Neutralizing antibody to hepatitis A virus in immune serum globulin and in the sera of human recipients of immune serum globulin

We determined the titer of neutralizing antibody to hepatitis A virus in five lots of immune serum globulin and in the sera of human recipients of immune globulin using a new and sensitive procedure, the radioimmunofocus inhibition assay. The neutralizing antibody titer of four immune globulin lots ranged from 1:170,000 to 1:406,000, and was approximately 100-fold the antibody titer determined by radioimmunoassay. The neutralizing antibody titer of a Bureau of Biologics reference immunoglobulin was 1:794,000. Sera collected from 18 healthy men who had undergone prophylaxis with immune globulin (0.02 ml/kg body wt) were negative when tested by radioimmunoassay. However, 2 of 18 sera collected before administration of immune globulin and sera from all 18 men collected 3 and 55 days later contained detectable neutralizing antibody. The measurement of neutralizing antibody should prove useful for standardizing passive immunoprophylaxis against hepatitis A as well as for evaluating the potential efficacy of new hepatitis A virus vaccines.     

Comparative protective activity of human monoclonal and hyperimmune polyclonal antibody against group B streptococci

Group B streptococcal (GBS) infections cause significant morbidity and mortality in neonates and compromised hosts, who usually lack opsonic antibody to their infecting strain. Unfortunately, most conventional immunoglobulin preparations possess little GBS antibody. The protective activity of a human monoclonal antibody (HuMAb) and a human hyperimmune intravenous immunoglobulin (HivIg) were evaluated against these organisms and compared with a conventional intravenous immunoglobulin (ivIg). The HuMAb and the HivIg possessed significant protective activity (50%-95%) against extremely virulent strains of types I, II, and III GBS in doses as low as 4-20 mg/kg. In contrast, the conventional ivIg had little protective activity against some of these strains in doses as high as 500 mg/kg. The opsonic activity of the HuMAb and HivIg also usually exceeded that of the conventional ivIg. These studies suggest HivIg or HuMAb with markedly enhanced specific activity may provide optimal immunotherapy for GBS infections.     

Absence of seroconversion following treatment with hepatitis B immune globulin containing antibody to human immunodeficiency virus

Recent studies have demonstrated that commercial preparations of hepatitis B immune globulin often contain antibody to the human immunodeficiency virus. The presence of this antibody has aroused concerns that treatment with hepatitis B immune globulin might passively induce human immunodeficiency virus antibody seropositivity, leading to incorrect diagnoses of human immunodeficiency virus exposure. We studied a group of 16 normal volunteers who received an intramuscular dose of hepatitis B immune globulin (0.06 ml per kg) which was later discovered to contain human immunodeficiency virus antibody. None of the subjects had human immunodeficiency virus antibody before receiving hepatitis B immune globulin. Serum specimens collected at 1 to 4, 6, 8, 12, 16, 20 and 24 weeks after the injection were consistently negative for human immunodeficiency virus antibody. There was no detectable human immunodeficiency virus antibody in any specimen from any subject. We conclude that intramuscular therapy with hepatitis B immune globulin in the recommended dose does not appear to place patients at risk of passive seroconversion to human immunodeficiency virus antibody positivity, despite the presence of antibody in the injected material.     

A monoclonal antibody reactive with human eosinophils

EO-1, an IgGl murine monoclonal antibody raised against human eosinophilic leukemia cells, reacts with eosinophils, basophils, platelets, and a few (2%) mononuclear cells but not with neutrophils. In the bone marrow, mature and immature eosinophils and basophils express the EO-1 antigen, whereas immature myeloid cells do not. The distribution of EO-1 antigen on leukemic cells is concordant with this finding, ie, typical myeloid lines (HL-60, KG-1, and ML-1) and fresh acute myelogenous leukemia cells are all unreactive with EO-1. Immunoprecipitation of an extract from surface-131I-labeled platelets with EO-1 and sodium dodecyl sulfate polyacrylamide gel electrophoresis, under reducing or nonreducing conditions, yielded a specific band of molecular weight 23,000. Previously described monoclonal antibodies reacting with eosinophils also recognize neutrophils. EO-1 is a unique antibody with specificity restricted to eosinophils, basophils, and platelets and might therefore be a valuable reagent for the study of their function and differentiation.     

A monoclonal antibody reactive with human hepatocytes

A monoclonal antibody, RL23/36, reacting preferentially with a determinant expressed on normal human hepatocytes is described. Use of an immunohistochemical technique on frozen sections from a range of 75 human liver biopsy specimens revealed that the determinant detected by RL23/36 was not expressed on hepatocytes from a number of patients with biopsy-proven liver disease. Although a normal staining pattern was observed in 28 of 29 biopsy specimens from patients with no evidence of liver disease, the antibody did not bind to hepatocytes in some cases of chronic active hepatitis (2/13), alcoholic liver disease (2/9), haemochromatosis (1/1), cirrhosis (1/2) and liver metastases (2/8). Furthermore, as in a previous study undertaken in the rat, the antibody failed to bind to tumour cells in the single human hepatoma observed in this study. These results suggest that further studies using RL23/36 may shed light on the pathogenesis of a number of liver diseases, including primary hepatocellular carcinoma.     

A monoclonal antibody reacting with human basophils

Bsp-1 is an IgM murine monoclonal antibody raised against the human erythroblastic leukemia cell line (HEL) that reacts with basophils but not neutrophils or eosinophils. Western blotting techniques showed that Bsp-1 reacts with a 45-kilodalton surface antigen on HEL cells. The distribution of Bsp-1 antigen on leukemic cells is confined to a basophilic leukemia cell line, KU812, chronic myeloid leukemia with basophilia, and some cases of acute undifferentiated leukemia. Bsp-1 might therefore be a useful reagent for the study of basophil function and differentiation.     

Reversal of immune thrombocytopenia in mice by cross-linking human immunoglobulin G with a high-affinity monoclonal antibody

Intravenous immunoglobulins (IVIgs) are used to treat an increasing number of autoimmune diseases, but their exact mechanism of action remains unknown. This study showed that cross-linking of human IgG present in IVIg preparations using a mouse monoclonal anti-human IgG generated complexes that prevented or reversed thrombocytopenia in mice more efficiently than IVIg. Furthermore, biologically active complexes were obtained simply by adding the monoclonal antibody to human serum. These results suggest the possible development of an IVIg-free substitute through the ex vivo, and possibly in vivo, formation of immune complexes containing autologous IgG of immune thrombocytopenic purpura patients.     

Anti-CD25 monoclonal antibody against polyclonal antibodies in pediatric renal transplantation

Although usually reversible, acute rejection of kidney graft is a negative factor in long-term graft survival. Commonly used in pediatric renal transplantation, immunosuppresive induction therapy is established to prevent it. New immunosuppressive agents have been developed in recent years and among them anti-CD25 monoclonal antibody appears to be specially interesting. AIM: To evaluate efficacy and safety of anti-CD325 monoclonal antibody (basiliximab) versus polyclonal antibodies as induction therapy in renal transplantation. MATHERIAL Y METHODS: Thirty consecutive kidney transplants performed in children 4-16 years age in Hospital Infantil La Fe through 1997-2000. The first 15 patients received polyclonal antibodies as induction therapy, and 15 consecutive ones received monoclonal anti-CD25 antibodies. Receptor, donor and graft characteristics were similar in both groups. Also, maintenance immunosuppression was the same. RESULTS: The follow-up was over one year in all patients. Four patients in the polyclonal antibody group suffered one acute rejection episode and four other patients had some drug reaction. In the anti-CD25 treatment group there was one episode of acute graft rejection and no collateral effects were observed. Glomerular filtration rate, proteinuria, hypertension, infection episodes, graft and patient survival were similar in both groups. CONCLUSIONES: Induction therapy for pediatric renal transplantation with anti-CD25 antibody has been effective and safe. Compared with polyclonal antibodies as standard treatment, basiliximab reduced acute rejection episodes and had no collateral side effects. Graft and patient one year survival were identical in the two groups.     

Mouse/human chimeric monoclonal antibody in man: kinetics and immune response.

A mouse/human chimeric monoclonal antibody (mAb) composed of the variable regions of murine 17-1A mAb and the constant regions of human IgG-1K immunoglobulin was administered to 10 patients with metastatic colon cancer. Four patients received single infusion of 10 mg (n = 2) or 40 mg (n = 2). Six patients received three infusion of 10 mg (n = 3) or 40 mg (n = 3) at 2-week intervals. The pharmacokinetics were similar at both dose levels and at the second and third infusions. The plasma disappearance curves were best fit by a two-compartment model having a mean alpha T1/2 of 17.5 hr (range 13-23 hr) and a mean beta T1/2 of 100.5 hr (range 65-139 hr). One patient who received three 40-mg doses of chimeric IgG-1K 17-1A mAb (day 0, 14, and 28) was the only patient to exhibit a detectable but modest antibody reactivity to chimera on days 63 and 84. The antibody reactivity was inhibited by murine 17-1A mAb, indicating that the antibody response was directed to the murine variable region of the chimera. The patients had no toxic or allergic reactions. This chimeric form of 17-1A mAb has an approximate 6-fold longer circulation time and appears to be substantially less immunogenic than its murine counterpart. These characteristics may provide an advantage in the clinical application of such chimeric molecules in therapeutic trials in humans.     

霜天蛾昆虫变应原多克隆抗体的制备及免疫特性分析

目的 制备兔抗霜天蛾变应原多克隆抗体,分析其与特异性过敏患者血清抗体成分的异同,为免疫筛选cDNA文库,制备基因重组霜天蛾变应原奠定基础.方法 应用霜天蛾变应原提取液免疫家兔获得霜天蛾变应原多克隆抗体,用酶联免疫吸附试验(ELISA)法测定混合免疫兔血清抗体效价:应用免疫印迹的方法对比分析免疫兔血清与特异性过敏患者血清抗体成分的异同.结果 混合免疫兔血清效价经ELISA检测,效价>1:10 000,免疫印迹检测兔抗血清免疫球蛋白G相似文献   

霜天蛾昆虫变应原多克隆抗体的制备及免疫特性分析

目的制备兔抗霜天蛾变应原多克隆抗体,分析其与特异性过敏患者血清抗体成分的异同,为免疫筛选cDNA文库,制备基因重组霜天蛾变应原奠定基础。方法应用霜天蛾变应原提取液免疫家兔获得霜天蛾变应原多克隆抗体,用酶联免疫吸附试验(ELISA)法测定混合免疫兔血清抗体效价;应用免疫印迹的方法对比分析免疫兔血清与特异性过敏患者血清抗体成分的异同。结果混合免疫兔血清效价经ELISA检测,效价>1:10000,免疫印迹检测兔抗血清免疫球蛋白G(IgG)可以特异性识别霜天蛾10种蛋白组分,相对分子质量分别为100000、92000、79000、74000、66000、49000、43000、36000、25000和16000;患者血清IgG可以识别6种蛋白组分,相对分子质量分别为79000、74000、66000、49000、36000和25000。结论制备出的兔抗血清与特异性霜天蛾过敏患者血清特异性识别霜天蛾变应原的结果接近,比患者可以识别更多的蛋白条带,可以应用免疫兔血清作为筛选霜天蛾cDNA文库的探针及重组霜天蛾变应原表达蛋白的鉴定分析。     

HLA-C expression on platelets: studies with an HLA-Cw1-specific human monoclonal antibody

BACKGROUND AND OBJECTIVES: The expression of HLA-C on the surface of platelets is rarely studied due to the lack of proper alloantisera. We addressed this question using an IgM human monoclonal antibody directed against HLA-Cw1 (VP6G3). MATERIAL AND METHODS: Both flow cytometry and complement dependent cytotoxicity studies were used in the current analysis. RESULTS: The expression of the HLA-Cw1 antigen on platelets is lower than on peripheral blood lymphocytes as shown by flow cytometry. Variation in expression levels between individuals is also observed. Using this antibody in a complement-dependent cytotoxicity assay, we did not observe lysis using platelets as targets, whereas peripheral blood lymphocytes of the same blood donors were adequately lysed. CONCLUSIONS: These results confirm that platelets indeed express HLA-C. Furthermore, the results support the insignificant role of HLA-C in immunological platelet refractoriness.     

Comparison of intravenous immune globulin and high dose anti‐D immune globulin as initial therapy for childhood immune thrombocytopenic purpura

This report documents our experience with intravenous immune globulin (IVIG) (1 g/kg, iv) and high‐dose, anti‐D immune globulin (anti‐D) (75 μg/kg) as initial treatment for childhood immune thrombocytopenic purpura (ITP). The medical records of children diagnosed with ITP at a single institution between January 2003 and May 2008 were retrospectively reviewed. Participants received either IVIG or high‐dose anti‐D immune globulin as their initial treatment for ITP. For the 53 patients included for analysis, there was no statistical difference in efficacy between each group; however, patients who received anti‐D experienced a higher rate of adverse drug reactions (ADRs), particularly chills and rigours, and 2 of 24 patients in the anti‐D group developed severe anaemia requiring medical intervention. Patients who presented with mucosal bleeding had higher rates of treatment failure (32%) compared to those who presented with dry purpura (6%), regardless of treatment. Both IVIG and high‐dose anti‐D are effective first‐line therapies for childhood ITP. However, we observed increased ADRs in the high‐dose anti‐D group in contrast to previously published reports. Further studies are needed to evaluate safety and premedications for high‐dose anti‐D and to determine the utility of using the presence of mucosal bleeding to predict treatment failure.     

Monoclonal antibody 6b6.6 defines a cross-reactive kappa light chain idiotope on human monoclonal and polyclonal rheumatoid factors

Mouse monoclonal antibody (MAb) 6B6.6 was raised against a cross-reactive idiotope (CRI) present on the light chains of 2 human IgM paraproteins with rheumatoid factor (RF) activity. The MAb inhibited the IgG-binding activity of these proteins, and thus appears to react with an epitope located at or near the RF-binding site. Enzyme-linked immunosorbent assay (ELISA) and Western immunoblotting studies indicate that the 6B6.6 CRI is associated with kIIIa sub-subgroup light chains, is not related to the Wa, Po, and Bla RF cross-idiotypic specificities, and is clearly distinct from the kIIIb-associated CRI detected by MAb 17.109. Using an ELISA, we detected 6B6.6 CRI in 59% of 107 sera and 48% of 50 synovial fluids from patients with seropositive rheumatoid arthritis (RA). However, the quantities of CRI-positive RF were small, and the amount of CRI-positive RF did not correlate with the amount of IgM-RF. The 6B6.6 CRI was shown to occur primarily in the IgM fraction of RA sera by both chromatographic studies and isotype-specific ELISA, although small quantities appeared to be associated with IgA and IgG in some sera. The presence of 6B6.6 CRI on both monoclonal and polyclonal RF is consistent with the view that both are derived, at least in part, from a common gene pool. However, its occurrence in relatively low levels suggests that the number of germline genes encoding for RF is large or that extensive mutation occurs in the course of RF expression in RA.     

Characterization of human serum spreading factor with monoclonal antibody.

Serum spreading factor is a glycoprotein isolated from human serum that promotes spreading of a variety of cell types on culture dishes. We developed mouse hybridoma lines secreting monoclonal antibody to serum spreading factor that markedly inhibited the rate of serum spreading factor-promoted spreading of both fibroblastic and epithelial cells in culture. Fibronectin-promoted cell spreading was unaffected by monoclonal antibody to serum spreading factor, and the factor appeared to be distinct by several criteria from fibronectin or laminin. Human serum-promoted cell spreading was partially inhibited by monoclonal antibody to serum spreading factor. The antibody recognized primarily two forms of serum spreading factor that migrated in NaDodSO4/polyacrylamide gel electrophoresis in a manner consistent with molecular weights of 65,000-70,000 and 75,000-78,000. In addition to being found in plasma, serum spreading factor was also found associated with washed human platelets.     

Production of human monoclonal antibody reactive with gastrointestinal carcinoma]

Lymphocytes obtained from regional lymph nodes and spleen in the patients with gastrointestinal carcinoma were fused with the human B lymphoblastoid cell line GC01 and human hybridomas producing human monoclonal antibody (MoAb) were derived. Human MoAb No. 235 (IgM) derived from spleen cell of a gastric cancer patient reacted with adenocarcinoma of stomach, colon, and pancreas in the new immunohistochemical assay, modified direct immunoperoxidase method, and reacted with KATO III cells in cultured cell lines. The antigenic determinant of this antibody was suspected to be protein moiety after enzyme treatment. The competitive binding inhibition assay indicated that its epitope was different from anti-CEA monoclonal antibodies (KM10, A10, B9, AH3, JA4) and KM01. These findings suggested the possible use of human MoAb No. 235 for clinical application of targeting cancer chemotherapy in the future.     

Does OKT3 monoclonal antibody react with an antigen-recognition structure on human T cells?

OKT3 monoclonal antibody to human T cells inhibits the target cell lysis mediated by allogeneic cytotoxic T cells and the generation of these effector cells in mixed lymphocyte culture. This marked inhibition of cell-mediated lysis is not found with other monoclonal antibodies also reactive with cell surface antigens of human T cells (OKT1, OKT4, OKT5, OKT6, OKT8, and OKT11). OKT3 antibody is mitogenic and this effect appears to require receptor activation in that it occurs at low concentrations (10(-12) M range) of OKT3 antibody, requires intact OKT3 IgG, and is inhibited by a factor(s) in human plasma. By contrast, the inhibition of allogeneic cell-mediated lysis by OKT3 antibody appears to be due to steric hindrance in that it requires higher concentrations of OKT3 antibody (10(-8) M range), Fab fragments retain approximately 10% activity, and inhibition is demonstrable in the presence of human plasma. These findings are consistent with the suggestion that OKT3 antibody reacts with the human T-cell antigen-recognition structure.