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M J Seghatchian

Publications and source records attributed to M J Seghatchian.

At least 37 records · Page 2Linked to original sources
PubMed1996

Cytokine levels in platelet concentrates: quantitation by bioassays and immunoassays.

Some adverse reactions to the transfusion of platelet concentrates (PCs) cannot be attributed to antibodies against blood cells or to subclinical microbial agents. It has been suggested that leucocyte-derived inflammatory cytokines such as interleukin (IL)-1, IL-6 and tumour necrosis factor (TNF) may contribute to a larger number of unexplained non-antibody-mediated adverse reactions. Three types of PCs, containing different levels of leucocytes, are currently produced. Filtration is used on demand to further reduce leucocyte contamination of these components. we have monitored the plasma of PCs prepared by the platelet-rich plasma method (PRP), the buffy-coat method or by apheresis for IL-6, IL-1, transforming growth factor-beta (TGF-beta), TNF and interferon gamma (IFN gamma). Biologically active IL-6 increased in stored PRP-PCs from a mean of 140 pg/ml on day 1 to 2395 pg/ml on day 5/6. Elevated levels of IL-8, as detected by immunoassay, were evident in PRP-PCs during routine storage under blood bank conditions. Small amounts of immunoreactive IL-1 with only minimal biological activity were present in some PRP-PCs by day 5/6. No significant increase in the levels of IL-8, IL-6 or IL-1 were seen in buffy-coat PCs during storage for 5/6 d. For apheresis PCs, an increase in IL-8 content, but not in IL-6 over 6 d was observed. In all three types of PCs, elevated amounts of both bioactive and immunoreactive TGF beta were present, but there was no evidence of any biologically active or immunoreactive TNF alpha. Pre-storage filtration of PRP-PCs for depletion of leucocytes prevented the increase in IL-8 and IL-6 levels of these PCs. Our results show that leucocyte reduction by buffy-coat method reduces cytokine levels to a comparable level to filtered or apheresis PCs, containing low levels of leucocytes, but use of these PCs in minimizing the severity and incidence of reactions in recipients will require clinical evaluation. This is the first comprehensive and comparative study which, on the basis of biological activity of cytokines, directly indicates that the mode of platelet production grossly influences the levels of cytokines.

Biological Assay↗
PubMed1996

New horizons in blood transfusion medicine: present status and future trends.

In the past two decades, we have witnessed enormous advances in all areas of transfusion medicine, from simple and practical aspects of blood component collection and processing to the development of "designer products" and the use of recombinant products or other alternatives. Considerable efforts were directed, in particular, towards transfusion support for specific categories of patients, such as neonates and those undergoing transplant procedures, where patients' clinical states ultimately influence the choice of product(s) and where emphasis should be placed on both the optimisation of clinical effectiveness and safety, as well as minimising the adverse/untoward effects of transfusion. The objective of this Forum Discussion is to provide an overview of what is currently on the horizon and then describe the potential changes that are expected on the new horizon, within the next decade. In this BBTS-Component Special Interest Group, therefore, we have attempted to build a bridge between the new expanding areas of related specialties at both cellular and molecular levels and the equally important practical and clinical aspects. Thus, alongside the presentation on the overall safety/efficacy of standard products, the potential use of some alternatives and recombinant products were discussed. Emphasis is also placed on the new generation test for function testing and the potential application of DNA-based technologies in blood transfusion, which will continue to be more innovative in respect to the avoidance of transfusion associated infections and its immunological risks, and will bring about continual improvement of the clinical effectiveness of products derived from human blood.

Blood Transfusion↗
PubMed1995

Transfusion-associated graft-versus-host disease: current concepts and future trends.

Since the initial reports, in the early 1960s, of Transfusion-Associated Graft-versus-Host Disease (TA-GVHD) in infants with congenital immunodeficiency and individuals with various haematological malignancies, our knowledge of this rare but uniformly fatal consequence of transfusion has improved. Today, it is possible to define with greater certainty patients who are most at risk; the blood components capable of causing TA-GVHD; and the methods for preventing TA-GVHD. In the absence of effective treatment for TA-GVHD, attention is currently focused on potential preventative measures, in particular using u.v.- or gamma-irradiated blood components. This overview deals with some general aspects of the current concepts and future trends in treatment of TA-GVHD.

Blood Transfusion↗
PubMed1995

Platelet transfusion.

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Antigens, Human Platelet↗