Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0026764 (multiple myeloma)
 36,148 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A case of pseudohyperphosphataemia detected in a male patient with multiple IgG myeloma is reported. Phosphataemia, measured by a technique without previous deproteinization, reached 5.66 mM before any treatment and varied with treatment-induced changes in monoclonal immunoglobulin levels. Conversely, normal phosphataemia levels were found in blood samples taken before and after treatment when serum was deproteinized. This pseudohyperphosphataemia resulted from an increase in optic density due to interference between monoclonal immunoglobulin and the molybdic reagent used to determine phosphataemia. A retrospective investigation yielded three similar cases: two in patients with myeloma and one in a patient with non-myelomatous monoclonal dysglobulinaemia. A brief prospective study showed that this phenomenon was relatively frequent, as it was found in 2 out of 9 patients with monoclonal immunoglobulin (IgG in all 9 cases). These data indicate that the finding of marked hyperphosphataemia in subjects with monoclonal dysglobulinaemia should always prompt a control assay performed on deproteinized blood.
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PMID:[False hyperphosphoremia in multiple myeloma. Interference of monoclonal immunoglobulin G with the determination of blood phosphorus level]. 175 64

Serum fructosamine levels in 36 subjects with various types of multiple myeloma and in 64 normal controls were evaluated by means of a Nitroblue tetrazolium colorimetric assay. Only the IgA myeloma group showed significantly raised serum fructosamine values (P less than 0.001). In the IgG myeloma group, which showed a higher mean serum protein concentration, serum fructosamine levels were not significantly different from controls. The study shows that elevated IgA levels do influence serum fructosamine and this effect should be taken into due consideration in order to avoid possible misinterpretations in evaluating this widely used index of glucose metabolism.
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PMID:Influence of serum proteins on fructosamine concentration in multiple myeloma. 181 55

The interference of immunoglobulins in the radioimmunoassay (RIA) of human beta-endorphin was investigated. Human IgM showed no cross-reactivity. Human IgA showed a weak cross-reaction, but the dilution curve of IgA did not show parallelism with the standard curve of beta-endorphin, thus indicating its antigenic difference. The dilution curves of human IgG showed 0.18% displacement with respect to the human beta-endorphin standard curve, with good parallelism. Moreover, five patients with multiple myeloma of the IgG type showed falsely elevated beta-endorphin levels. We investigated the possibility that certain IgGs may be responsible for the displacement of [125I]beta-endorphin in the beta-endorphin kit. The apparent beta-endorphin level of plasma from multiple myeloma patients was markedly decreased after affinity chromatography of the serum on protein A-Sepharose. In another 3 patients with multiple myeloma, we examined IgG interference by measuring the beta-endorphin levels in their lyophilized IgG diluted with saline. The results demonstrated high values of 20.2, 25.5 and 21.2 pmol/l respectively, also showing good parallelism. These immunological parallels to human beta-endorphin verify that a part of the amino acid sequence of human IgG is similar to that of human beta-endorphin. Consequently, in the measurement of beta-endorphin with polyclonal antibody, the results may sometimes be spuriously high due to cross-reaction with IgG, e.g., in patients with IgG myeloma. To avoid IgG interference, a specific monoclonal antibody to synthetic beta-endorphin should be used rather than polyclonal antibodies.
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PMID:Interference of immunoglobulins in the radioimmunoassay of human beta-endorphin. 208 65

Human IgG of four subclasses, semi-purified from pooled human serum by a series of DEAE ion exchange and protein A affinity chromatographies, were used as immunogens and initial screening antigens to produce subclass-specific and -restricted monoclonal antibodies (McAbs). These McAbs were bound to CNBr-activated Sepharose 4B and utilized in immunoaffinity chromatography to prepare four polyclonal human IgG subclasses of satisfactory purities, which were then used as final screening antigens. Subclass-specific McAbs thus chosen were further evaluated for subclass- and especially allotype-specificity using a panel of monoclonal IgG myeloma proteins with representative Gm markers for each subclass in micro enzyme-linked immunosorbent assay (ELISA). A total of 10 clones of subclass-specific McAbs (one for anti-IgG1, three anti-IgG2, two anti-IgG3, four anti-IgG4) were established. Among them, IgG2-specific clones of HG2-30F and HG2-56F, IgG3-specific HG3-7C and HG3-32C, and IgG4-specific HG4-53G McAbs were superior to the corresponding specificity standard McAbs chosen by the Human Immunoglobulins Subcommittee of the WHO/International Union of Immunological Societies (IUIS) in 1985. As allotype-specific McAbs, HG1-1E for G1m(az) and HG3-3B for G3m(b) were obtained. In micro ELISA of this study as well as all protocols of the previous WHO/IUIS collaborative study, antigens (myeloma IgG subclasses) were immobilized or fixed to a solid phase, resulting in possible variations in their epitope expressions. We developed a new assay system, micro radioimmunoassay (RIA), in which reactivities of McAbs against free IgG subclasses in solution can be evaluated. HG2-30F, having extremely high reactivities to coated IgG2 in micro ELISA, remarkably reduced its reactivities to free IgG2 in solution in micro RIA. Two other clones also showed some different reactivities in micro RIA and micro ELISA. We believe that this micro RIA is valuable for evaluation of McAbs reactivities against native human IgG subclasses in solution.
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PMID:Evaluation of production and characterization of monoclonal antibodies to human IgG of four subclasses. 250 25

Bone marrow aspirates from 10 patients with multiple myeloma (6 IgG myeloma, 3 IgA myeloma, 1 Bence Jones myeloma) were examined for nucleolus-associated localization of J chains. On light microscopy using the PAP method, almost all or a significant number of myeloma cells exhibited intranuclear spots stained with anti-J chains in 3 (IgG myeloma) out of the 8 cases positive for cytoplasmic J chains. In contrast, the nucleus of myeloma cells examined was constantly negative for anti-heavy and -light chains. Immunoelectron microscopically, J chain was identified as dicrete round electron-dense precipitates, corresponding to the whole nucleolus, and as sparsely distributed, small electron-dense deposits in the nucleus. In addition, some connections were found between nuclear and nucleolar electron-dense precipitates. Several possible explanations have been proposed to account for this localization of J chains.
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PMID:Nucleolus-associated J chains in myeloma cells. 310 Nov 68

Concanavalin A binding to glycoprotein bands on nitrocellulose blots was used to detect mannose, sorbose, N-acetylgalactosamine and/or glucose residues on 100% (31/31) of human Bence Jones protein light chains, following sodium dodecyl sulphate-polyacrylamide gel electrophoresis. All (20/20) light chains form IgG myeloma proteins and light chains from a preparation of normal polyclonal human IgG were also bound by concanavalin A. The specificity of concanavalin A for glycoproteins was demonstrated by its binding to human Fc fragments and a human monoclonal anti-Rhesus D antibody (REG-A), but not to human albumin pFc' fragments and aglycosylated REG-A derived from cells grown in the presence of the glycosylation inhibitor tunicamycin. These results suggest that all Bence Jones proteins and light chains from myeloma IgG proteins contain mono- or oligosaccharides linked O-glycosidically to serine or threonine residues.
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PMID:Immunogenicity and antigenicity of immunoglobulins: detection of human immunoglobulin light-chain carbohydrate, using concanavalin A. 311 95

The aim of this study was to determine the effects of interferon on in vitro immunoglobulin synthesis by the plasma cells of patients with multiple myeloma. Bone marrow cultures were set up in the presence of media alone or alpha-interferon. Supernatants were harvested over a 24-hour period and assayed for paraprotein immunoglobulin synthesis using radio-immunoassays developed in this department. The 24-hour paraprotein synthesis ranged from 9 to 493 micrograms/10(6) plasma cells in patients with IgG myeloma (n = 11), and from 0.3 to 8.3 micrograms/10(6) plasma cells in those with IgA (n = 4). Alpha-Interferon had variable effects on paraprotein synthesis in IgG myelomas, causing an inhibition of synthesis (up to 61%) in 3 patients and an enhancement of synthesis (up to 95%) in 5 cases. In IgA myelomas, on the other hand, alpha-interferon caused inhibition of synthesis in 1 case. In the 2 patients studied during alpha-interferon administration, IgG synthesis was significantly reduced. More cases are currently being investigated. Clearly, immunoglobulin synthesis by plasma cells shows variable modulation by alpha-interferon in vitro.
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PMID:Effect of interferon on the in vitro synthesis of paraprotein by plasma cells in myeloma. 312 75

Unreduced human immunoglobulin G (IgG) which was not aggregated showed anomalous apparent molecular masses on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). It migrated mainly as three distinct bands with apparent molecular masses from 190 to 240 kDa on gels containing 8% polyacrylamide, when denatured at 37 degrees C. Generation of this banding pattern has two reasons: (a) the pattern is a superposition of bands originating from the four IgG subclasses that differ in molecular masses and structures; and (b) the complexity of the band pattern is further increased, because IgG myeloma proteins of the IgG1 and IgG2 subclass migrated as doublets, while IgG3 and IgG4 formed primarily one band with slightly different apparent molecular masses. These properties were independent of the type of light chain in all myeloma proteins studied. Generation of doublets suggests heterogeneities of monoclonal proteins. The two separable protein populations from IgG1 differ in their susceptibility to reduction. Reduction at 37 degrees C cleaved the larger into heavy and light chain, while it generated heavy chain dimer and light chain from the smaller species. Hence, it is possible that monoclonal IgG1 are comprised of at least two subpopulations of molecules with different S-S bonds. Doublet formation of IgG2 remains unexplained, since both species were equally sensitive to reduction. Knowledge on the anomalous properties of IgG on SDS-PAGE is a prerequisite to run immunoblots from unreduced cellular antigens without confounding cell-associated IgG with cellular antigens.
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PMID:Electrophoretic properties of human IgG and its subclasses on sodium dodecyl-sulfate-polyacrylamide gel electrophoresis and immunoblots. 323 61

To determine the extent of clonal involvement of the secretory immune system and the origin of salivary immunoglobulins (Ig) in monoclonal gammopathy patients, saliva and serum samples were collected from five affected individuals (two IgA myelomas, one IgG myeloma, one IgG benign monoclonal gammopathy, and one IgM lymphoma) and were assayed for the presence of monoclonal Ig. Purified polyclonal or monoclonal anti-idiotype (Id) antibodies were prepared against each of the isolated serum paraproteins. In all five individuals, the patient saliva samples inhibited the binding of 125I-labeled homologous Ig to the corresponding anti-Id antibodies, but normal saliva did not. The concentration of Id in patients' saliva varied from 1 to 400 micrograms/ml; i.e., 0.004 to 1.0% of the corresponding serum values. Saliva of a lymphoma patient whose IgM kappa protein exhibited rheumatoid factor (RF) activity also contained RF. The salivary Id-bearing molecules were found to have the same Ig isotype as the serum paraproteins. The myeloma IgA represented a minor component (0.4 and 3.9%) of the total salivary IgA. The salivary IgA myeloma proteins were associated at least in part with secretory component, but the salivary IgG paraproteins were not. In an IgA myeloma patient, a minority (17%) of the IgA+ plasma cells found in the lacrymal gland biopsy specimen were Id+, whereas the great majority (98%) of bone marrow IgA plasma cells were Id+. The results suggest active transport rather than passive transudation of myeloma IgA into the patients' saliva, and the integrity of the secretory immune system was not compromised by the neoplastic process.
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PMID:Analysis of paraprotein transport into the saliva by using anti-idiotype antibodies. 379 39

Natural killer (NK) activity and antibody-dependent cell-mediated cytotoxicity (ADCC) were studied by routine methods in 11 patients with untreated malignant monoclonal gammopathy. NK and/or ADCC activity was clearly reduced in three patients with advanced disease. Moreover, sera from some myeloma patients impaired the ADCC and NK activity. A large quantity of purified monoclonal IgG from one patient appeared to inhibit NK and ADCC activity as did high concentrations of pooled polyclonal immunoglobulin from healthy persons. In two of these 11 patients, other malignancies were diagnosed prior to chemotherapy. One of these patients, who had nonsecretory myeloma, had marked impairment of NK and ADCC activity; the other, with IgG myeloma, had normal NK and ADCC activity.
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PMID:Natural killer activity and antibody-dependent cell-mediated cytotoxicity in multiple myeloma. 409 94


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