TURNOVER OF LABELED NORMAL GAMMA GLOBULIN IN MULTIPLE MYELOMA

Aberrations of protein metabolism in multiple myeloma have been studied by a number of in-vestigators (1-6) to ascertain whether the globu-lins in the blood consist of excesses of normal globulins or of chemically abnormal globulins, or both. Such research has been directed toward determining whether "characteristic protein ab-normalities " could be distinguished by 1) sepa-ration of the serum proteins with identification of their physicochemical properties by using the Tiselius electrophoresis apparatus and the analyti-cal ultracentrifuge; 2) certain structural relation-ships indicated by the amino end-group method; 3) immunochemical procedures; and 4) detection of formation of abnormal protein by administering to the patient isotopically labeled amino acids, the tracers being the stable isotopes N15 and C13 or radioactive carbon, C14. By use of such experi-mental methods it has been reported that at least some, if not all, of the quantitatively exces-sive globulins produced in this disease are ab-normal. Our approach to the investigation of certain fundamental aspects of protein metabolism in this disease has been concerned with the patient's turnover of globulins. Data are being presented which were obtained by determining the biologi-cal half-life of gamma globulin fractionated from normal individuals, labeled with I131 and injected into ten patients with clinically proven multiple myeloma. A subsequent report will be devoted to the findings when the source of the fractionated gamma globulin was from patients with multiple myeloma. The latter study permitted observa-tions on the half-life of labeled autologous and homologous preparations in this disease. The electrophoretic pattern of the serum of eac

Transient Pretreatment With Glucocorticoid Ablates Innate Toxicity of Systemically Delivered Adenoviral Vectors Without Reducing Efficacy

More than 300 human clinical trials utilize recombinant adenoviruses (rAds) as a gene transfer vector, confirming that rAds continue to be of high clinical interest. A primary weakness of rAds is their known propensity to trigger an innate, proinflammatory immune response rapidly after high-dose, systemic administration. In this study, we investigated what affects that pre-emptive treatment with anti-inflammatory glucocorticoids might have upon Ad vector-triggered inflammatory immune responses. We found that a simple pretreatment regimen with Dexamethasone (DEX) can significantly reduce most Ad-induced innate immune responses. DEX prevented rAd induction of systemic cytokine/chemokine releases in a dose-dependent fashion, with higher dosages preventing rAd induction of acute thrombocytopenia, endothelial cell activation, proinflammatory gene induction, and leukocyte infiltration into transduced organs. Transient glucocorticoid pretreatment also significantly reduced rAd-induced adaptive immune responses, including a decreased induction of Ad-neutralizing antibodies (NAbs). Importantly, use of DEX did not reduce the efficacy of rAd-mediated gene transduction nor rAd-derived transgene expression. Our results demonstrate that a simple, pre-emptive and transient glucocorticoid pretreatment is a viable approach to reduce rAd-associated acute toxicities that currently limit the use of Ad vectors in systemic clinical applications