1/64. Demonstration of drug-dependent antibodies in two patients with neutrophenia and successful treatment with granulocyte-colony-stimulating factor.BACKGROUND: Many drugs have been reported as being capable of inducing immune neutropenia, but the causative drug-dependent antibodies were rarely demonstrated. STUDY DESIGN AND methods: This report describes the results of serologic testing and treatment in two children with immune neutropenia related to cefotaxime and metamizole, respectively. serum samples were tested in the presence and the absence of the drugs using the granulocyte agglutination test (GAT), the granulocyte immunofluorescence test (GIFT), and the monoclonal antibody-specific immobilization of granulocyte antigens (MAIGA) assay. RESULTS: The serum of one child contained cefotaxime-dependent antibodies that were detectable by the GAT and the MAIGA assay, but not by the GIFT. The serum of the other child gave positive reactions in the GAT and GIFT due to HLA antibodies and in the MAIGA assay only in the presence of metamizole. While cefotaxime-dependent antibody was directed against CD16, the metamizole antibody was directed against CD11b and CD35. The administration of granulocyte-colony-stimulating factor led to an abrupt increase in circulating neutrophils in both cases. CONCLUSION: The use of more than one technique is necessary for detection of drug-dependent antibodies against neutrophils, and early administration of granulocyte-colony-stimulating factor may result in fewer complications in these patients.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
2/64. Neutrophil antigen 5b is carried by a protein, migrating from 70 to 95 kDa, and may be involved in neonatal alloimmune neutropenia.BACKGROUND: Neutrophil antigen 5b has been described as involved in transfusion reactions and not in neonatal alloimmune neutropenia. CASE REPORT: Anti-5b was found in the serum of a mother of a persistently neutropenic newborn, who had several bacterial infections. The neutropenia responded to treatment with recombinant human granulocyte-colony-stimulating factor. immunoprecipitation experiments performed with this and three other 5b antisera identified a protein, migrating from 70 to 95 kDa, as carrier of 5b. The observed pattern of migration may point to heavy glycosylation of this protein. RESULTS: Six 5b-negative donors were identified among 54 screened white donors, for a 5b gene frequency of 0.66. CONCLUSION: Alloimmunization to 5b in pregnancy is rare. In the patients with neonatal neutropenia analyzed in the last decade, this was the first case discovered.- - - - - - - - - - ranking = 5keywords = antigen (Clic here for more details about this article) |
3/64. Neonatal alloimmune neutropenia in premature monozygous twins.Alloimmune neonatal neutropenia (ANN) is an uncommon but potentially life-threatening disorder of the neonate and young infant. Hematologically, the mother's peripheral neutrophil count is normal. However, the passive transfer of maternal immunoglobulin g neutrophil-specific antibodies and the subsequent sensitization of fetal neutrophils can result in severe neutropenia in the neonate. Generally, ANN is a self-limiting condition, but with severe bacterial infection, mortality can be high. We present the clinical features of monozygous twins delivered at 33 weeks' postconception with this condition. This case report is unique in that it occurred in twins born prematurely and was attributable to antibodies against 2 neutrophil-specific antigens, NA1 and NB1. A brief review of the diagnosis, management, and treatment of ANN is presented.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
4/64. Transient effect of granulocyte colony-stimulating factor in allo-immune neonatal neutropenia.The effect of recombinant human granulocyte colony-stimulating factor (rhG-CSF) administration at 10 microg/kg/day for 15-30 min over 3 consecutive days in 3 preterm neonates with allo-immune neonatal neutropenia (ANN) is reported. patients 1 and 2 had antibodies against antigen NA2, while patient 3 had antibodies against NA1. All neonates developed a rapid increase in absolute neutrophil count which reached the normal range within 48 h (from 75-640/mm(3) to 2,520-4,700/mm(3)). However, 23-25 days later, all 3 neonates relapsed into a second phase of severe neutropenia (408-870/mm(3)). Antibodies against neutrophil antigens were still positive during this period. This second-phase neutropenia persisted for 20-30 days and resolved spontaneously. It may be possible that when rhG-CSF is administered within a short time after birth in neonates with ANN, its effect is exhausted before the concentration of circulating antibodies decreases, with the result that a second phase of neutropenia can be expected.- - - - - - - - - - ranking = 2keywords = antigen (Clic here for more details about this article) |
5/64. Macrothrombocytopenia with abnormal demarcation membranes in megakaryocytes and neutropenia with a complete lack of sialyl-Lewis-X antigen in leukocytes--a new syndrome?A new megathrombocytopenic syndrome with giant platelets in peripheral blood and severe thrombocytopenia was diagnosed in a 4-month-old boy. His clinical course included repeated hemorrhagic incidents leading to death at age 37 months. bone marrow ultrastructural analysis revealed numerous dystrophic megakaryocytes with giant membrane complexes. Although these features were similar to those described for megakaryocytes in mice lacking the gene for transcription factor p45-NF-E2, no abnormalities in the p45-NF-E2 gene could be documented. Platelet membrane analysis showed a reduction in glycoprotein (GP) Ib, but normal content of GPIIb and GPIIIa. Analysis of genes encoding for GPIb alpha and beta, GPV, and GPIX ruled out the possibility that the observed platelet abnormality is a variant of bernard-soulier syndrome. A moderate neutropenia was associated with a complete lack of expression of sialyl-Lewis-X on the surface of polymorphonuclear neutrophils. A common defect in posttranslational modification of glycoproteins could account for the diverse cellular abnormalities.- - - - - - - - - - ranking = 4keywords = antigen (Clic here for more details about this article) |
6/64. Isoimmune neonatal neutropenia due to anti-Fc(gamma) RIIIb antibody in a mother with an Fc(gamma) RIIIb deficiency.A rare case of neutropenia in a newborn due to anti-Fc(gamma) RIIIb antibody is described. The newborn, born from the 5th pregnancy, had severe infection and no neutrophils. Full clinical and neutrophil count recovery was observed when the child was 5 weeks old. In maternal serum, panreactive granulocyte alloantibodies were detected. The mother's and her two sisters' granulocytes appeared to be Fc(gamma) RIIIb deficient as found using pheno- and genotyping methods. All of them were healthy. The anti-Fc(gamma) RIIIb specificity of antibodies was identified by the monoclonal antibody immunobilization of neutrophil antigen assay. Such antibodies were not found in both sisters with the Fc(gamma) RIIIb deficiency, although they were pregnant, one of them on the seventh occasion.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
7/64. A possible role for maternal HLA antibody in a case of alloimmune neonatal neutropenia.BACKGROUND: Alloimmune neonatal neutropenia (ANN) is caused by a reaction of maternal alloantibodies with paternally inherited antigens on the fetal neutrophils. While human neutrophil antigens (HNA) antibodies are found in half of ANN cases, specific antibodies have not been defined in the remaining cases. STUDY DESIGN AND methods: Reported here is a neonate with omphalitis due to neutropenia. To elucidate the cause of ANN, flow cytometric and PCR analyses were used. Reactions of the patient's and mother's sera with neutrophils, lymphocytes, and platelets were examined by lymphocytotoxicity test (LCT), anti-human immunoglobulin-LCT, and mixed passive hemagglutination test. RESULTS: The maternal sera reacted with neutrophils, lymphocytes, and platelets of the patient and father. The platelet adsorption eliminated the reaction of the maternal serum with the patient's neutrophils. The HLA typing of the family and an LCT using a panel of lymphocytes of 20 HLA-typed donors showed hla-a2 antigen as a target of antibodies in the maternal serum. According to anti-human immunoglobulin-LCT, the anti-HLA-A2 was present in the neonatal serum. On the other hand, HNA antibodies were not detectable in the patient's or the mother's serum. CONCLUSION: These results suggest that the transplacental passage of the maternal HLA antibody caused neutropenia in this patient.- - - - - - - - - - ranking = 3keywords = antigen (Clic here for more details about this article) |
8/64. Immune neutropenia associated with anti-human neutrophil antigen-2a (NB1) antibodies following unrelated donor stem cell transplantation for chronic myeloid leukaemia: perpetuation by granulocyte colony-stimulating factor.A case of immune neutropenia following unrelated stem cell transplantation for chronic myeloid leukaemia is described. The neutropenia developed following herpes zoster viral infection and was associated with antibodies to the human neutrophil antigen (HNA)-2a (formerly known as NB1). The neutropenia was prolonged, profound and unresponsive to granulocyte colony-stimulating factor (GCSF). The neutrophil count recovered after GCSF was discontinued. HNA-2a has been reported to be upregulated following GCSF administration. In the present case, it appears that the immune neutropenia may have been perpetuated by GCSF administration.- - - - - - - - - - ranking = 5keywords = antigen (Clic here for more details about this article) |
9/64. Autoimmune neutropenia in pregnant women causing neonatal neutropenia.Autoimmune neutropenia (AIN) can occur during pregnancy. However, neonatal neutropenia occurring in an infant born to a mother with AIN has only rarely been documented. Recently, we have experienced two cases of AIN during pregnancy, both of which caused severe yet transient neonatal neutropenia (< 0.3 x 10(9)/l), probably as a result of transplacental maternal anti-neutrophil autoantibodies. The anti-neutrophil antibodies seemed to be against antigens other than NA1/NA2 because the autoantibodies did not bind to neutrophils of specific NA types selectively in the granulocyte indirect immunofluorescence test. Although AIN is a relatively uncommon disease, neonatal neutropenia caused by maternal AIN may not be quite as rare.- - - - - - - - - - ranking = 1keywords = antigen (Clic here for more details about this article) |
10/64. Drug-induced neutropenia associated with anti-neutrophil cytoplasmic antibodies (ANCA): possible involvement of complement in granulocyte cytotoxicity.Although antineutrophil antibodies are thought to be involved in drug-induced neutropenia, neither the precise mechanisms nor the particular antigens on the neutrophil surface have yet been clarified. Recently, we examined a patient with Graves' disease who developed antineutrophil cytoplasmic antibodies (ANCA) after propylthiouracil treatment and exhibited neutropenia. Because several target antigens of ANCA are expressed on the surface of neutrophils, it was suggested that ANCA might contribute to neutropenia. The patient's serum bound specifically to neutrophils and hl-60 cells differentiated into granulocytes, and lysed the hl-60 cells via a complement-mediated mechanism. Furthermore, two representative ANCA antigens, proteinase 3 and myeloperoxidase, significantly inhibited both the binding and cytotoxicity of the serum. Finally, tumour necrosis factor-alpha, which is known to up-regulate cell surface expression of several ANCA antigens, enhanced both the binding and cytotoxicity of the serum. These findings suggest that ANCA induced by propylthiouracil contributed to leucopenia through a complement-mediated mechanism.- - - - - - - - - - ranking = 4keywords = antigen (Clic here for more details about this article) |
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