Symptoms of fever and/or rigours after transfusion continue to occur commonly in patients receiving platelets leucocyte-reduced after storage. A cohort of 24 consecutive patients who had experienced severe or repeated febrile nonhaemolytic reactions to post-storage leucocyte-reduced platelet transfusions were treated with saline-washed, post-storage leucocyte-reduced platelets. The frequency of reactions declined from 20% of transfusions (n = 191) to 0.6% (n = 331) after instituting saline-washed, post-storage leucocyte-reduced platelet transfusions. These results support the hypothesis that substances present in the supernatant of stored platelet concentrates mediate febrile nonhaemolytic transfusion reactions, and provide one strategy for preventing their occurrence.
An implementation trial of leukocyte-reduced transfusions in cardiac surgery (primary coronary artery bypass graft and valve replacement) was performed from July to December 1998; comparisons were made with data from the same period in 1997. Patients from both periods were similar in important preoperative and intraoperative variables (age, sex, weight, number of units of RBCs transfused, ejection fraction). The mean total number of complications was statistically significantly decreasedfrom 0.26 complications per patient in the non-leukocyte-reduced to 0.19 in the leukocyte-reduced recipients. Overall, the mean +/- ISD costs of care per patient decreasedfrom 1997 ($27,615 +/- $33,973) to 1998 ($27,038 +/- $24,107). Mean costs decreased $1,700 per patient for recipients of leukocyte-reduced blood in 1998 compared with recipients of non-leukocyte-reduced blood in 1997 Mean costs increased $4,000 per patient in patients who did not receive transfusions in 1998 compared with 1997. Hospitalization costs decreased when leukocyte-reduced transfusions were implemented for patients undergoing cardiac surgery in our institution. Implementation of leukocyte reduction may be cost neutral or cost saving in at least some settings.
A method for the correction of background fluorescence in flow cytometry with special relevance to the quantitation of low levels of cellular surface membrane antigens is presented. The method is based on the mathematical modeling of cellular fluorescence distributions of background fluorescence (autofluorescence control or irrelevant antibody control) and total fluorescence (positively stained cells). Algorithms based on two models and utilizing only the routinely available background and total fluorescence histograms are developed and implemented in computer programs. These allow estimation of the fluorescence histogram corresponding exclusively to immunofluorescence staining of the cell surface antigen of interest. Thus, the correction of background fluorescence is effected solely with software processing of routinely available data; no additional hardware or parameter determinations are necessary.Two models were chosen to be physically plausible and to represent extremes in correlation between background and probe fluorescence. Extremes were chosen to assess the solution dependence on model and to provide bounds to the actual solution when no information on correlation is available. Results are presented for both computer simulations and for an actual assay of the CR1 complement receptor on human erythrocytes to test and illustrate the technique. Alternatively, data can be tested assuming a particular model to explore the relationship, if any, between specific and nonspecific fluorescence.Key terms: Immunofluorescence quantitation, CR1 complement receptor, deconvolution Quantitation of cell surface membrane antigens with flow cytometric immunoassay is problematic when cellular immunofluorescence is only slightly more intense than cellular autofluorescence andor fluorescence from nonspecific binding of immunoreagents. As there are experimental limitations to the optimization of the signal-to-noise ratio, it is desirable to have a method available to separate autofluorescence and nonspecific fluorescence from total cellular fluorescence in flow cytometric immunoassays to increase sensitivity. Additionally, as flow cytometry is one of the few techniques allowing parameter determination on a cell-by-cell basis, any truly useful technique for the correction of autofluorescence should ideally preserve this characteristic. To these ends, several recent reports have appeared describing various strategies for dealing with autofluorescence. Roederer and Murphy (6) presented a cell-by-cell autofluorescence correction for low signal-tonoise systems by simultaneous measurement of another parameter highly correlated with the autofluorescence and not affected by fluorescence from the relevant fluorochrome. Steinkamp and Stewart (9) reported the use of a dual laser system for cell-by-cell autofluorescence correction in which the first laser excites both autofluorescence and probe fluorescence and the second laser, spatially 250-300 Frn away and at a shorter wavelength, excites autofluorescence and also probe fluorescence, ...
We hypothesized that antibodies to HLA-linked polymorphic plasma proteins could be involved in platelet refractoriness by an 'innocent bystander' or immune complex mechanism. Employing a kinetic enzyme-linked immunosorbent assay (ELISA) technique the ability of IgG from the plasma of refractory patients to bind to albumin, fibrinogen, complement components C2 and C4 was measured. As compared with controls a high percentage of refractory patients had increased IgG capable of binding to all four plasma proteins: C2 (83%), C4 (83%), albumin (75%), fibrinogen (34%). In the presence of exogenous plasma proteins these antibodies mediated increased deposition of IgG onto normal donor platelets. The plasma protein binding IgG consisted both of monomeric IgG and a broad range of high molecular weight complexes. IgG anti-plasma protein antibody could be eluted from platelets of refractory patients. The development of anti-plasma protein IgG was studied during the course of platelet transfusion therapy and found to increase progressively so that by the 20th transfusion greater than 90% of samples were positive. The presence of plasma protein binding activity correlated with the development of increased levels of platelet bound IgG and refractoriness. Multiple platelet transfusions lead to sensitization to polymorphic determinants on C2 and C4 as well as the formation of high molecular weight complexes. These antibodies and complexes contribute to the deposition of IgG on platelets and may contribute to refractoriness.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.
Copyright © 2025 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.