Effect of microfiltration on the histamine levels in stored human blood

Effects of leukoreduction on N-methylhistamine concentration in stored units of canine whole blood

OBJECTIVE

To determine the effects of leukoreduction on N-methylhistamine (NMH; a stable histamine metabolite) concentration in units of canine whole blood during storage and incubation at room temperature (approx 22 °C) to simulate temperature conditions during transfusion.

ANIMALS

8 healthy adult Walker Hounds.

PROCEDURES

A standard unit of blood (450 mL) was obtained from each dog twice, with at least 28 days between donations. Blood units collected from 4 dogs during the first donation underwent leukoreduction, whereas the blood units collected from the other 4 dogs did not undergo leukoreduction, prior to storage at 4 °C. The alternate treatment was applied to blood units collected during the second donation. A sample from each unit was obtained for determination of plasma NMH concentration the day of donation (before and after leukoreduction when applicable) and before and after incubation at room temperature for 5 hours on days 14 and 28 of storage.

RESULTS

Units that underwent leukoreduction had substantially lower leukocyte and platelet counts than nonleukoreduced units. Plasma NMH concentration increased immediately after leukoreduction but did not change significantly during the subsequent 28 days of storage, nor did it differ between units that did and did not undergo leukoreduction.

CONCLUSIONS AND CLINICAL RELEVANCE

Leukoreduction and simulated transfusion temperature did not affect the histamine load in units of canine whole blood during the first 28 days of storage. Further research is necessary to determine whether histamine contributes to the development and severity of blood transfusion reactions in dogs.

Enrichment of human platelet membranes for proteomic analysis

Platelets (thrombocytes) are the smallest human blood cells and are pivotal in processes of hemostasis and thrombosis. Central to their function, the activation of platelets includes a complex interplay of adhesion and signalling molecules mediated via the plasma and inner membrane. Because platelets are enucleated, the analysis of the proteome is the best way to approach their biology. Here, we employ mass spectrometry (MS)-based proteomics to characterise membrane proteins derived from non-stimulated human platelets. This protocol details the extraction and purification of platelet membrane proteins from whole blood using SDS-PAGE in conjunction with LC-MS/MS. This method allowed the identification, and characterization of 207 platelet membrane proteins (PMP) from approximately 9.95 x 10(9) platelets (16).

The effect of cromoglycate on time-dependent histamine and serotonin concentrations in stored blood products

Biogenic amines, having vascular and inflammatory effects, are accepted as a potential threat for some non-hemolytic transfusion reactions. The aim of this study was to investigate time-dependent histamine/serotonin levels in stored blood products and to see whether cromoglycate has any effect on these mediators. Either for platelet or whole blood, 10-fold concentrations of cromoglycate (1 microg ml(-1), 10 microg ml(-1), 100 microg ml(-1)) with controls prepared as pairs of replicate bags collected from two healthy subjects, separately. By using enzyme immunoassay, histamine and serotonin levels were determined in platelet or blood replicates. Histamine levels increased significantly with time but serotonin remained unchanged during the storage of platelet or blood specimens. Cromoglycate had no effect on these biogenic amines except an increase of serotonin in whole blood specimens containing 100 microg ml(-1) of it. So, cromoglycate cannot protect blood products against rising levels of histamine or serotonin.

Filters in anaesthesia and intensive care

The use of various types of filters in anaesthesia and intensive care seems ubiquitous, yet authentication of the practice is scarce and controversies abound. This review examines evidence for the practice of using filters with blood and blood product transfusion (standard blood filter, microfilter, leucocyte depletion filter), infusion of fluids, breathing systems, epidural catheters, and at less common sites such as with Entonox inhalation in non-intubated patients, forced air convection warmers, and air-conditioning systems. For most filters, the literature failed to support routine usage, despite this seemingly being popular and innocuous. The controversies, as well as guidelines if available, for each type of filter, are discussed. The review aims to rationalize the place of various filters in the anaesthesia and intensive care environment.

Separation of buffy coat using the top and bottom drainage system: reduction of red blood cell loss

We studied the effect of automated separation of the buffy coat in a top and bottom "drainage system" using a standard and a modified backplate. The use of the modified method results in reduction of the volume (36 +/-3 mL vs 49 +/-2 mL, P less than 0.001) and the red blood cell content (8 +/- 1% vs 15 +/- 2%, P less than 0.001) of the buffy coat, but also increases the leukocyte content (27 +/- 11% vs 17 +/- 11%, P less than 0.001) of the red cell concentrate. The leukocyte content of the red cell concentrate obtained with the modified method compares well with the reported results of manual buffy coat removal. Therefore the same advantages can be expected.

The role of blood microfilters in clinical practice

Blood filters have been available since the 1930s. In this review we evaluate the role of microaggregate filters (MF) in certain transfusion complications, namely non-haemolytic febrile transfusion reactions (NHFTR), pulmonary injury, thrombocytopenia, fibronectin depletion and histamine release. We review the latest generation of leucocyte depleting filters and discuss their role in preventing alloimmunisation, immunosuppression and CMV transmission. Finally, we provide a rationale for the role of blood microfiltration in the present day practice of intensive care medicine.

Sympathetic activation: a mechanism for morphine induced pain and rises in liver enzymes after cholecystectomy?

In patients with biliary type pain after cholecystectomy, morphine often precipitates pain and may induce rises in plasma concentrations of liver enzymes because of exaggerated or prolonged rises in intrabiliary pressure. In this study, changes in plasma concentrations of catecholamines and histamine were determined after the administration of morphine in patients with and without a two-fold or greater rise in the plasma concentration of aspartate aminotransferase at four hours. Those showing rises in aminotransferase had higher concentrations of noradrenaline at 40 and 60 minutes after morphine and higher concentrations of dopamine at 40 minutes after morphine. The two groups had similar concentrations of adrenaline and histamine. Attempts to inhibit rises in aminotransferase after morphine by pretreatment with histamine, serotonin and alpha-receptor blockers were largely unsuccessful, although inhibition was observed with phenoxybenzamine in two of five patients. Higher plasma concentrations of noradrenaline and dopamine before and soon after induction of pain in patients showing rises in aminotransferase are consistent with sympathetic activation but heterogeneity appears to exist in the response to alpha-receptor blockade.

Influence of blood storage time and plasma histamine levels on the pattern of transfusion reactions

The data from 359 transfusion reactions reported over a 3-year period have been compared with those obtained from 359 matched units given at the same time as the former but not implicated in a reaction. It was found that patients who developed reactions which were not accompanied by a change in body temperature received units with a longer storage time than patients experiencing febrile reactions. In addition it was noted that reactions which included a skin rash also tended to be associated with units stored for longer. In a further prospective assessment plasma histamine levels were measured in a group of 71 patients experiencing 'anaphylactoid', febrile and mixed transfusion reactions as well as in individuals in whom blood transfusions did not cause a reaction. The 'anaphylactoid' reaction group demonstrated a mean plasma histamine level in excess of 1 ng/ml, whereas mean concentrations below 0.50 ng/ml were recorded in the other 3 groups. Our data also suggested that in general, more and 'older' blood was given to the 'anaphylactoid' reactors. The high plasma histamine concentrations could readily contribute to the rash, wheeze and flushing recorded in these individuals. Thus, if a long shelf-life for stored blood is required, strategies which remove histamine from the unit may be worth considering.