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Donor-specificity of Increased Glycolysis Rates in Apheresis Platelets
Tania VandenBroeke, Mark Hillam, Crystal Fenton, Gina Aga, Joe Rice, Ashley Parr
CaridianBCT, Lakewood, CO, USA
Introduction
On occasion, certain apheresis platelet products
demonstrate a low pH after only a few days of storage.¹
These products show increased rates of glycolysis for
reasons that are not understood, but may be unique to
specific donors. A strong correlation between donor and
basal rates of lactic acid generation has also been
previously described.²
Table 1: Key cell quality parameters on days 0 and 5 of storage. Values are means ±sd (range).
Parameter
Platelet Conc (x103/µL)
pH, 22°C
Lactate Conc (mM)
Objective
The objective of this study was to evaluate the
repeatability of in vitro storage characteristics for
products that demonstrated increased rates of glycolysis.
p-selectin (% activated)
HSR (% reversal)
ESC (%)
Kunicki Score (400=max)
Methods
Apheresis platelet products were collected on the Trima
Accel® Automated Blood Collection System and were
stored in plasma under traditional blood banking
conditions. All products were within the manufacturer’s
recommendations for concentration and volume.
Platelet metabolism (as measured by lactate and glucose
concentration profiles) and other tests for in vitro
platelet quality were made on day 0 and day 3 and/or
day 5. These tests included pH, platelet concentration,
p-selectin, HSR, ESC, and Kunicki Morphology Score.
Donors of products displaying increased rates of
glycolysis were asked to return several weeks later for a
subsequent donation and quality tests were repeated.
Figure 1: Profile of pH22°C as a function of storage time.
Results
Twenty-two platelet products were collected. Results of
day 0 testing showed no remarkable differences (Table
1). Most products (21 of 22) maintained high in vitro
platelet quality over 5 days (Table 1). One product,
however, from “Donor R” demonstrated a low pH at day
5, with corresponding decline in other parameters.
Interim (day 3) measurements had not been taken on
this product. Upon subsequent donation, storage
profiles for the various parameters for this donor’s
platelets were nearly identical to the initial platelet
product (Table 1).
Figure 3: Lactate concentration as a function of storage time.
Figure 2: p-selectin as a function of storage time.
Lactate generation rate
(umol/hr*E12 plts)
“normal
products”
n=21
1361 ±186
(1129-1747)
7.21 ±0.03
(7.16-7.26)
2.0 ±0.5
(1.2-2.9)
7.5 ±4.2
(2.3-15.9)
95.7 ±4.3
(86.4-102.9)
25.9 ±3.7
(20.1-32.8)
364 ±10
(347-382)
45 ±11
(28-66)
Day 0
Identified
Outlier
n=1
1860
Subsequent
Donation n=1
1886
7.17
7.07
3.8
3.6
18.8
10.4
105.4
97.8
27.5
24.9
373
360
142
144
“normal
products”
n=15
1382 ±186
(1133-1768)
7.39 ±0.11
(7.12-7.55)
9.6 ±2.3
(6.8-14.4)
21.4 ±8.8
(7.8-39.1)
93.7 ±5.9
(81.2-105.7)
27.1 ±2.3
(22.4-30.8)
319 ±30
(254-364)
Day 5
Identified
Outlier
n=1
1238
Subsequent
Donation n=1
1648
< 6.00
6.08
35.6
36.6
96.0
94.1
<0
4.2
0.6
2.1
148
151
Results (continued)
Figures 1-6 illustrate the behavior of platelet products from one donor
that are inconsistent with the rest of the collections, and also
demonstrate that the pattern is repeated upon subsequent donation
across a variety of measured parameters. Both products from this donor
were statistical outliers (Grubbs’ Test) at day 5 for all parameters except
platelet concentration. While these two products did have the highest
platelet concentration at day 0, this initial difference was not significant
in that the values were not statistical outliers.
Figure 4: HSR as a function of storage time.
Conclusion
The frequency of increased lactate production observed in this study is
consistent with a previous report.¹ While the cause of the increased
lactate generation in certain apheresis platelet products may be multifactorial, the influence of donor-related factors is very important.
Further exploration is needed to determine long-term stability of these
rates and ultimately identify alternative donor-management options for
these specific donors.
References
Figure 5: Platelet morphology as a function of storage time.
Poster SP21 Presented at AABB in Baltimore, MD, USA October 9-12, 2010
Figure 6: Lactate generation rate by donor.
1) Dumont LJ, VandenBroeke T. Seven-day storage of apheresis platelets:
report of an in vitro study. Transfusion 2003;43:143-150.
2) Dumont LJ, VandenBroeke T. Donor dependent glycolysis rates for platelets
stored in plasma. Transfusion 2004;44S:29A.