Potential application of a new screening test for alpha-thalassemia-1 carriers

A murine hybridoma cell line secreting monoclonal anti-human embryonic zeta-globin chain antibody has been established. Using this monoclonal antibody, a slot blot immunobinding assay for the detection of zeta-globin chains in adult hemolysates has been developed. This simple test can identify individuals who are alpha-thalassemia-1 carriers due to the (-SEA/) deletion. It is proposed that this test should be made generally available in Southeast Asia and Southern China, in order to identify couples who are at risk of begetting fetuses afflicted with homozygous alpha-thalassemia.     

A novel monoclonal antibody immunoassay for the detection of human serum hepcidin

Background  

Hepcidin is a liver-derived peptide hormone regulating iron metabolism. Changes in the expression of hepcidin are known to be the key pathogenic factors in hereditary hemochromatosis and are associated with infection and inflammation. To better understand the hormone’s function in human disease, we aimed to establish an immunoassay to determine hepcidin concentrations in serum.     

A novel beta-Thalassemic allele due to a two nucleotide deletion: beta76 (-GC)

We have identified and characterized a novel beta-thalassemic mutation in a North African adult. The molecular defect consists of a two nucleotide (nt) deletion in the beta-globin gene at codon 76 [beta76 (-GC), c.229-230delGC]. This frameshift mutation generates a TGA stop codon at position 89. The carrier presented with mild microcytic anemia (Hb 12.8 g/dL, MCV 60 fL), no detectable Hb F, an elevated Hb A2 level (5.5%) with no other mutation in the beta-globin gene and none of the more common known deletions in the alpha-globin cluster. No abnormal hemoglobin (Hb) was present in routine electrophoresis or in high performance liquid chromatography (HPLC) analyses. Pathologic inclusions were absent in both mature red cells and in reticulocytes. This observation reinforces the hypothesis that nonsense and frameshift mutations that result in a premature stop codon in exon 1 or exon 2 inherited in the heterozygous state do not generate dominant beta-thalassemia (thal). This is the first example of a premature stop codon at position 89.     

Type 1 hyperlipoproteinemia due to a novel deletion of exons 3 and 4 in the GPIHBP1 gene

Objectives

Type 1 hyperlipoproteinemia is an autosomal recessive disorder characterized by severely elevated plasma triglyceride levels, which may lead to abdominal pain and pancreatitis, eruptive xanthomas and failure to thrive. Mutations in the genes encoding lipoprotein lipase (LPL), apolipoprotein CII (APOC2), apolipoprotein AV (APOA5), lipase maturing factor 1 (LMF1) or glycosylphosphatidylinositol-anchored high density lipoprotein-binding protein 1 (GPIHBP1) have been found to cause Type 1 hyperlipoproteinemia.

Methods

Two sibpairs belonging to two different branches of an extended pedigree were referred for molecular elucidation for their increased plasma triglyceride levels, which untreated were >27 mmol/L. The genes LPL, APOC2, APOA5, LMF1 and GPIHBP1 were analyzed by DNA sequencing.

Results

No mutations were found in LPL, APOC2, APOA5 or LMF1. No PCR products were obtained for exons 3 and 4 of GPIHBP1 from DNA of the 4 affected subjects. Subsequent long-range PCR revealed that the four affected were homozygous for a deletion comprising exons 3 and 4 of GPIHBP1. No increase in LPL activity was found in post-heparin plasma from the subjects.

Conclusion

Homozygosity for a deletion of exons 3 and 4 of GPIHBP1 results in Type 1 hyperlipoproteinemia.     

A novel monoclonal antibody specific for human pre-B cell leukemia/lymphoma

A novel monoclonal antibody, designated WH14-antibody (WH14-Ab), was produced by using a non-T ALL cell line (HBL-3) as an immunogen. 35S-labelled immunoprecipitate revealed that the antigen reacting with WH14-Ab was estimated to be 30 Kd. Immunoglobulin isotype of WH14-Ab was IgG1. In the normal hematopoietic tissue, WH14-Ab reacted with a small number of monocytes (less than 30%) in the peripheral blood, but neither with the lymphocytes nor granulocytes. WH14-Ab reacted with HBL-3 and REH, but not with other B-cell leukemia/lymphoma and EBV-transformed cell lines. In addition, WH14-Ab reacted with most non-T ALL and pre-B lymphoblastic lymphoma. WH14-Ab did not react with all T-cell lymphomas. These findings indicate that the WH14-Ab may recognize the cell surface determinant shared by immature B cells, especially pre-B cells, in the B-cell lineage. WH14-Ab may be useful not only for the detection of pre-B cell leukemia/lymphomas but also for the investigation of maturation and differentiation of B-cell lineage.     

A monoclonal antibody (WT1) for detecting leukemias of T-cell precursors (T-ALL)

The selectivity of a monoclonal anti-T antibody, designated WT1, has been assessed in a series of 906 leukemias and lymphomas. In acute lymphoblastic leukemias, WT1 reacts comprehensively and selectively with thymic acute lymphoblastic leukemia (ALL) cells in untreated or relapsed patients, thus overriding the extensive antigenic diversity of this cancer and the immaturity of the cell type involved. All 80 cases of thymic ALL examined were WT1-positive. In addition, 18 cases of presumptive prethymic ALL were also WT1-positive, but were unreactive with other maturation-linked T-cell markers. The phenotype WT1+ HLA-DR TdT+ appears to be unique to T-ALL and can therefore be used systematically for the differential diagnosis of this poor prognosis subtype of ALL. Virtually all ALL cases can now be placed into one of two major subgroups representing transformed precursors of either the T- or B-cell lineage. WT1 identifies a single polypeptide of approximately 40,000 mol wt and is similar to two previously described monoclonal antibodies.     

Hydrops fetalis due to homozygosity for alpha-thalassemia-1, -(alpha)-20.5 kb: the first observation in a Turkish family

We report data on a fetus with hydrops fetalis due to a homozygosity for alpha-thalassemia-1, type -(alpha)-20.5 kb; this is the first reported case in a Turkish family. Characterization of the abnormality was based on data from family studies and from alpha-globin gene mapping of the DNA from the parents.     

A plasmocyte selective monoclonal antibody (B-B4) recognizes syndecan-1

We developed a new monoclonal antibody, B-B4, which specifically identifies human plasma cells. It strongly reacts with all multiple myeloma cell lines and with malignant plasma cells of all tumour samples of the multiple myeloma patients tested. B-B4 does not react with any peripheral blood, bone marrow or tonsil cells. Cloning of the B-B4 antigen reveals that the monoclonal antibody recognizes syndecan-1. It appears that the monoclonal antibody B-B4 is a suitable marker for human plasmocyte identification among haemopoietic cells and a useful probe for the diagnosis of haematological malignancies. Furthermore, this monoclonal antibody can be used for depletions prior to CD34 grafting.     

A monoclonal antibody against peripheral human blood monocytes (RoMo-1)

The monoclonal IgG2a-antibody RoMo-1 binds to peripheral human blood monocytes but does not react with other blood cells, tissue macrophages, HL-60, K 562 or U 937. It seems possible, that the antibody defines an antigen expressed on the premonocytic and monocyte stages of cells from the mononuclear phagocytic system only. The antibody is cytotoxic.     

A monoclonal antibody to alpha1beta1 blocks antigen-induced airway responses in sheep

The integrin alpha1beta1 (very late antigen-1; CD49a/CD29) is a major adhesion receptor for collagen I, IV, and VI, and its induced expression on activated monocytes and lymphocytes plays a central role in their retention and activation at inflammatory sites in autoimmune pathologies. However, the role of alpha1beta1 in allergic settings has not been explored. In this study, we show that a single 45-mg dose of aerosolized monoclonal antibody AQC2 to the alpha1 chain of human and sheep very late antigen-1, given 30 minutes before challenge, blocks both the allergen-induced late response and the associated airway hyperresponsiveness, functional indicators of allergen-induced inflammation, in sheep. AQC2 does not affect the early response. Consistent with these effects, AQC2 tended to reduce the cell response associated with local antigen instillation. An isotype-matched control antibody had no protective effects. Two humanized versions of AQC2, a wild-type IgG1 and an aglycosyl form of the same monoclonal antibody, which has reduced Fc receptor-mediated effector functions, are equally effective in blocking the antigen-induced late response and airway hyperresponsiveness in the sheep model. These data suggest that mononuclear leukocyte adhesion-dependent pathologies contribute to allergic lung disease and provide proof-of-concept that antagonists of alpha1 integrins may be useful in preventing these events.     

Phage display generation of a novel human anti-CD1A monoclonal antibody with potent cytolytic activity

CD1A is a cell surface protein expressed on Langerhans cells and cortical thymocytes that could potentially be used as an immunotherapeutic target in Langerhans Cell Histiocytosis (LCH), the cortical subtype of T-cell acute lymphocytic leukaemia (T-ALL) and other CD1A-positive tumours. The monoclonal antibody (mAb) CR2113 was selected from a panel of six fully human mAbs isolated from a semi-synthetic phage display library, based on specificity and avidity against cells expressing CD1 antigen variants. CR2113 recognized CD1A in T-ALL cell lines and patient samples. Confocal microscopy revealed that the CR2113-CD1A complex was internalized at 37°C. Furthermore, while CR2113 induced moderate complement-dependent cytotoxicity (CDC), potent antibody-dependent cell cytotoxicity (ADCC) activity was observed against CD1A expressing cell lines as well as T-ALL cell lines and T-ALL patient samples. In vivo experiments showed that CR2113 as a naked antibody has modest but specific anti-tumour activity against CD1A-expressing tumours. CR2113 is a high-affinity human anti-CD1A mAb with significant ADCC activity. These properties make CR2113 a candidate for clinical diagnostic imaging and therapeutic targeting of LCH as well as potential use in other clinical applications.     

A monoclonal antibody detecting a novel antigen expressed in the HTLV-I- infected cells

A monoclonal antibody, FTF 148, was prepared by hybridizing murine myelomal cells (NS-1) and spleen cells of BALB/c mice immunized with cultured cells derived from an adult T cell leukemia (ATL) patient (KUT- 2 cells). This monoclonal antibody reacted with all of the human T cell leukemia virus I (HTLV-I)-infected cell lines tested but did not react with other T cell lines derived from acute lymphocytic leukemia, Epstein-Barr virus-transformed B cell lines, or an erythroleukemic cell line. This monoclonal antibody was not directed to viral antigens because it reacted equally well with almost all KUT-2 and MT-1 cells, only 1% to 3% of which were ATL-associated antigen-positive. In contrast to interleukin 2 receptors expressed on both ATL cells and normal phytohemagglutinin-stimulated blasts, this antigen was not expressed on the latter cells. The antigen, mainly expressed on the cell membrane, was analyzed by metabolic labeling with 3H-leucine and surface labeling with 125I followed by cell lysis and immunoprecipitation with the FTF 148 antibody. The findings obtained by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed that p50 and p74 proteins were specifically precipitated and the antigen was also different from the product of the Xs gene of HTLV-I.     

狂犬病毒新型快速荧光斑点抑制实验方法的建立

目的建立一种新型的快速荧光斑点抑制实验用于狂犬病毒抗体的检测。方法本研究以携带绿色荧光蛋白基因的嵌合狂犬病毒HEP-GFP株为基础毒株,建立了一种新型快速荧光斑点抑制实验(RFFIT-GFP);并对多份人、犬、猫的血清进行了检测,还将该检测结果与传统的RFFIT,ELISA相比较。结果与结论RFFIT-GFP和RFFIT,ELISA测定的结果基本相一致,特异性都比较高,而且RFFIT-GFP是一种比它们更为简便、经济的检测方法。     

HA-1A. A human monoclonal antibody for the treatment of gram-negative sepsis.

HA-1A is a human monoclonal IgM antibody that binds to endotoxin. The results of the clinical trials of HA-1A demonstrate that HA-1A reduces mortality among patients with sepsis and gram-negative bacteremia. Secondary endpoints, including resolution of organ failure, discharge from intensive care unit, and discharge from the hospital, support the beneficial effects of the antibody. The antibody is well tolerated with rare side effects, including hypotension and urticarial rash. No anti-HA-1A antibodies have been detected.     

Evaluation of the intrathecal antibody response to Borrelia burgdorferi as a diagnostic test for Lyme neuroborreliosis

The intrathecal antibody response to Borrelia burgdorferi was evaluated in American and West German patients with Lyme neuroborreliosis. By an antibody capture enzyme immunoassay, 12 (92%) of 13 patients from the USA with Lyme meningitis were found to have intrathecal antibody production to B. burgdorferi, usually of multiple isotypes, most commonly IgA. Of 12 patients with putative late central nervous system manifestations of Lyme disease, 5 (42%) had local production of IgG or IgA spirochetal antibody, but cerebrospinal fluid (CSF) abnormalities could not be demonstrated in 6 patients with late peripheral nervous system manifestations of the disorder. Compared with American patients, 30 European patients with neuroborreliosis had significantly higher CSF:serum ratios of specific antibody both early and late in the illness. Intrathecal antibody determinations are the most specific diagnostic test currently available for Lyme neuroborreliosis, but local antibody production in CSF is an inconsistent finding in American patients with late neurologic manifestations of the disorder.