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.

The effect of donor's characteristics on plasmapheresis products: insights for a personalised approach.

BACKGROUND: Anticoagulant concentration in plasma units is extremely variable. Understanding the underlying causes of this variability could help personalise plasmapheresis procedures in order to optimise the risk-benefit ratio. We studied the association between anticoagulant solution A (usually ACD-A, Citrate Dextrose Solution A) volume in plasma units and donor characteristics to build a model to determine the needed weight of the final plasma unit to have an 80% probability of reaching 600 mL net plasma. MATERIALS AND METHODS: We experimentally measured ACD-A in 296 plasma units from an Italian blood donor centre, where machines are set for the collection of 700 g of plasma. Next, we built a statistical model to predict how the final volume of the unit should be set to obtain 50%, 80% or 90% probability of having at least 600 mL net plasma. RESULTS: ACD-A volume was associated with haemoglobin, total proteins and triglycerides. Donors with low haemoglobin reach an 80% probability of at least 600 mL net plasma with units of approximately 690 g, while 720 g are needed for donors with high haemoglobin levels. For total proteins and triglycerides, plasma units may vary within a range of ±20 g. DISCUSSION: Our model, based on easily measurable individual characteristics, makes it possible to customise plasmapheresis procedures by determining the blood volume to be processed for each donor. Tailored plasma donations might result in both a reduction in adverse events and an increase in the quality of collected plasma.