Generation of reticulated platelets in response to whole blood donation or plateletpheresis

Analysis and clinical significance of peripheral blood routine changes of platelet donors with ultra-high frequency donation

BACKGROUND

Increasing platelet donation frequency has become an important way to meet the growing clinical platelet need. Accordingly, the problem of whether the increase in platelet donation times will have an adverse effect on the health of donors has attracted more and more attention, and become an important factor affecting the donor enthusiasm and the safety of blood collection and supply.

METHODS

Eleven ultra-high frequency platelet donors who donated more than or equal to 20 times in 2021 were selected, and the main peripheral blood routine indicators of hemoglobin, platelet and hematocrit were analyzed.

RESULTS

The above indicators of all donors fluctuated with the increase of donation times. Among them, older donors (≥50 years old) exhibited a significant downward trend in the above three indicators, and one young donor showed a downward trend in hemoglobin and hematocrit indicators. While the other donors showed the relatively stable performance of the above indicators.

CONCLUSION

The effect of ultra-high frequency platelet donation on the main peripheral blood indexes of donors shows obvious age compliance, that is, the potential harm to ultra-high frequency donors older than 50 years is significantly greater than that of donors of other ages. Older platelet donors should be cautious about ultra-high frequency donations to avoid adverse health hazards. Meanwhile, the work will provide technical reference for the more scientific and efficient development of the platelet harvesting work and the establishment of the clinical blood supply system for related patients.

Reference interval of platelet counts and other platelet indices in apparently healthy blood donors in North India according to Clinical and Laboratory Standards Institute guidelines: Need to redefine the platelet count cutoffs for repeat plateletpheresis donation?

BACKGROUND

In clinical practice, laboratory results are of great importance for the diagnosis and treatment. Reference intervals of different parameters aid health-care professionals in the interpretation of results. There are very few studies on reference intervals from India. This prospective study was conducted to determine the reference intervals for platelet count (PLT) and PLT indices; mean PLT volume (MPV), PLT distribution width (PDW), and PLT large cell ratio (P-LCR). These values can be obtained as a part of a routine complete blood count (CBC) and have diagnostic and prognostic significance in certain diseases. PLT count is an important criterion for the selection of donors for repeat plateletpheresis donation.

MATERIALS AND METHODS

Sixteen hundred and thirty-four first-time healthy volunteer plateletpheresis donors were enrolled for the study. CBC was done, values of PLT, MPV, PDW, and P-LCR were noted, and the results were analyzed. The 95% of the reference distribution was estimated using the 2.5th and 97.5th percentiles following Clinical and Laboratory Standards Institute guidelines. Adverse donor reactions, if any and quality parameters of single donor PLTs (SDP) were also studied.

RESULTS

Reference range values of PLT, MPV, PDW, and P-LCR were 137,825-355,175/μl, 8.1-13.9/fl, 9.1-22.5/fl, and 11.7%-52.9%, respectively, and compared well with other published studies from India. It was observed that reference values of PLT count obtained in the study were lower than reference values that are currently used in most laboratories (150,000-450,000/μl) in India.

CONCLUSION

Based on our results, we are of the opinion that the PLT count cutoffs for repeat plateletpheresis donation may need to be revised downwards for our country which would also mitigate the scarcity of apheresis donors.

Effect of plateletpheresis on total platelet count and mean platelet volume: A meta-analysis

OBJECTIVE

Currently, there are discrepancies in the reports on the extent of the reduction in platelet count after platelet donation by apheresis, and its impact on mean platelet volume (MPV). This study was conducted to meta-analyze the effect of plateletpheresis on platelet count and on mean platelet volume, based on studies published between 1980 and 2018.

METHODS

Medline-Pubmed, Scielo, ScienceDirect, and Scopus databases were searched from inception to December 31 2019. The PRISMA guidelines, reproducibility, and evaluation of the methodological quality were guaranteed. Heterogeneity was evaluated with DerSimonian-Laird's, publication bias with a Begg's test. Sensitivity analysis and cumulative meta-analysis were also conducted, as well as a forest plot.

RESULTS

Twenty-five studies with 3769 donors were systematized to analyze platelet count, and seven studies with 1176 donors to observe MPV. Most studies were published in India and the United States. There was a postprocedure reduction in both variables. The reduction in platelet count was 14.3 × 10³ /μL (95% CI 11.4 to 17.1 × 10³ ⁄μL). The reduction in MPV was 1.43 fL (95% CI 0.3 to 2.5 fL). The analysis of subgroups showed that, in the case of platelet count, the reduction is not statistically significant two weeks after donation.

CONCLUSION

Platelet donation by apheresis reduces platelet count and MPV in donors, which is detrimental to the purposes of the procedure; although the decrease is not clinically significant for the donor or the recipient. This demonstrates the need for subsequent studies to evaluate variables, such as donation frequency and donation intervals, should be considered to evaluate if the reported decrease is easily compensated, without adverse consequences for donors, or if modifications in donor selection criteria are required.

Recovery of Platelet Count among Apheresis Platelet Donors

INTRODUCTION

Increase in awareness regarding use of single donor platelets and the availability of technology has resulted in increased platelet pheresis procedures. The interval between two succesive plateletpheresis donations is much less compared to whole blood donations. Plateletpheresis procedures are associated with short term and long term adverse events. The effect of plateletpheresis on haematopoietic system remains significant.

AIM

To study the recovery of platelet count to baseline in plateletpheresis donors.

MATERIALS AND METHODS

Fifty, first time apheresis donors were followed for platelet count recovery. Platelet count was measured before donation and at 30 minutes, 48 hours, 7^th day and 14^th day post-donation. Donor platelet count recovery to baseline was observed during the two week period. Results were analysed statistically, p<0.05 was considered statistically significant.

RESULTS

Platelet count recovered to baseline by 7^th day post-donation in 50% of donors in groups I (Pre-donation platelet count 1.5 lacs/μl to 2.2 lacs/μl) and II (Donors with platelet count >2.2 lacs/μl to 2.75 lacs/μl), 30% of donors in group III (Donors with platelet count >2.75 lacs/μl to 3.5 lacs/μl) of the donors. Donor's platelet count recovered to baseline in 85% of donors by day 14 in across the three groups. Recruitment of platelets from spleen was observed in donors with pre-donation platelet count on the lower limit of normal.

CONCLUSION

By day 7, donor's platelet count recovered to baseline in majority of the donors. Allowing enough recovery periods for donor platelet count, the minimum interval between two apheresis donations can be 7 days till more prospective studies conclude on the frequency and minimum interval between plateletpheresis donations.

Periodic acid-Schiff (PAS) staining of immature platelets in donors

Glycogen in platelets (PLTs) on smears of peripheral blood of 40 donors was investigated by the periodic acid-Schiff (PAS) method. Three groups were formed. Group 1 was consisted of 21 men undergoing the donor selection procedure. Additionally, 9 first-time donors undergoing plateletpheresis (Group 2) and 10 donors who frequently underwent platelet apheresis (Group 3) were studied as a model of relative thrombocytopenia. Cell sizes were measured with the use of a Image Analyzer "ASPBC" (Russia). The training procedure and classification of PAS-blood PLTs were made on the basis of expert evaluation. In this article, we have established three facts. First, the PAS-positive PLT area was larger than that of the PAS-negative cells (9.5 ± 3.6 sq.mkm vs. 3.9 ± 1.3 sq.mkm, p < 0.001, n = 21). The PAS-positivity of PLTs was 23.1 ± 9.2%. Second, the PAS-positivity correlated (r(S) = 0.63, p < 0.05) with the immature platelets fraction (IPF %), determined using Sysmex XE-2100. The mean IPF was 2.1 ± 1.0% (range 0.3-4.6%). Third, using the IPF% values obtained in Group 1, we found a significantly higher level of IPF in the samples both in Group 2 [mean value 4.2 ± 2.0% (range 1.9-7.0), p < 0.01] and in Group 3 [mean value 5.1 ± 2.5% (range 1.2-8.6), p < 0.004] with relative thrombocytopenia [Group 2: median 198 (95% confidence interval, CI 166-227) vs. median 229 (95% CI 206-267), p < 0.05; Group 3: median 142.5 (95% CI 132-173) vs. median 214.5 (95% CI 196-267), p < 0.01] after plateletpheresis. There was also a significant difference between the pre- and post-plateletpheresis for IPF% in Group 2 and Group 3: median 1.7 (95% CI 1.4-4.0) vs. median 4.0 (95% CI 2.7-5.8), p < 0.05 and median 4.0 (95% CI 2.7-6.0) vs. median 5.1 (95% CI 3.3-6.9), p < 0.01. The increased IPF shows a correlation with the PAS positivity [r(S) = 0.5 (p = 0.14) and r(S) = 0.6 (p = 0.05)] which has a tendency to increase [Group 2: median PAS 24.3% (95% CI 14.8-26.2) vs. median PAS 30% (95% CI 21.6-34.2), p = 0.05 and Group 3: median PAS 31% (95% CI 19-36.4) vs. median PAS 27.4% (95% CI 18.7-34.9), p = 0.35] and correlated negatively with the decrease in the platelet count [Group 2: r(S) = -0.7 (p = 0.21) and Group 3: r(S) = -0.5 (p = 0.14)]. Our findings support the significance of platelet evaluation by light microscopy to understand why morphologic changes of thrombocytopoiesis may be expected in thrombocytopenia due to donation of platelets.

The influence of conditions utilized to hold apheresis and whole blood-derived platelet samples before platelet enumeration with three hematology analyzers

BACKGROUND

The Advia 120 (Siemens Diagnostics) hematology analyzer is different from other hematology analyzers in that it requires platelets (PLTs) to be "effectively spherical" to be counted. Our study evaluated how PLT counts with this hematology analyzer and two other models were influenced by the holding of PLT product samples.

STUDY DESIGN AND METHODS

Samples were prepared from apheresis PLT products (APs) collected in ACD-A and from whole blood-derived PLT concentrates (PCs) in CP2D or ACD-A. Samples were stored in K(2) and K(3) ethylenediaminetetraacetate (EDTA) tubes at room temperature (RT) and in the cold. PLT counts were determined immediately, after 1 and 4 hours, and after an overnight hold, using Advia 120, XE-2100D, and Cell-Dyn 3700 hematology analyzers.

RESULTS

A time-dependent increase in PLT counts was observed with AP samples held at RT using the Advia 120, but not with the other two hematology analyzers. AP samples held in the cold did not show a substantial time-dependent increase with any of the hematology analyzers. With the Advia 120, the PLT counts in the immediate samples were approximately 14% lower compared to those in cold or overnight-held RT samples. PC samples with all holding conditions and hematology analyzers did not show any substantial time-dependent increase in counts.

CONCLUSIONS

With the Advia 120 hematology analyzer, the time-dependent increase in PLT counts with RT-held samples may be related to the need to have effectively sphered PLTs unlike that with the other two hematology analyzers. The absence of a holding effect with PC samples may indicate that only AP samples have population(s) that are slow to convert to spherical PLTs.

Apheresis donors and platelet function: inherent platelet responsiveness influences platelet quality

BACKGROUND

Process-induced platelet (PLT) activation occurs with all production methods, including apheresis. Recent studies have highlighted the range and consistence of interindividual variation in the PLT response, but little is known about the contribution of a donors' inherent PLT responsiveness to the activation state of the apheresis PLTs or the effect of frequent apheresis on donors' PLTs.

STUDY DESIGN AND METHODS

The relationship between the donors' PLT response on the apheresis PLTs was studied in 47 individuals selected as having PLTs with inherently low, intermediate, or high responsiveness. Whole-blood flow cytometry was used to measure PLT activation (levels of bound fibrinogen) before donation and in the apheresis PLTs. The effects of regular apheresis on the activation status of donors' PLTs were studied by comparing the in vivo activation status of PLTs from apheresis (n = 349) and whole-blood donors (n = 157), before donation. The effect of apheresis per se on PLT activation was measured in 10 apheresis donors before and after donation.

RESULTS

The level of PLT activation in the apheresis packs was generally higher than in the donor, and the most activated PLTs were from high-responder donors. There was no significant difference in PLT activation before donation between the apheresis and whole-blood donors (p = 0.697), and there was no consistent evidence of activation in the donors immediately after apheresis.

CONCLUSION

The most activated apheresis PLTs were obtained from donors with more responsive PLTs. Regular apheresis, however, does not lead to PLT activation in the donors.

Frequently used plateletpheresis techniques result in variable target yields and platelet recruitment of donors

BACKGROUND

Standard plateletpheresis techniques and effects on platelet (PLT) donors were investigated to provide an informative basis for advancement of apheresis software.

STUDY DESIGN AND METHODS

Three paired groups with 33 male and 22 female blood donors were prospectively investigated by analyzing blood counts of donors and products. Four apheresis platforms, the COBE Spectra LRS and the Trima v4 (Gambro BCT) and the AS.TEC204 and the COM.TEC (Fresenius Hemocare), were compared. Deviations of the collected from programmed PLT targets and donor PLT recruitment were calculated for single-unit PLT concentrates (SU-PCs; 3 x 10(11) PLTs) and double-unit PLT concentrates (DU-PCs; 6 x 10(11) PLTs).

RESULTS

Regarding SU-PCs, the productivity of the COM.TEC machine was superior to the AS.TEC204 machine, because of shorter processing time (54 min vs. 67 min) and higher yields (2.90 x 10(11) PLTs vs. 2.75 x 10(11) PLTs). Compared to the Spectra machine, the Trima v4 machine showed higher collection efficiencies (CEs) and shorter processing time and complied better with the programmed target (SU-PCs, 3.24 x 10(11) PLTs vs. 3.70 x 10(11) PLTs; DU-PCs, 6.87 x 10(11) PLTs vs. 7.56 x 10(11) PLTs). Harvests of the Spectra machine (DU-PCs) exceeded the target by 40 percent, which resulted in high PLT loss for donors. A longer processing time resulted in some higher CEs (SU-PCs, 53%; DU-PCs, 58%), which could contribute to this result. PLT recruitment compensated PLT loss to some extent.

CONCLUSION

The major finding was that the newer devices (COM.TEC and Trima) gave more predictable yields than the older devices (AS.TEC204 and Spectra) and resulted in lower PLT deficit. PLT software should be improved to minimize relevant variations of collected yields regarding the programmed target.

Safety of donating multiple products in a single apheresis collection: Are we expecting too much?

Modern blood separators rapidly process many liters of donor blood and efficiently collect vast quantities of blood components from donors, who may be stimulated with potent recombinant hematopoietic growth factors or cytokines. Accordingly, the potential risks of modern multiple product/unit apheresis donations and recombinant growth factors is analyzed in this report. As is true for all medical procedures, risks are associated with apheresis donations. Risks of a "standard" apheresis donation, in which one unit of PLTs or plasma is collected, are comparable to the risks of whole blood donation. Risks of multiple unit apheresis donations, in which either vast quantities of a single blood component or multiple units of various components are collected, are incompletely understood, particularly, when donors are stimulated with recombinant hematopoietic growth factors to increase component yields. To minimize donor risks and to increase knowledge of multiple component apheresis donations, both short-term problems (e.g., donor reactions accompanying apheresis procedures and pre- vs. post-procedure changes in results of donor laboratory studies) and long-term problems (e.g., medical diagnoses/problems and abnormalities of donor blood counts and laboratory test results) should be monitored, ideally, by a repeat donor registry. When recombinant hematopoietic growth factors are prescribed, donors should give informed consent, and blood center professionals must be aware of 1) the effects of these drugs given at pharmacologic, rather than physiologic, doses; 2) the differences between the molecular structure of recombinant vs. natural/endogenous growth factors; 3) the fact that recombinant growth factors have both narrow/focused and broad biological activities; and 4) the probability that results of studies in sick/immunosuppressed patients may not be applicable to healthy/immunocompetent donors.

A randomized comparison of plateletpheresis with the same donors using four blood separators at a single blood center

At one blood center, each of 20 donors underwent plateletpheresis on four blood cell separators in random order. We compared the CS3000+, Amicus V 2.41, MCS Plus, and Spectra LRS V 7 Turbo regarding platelet (PLT) yield, pre- and post-procedure PLT counts, percent fall in donor PLT count, process time, efficiency, PLT product and donor PLT volume (MPV). Using >or= 150 x 10(9) PLTs/L pre-donation counts, a goal was set of 4.5 x 10(11) PLTs unit in up to 100 minutes processing time. Results were (mean values) PLT yields of Amicus, Spectra, CS3000+, and MCS Plus: 4.3, 4.6, 4.3, 4.0 x 10(11) PLTS, respectively; percent donor PLT fall: 24, 32, 30, 29%, respectively; processing times: 50, 74, 87, 101 minutes, respectively; relative efficiency (RE): 2.2, 1.6, 1.2,1.0, respectively (based on the MCS Plus performance with RE of 1 = 4 x 10(9) PLTS/min); PLT product MPV: 6.7, 7.4, 6.8,7.1 fL, respectively; pre-procedure donor MPV: 7.7, 7.3, 7.6 and 7.6 fL, respectively; and percent donor MPV change: -5.2, 0, -6.6, and -10%, respectively. Significant changes in the donor MPV were noted (P < 0.05) but could not be related to product MPV. Spectra seemed to collect larger PLTs (higher MPV); the significance remains unknown for both donors and recipients. Importantly, all four separators gave acceptable and comparable PLT yields (P < 0.05) with Spectra trending higher. The short process time and high RE together indicate highly efficient collections particularly by Amicus and Spectra.