Effect on cardiovascular function and iron metabolism of the acute removal of 2 units of red cells

Effect of large volume red blood cell apheresis on cardiovascular functions in healthy donors

BACKGROUND

Requirements of blood transfusions rise rapidly in China. Improving the efficiency of blood donation could help maintaining sufficient blood supplement. We conducted a pilot research to investigate the reliability and safety of collecting more units of red blood cell by apheresis.

METHODS

Thirty-two healthy male volunteers were randomized into two groups: red blood cell apheresis (RA) (n = 16) and whole blood (WB) donation (n = 16). RA group donated individualized RBC volumes by apheresis according to the volunteers' basal total blood volumes and haematocrit levels, WB group donated 400 mL whole blood. All volunteers were scheduled seven visit times in 8 weeks' study period. The cardiovascular functions were assessed by laboratory examinations, echocardiography and cardiopulmonary functional tests. All results were compared between groups at the same visit time and compared between visit 1(before donation) and other visit times within the same group.

RESULTS

The average donated RBC volume in RA group and in WB group was 627.25 ± 109.74 mL and 175.28 ± 8.85 mL, respectively(p < 0.05); the RBC, haemoglobin and haematocrit levels changed significantly between times and between groups (p < 0.05). Cardiac biomarker levels such as NT-proBNP, hs-TnT and CK-MB did not change significantly between times or between groups (p > 0.05). The echocardiographic and cardiopulmonary results did not change significantly between times or between groups during the whole study period(p > 0.05).

CONCLUSIONS

We provided an efficient and secure method for RBC apheresis. By harvesting more RBC volumes at one single-time, the cardiovascular functions did not change significantly compared with traditional whole blood donation.

Impact of allogeneic 2-RBC apheresis on iron stores of Brazilian blood donors

One limiting factor for automated two-red blood cells collections (2-RBC) is its potential iron depletion. We analyzed hematological parameters and iron balance before, two and four months after 2-RBC of 96 non-supplemented male donors. Four months after 2-RBC, ferritin level was significantly lower (P<0.01) than baseline levels and the number of donors who presented ferritin <30 ng/ml increased from 18 to 47. We concluded that four months was not sufficient for iron recuperation in the population studied. In an attempt to avoid iron depletion after 2-RBC, we recommend augmentation in the interval between blood donations and pre-donation ferritin measurement.

[Therapeutic erythrocytapheresis: technical aspects and clinical applications]

PURPOSE

Therapeutic erythrocytapheresis is a selective red cell-depletion aphaeresis technique.

CURRENT KNOWLEDGE AND KEY POINT

Using a discontinuous or continuous flow blood cell separator, the technique safely allows quickly and automatically collecting a large volume of red cells. The main obstacle of implementation is a poor peripheral venous access. The procedure is well-tolerated. Polycythemia vera, hereditary hemochromatosis, complicated sickle-cell-disease and retinal venous occlusion are the main clinical applications.

PROSPECT AND PROJECT

Therapeutic erythrocytapheresis is a more modern and more effective method than the classic patient-bleeding. It has to be preferred in the early treatment of patients with polycythemia vera and hereditary hemochromatosis.

Automated red cell collection--quality and value

Automated red cell collection was initially used largely for therapeutic purposes. New technology has rendered the procedure safer for donors and easier for machine operators. Optimal additive solution can be automatically added and the red cells filtered to provide a leucodepleted product. Two units of red cells may be collected during a single procedure from individuals who have a high enough red cell mass, whilst a single unit of red cells plus platelets or plasma can be collected from smaller donors. In vitro studies suggested that red cells collected by automated methods would be of better quality than those collected by gravity. This was not confirmed in vivo, but red cells collected by automated methods have the major advantage of consistency in terms of haemoglobin content, volume and haematocrit, compared with red cells collected by gravity. This standardised product is of particular value for transfusion dependent patients as the patient's haemoglobin can be maintained within narrow limits. The use of a double dose red cell product for transfusion to a single patient also confers benefit in terms of reduction in donor exposure.

Safety of RBC apheresis and whole blood donation in allogeneic and autologous blood donors

Automated red cell collection is now a well-established technology. As with any new method, the risks and benefits must be weighed against older approaches, in this case manual collection. Although widely perceived to be safe, manual collection is associated with a number of potential complications, some of which can be serious, even debilitating. The safety record of 2-RBC and other RBC automated procedures is excellent. Physiologic, cardiovascular, and neurocognitive responses are modest and fall within those seen for manual collection. The long term effects related to erythropoietic response and iron loss are manageable and are similar to the effects of repeated whole blood donation. The collection of whole blood by manual means has been performed for nearly a century and as result the safety of this procedure is assumed. Conversely, the safety of automated collection in general and particularly RBC has had to "prove" itself, primarily because it is much more recent and is a different paradigm. Millions of procedures have been performed using both approaches. The blood donor, the "raw material" which makes hemotherapy possible, is the essential enabler in these processes. This article examines the complications of both manual and automated RBC collection.

Multicomponent apheresis blood collection in the United States: Current status and future directions

Transfusion medicine in the USA confronts the ongoing challenges posed by a worsening blood supply, regulatory pressure, public pressure for increased safety and cost pressure. Multicomponent apheresis collection (MAC) is a powerful tool for addressing these issues. There are both clinical and operational advantages to MAC. The most important MAC procedures currently performed are platelet and two-red blood cell apheresis. Both procedures are growing in importance to the blood supply as the demand for platelets and red blood cells (RBC) increase. As the demand for safer and more standardized blood components increases, red cell apheresis may possibly become the collection standard.

Iron supplementation and 2-unit red blood cell apheresis: a randomized, double-blind, placebo-controlled study

BACKGROUND

The benefits of 2-unit red blood cell (RBC) apheresis are evident, but iron depletion may be a limiting factor in using this technology. Regular iron supplementation may allow a better utilization of this technique.

STUDY DESIGN AND METHODS

In this study, 260 regular blood donors donated 2-unit RBCs on each of a total of seven visits at intervals of 8 to 10 weeks. The volunteers were randomly assigned to receive 100 mg of iron(II) or placebo daily. Group A received iron capsules after the first three donations, and Group B after the second three donations, respectively. Hemoglobin, serum ferritin, and serum iron were measured before each donation.

RESULTS

Mean serum ferritin concentration decreased after each donation in the placebo phase of both treatment groups, but it remained largely constant during the iron phase in Group A, and even increased during the iron phase in Group B.

CONCLUSION

Regular iron supplementation prevents iron depletion in the majority of donors after 2-unit RBC apheresis within an 8- to 10-week period.

Restoration of red blood cell volume following 2-unit red blood cell apheresis

BACKGROUND AND OBJECTIVES

Blood donors who weigh at least 130 lbs (59 kg) and have a haematocrit of at least 40 V per cent can donate 2 units of blood, from which a 360-ml volume of red blood cells (RBC) can be isolated. This study was carried out in seven healthy male blood donors to assess the restoration of the RBC volume 1 month following a 2-unit RBC apheresis procedure.

MATERIALS AND METHODS

RBC volumes were measured prior to donation and 4 weeks after the 2-unit RBC apheresis procedure without oral iron supplementation.

RESULTS

Four weeks after the removal of 2 units of RBC from the male donors not supplemented with oral iron, the RBC volume was restored to 92% of the precollection value. The 360-ml volume of RBC collected represented 12-19% of the donor's original RBC volume.

CONCLUSIONS

Male donors can safely donate 2 units of RBC and will restore a mean of 92% of their RBC volume within 1 month without iron supplementation.

Prolonged iron depletion after allogeneic 2-unit RBC apheresis

BACKGROUND

Allogeneic 2-unit RBC apheresis is a safe procedure offering many advantages for donors and blood banks. A controlled study was performed to determine whether the recommended minimum interval of 4 months between 2-unit RBC apheresis donations is appropriate in terms of the recovery of RBCs and the regeneration of iron stores.

STUDY DESIGN AND METHODS

Twenty male subjects each donated 2 units of RBCs by apheresis. The RBC count, reticulocyte count, EPO, and measures of iron status were analyzed before and during the 4 months after donation.

RESULTS

A significant decrease in Hb (15.89 +/- 0.82 [mean +/- SD] vs. 14.08 +/- 0.97 mg/dL, baseline vs. Day 7; p<0.001) was equalized within 2 months. In contrast, ferritin values declined significantly from 54.2 +/- 33.7 to 23.42 +/- 21.94 microg per L (predonation vs. Day 30) and remained significantly below predonation values, but within the normal range, until the end of the study period.

CONCLUSION

A donation interval of 4 months is appropriate in terms of RBC recovery, but may not be appropriate in terms of iron store regeneration. The tendency to shorten the donation interval should be reconsidered in light of the measurements of iron storage. The use of ferritin levels is recommended as a preselection criterion for allogeneic 2-unit RBC apheresis.

A pilot study of large volume apheresis of red blood cells and plasma during one donation by allogeneic blood donors

As a pilot study, we assessed large volume apheresis of red blood cells (RBC) and plasma. The protocol was as follows: (a) 3-RBC group: 3 units (240 ml) of RBC were drawn, (b) RBC+P group: 2 units (160 ml) of RBC and 400 ml of plasma were drawn during one apheresis procedure, and (c)

CONTROL GROUP

400 ml of whole blood was drawn by a manual method. Each group contained 7 healthy male donors of body weight 54-65 kg. We were able to perform these apheresis procedures without serious complications. Recovery of RBC for the donors of the 3-RBC group was delayed, but the level returned to the pre-donation level within nine weeks. The decreased total protein and albumin in the RBC+P group recovered within one week. The apheresed RBCs demonstrated the same quality as the manually collected RBC. These findings suggest that this apheresis approach may be applicable for routine donation.

Evaluation of a particle-enhanced turbidimetric immunoassay for the measurement of ferritin: application to patients participating in an autologous blood transfusion program

OBJECTIVES

To evaluate a turbidimetric immunoassay for the measurement of ferritin, and to assay this method in a group of patients undergoing an autologous blood transfusion program.

DESIGN AND METHODS

We used an ILab 900 analyzer. This instrument automates a particle-enhanced immunoturbidimetric assay with an analysis time of 9 min. This technique was compared with a microparticle immunoassay. The turbidimetric assay was used to measure ferritin in a group of 30 patients undergoing an autologous blood transfusion program.

RESULTS

The assay was linear in the range 3-1400 microg/L (r = 0.9999). The intra- and inter-assay imprecision (CV) at 20, 97 and 469 microg/L were <3.0 and <5.0%, respectively. Recovery was 88. 7 to 97.4%. The detection limit was 3 microg/L. Hemoglobin (</=4 g/L), mild hyperbilirubilinemia (bilirubin </=50 micromol/L), triglycerides (</=10 mmol/L) and myeloma paraproteins did not interfere with the assay. The assay showed good correlation with a microparticle enzymoimmunoassay (r = 0.994) with a mean difference between methods of -6 +/- 16 microg/L. This method was sensitive, accurate, and fast enough for an efficient follow-up of autologous blood transfusion patients.

CONCLUSIONS

The new automated serum assay for ferritin is an attractive alternative that avoids the need for dedicated instrumentation.