1/30. 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 = 1keywords = antigen (Clic here for more details about this article) |
2/30. Fy phenotype and gender determine plasma levels of monocyte chemotactic protein.BACKGROUND: in vitro studies indicate that the Fy blood group system antigens serve as receptors for chemokines such as monocyte chemotactic protein-1 (MCP-1) and RANTES. However, it is unclear whether subjects with the Fy(a-b-) phenotype exhibit altered clearance and hence altered plasma levels of chemo-kines, because they still express Fy on endothelial cells. STUDY DESIGN AND methods: To clarify a possible in vivo role of Fy on RBCs in the regulation of chemo-kine levels, healthy young volunteers of common Fy phenotypes were compared in a cross-sectional study. RESULTS: More than 90 percent of the 34 subjects of African origin were Fy(a-b-), one black volunteer was Fy(a b-), and two were Fy(a-b ). As expected, all 65 white volunteers were positive for either Fy(a) and/or Fy(b). Unexpectedly, persons expressing either Fy(a) and/or Fy(b) had significantly higher plasma levels of MCP-1 than Fy(a-b-) volunteers (women: 154 vs. 110 ng/L, p<0.01; men: 179 vs. 169 ng/L, p = 0.03). Surprisingly, plasma levels of MCP-1 were found to be sex-dependent: median MCP-1 levels averaged 180 ng per L in men but only 139 ng per L in women (p<0.001). Further, MCP-1 levels decreased significantly throughout the menstrual cycle of 18 women studied longitudinally. CONCLUSION: MCP-1 levels are about 30 percent higher in men than in premenopausal women, and MCP-1 levels are also higher in persons with RBCs expressing Fy antigens than in Fy(a-b-) persons. These findings have direct implications for the concept and interpretation of clinical studies measuring MCP-1 levels; the role of the observed differences in MCP-1 levels for the pathogenesis of MCP-1-dependent diseases, such as atherosclerosis, merits further investigation.- - - - - - - - - - ranking = 0.4keywords = antigen (Clic here for more details about this article) |
3/30. "Ground-glass" hepatocytes."Ground-glass" hepatocytes are liver cells which have eosinophilic granular, glassy cytoplasm on light microscopy. This appearance corresponds to a proliferated smooth endoplasmic reticulum ultrastructure. These changes may be drug-induced or associated with hepatitis b antigenaemia, particularly in carriers. In the latter case, hepatitis b antigen may be demonstrated in the liver cell cytoplasm, with a modified orcein stain, by immunofluorescence, electron microscopy and immuno-electron microscopy. Two patients are described in whom "ground-glass" hepatocytes were noted on liver biopsy. One patient had been treated with high doses of phenobarbitone, the other is a hepatitis b antigen carrier as was demonstrated by the modified orcein stain.- - - - - - - - - - ranking = 0.6keywords = antigen (Clic here for more details about this article) |
4/30. Neonatal alloimmune thrombocytopenia with HLA alloimmunization: case report with immunohematologic and placental findings.Severe neonatal thrombocytopenia is associated with a significant risk of neonatal bleeding complications. It may result from increased consumption, increased destruction, deficient production, or abnormal sequestration within the spleen. When immune mediated, most cases of clinically significant neonatal thrombocytopenia are due to maternal alloimmunization to paternally derived platelet antigens present on fetal platelets. We present the clinical, placental, and immunohematologic findings of a case of severe neonatal alloimmune thrombocytopenia (NAITP) complicated by additional HLA group alloimmunization. The placenta showed chronic villitis of unknown etiology (VUE) and diffuse microthrombi within the villous capillaries, indicating that abnormal thrombogenesis can be a complication of severe NAITP.- - - - - - - - - - ranking = 0.2keywords = antigen (Clic here for more details about this article) |
5/30. Ultraviolet light exposure is not a requirement for the development of cutaneous neonatal lupus.Cutaneous neonatal lupus erythematosus (NLE) is a rare disorder, linked to the presence of transplacentally acquired maternal autoantibodies (anti-ENA). NLE skin lesions frequently appear in the second or third month of life, and ultraviolet exposure is thought to be an initiating factor since it can externalize intranuclear autoantigens at the cell surface. We report a baby who was born already with an extensive NLE rash, suggesting that sun exposure is not a requirement for the development of NLE skin lesions. A 31-year-old woman affected with mixed connective tissue disease gave birth to a female after 38 weeks of gestation. pregnancy was uneventful and no perinatal complications were seen. The mother was positive for anti-RNP, but negative for anti-SSA/Ro and SSB/La autoantibodies. Already at birth, an extensive scarring rash with a few erythematosus lesions was present on the baby's face and scalp; this progressed over the following months, and subsequently stabilized. Anti-RNP were present in the baby's serum. Due to the unusual features of the disease expression, a skin biopsy was performed at age 5 months; results were consistent with the diagnosis of NLE, showing mononuclear cell infiltration and immunoglobulin deposition. No other features of NLE were detected. This observation is unusual for: (1) the presence of an NLE rash in the absence of anti-SSA/Ro; (2) the scarring and atrophic characteristics of the lesions; and (3) the development already in utero. This latter finding argues against sun exposure being necessary for lesion induction.- - - - - - - - - - ranking = 0.2keywords = antigen (Clic here for more details about this article) |
6/30. Cryptococcal meningitis in a neonate.A case of cryptococcal meningitis in a neonate born to an hiv-negative women is described. The cryptococcal infection was proved using standard microbiological and antigen detection techniques. Although cryptococcal meningitis has previously been described in both immunocompromised and immunocompetent children, the present case represents youngest case of cryptococcosis reported to date.- - - - - - - - - - ranking = 0.2keywords = antigen (Clic here for more details about this article) |
7/30. Late onset neonatal anaemia due to maternal anti-Ge: possible association with destruction of eythroid progenitors.There have been no reports of severe haemolytic disease of the newborn (HDN) due to Gerbich (Ge) antibodies. Two babies with HDN due to anti-Ge3, both born to the same mother, are described. The anti-Ge appeared in the first pregnancy and was not detectable in the first trimester, the babies' reticulocyte and bilirubin values were not greatly elevated (similar to HDN due to Kell antibodies), and the anaemia in both cases was either not apparent or not severe until 2 to 4 weeks after birth. Ge antigens are found on glycophorins (GPs) C and D; GPC, like Kell, has been shown to be expressed early on erythroid progenitor cells. The maternal anti-Ge3 was shown to promote phagocytosis of Ge early erythroid progenitors by monocytes (similar to what has been reported with anti-K and K progenitor cells). Thus, anti-Ge3 may cause immune destruction of erythroid progenitors and possibly suppression of erythropoiesis (which would explain the reticulocyte and bilirubin values seen in both cases). Anti-Ge3 appears to be capable of causing severe HDN. We suggest that babies born to mothers with anti-Ge should have their haemoglobin concentrations monitored for signs of anaemia for several weeks after birth. Functional assays may prove useful.- - - - - - - - - - ranking = 0.2keywords = antigen (Clic here for more details about this article) |
8/30. Neonatal hypothalamic hamartoma: a differentiating nonlethal hamartoblastoma.The authors report on a patient with a large hypothalamic hamartoma with a cleft lip and palate and seizures. neuroimaging revealed a large extraaxial, intradural mass in the prepontine and interpeduncular cisterns with significant distortion of the brainstem. A stereotactic transfontanel needle biopsy revealed a cellular lesion that contained immature-appearing neuroepithelial cells consistent with prior descriptions of hypothalamic hamartoblastoma. While having a low level of proliferation by Ki67 (MIB-1) labeling, the lesion also contained evidence of neuronal maturation, with many cells expressing neuronal nuclear antigen as observed during immunohistochemical analysis. Further clinical evaluation revealed no other significant congenital abnormalities, and the patient was discharged home. Outpatient follow up has continued for 2 years and the patient has been doing well, requiring no further treatment. This case illustrates that, despite its immature and proliferative histological appearance, this rare neonatal mass can be regarded as a "differentiating" hypothalamic hamartoma and can have a favorable prognosis.- - - - - - - - - - ranking = 0.2keywords = antigen (Clic here for more details about this article) |
9/30. A case report of neonatal alloimmune thrombocytopenic purpura: the importance of correct diagnosis for future pregnancies.CONTEXT: Neonatal alloimmune thrombocytopenic purpura (NAITP) is a neonatal disorder characterized by maternal alloimmunization against fetal platelet antigens inherited from the father. Intracranial hemorrhage leading to death or permanent neurological disability may occur in the fetus. CASE REPORT: A healthy 30-year-old woman gave birth to her first baby by cesarean after an uneventful 36-week pregnancy. Ten hours after birth, the infant presented severe petechiae, with platelet count of 8 x 10(3)/microl. The mother's platelet count was normal (180 x 10(3)/microl). The infant re ceived intravenous immunoglobulin and was discharged 18 days later, with platelet count of 100 x 10(3)/microl. The cause of thrombocytopenia was not elucidated at that time. One year later, the infant died of neuroblastoma. Since the parents wanted another child, they were referred for investigation of this thrombocytopenia. Platelet genotyping and platelet antibody screening were performed, showing total HPA-1 system mismatch between mother (HPA-1b1b) and father (HPA-1a1a), with anti-HPA-1a antibodies in the mother's serum. We concluded that the first baby was born with NAITP. Thus, in the second pregnancy, the mother was treated with several infusions of intravenous immunoglobulin. Careful ultrasound monitoring was performed, with normal results for mother and fetus throughout the pregnancy. The second baby was born by cesarean at 39 weeks, presenting 92 x 10(3) platelets/microl six hours after birth. The baby's platelets were genotyped as HPA-1a1b and the mother's serum again showed anti-HPA-1a antibodies. No clinical bleeding was observed. Intravenous immunoglobulin therapy was an effective treatment for preventing NAITP in the second baby.- - - - - - - - - - ranking = 0.2keywords = antigen (Clic here for more details about this article) |
10/30. Maternal genomic neutrophil FcRIII deficiency leading to neonatal isoimmune neutropenia.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.- - - - - - - - - - ranking = 0.6keywords = antigen (Clic here for more details about this article) |
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