49 resultados para Immunoglobulin G -- administration

em BORIS: Bern Open Repository and Information System - Berna - Suiça


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The effect of induction of parturition with a PGF(2)alpha analog on plasma concentration of prolactin (PRL) and its effects on colostrum concentration of IgG and chitotriosidase (ChT) activity were studied in 16 pregnant Majorera goats. Treated goats, those in which parturition was induced, had greater concentrations of PRL than control goats 24 h before parturition (P < 0.05) and 48 h after parturition (P < 0.05). Control goats had greater concentrations of PRL than treated goats 96 h after parturition (P < 0.05). Plasma concentration of IgG did not differ between groups during the experimental period, but colostrum concentrations of IgG were greater in control goats than in treated goats at parturition (P < 0.05). Plasma ChT activity decreased during the period 72 h before parturition to 24 h after parturition in control and treated goats. Time evolution after partum affected the colostrum ChT activity, being greater at parturition than after parturition in both groups (P < 0.05). In summary, concentration of IgG in colostrum is slightly diminished if parturition is induced. Induction of parturition causes an early increase in PRL, which is most likely responsible for preterm suppression of IgG transport into mammary secretions. (C) 2011 Elsevier Inc. All rights reserved.

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The provision of quality colostrum with a high concentration of immunoglobulins is critical for newborn calf health. Because first colostrum may be low in overall concentration to effectively reduce the risk of newborn infections, we tested equivalent milking fractions of colostrum for possible IgG differences. The objective of this study was to determine if the fractional composition of colostrum changes during the course of milking with a focus on immunoglobulins. Twenty-four Holstein and Simmental cows were milked (first colostrum) within 4h after calving. The colostrum of 1 gland per animal was assembled into 4 percentage fractions over the course of milking: 0 to 25%, 25 to 50%, 50 to 75%, and 75 to 100%. The IgG concentration among the various fractions did not change in any significant pattern. Concentration of protein, casein, lactose and somatic cell count remained the same or exhibited only minor changes during the course of fractional milking colostrum. We determined that no benefit exists in feeding any particular fraction of colostrum to the newborn.

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Colostrum formation and lactogenesis in the mammary gland and the timing of parturition are regulated by endocrine signals. Changes in progesterone (P4) and prolactin (PRL) are considered key events that inhibit colostrum formation, trigger parturition, and signal the onset of lactation. The goal of our study was to determine if colostrum yield and composition and immunoglobulin transfer are affected by prepartum milking relative to the decrease in P4, peak of PRL, or occurrence of parturition. Twenty-three multiparous cows were randomly assigned to 1 of 2 groups: (1) control with first milking at 4h postcalving (CON, n=11), and (2) treatment group with first milking approximately 1d before calving and second milking at 4h after parturition (APM, n=12). Colostrum yields were recorded and proportional samples were analyzed for immunoglobulin G (IgG) concentration. Blood plasma samples for the analyses of P4 and PRL were collected 3 times daily at 8-h intervals for 4d prepartum and again taken at 4h after parturition. Total colostrum mass of APM cows was higher than that of CON cows. Immunoglobulin G concentration and protein content did not differ between antepartum milking in APM cows and postpartum milking in CON cows. Colostrum IgG concentration and protein content in APM cows at the postpartum milking were lower compared with the IgG concentration established at the prepartum (APM) and postpartum milkings of CON cows. Immunoglobulin G mass did not differ in first and second colostrum collection in APM cows but was lower compared with that of CON cows. The sum of IgG mass in APM cows (prepartum + postpartum collections) did not differ from that of CON cows. Lactose and fat in milk (concentration and mass) increased from first to second milking in APM cows. Total mass of lactose and fat in APM cows (prepartum + postpartum collections) was greater compared with that of CON cows. The finding that the time of milking relative to parturition, P4 decrease, and PRL peak slightly affected yield and quality of colostrum emphasizes the complex interactions of numerous endocrine and morphological changes occurring during colostrogenesis and lactogenesis in dairy cows. The considerably rapid transfer of immunoglobulins into colostrum of prepartum-milked cows within a few hours leads to the hypothesis that the transfer of IgG can be very fast and-contrary to earlier findings-persist at least until parturition.

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Different therapeutic approaches have been used in fetal-neonatal alloimmune thrombocytopenia, but many centers administer immunoglobulin G infusions to the pregnant woman. We studied the effect of maternal antenatal immunoglobulin infusions on fetal platelet counts in pregnancies with fetal alloimmune thrombocytopenia.

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Colostrum feeding in small ruminants is crucial during the first hours after birth due to the lack of Ig transfer during pregnancy via the placenta. In addition the immature immune system of the neonate is slow to produce its own Ig during the first weeks of life. Colostrogenesis, i.e. the transfer of Ig from blood into mammary secretions, starts several weeks prepartum. In goat plasma, immunoglobulin G (IgG) concentration decreases by around 38% from the third month of gestation until partum, which coincides with the dry period. Thus, management during the dry period is crucial for the course of colostrogenesis. The colostrum synthesis is determined by the nutrition during the prepartum period, but the transfer of Ig is obviously independent of nutritional influences. The administration of conjugated linoleic acid during the dry period to dairy goats causes a less pronounced decrease of blood plasma IgG concentration (6%) but it did not change colostral IgG levels. In cattle, IgG1 is transported from blood into colostrum by an IgG1 specific receptor located on the surface of alveolar epithelial cells during colostrogenesis, and this is most likely similar in small ruminants. Via inactivation of this receptor, the Ig transfer is downregulated by increasing prolactin (PRL) during lactogenesis. It was recently observed in goats treated with PGF2 alpha, in order to induce parturition, lower colostrum IgG concentrations occurred concomitantly with an earlier increase of plasma PRL as compared to untreated animals. The effect of litter size and number of lactations on colostral IgG concentration in small ruminants has not been made fully clear until now most likely due to the different breeds used in the published studies.

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It was a long way from the use of hyperimmune animal sera for the treatment of toxin-producing infections to the production of polyclonal, polyspecific human immunoglobulin preparations and the use of NAbs as therapeutic tools for autoimmune and inflammatory diseases. Some highlights of the development of knowledge in blood fractionation techniques, basic science and clinical wisdom are reviewed in this chapter. Proudly we mention the outstanding contribution of Swiss scientists and clinicians in the development of IVIG as clinical tool for some otherwise untreatable diseases or taking advantage of its low adverse event profile in long-term treatment of other chronic autoimmune and inflammatory diseases. This chapter summarizes some of the characteristics and the effects in humans of NAbs which are present in IgG concentrates. We call attention to the fact that the human data remain, at least in part, incomplete, among others because even with the most efficient large-scale techniques available not more than approximately 50% of the total IgG in plasma can be fractionated into an immunoglobulin G concentrate.

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Recently, we demonstrated that circulating levels of vascular endothelial growth factor (VEGF) and placental growth factor (PlGF) are increased in sepsis (Yano, K., P.C. Liaw, J.M. Mullington, S.C. Shih, H. Okada, N. Bodyak, P.M. Kang, L. Toltl, B. Belikoff, J. Buras, et al. 2006. J. Exp. Med. 203:1447-1458). Moreover, enhanced VEGF/Flk-1 signaling was shown to contribute to sepsis morbidity and mortality. We tested the hypothesis that PlGF also contributes to sepsis outcome. In mouse models of endotoxemia and cecal ligation puncture, the genetic absence of PlGF or the systemic administration of neutralizing anti-PlGF antibodies resulted in higher mortality compared with wild-type or immunoglobulin G-injected controls, respectively. The increased mortality associated with genetic deficiency of PlGF was reversed by adenovirus (Ad)-mediated overexpression of PlGF. In the endotoxemia model, PlGF deficiency was associated with elevated circulating levels of VEGF, induction of VEGF expression in the liver, impaired cardiac function, and organ-specific accentuation of barrier dysfunction and inflammation. Mortality of endotoxemic PlGF-deficient mice was increased by Ad-mediated overexpression of VEGF and was blocked by expression of soluble Flt-1. Collectively, these data suggest that up-regulation of PlGF in sepsis is an adaptive host response that exerts its benefit, at least in part, by attenuating VEGF signaling.

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Immunoglobulin (Ig) administration via the subcutaneous (s.c.) route has become increasingly popular in recent years. The method does not require venous access, is associated with few systemic side effects and has been reported to improve patients' quality of life. One current limitation to its use is the large volumes which need to be administered. Due to the inability of tissue to accept such large volumes, frequent administration at multiple sites is necessary. Most studies conducted to date have investigated the use of subcutaneous immunoglobulin (SCIg) in patients treated previously with the intravenous (i.v.) formulation. New data now support the use of s.c. administration in previously untreated patients with primary immunodeficiencies. SCIg treatment may further be beneficial in the treatment of autoimmune neurological conditions, such as multi-focal motor neuropathy; however, controlled trials directly comparing the s.c. and i.v. routes are still to be performed for this indication. New developments may further improve and facilitate the s.c. administration route. For example, hyaluronidase-facilitated administration increases the bioavailability of SCIg, and may allow for the administration of larger volumes at a single site. Alternatively, more concentrated formulations may reduce the volume required for administration, and a rapid-push technique may allow for shorter administration times. As these developments translate into clinical practice, more physicians and patients may choose the s.c. administration route in the future.

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Mastitis induced by Escherichia coli is often characterized by severe clinical signs, indicating a more powerful combat of the immune system against the pathogen compared with Staphylococcus aureus infections, which are often represented by chronic and subclinical diseases. The aim of this study was to test the major pathogenic component lipopolysaccharide (LPS) from E. coli and lipoteichoic acid (LTA) from Staph. aureus for their effects on blood-milk barrier integrity and the related transfer of immunoglobulins and lactate from blood into milk. A similar somatic cell count (SCC) increase was achieved by intramammary challenge of 1 quarter of 5 cows with 20 µg of LTA, and 8 cows with 0.2 µg of LPS (maximum log SCC/mL: 7). Milk IgG(1) concentrations increased in LPS- but not in LTA-challenged quarters. Milk IgG(2) concentrations were increased in treated quarters at 3h after LPS, and 6h after LTA challenge. Higher maximum levels of IgG(2) were reached in milk of LPS-treated quarters (173 ± 58 μg/mL) than of LTA-challenged quarters (62 ± 13 μg/mL). Immunoglobulin G(1) and IgG(2) levels did not change in control quarters. l-Lactate concentrations in milk increased 4h after LPS and 5h after LTA challenge and reached higher maximum levels in LPS- (221 ± 48 mg/L) than in LTA-treated quarters (77 ± 18 mg/L). In conclusion, a mammary inflammation on a quantitatively similar level based on SCC increase achieves a more efficient transfer of blood components such as IgG(2) via the blood-milk barrier if induced by LPS from E. coli than by LTA from Staph. aureus. This pathogen-specific difference may play an important role in the cure rate of the respective intramammary infection, which is usually lower in Staph. aureus- than in E. coli-induced mastitis.

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Therapy by human immunoglobulin G (IgG) concentrates is a success story ongoing for decades with an ever increasing demand for this plasma product. The success of IgG concentrates on a clinical level is documented by the slowly increasing number of registered indication and the more rapid increase of the off-label uses, a topic dealt with in another contribution to this special issue of Frontiers in Immunology. A part of the success is the adverse event (AE) profile of IgG concentrates which is, even at life-long need for therapy, excellent. Transmission of pathogens in the last decade could be entirely controlled through the antecedent introduction by authorities of a regulatory network and installing quality standards by the plasma fractionation industry. The cornerstone of the regulatory network is current good manufacturing practice. Non-infectious AEs occur rarely and mainly are mild to moderate. However, in recent times, the increase in frequency of hemolytic and thrombotic AEs raised worrying questions on the possible background for these AEs. Below, we review elements of non-infectious AEs, and particularly focus on hemolysis and thrombosis. We discuss how the introduction of plasma fractionation by ion-exchange chromatography and polishing by immunoaffinity chromatographic steps might alter repertoire of specificities and influence AE profiles and efficacy of IgG concentrates.

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Sepsis is a major cause for death worldwide. Numerous interventional trials with agents neutralizing single pro-inflammatory mediators have failed to improve survival in sepsis and aseptic systemic inflammatory response syndromes. This failure could well be explained by the widespread gene expression dysregulation known as "genomic storm" in these patients. A multifunctional polyspecific therapeutic agent might be needed to thwart the effects of this "storm". Licensed pooled intravenous immunoglobulin preparations seemed to be a promising candidate but they have also failed in their present form to prevent sepsis-related death. We report here the protective effect of a single dose of intravenous immunoglobulin preparations with additionally enhanced polyspecificity in three models of sepsis and aseptic systemic inflammation. The modification of the pooled immunoglobulin G molecules by exposure to ferrous ions resulted in their newly acquired ability to bind some pro-inflammatory molecules, complement components and endogenous "danger" signals. The improved survival in endotoxemia was associated with serum levels of pro-inflammatory cytokines, diminished complement consumption and normalization of the coagulation time. We suggest that intravenous immunoglobulin preparations with additionally enhanced polyspecificity have a clinical potential in sepsis and related systemic inflammatory syndromes.

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The number of immunoglobulin G constant heavy chain genes (cgamma genes) varies broadly among mammalian species, reflecting structural and functional differences between expressed immunoglobulin G (IgG) isotypes and allotypes. Up to now equine IgG isotypes have been defined only at the biochemical and serological level. It is still not clear how many IgG isotypes exist in horses and whether there are any allotypes. Here, we describe the isolation and characterisation of equine cgamma genes. An equine genomic lambda phage library was screened with a human cgamma4 probe. Cross-hybridising equine cgamma sequences were cloned twice and characterised by restriction mapping with the human cgamma4 and a murine sgamma1 probe. Genomic equine DNA probes for both, cgamma genes and corresponding switch regions (sgamma), were isolated and used for a more detailed BamHI restriction analysis, comparing genomic DNA of various horses. This analysis reveals the existence of at least five, or probably six cgamma genes in the equine haploid genome. Beside the porcine system, this is the highest number of cgamma genes described for any mammalian species. Moreover, for two of these cgamma genes, BamHI restriction fragment length polymorphism became evident.

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During pregnancy, most patients with rheumatoid arthritis (RA) experience spontaneous improvement of their disease activity. Among the soluble candidates that have been investigated in search for the most relevant disease-remitting factor are the galactosylation levels of immunoglobulin G (IgG). In RA, a higher percentage of IgG lacking the terminal galactose residues, thought to play a pro-inflammatory role, is found. During pregnancy, however, IgG galactosylation levels increase and correlate with improved disease activity. The question remains whether the increase in IgG galactosylation during pregnancy is a mere epiphenomenon or a true remission-inducing factor.

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We screened 735 HIV-infected patients in Switzerland with unexplained alanine aminotransferase elevation for hepatitis E virus (HEV) immunoglobulin G. Although HEV seroprevalence in this population is low (2.6%), HEV RNA can persist in patients with low CD4 cell counts. Findings suggest chronic HEV infection should be considered as a cause of persistent alanine aminotransferase elevation.