Source plasma collection in the United States: Toward a more personalized approach

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.

Large-scale real-world data analysis of source plasma collections using a novel technology-enabled nomogram

BACKGROUND

Source plasma collections are needed to satisfy the growing demand for plasma-derived medicinal products. The US plasma collection target volume has been guided by a standard weight-based FDA-issued nomogram (STAN) since 1992. In this research, large-scale US-based real-world data (RWD) were analyzed to confirm the safety and volume gains of a newly introduced personalized nomogram (PERS) that was previously studied in a premarket randomized controlled environment.

STUDY DESIGN AND METHODS

A non-inferiority (NI) analysis was conducted to compare the novel nomogram's significant hypotensive adverse event (AE) incidence rate with large historical standard nomogram AE datasets. Additionally, the average target volumes and donor return rates were compared for collections following PERS and STAN.

RESULTS

A total of 4,816,784 donations (PERS) by 414,957 donors resulted in a rate of 0.0998% (95% CI [0.0970, 0.1027]) significant hypotensive AEs. NI analysis suggested strong non-inferiority of the new technology (Δ = -0.0082%, 95% CI [-0.0113, -0.0050], prespecified NI margin = 0.1080). Average plasma collection target volumes increased by 66.39 mL (8.49%; p < .0001). Consecutive weekly donor return rates were consistent between the two nomograms (PERS: 73.6%, 95% CI [69.6%-76.7%]; STAN: 74.1%, 95% CI [66.1%-77.2%]).

DISCUSSION

This analysis confirms in a large-scale real-world dataset the key safety parameter and collection benefit of a novel, technology-enabled nomogram. The nomogram may help meet the growing demand for plasma-derived therapies by providing approximately 8.5% more plasma per donation on average while maintaining donor safety and return rates.

Risk factors for T-cell lymphopenia in frequent platelet donors: The BEST collaborative study

BACKGROUND

Severe T-cell lymphopenia of uncertain clinical significance has been observed in frequent apheresis platelet donors. Two commonly used plateletpheresis instruments are the Trima Accel, which uses a leukoreduction system (LRS) chamber to trap leukocytes and the Fenwal Amicus, which does not use an LRS chamber.

STUDY DESIGN AND METHODS

We performed an international, multicenter, observational study comparing T-cell populations in frequent platelet donors collected exclusively using the Trima instrument (n = 131) or the Amicus instrument (n = 77). Age- and sex-matched whole blood donors (n = 126) served as controls.

RESULTS

CD4+ T-cell counts <200 cells/μL were found in 9.9% of frequent Trima (LRS+) platelet donors, 4.4% of frequent Amicus (LRS-) platelet donors, and 0 whole blood donors (p < .0001). CD4+ T-cell counts <200 cells/μL were only seen in platelet donors with ≥200 lifetime donations. In multivariable analysis, age, lifetime donations, and instrument (Trima vs. Amicus) were independent risk factors for lymphopenia. In 40 Trima platelet donors, a plasma rinseback procedure was routinely performed following platelet collections. No Trima platelet donors receiving plasma rinseback had a CD4+ T-cell count <200 cells/μL versus 13/91 Trima platelet donors not receiving plasma rinseback (p = .01).

DISCUSSION

Recurrent bulk lymphocyte removal appears to contribute to the development of T-cell lymphopenia in frequent, long-term platelet donors. Lymphopenia is more common when an LRS chamber is used during platelet collection but can occur without an LRS chamber. Blood centers using LRS chambers can mitigate donor lymphopenia by performing plasma rinseback.

Safety of Plasmapheresis in Donors with Low IgG Levels: Results of a Prospective, Controlled Multicentre Study

Background and Objectives

Although plasmapheresis is generally considered safe, there are still concerns about the long-term effects of plasma donation on immunoglobulin G (IgG) levels. The aim of the present study was to investigate if there is a need to permanently defer donors who donated three times with an IgG level below 6.0 g/L.

Study Design and Methods

From September 2007 to December 2017, adverse events (AEs) including infections were analysed from data of a prospective, controlled multicentre study of healthy volunteer donors, participating in an individualized plasmapheresis programme stratified by initial IgG level and body weight (individualized arm) or in standard plasmapheresis according to national guidelines (control arm). IgG was monitored at every fifth donation, and donors with IgG levels below the threshold were identified and followed up for possible AEs.

Results

In total, 97,540 donations in 1,462 donors in the control arm and 1,491,223 donations in 14,281 donors in the individualized arm were included. Donation-based incidences of at least severe AEs and any infections were 0.019% and 0.192% in the control arm, and 0.014% and 0.153% in the individualized arm. Three or more IgG-measurements below the threshold occurred in 38.2% of control arm donors and 20.9% of individualized arm donors. There were no increased incidence rates of at least severe AEs or any infections in donors with ≥3 IgG-measurements below the threshold in either donor's arm.

Conclusions

Our data show no signs of compromised donor safety in donors with ≥3 IgG-measurements below the threshold, indicating that plasmapheresis is feasible and safe in these donors.

Repeat donation and deferral rates in US source plasma donors: Exploratory analysis from the IMPACT trial

Background

The IMPACT trial demonstrated the safety of a new personalized nomogram for plasma donation and provided an opportunity to explore short‐ to mid‐term impact on repeat donation and deferral rates, and factors affecting these.

Study Design and Methods

In the IMPACT trial, participants were randomized to donate plasma using an established weight‐based nomogram (control) versus a new personalized nomogram incorporating height, weight, and hematocrit (experimental). In this exploratory analysis, repeat donations (per donor, by study arm) were analyzed using negative binomial generalized linear regression models and descriptive statistics. The mean number of donor deferral events was compared between the two arms using logistic regression and count data modeling approaches and were analyzed by lead cause.

Results

The predicted mean number of repeat donations was similar between the control and experimental arms (6.82 vs. 6.62, respectively; p = .22). Overall, the predicted mean number of repeat donations was significantly higher in males compared with females (p < .0001). Naïve donors had on average 2.8/2.7 (control/experimental) fewer repeat donations compared with experienced donors. In 23, 137 donations from 3443 donors, 798 donors (376 control, 422 experimental, p = .80) had at least one deferral (for any cause). The predicted mean number of deferrals in all categories of interest was not statistically different between the study arms.

Conclusion

Similar repeat donation and deferral rates between arms suggest that the new nomogram did not result in disruptions to subsequent donation. Further longitudinal research on mid‐ to long‐term effects is warranted.

Personalized collection of plasma from healthy donors: A randomized controlled trial of a novel technology-enabled nomogram

Background

Source plasma is essential to support the growing demand for plasma‐derived medicinal products. Supply is short, with donor availability further limited by the coronavirus disease 2019 (COVID‐19) pandemic. This study examined whether a novel, personalized, technology‐based nomogram was noninferior with regard to significant hypotensive adverse events (AEs) in healthy donors.

Study Design and Methods

IMPACT (IMproving PlasmA CollecTion) was a prospective, multicenter, double‐blinded, randomized, controlled trial carried out between January 6 and March 26, 2020, in three U.S plasma collection centers. Donors were randomly assigned to the current simplified 1992 nomogram (control) or a novel percent plasma nomogram (PPN) with personalized target volume calculation (experimental). Primary endpoint was the rate of significant hypotensive AEs. Noninferiority (NI) was tested with a margin of 0.15%. Collected plasma volume was a secondary endpoint.

Results

A total of 3443 donors (mean [SD] BMI: 32 [7.74] kg/m²; 65% male) underwent 23,137 donations (median [range]: 6 [1–22] per subject). Ten significant hypotensive AEs were observed (six control; four experimental), with model‐based AE incidence rate estimates (95% CI) of 0.051% (0.020%–0.114%) and 0.035% (0.010%–0.094%), respectively (p = .58). NI was met at an upper limit of 0.043% versus the predefined margin of 0.15%. There was no statistical difference between total AEs (all AE types: p = .32). Mean plasma volume collected was 777.8 ml (control) versus 841.7 ml (experimental); an increase of 63.9 ml per donation (8.2%; p < .0001).

Conclusion

This trial showed that a novel personalized nomogram approach in healthy donors allowed approximately 8% more plasma per donation to be collected without impairing donor safety.