Distribution of citrate and citrate infusion rate during donor plasmaphereses

A donor safety evidence literature review of the short- and long-term effects of plasmapheresis

Many blood establishments are expanding plasmapheresis collection capacity to achieve increasing plasma for fractionation volume targets, driven by immunoglobulin product demand. Some adverse events occur in both apheresis and whole blood collection, such as venepuncture-related trauma and vasovagal reactions. Others are specifically related to the apheresis procedure, such as citrate reactions, haemolysis, infiltration and air embolism. Whilst plasmapheresis procedures are generally well tolerated, theoretical longer term donor health considerations, such as the effects on donor plasma protein levels, bone mineral density, iron deficiency and malignancy also require consideration. An evidence-based framework that supports a safe and sustainable increase in the collection of plasma is essential. Our review demonstrates a lack of high-quality evidence on risks and outcomes specifically in plasmapheresis. Whilst conservative procedural controls and donor harm minimization policies will mitigate risk, high-quality evidence is needed to facilitate practice change that is safe and sustainable and maximizes the potential of individual donor differences.

Quantitative assessment of the anticoagulant in plasma units collected by plasmapheresis

BACKGROUND

To date, the quantification of the anticoagulant (ACD-A) in plasma units has been based on theoretical calculations. An accurate quantification could help minimize the risks associated with plasmapheresis, given that the total ACD-A used during the procedure is distributed between the donor and the plasma unit. Our aim was to experimentally quantify the volume of ACD-A in units collected by plasmapheresis.

STUDY DESIGN AND METHODS

We used proton nuclear magnetic resonance spectroscopy to measure the ACD-A volume in 295 plasma units collected by the Azienda USL-IRCCS of Reggio Emilia, Italy. We analyzed the determinants of the differences between estimated and measured ACD-A through multivariate regression models.

RESULTS

The experimentally measured ACD-A in plasma units was variable, with 45% of the samples showing a discrepancy of more than 15 mL compared to the manufacturer's estimate. ACD-A was underestimated for higher density of the units (p < 0.0005); a weak association was also observed with triglycerides (underestimated for higher levels, p = 0.015) and sex (overestimated in females, p = 0.008), but our model explained only 35% of the individual variability.

CONCLUSION

The manufacturer's algorithms do not accurately estimate the ACD-A in units collected by plasmapheresis. Donor-related characteristics may affect ACD-A distribution between donor and plasma unit, thereby explaining the discrepancies between estimate and measurement. Errors in the estimate of the ACD-A actually received by donors could hamper studies on dose-response relationship between anticoagulant and adverse reactions. Our work should stimulate research on tailored procedures aimed at minimizing the anticoagulant received by donors and increasing plasmapheresis safety.

Impact of frequent apheresis blood donation on bone density: A prospective, longitudinal, randomized, controlled trial

Background

Blood for transfusion is lifesaving and essential to many elements of modern medical practice. The global blood supply relies on volunteer blood donors. Apheresis is increasingly used to collect blood and requires anticoagulant to prevent extracorporeal coagulation. Citrate, the standard apheresis anticoagulant, chelates ionized calcium with consequent perturbations of serum calcium, parathyroid hormone, vitamin D, and markers of bone remodeling in donors. Cross-sectional studies of bone mineral density (BMD) among apheresis donors exhibit conflicting results.

Methods

The longitudinal, randomized, controlled ALTRUYST trial (NCT02655055) was undertaken to determine whether BMD declined following high frequency apheresis blood donation over 1 year. The study was powered at 80% to detect the primary outcome of a 3% decline in BMD. Subjects new to apheresis agreed to make ≥20 apheresis donations in a one-year period and were randomized to treatment (high frequency apheresis) or control (no apheresis). Dual-energy x-ray absorptiometry was performed before and after participation. Two-sided t-test and multivariable logistic regression were used to assess outcomes.

Findings

Mean lumbar spine BMD did not change during the study among control donors (−0.002 g/cm², 95%CI [−0.020, 0.016], p = 0.78), or among donors in the apheresis arm (mean change = 0.007 g/cm², 95%CI [−0.005, 0.018], p = 0.24). Mean total hip BMD did not change for control donors (mean change = 0.002 g/cm², 95%CI [−0.006, 0.009], p = 0.63) or apheresis donors (−0.004 g/cm², 95%CI [−0.10, 0.002], p = 0.16). Tests for differences in proportions of donors with change in BMD exceeding the least significant change at the lumbar spine in either a positive [8 apheresis (31%), 4 control (27%), p = 0.78] or negative direction [4 apheresis (15%), 5 control (33%)] were statistically non-significant (p = 0.18). Proportional increases [0 apheresis (0%), 1 control (7%), p = 0.18] and decreases [3 apheresis (12%), 1 control (14%)] were also not significantly different at the total hip (p = 0.61).

Interpretation

ALTRUYST is the first longitudinal trial to demonstrate that apheresis blood collection guidelines in the United States adequately protect the skeletal health of male volunteer blood donors.

Funding

Marquette University and the BloodCenter Research Foundation.

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ALTRUYST (NCT02655055) was a prospective RCT.

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It tested if BMD declined following high frequency apheresis blood donation.

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High frequency apheresis blood donation did not affect lumbar spine BMD.

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High frequency apheresis blood donation did not affect total hip BMD.

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High frequency apheresis blood donation did not affect trabecular bone score.

Anticoagulation, bleeding, and clotting at donor plasmapheresis

This article is based on a question of a colleague from North America how coagulation could be triggered between a donor's arm and a fistula needle during plasma donation (synonymous with donor plasmapheresis). The technique of venipuncture and citrate anticoagulation are described. Uncommon and rare problems such as prolonged bleeding, scarring, and thrombosis in plasma donors are discussed. If venous puncture and citrate: blood flow ratio at 1:16 are correctly performed, however, there will be no anticoagulation abnormalities due to plasma donation.

Report on 50 cases of severe acute hypotension at donor plasmaphereses: treatment and course

INTRODUCTION

This paper reports our experience in 50 cases with severe hypotensive reactions at plasma donations (synonymous with donor plasmaphereses).

METHODS

Plasma donors who developed a severe acute hypotensive reaction at donor plasmapheresis, and were treated by placing the donor in the Trendelenburg position and rapid infusion of 1,000 mL saline were investigated. Plasmaphereses were performed with the Haemonetics® plasma collecting system 2 (PCS2). The results were analyzed using Excel.

RESULTS

We observed 50 severe hypotensive reactions in plasma donors. The average systolic and diastolic blood pressures (SBP, DBP) were 128/75 mmHg - and heart rates were 78 beats/min (B/M) before plasmaphereses, 83/56 mmHg - 60 B/M at the event, and after treatment 119/71 mmHg - 69 B/M at the time of discharge. The volume of collected plasma was 602 ± 240 mL including anticoagulant (AC). The time until the event was 45 ± 20 minutes. With treatment 49 ± 18 minutes after the event all plasma donors had normal blood pressures and heart rates and could safely leave the center.

CONCLUSIONS

Treatment by placing the donor in the Trendelenburg position and rapid infusion of 1,000 mL saline appears to be an effective procedure for resolving severe acute hypotension associated with donor plasmaphereses.

No association between frequent apheresis donation and risk of fractures: a retrospective cohort analysis from Sweden

BACKGROUND

Citrate anticoagulation during apheresis induces transient alterations in calcium homeostasis. It is unknown whether the repeated, transient alterations in calcium homeostasis experienced by repeated apheresis donors affects bone turnover to increase fracture risk. Our aim was to investigate the risk of osteoporotic and nonosteoporotic fracture among voluntary, frequent apheresis donors.

STUDY DESIGN AND METHODS

All apheresis donors were identified from the Scandinavian Donations and Transfusions database (SCANDAT2), which includes information on over 1.6 million blood donors from Sweden and Denmark from the years 1968 and 1981, respectively. Only data from Sweden were used for these analyses. Information on fractures was obtained by linking SCANDAT2 to hospital registers. Poisson regression was used to compute incidence rate ratios of fractures in relation to the cumulative number of apheresis donations, both overall and in fixed time windows.

RESULTS

In total, 140,289 apheresis donors (67,970 women and 72,319 men) were identified from the SCANDAT2 database and were followed for up to 23 years. We observed no association between the frequency of apheresis donation and the risk of fracture either in the overall study period or during fixed-length time windows. The incidence rate ratio of fractures in donors who had made 100 or more cumulative apheresis donations was 0.99 (95% confidence interval, 0.92-1.06) compared with donors who had made from 9 to 24 donations. The results were similar in analyses stratified by sex and restricted to postmenopausal women.

CONCLUSIONS

The absence of an association between repeated apheresis donation and fracture risk indicates that apheresis collection is safe with regard to bone health.