis. In this paper, we describe the in vivo and in vitro findings on a patient with clinical features of a mild LAD-1 disorder, i.e., suffering from bacterial infections without apparent pus formation in the presence of a striking granulocytosis, showing no delayed-type hypersensitivity reaction upon skin testing, no specific antibody generation, but normal in vitro T cell proliferation responses after immunization. Expression levels of CD11/CD18 proteins were completely normal, but leukocyte activation did not result in CD11/ CD18 activation and high-avidity ligand-binding. in vitro chemotaxis and endothelial transmigration of the neutrophils as well as leukocyte aggregation responses were almost absent. On the other hand, beta1 and beta3 integrin-mediated adhesion functions were completely normal. During follow-up, a bleeding tendency related to decreased beta3 activation became clinically apparent, different from previously described cellular adhesion molecule variants. Therefore, this is the first well-documented case of a clinical combined immunodeficiency syndrome that results from nonfunctional CD11/CD18 molecules, and thus designated LAD-1/ variant.- - - - - - - - - - ranking = 2keywords = leukocytes (Clic here for more details about this article) |
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