PubMed · 3050306
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M de Salas, G Navarro. 1988-05-28. [Autotransfusion].. https://pubmed.ncbi.nlm.nih.gov/3050306/
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Studies comparing transfusion and nontransfusion patients suggest an increased risk of postoperative infections in transfusion groups. Supernatants of blood components have been shown to affect the function of T lymphocytes and natural killer cells. Here, we found that supernatants from stored red blood cells (RBCs) inhibit human neutrophil migration in response to formyl peptides and stimulate neutrophil locomotion. These effects can be observed with high dilutions of RBC supernatants, such as 1:5 x 106 (vol/vol), able to trigger locomotion as well as desensitization of the cells to alternative chemoattractants. The phenomenon might be mediated by chemoattractants present in the supernatants. As RBC supernatants failed to mobilize intracellular free calcium, the chemoattractants should belong to the group of pure chemoattractants, that is, soluble Fas ligand (sFasL) and transforming growth factor-beta1 (TGF-beta1), known to act without increasing calcium levels. Recombinant TGF-beta1, but not sFasL, was found to reproduce the ability of RBC supernatants to both inhibit neutrophil response to formyl peptides and stimulate neutrophil locomotion. Moreover, TGF-beta1-immunodepleted supernatants did not display neutrophil-directed activities. Finally, RBC supernatants from RBCs stored after depletion of leukocytes were incapable of affecting neutrophil function. With neutrophils acting as a first-line antimicrobial defense, the ability, shown here, of high dilutions of RBC supernatants to inhibit neutrophil chemotaxis through TGF-beta1 may be a relevant determinant of infections in the postoperative period for transfusion patients. Consistently, the neutrophil chemotactic response to formyl peptide was inhibited by the plasma obtained from 5 transfusion patients.
OBJECTIVE: To determine whether significant changes in the plasma concentrations of 17 hormones occur when human whole blood is held at 4 or 24 degrees C for up to 24 h before separation of the plasma fraction. DESIGN AND METHODS: Blood samples (EDTA) from healthy human volunteers were held at 4 degrees C or 24 degrees C for 0.5, 6 or 24 h before separation. Plasma concentrations of ACTH, aldosterone, gonadotrophin alpha-subunits, AVP, C-peptide, estradiol, FSH, GH, glucagon, IGF-1, IGFBP3, insulin, leptin, LH, prolactin, PTH and VIP were measured and the results compared to baseline values. Nonlinear regression was used to test for a significant mean rate of change. The time interval for median concentrations to change by 10% was determined. RESULTS: Significant changes were observed for ACTH (decrease at 18.6 hr, 4 degrees C; 17.5 hr, 24 degrees C); AVP (increase at 2.6 h, 24 degrees C); insulin (decrease at 16.8 hr, 4 degrees C; 16.9 hr, 24 degrees C) and VIP (increase at 18.6 h, 24 degrees C). No changes were detected for the remaining analytes.B CONCLUSIONS: The measurement of some hormones is compromised by a delay in plasma separation from normal human blood. While many hormones appear stable in normal whole blood, we recommend that processing occurs without delay.