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Approach to the Assessment of Platelet Function: Comparison between Optical-based Platelet-rich Plasma and Impedance-based Whole Blood Platelet Aggregation Methods
Anna M. Dyszkiewicz-Korpanty, MD,* Eugene P. Frenkel, MD,* and Ravindra Sarode, MD†
*Department of Medicine, †Department of Pathology, The University of Texas Southwestern Medical Center at Dallas, Dallas, Texas
Summary: Platelet aggregation studies play an important role in the assessment of hereditary and acquired platelet function defects. The first aggregation test introduced into laboratory practice used platelet-rich plasma (PRP) where aggregation was detected by an optical method. The assessment of platelet function using whole blood (WB) aggregation by an impedance method followed up nearly 20 years later. The WB impedance aggregation assay appears to be superior to the optical method because it 1) evaluates platelets in a physiologic milieu in the presence of red and white blood cells, which are known to modulate platelet function; 2) is faster; 3) has higher sensitivity; and 4) does not require centrifugation, thus avoiding injury to platelets and loss of giant thrombocytes. These two assays were compared. Clearly, the WB impedance aggregation methodology has many advantages over the optical PRP assay for the assessment of the hyperactive platelet syndrome and the effects of antiplatelet drugs.
(Clin Appl Thrombosis/Hemostasis 11(1):25-35, 2005)
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PLATELET FUNCTION TESTS PREDICT BLEEDING AND THROMBOTIC EVENTS AFTER OFF-PUMP CORONARY BYPASS GRAFTING
Robert Poston(1), Junyan Gu(1), Deyanira Prastein(1), Jamie Brown(1), James Gammie(1), Thrity Avari(2), Bartley Griffith(1)
(1)University of Maryland School of Medicine, Baltimore, United States; (2)Chrono-log Corp, Havertown, United States
Objectives: Minimizing bleeding and thrombotic events after CAB depends on a balanced coagulation system. However, the best method to monitor this balance has not been established. We used a series of tests of coagulation and platelet function to define the risk of bleeding and thrombotic events after OPCAB.
Methods: Standard coagulation tests (prothrombin time, fibrinogen level, d-dimer, platelet count), thrombelastography, and whole blood aggregometry were obtained perioperatively and on postoperative days (POD) 1 and 3 in 50 OPCAB patients. Intra- and postoperative blood loss was determined. Thrombotic events were monitored up to POD5 in all patients with duplex ultrasound (DVT), neurologic examination (stroke), troponin >13ng/ml (MI) and CT angiography (early graft thrombosis).
Results: Chest tube hemoglobin loss at 24 hours was 35.8±23.1 gm(895±477cc); a thrombotic event occurred in 22% (2 DVT, 2 MI, 1 CVA, 6 graft thrombosis). Perioperative changes in the standard coagulation tests showed no correlation with either bleeding or thrombosis. However, perioperative decline in platelet function as assessed by the area under the impedence curve for whole blood aggregometry correlated with intraoperative blood loss (R=0.42, p<0.05). A perioperative decline in the maximum amplitude of the T~G trace showed a significant correlation with 24hr hemoglobin loss (R=0.45, p<0.05). Compared to those with no thrombosis, patients with thrombotic events demonstrated increased platelet function at all time points with statistical significance achieved on POD3.
Conclusions: In contrast to standard coagulation testing, platelet function predicted both bleeding and thrombosis after OPCAB. Titration of perioperative platelet function using these tests may minimize thrombosis without increasing bleeding.
(Presented at the EACTS/ESTS Joint Meeting 2004 3rd EACTS/ESTS Joint Meeting)
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Aspirin Resistance: An Underrecognized Risk Factor in Early Vein Graft Thrombosis After Off-pump Coronary Artery Bypass (OPCAB)
Junyan Gu, Deyanira Prastein, Richard N Pierson II/, Charles White, Bartley P. Griffith, Univof Maryland School of Med, Baltimore, MD; Paul Gurbel, Sinai Hosp, Baltimore, MD; Jeffrey Manchio, Robert Poston, Univ of Maryland School of Med, Baltimore, MD
Purpose: Prior failure to respond to an ASA-containing medical regimen and the inflammatory effects of surgery place coronary artery bypass patients at high risk for postoperative ASA resistance. We hypothesized that ASA resistance plays an important role in the early failure of venous grafts after OPCAB. Methods: 72 OPCAB patients with 138 venous grafts were given aspirin as the sole antiplatelet agent. Perioperative ASA resistance was investigated in using a spectrum of complimentary assays: Thrombelastography (MA>50% with arachidonic acid vs. kaolin), whole blood aggregometry (>50% response to 1 vs. 5mg/ml collagen) and flow cytometry (increased P-selectin expression after arachidonic acid). %endothelial integrity was assessed in each conduit by CD31 histochemistry. PAI-1, tissue factor, tPA, thrombomodulin expression were analyzed on vein biopsy by histochemistry (score 0-2) and ELI SA. Each graft was analyzed intraop for blood flow by transit time ultrasound and patency on day 5 using by CT angiography.
Results: Thrombosed grafts (n=8) had similar tissue factor, PAI-1 and tPA expression but reduced endothelial integrity (16.7::!:21.5% vs. 55.2::!:35.7%, p<0.01) and thrombomodulin scores (0.57::!:0.53 vs. 1.10::!: 0.78, p<0.05) vs. patent grafts (n=125). ASA resistance, defined by both TEG and aggregometry, developed postop in 25 patients. Early vein graft failure was seen in 6 of 25 resistant patients vs. 2 of 47 with normal ASA sensitivity (p<0.04).
Conclusions: ASA resistance is common after OPCAB and associated with vein graft thrombosis. These data support a policy of screening for ASA resistance after OPCAB to guide the use of alternate antiplatelet agents (e.g. Plavix).
Presented at American Heart Association, November 7-10,2004
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Safety and Efficacy of Aprotinin in Off-Pump Coronary Artery Bypass Grafting (OPCAB): A Double-Blind, Placebo-Controlled Randomized Trial
Robert S Poston, Charles White, Junyan Gu, Katrina Read, James Brown, James Gammie, Richard N Pierson 111, Andrew Lee, Jeffrey Manchio, Univ of Maryland School of Med, Baltimore, MD; ThrityAvari, Chronolog, Inc., Havertown, PA; Trevor Huang, Medtronic, Inc., Minneapolis, MN; Robert Christenson, Ingrid Connerney, Univ of Maryland School ofMed, Baltimore, MD; Eli Cohen, Haemoscope, Inc., Chicago, IL; Udaya Tandry, Sinai Hosp, Baltimore, MD; Bartley P. Griffith, Univ of Maryland School of Med, Baltimore, MD; Paul Gurbel, Sinai Hosp, Baltimore, MD
Introduction: The rationale for hemostatic drugs is well established for cardiac surgery performed on-pump. In light of concerns that preserved coagulation in the absence of the pump renders these drugs unnecessary and risky, we performed a randomized trial to analyze the efficacy and safety of aprotinin during OPCAB.
Methods: 60 patients were randomized to full-dose aprotinin or placebo; creatinine >2mg/dl, on-pump conversion, or GPllb/llla inhibitors led to exclusion. Heparin was given to a kaolin-based ACT >300 sec. Hemorrhage was quantified by intraop blood collected and chest tube hematocrit x volume at 24 hr. Aspirin resistance and platelet reactivity were monitored at baseline and on postoperative days 1 and 3 using modified thrombelastography, whole blood aggregometry and flow cytometry. A composite endpoint of thrombotic events was determined by serial troponin I levels (postop MI), clinical exam (stroke), and CT angiography on day 5 (bypass graft failure).
Results: Transfusions were similar, but intraoperative bleeding and 24hr blood loss were reduced by aprotinin (figure). Postop aspirin resistance, but not platelet reactivity, was reduced in the aprotinin group relative to placebo (20 vs. 46%, p<0.05) as was the composite end-point of thrombotic events (3 vs. 23%, p<0.05). MI (3 vs. 1), stroke (1 vs. 0) and early graft thrombosis (3 vs. 0) were all decreased after aprotinin relative to control.
Conclusions: Aprotinin significantly reduced bleeding and thrombotic events after OPCAB in this randomized, controlled trial. Rather than increasing risk, aprotinin actually provided prophylaxis against thrombosis, potentially via a reduction in aspirin resistance.
Presented at American Heart Association, November 7-10,2004
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Platelet Dysfunction in Myelodysplastic Syndromes: A Clinicopathological Study
A. Manoharan, T. Brighton, R. Gemmell, I K. Lopez, I S. Moran, P. Kyle
Department of Clinical Haematology, St. George Hospital, University of New South Wales, Sydney, Australia
Summery: Forty-eight patients with myelodysplastic syndromes and a platelet count greater than
80 x 109/L were the subjects of a study of platelet function. A whole-blood platelet lumi- aggregometer was used for simultaneous measurement of platelet aggregation by the impedance method and of adenosine triphosphate-dense granule release. The results were correlated with skin bleeding time and episodes of clinical bleeding or thrombosis. Thirty-five patients had at least 1 abnormal result indicating platelet hypoactivity; 7 patients had mixed platelet hypoactivity and hyperactivity; and 4 patients had platelet hyperactivity. Only 2 patients had normal results. There was good correlation between platelet hypoactivity and prolonged skin bleeding time (P = .005); however, several patients with platelet hypoactivity had normal skin bleeding times. This finding suggested that whole-blood platelet aggregation studies may be more sensitive than bleeding time in identification of patients at risk of bleeding. Clinical hemorrhage was frequent (32 patients) in this cohort despite platelet counts greater than 100 X 109/L. This finding indicated platelet hypofunction was clinically important. In contrast, only 2 of the 13 patients with thrombotic events had evidence of platelet hyperactivity, suggesting that other clinical factors are probably more important determinants of thrombosis. These observations confirm that platelet dysfunction is common in patients with myelodysplastic syndromes and suggest a useful role for routine whole-blood platelet aggregation studies to identify patients at risk of bleeding.
(Int J Hematol. 2002;76:272-278)
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Platelet functional defects in women with unexplained menorrhagia
C. S. Philipp,* A. Dilley**, C. H. Miller**, B. Evatt**, A. Baranwal,* R. Schwartz,* G.
Bachmann** and P. Saidi*
* Division of Hematology and Women's Health Institute,UMDNJ-Robert Wood Johnson
Medical School, New Brunswick, New Jersey; and **Hematologic Diseases Branch, Centers for
Disease Control and Prevention, Atlanta, Georgia, USA
Summary. Menorrhagia is a common clinical problem and is unexplained in more
than 50% of women. Although studies suggest that von Willebrand's Disease
(VWD) is found in a substantial number of women with unexplained menorrhagia,
the prevalence of platelet defects in women with menorrhagia is unknown. To
determine the prevalence of platelet and other hemostatic defects, we evaluated
women ages 17-55 diagnosed with unexplained menorrhagia. Seventy-four
women (52 white, 16 black, six other) were studied. Bleeding time was prolonged
in 23 women (31.5%). Maximal percent platelet aggregation was decreased with
one or more agonists in 35 (47.3%) women. The most commonly found platelet
function defects were reduced aggregation responses to ristocetin in 22 women
and to epinephrine in 16 women. Sixteen of 22 women with reduced ristocetin
aggregation had von Willebrand ristocetin cofactor (VWF:RCo) and von Willebrand
factor antigen (VWF:Ag) > 60%. Platelet ATP release was decreased with one or
more agonists in 43 (58.1%) women. Of the black women studied, 11/16 (69%)
had abnormal platelet aggregation studies compared with 20/52 white women
(39%) (P = 0.06). Black women with menorrhagia had a higher prevalence of
decreased platelet aggregation in response to ristocetin and epinephrine than did
white women (P = 0.0075, P = 0.02). Ten women (13.5%) had VWF:RCo and/or
VWF:Ag < 60%. Using race and blood group specific ranges, 5 (6.8%) women had
decreased VWF:RCo, VWF:Ag and/or collagen binding (VWF:CB). Mild factor XI
deficiency was found in two women and one woman with mild factor V deficiency
and one hemophilia A carrier were identified. We conclude that the prevalence of
platelet function defects and other inherited bleeding disorders is substantial in a
multiracial US population of women with unexplained menorrhagia.
(Journal of Thrombosis and Haemostasis Volume 1 Issue 3 Page 477 - March 2003)
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Thrombosis and bleeding in myeloproliferative disorders:
identification of at-risk patients with whole blood
platelet aggregation studies
A. Manoharan, R. Gemmell, T. Brighton, S. Dunkley, K. Lopez and P. Kyle
Department of Clinical Haematology, St George Hospital, Kogarah, New South
Wales, Australia
Summary. Seventy-five patients with chronic myeloproliferative disorders were
studied to investigate platelet function by simultaneous measurement of platelet
aggregation by the impedance method and ATP dense granule release using a whole
blood platelet lumi-aggregometer, in an attempt to identify patients at risk for
thrombosis and bleeding.
Thirty-nine patients had at least one abnormal result indicating platelet
hyperactivity (i.e. impedance or release with one agonist being above the
reference range): 16 patients had platelet hypoactivity (i.e. at least one
result was below the reference range), whilst 14 had co-existence of hyper- and
hypoactivity. Six patients had normal results. 20/53 patients with platelet
hyperactivity (alone or mixed) had a positive history of venous and/or arterial
thrombosis: in comparison only two of the other 22 patients had a positive
history. During a median follow-up of 33 months, nine patients with and one
patient without platelet hyperactivity respectively developed new thrombotic
events before the addition of specific therapy. A total of 50 patients with and
eight patients without platelet hyperactivity respectively received specific
treatment including aspirin and/or cytotoxic therapy. All but one elderly
patient with platelet hyperactivity have remained free of new thrombotic events
on specific therapy. Two of the 17 patients with platelet hypoactivity had
major clinical bleeding.
These observations highlight the need to test platelets for hyper-as well as
hypo-function and suggest a useful role for routine whole blood platelet
aggregation studies to identify the patients at risk for thrombosis or bleeding.
(British Journal of Haematology, 1999, 105, 618-625)
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Rapid Assessment of Platelet Function With a Modified Whole-Blood Aggregometer
in Percutaneous Transluminal Coronary Angioplasty Patients Receiving
Anti-GP Ilb/Illa Therapy
Mary A. Mascelli, PhD; Seth Worley, MD; Nicholas J. Veriabo; Ellen T. Lance, MS;
Sabina Mack; Tom Schaible, PhD; Harlan F. Weisman, MD; Robert E. Jordan, PhD
Background. The glycoprotein (GP) Ilb/Illa receptor antagonist
abciximab (c7E3 Fab, ReoPro) is approved for use in
high-risk percutaneous transluminal coronary angioplasty
(PTCA). At present, no "point of care" exists for measuring
pharmacological GP IIb/IIIa blockade. To address this need,
the Chrono-log Whole Blood Aggregometer, which measures
platelet aggregation by electrical impedance, was adapted to
test platelet function at the bedside.
Methods and Results. GP Ilb/Illa receptor blockade, impedance
(5 ug/mL Collagen), and turbidimetric aggregation (5 and
20 umol/L ADP) measurements were obtained on 14 PTCA
patients who received the standard bolus plus a 12-hour
infusion of abciximab. During abciximab administration, mean
GP Ilb/Illa receptor blockade was >91%, and both impedance
and turbidimetric aggregation were inhibited by >/- 90%. At 12
hours after abciximab treatment, the mean inhibition of turbidimetric
platelet aggregation to 5 and 20 umol/L ADP was 65+/-20% and
49+/-14%, respectively, and inhibition of impedance aggregation
was 69+/-12%. GP lIb/Illa receptor blockade was 67+/-8%.
At 36 hours after abciximab treatment (n=8), the mean
inhibition of turbidimetric platelet aggregation to 5 and
20 umol/L ADP was 44+/-21% and 30+/-14%, respectively,
whereas impedance aggregation was inhibited by 60+/-14%.
GP lIb/Illa receptor blockade was 57+/-7%.
Conclusions. During and at 12 hours after abciximab therapy,
impedance and turbidimetric platelet aggregation to
5 umol/L ADP were comparable and closely correlated with
GP Ilb/Illa receptor blockade. However, at 36 hours after
abciximab treatment, impedance platelet aggregation more
closely paralleled GP Ilb/Illa receptor blockade and indicated
a slower recovery of platelet function than turbidimetric
agregometry.
(Circulation. 1997;96:3860-3866.)
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Heparin-induced thrombocytopenia: an improved method of detection based on
lumi-aggregometry
Michael W. Stewart, Wai S. Etches, Lynn K. Boshkov and Philip A.
Gordon
Summary. Heparin-induced thrombocytopenia (HIT) is a recognized
complication of heparin administration. Early detection of this
syndrome is essential in the prevention of immune-mediated
thromboembolic sequelae. The 14C-serotonin release assay (SRA) has
been used in reference laboratories to identify sera from patients on
heparin therapy capable of inducing platelet dense granule release.
In an attempt to improve existing methodologies, we employed
luminographic detection of platelet-dense granule ATP release as an
endpoint of HIT antibody-mediated platelet activation. Sera tested
included 10 SRA confirmed positive and five SRA confirmed negative
samples (to establish the assay), five samples from patients with
thrombocytopenia not on heparin therapy and 34 patients suspected of
HIT syndrome. AII SRA confirmed positive sera (n = 19) were
positive by the luminographic procedure. 24/26 SRA confirmed negative
sera and five sera from thrombocytopenic patients not on heparin
therapy were negative using luminography. Two of four sera yielding
equivocal SRA results were found to be positive by the luminographic
technique. The data suggest that the use of a lumi-aggregometer in
the coagulation laboratory to detect HIT antibody-induced platelet
activation is a reliable alternative to the SRA. The luminographic
procedure is both rapid and sensitive, and does not require the use of
biohazardous radio-isotopes.
(British Journal of Haematology, 1995, 91, 173-177)
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Preoperative Platelet Dysfunction Increases the Benefit of
Aprotinin in Cardiopulmonary Bypass
Michael J. Ray, BAppSc, Neville A. Marsh, PhD, Sarah J. E. Just, BAppSc,
Emma J. Perrin, BAppSc, Mark F. O'Brien, FRACS, and Geoffrey A. T. Hawson,
FRACP
Background. This study was designed to determine the benefit of aprotinin
therapy in reducing bleeding during and after cardiopulmonary bypass in
patients with preoperative platelet dysfunction. Platelet function
involvement in the mechanism by which aprotinin acts was also investigated.
Methods. In a double-blind, randomized study, patients received
high-dose aprotinin (n = 54) or placebo (n = 52). Whole blood aggregation
was measured preoperatively. Platelet function and activation in both
groups were assessed intraoperatively and postoperatively at five times.
Results. Aprotinin significantly reduced perioperative bleeding
and postoperative blood transfusion. Placebo-treated patients
with reduced preoperative platelet aggregation bled more postoperatively,
but aprotinin reduced the bleeding in patients
with normal or reduced platelet function to similar levels. Any
cardiopulmonary bypass--induced changes in platelet aggregation, platelet
activation as measured by P-selectin expression, and von Willebrand factor
antigen and function were similar in aprotinin-treated and placebo-treated
groups.
Conclusions. The mechanism by which aprotinin reduced bleeding
was independent of any effect on platelet function. However,
aprotinin produced a greater reduction in bleeding among patients whose
condition was hemostatically compromised by preoperative platelet
dysfunction.
(Ann Thorac Surg 1997;63:57--63)
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Relationship of Platelet Aggregation to Bleeding After Cardiopulmonary
Bypass
Michael J. Ray, BAppSc, Geoffrey A. T. Hawson, FRACP, Sarah J. E.
Just, BAppSc, Geoffrey McLachlan, PhD, and Mark O'Brien, FRACS
Excessive bleeding after cardiopulmonary bypass operations is a
persistent problem. This study assessed the influence of platelet
function on blood loss for 134 patients undergoing cardiopulmonary
bypass. Platelet function was measured by platelet aggregation in
platelet-rich plasma and whole blood using collagen as the agonist.
Adenosine triphosphate release was assessed concurrently. Measurements
were made 1 day before operation and 1 hour after the cessation of
cardiopulmonary bypass. Three important findings were made. First,
statistically significant correlations were shown between preoperative
and postoperative platelet aggregation and blood drainage for the
first 3 hours postoperatively. Second, correlations were greatest when
preoperative measurement was performed on whole blood and post-
operative measurement was performed on platelet-rich plasma. Third,
patients with reduced postoperative platelet aggregation in platelet-
rich plasma had significantly greater transfusion requirements in the
first 24 hours postoperatively. In defining the 16 patients who
bled excessively among the 134 patients studied, the preoperative
aggregation in whole blood had a sensitivity of 62%, specificity of
75%, positive predictive value of 26%, and negative predictive value
of 94%. The postoperative aggregation in platelet-rich plasma had a
sensitivity of 86%, specificity of 69%, positive predictive value
of 28%, and negative predictive value of 97%. These results indicate
that preoperative and postoperative measurement of platelet
aggregation may provide a rationale for the prophylaxis or treatment
of patients to reduce blood loss after cardiopulmonary bypass.
(Ann Thorac Surg 1994;57:981-6)
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Evaluation of Whole-Blood Lumiaggregation
John J. Podczasy, Ph.D., James Lee, M.S. and Ivana Vucenik, Ph.D.
Department of Medical Research Technology, University of Maryland
School of Medicine, Baltimore, Maryland. U.S.A.
Summary: An evaluation of whole-blood lumi-aggregation was conducted in a
normal population. Platelet aggregation and adenosine triphosphate (ATP)
secretion were monitored in a three-phase study that analyzed sample
dilution, agonist dose response, and method comparison. In the first phase,
the blood:saline ratio was varied; in the second phase, the concentration of
the agonists was varied; and in the last phase, a comparison of impedance
aggregation and ATP release in whole blood to optical aggregation and ATP
release in platelet-rich plasma (PRP)
was performed. Five common platelet agonists - collagen, adenosine
diphosphate (ADP), arachidonic acid, thrombin, and ristocetin - were used in
this evaluation of the lumi-aggregometer (Chrono-log Corp., Havertown, PA,-
U.S.A.). The data revealed that the optimum blood:saline ratio for conducting
platelet antigen studies is 1:1, although with some agonists other dilutions
can be used. The agonist dose-response phase basically confirmed the
manufacturer's concentration recommendations. Additionally, it was
determined that platelet aggregation using the whole-blood impedance
technique compared to the PRP optical method yielded similar information.
Furthermore, the advantages of whole-blood impedance aggregation include its
use in microsamples and more timely results due to minimal sample
preparation.
(Clin Appl Thrombosis/Hemostasis, 3(3):190-195,1997)
Whole Blood Lumiaggregation: Evaluation of Reagents
Ivana Vucenik, Ph.D., and John J. Podczasy, Ph.D.
Department of Medical and Research Technology, University of Maryland
School of Medicine, Baltimore, Maryland. U.S.A.
Summary: We evaluated the whole blood lumiaggregation system, which
analyzed the optimal sample dilutions and agonist concentrations. We
also showed that platelet aggregation using the whole blood impedance
technique, as compared to the platelet-rich plasma optical method,
yielded similar information. In the extension of that study, we
further evaluated the stability of the reagents used in platelet
aggregation. The most commonly used agonists thrombin, ristocetin,
arachidonic acid, adenosine diphosphate and collagen were monitored
over a 1-year period. Throughout the entire period, aliquots of the
reconstituted reagents were stored at -20 C. -50 C. and -70 C, with the
exception for collagen, which was kept at 4 C. Every 2 weeks tests were
performed using the whole blood from the same healthy volunteer.
Platelet aggregation and adenosine diphosphate release were measured
after stimulation with 1.0 U/mL thrombin, 1.0 mg/mL ristocetin, 0.5 mM
arachidonic acid, 10 uM adenosine diphosphate or 3 ug/mL collagen. The
results indicated that thrombin was stable at all temperatures over the
1-year period. Platelet agglutination with ristocetin was similar
among samples for about 2 months; after that time some deterioration of
ristocetin was noticed, especially at -20 C. Reconstituted arachidonic
acid, frozen at -20 C. was stable for about 1 month, and at the lower
temperatures this agonist was good for 4 months. On the contrary.
adenosine diphosphate and collagen exhibited stability throughout the
1-year period. Based on the information provided by this study, we
encourage more laboratories to use whole blood lumiaggregation to
evaluate platelet function.
(Clin Appl Thrombosis/Hemostasis 4(4):253-256, 1998)
A multi-laboratory evaluation of in vitro platelet
assays: the tests for extent of shape change and response to hypotonic
shock.
S Holme, G Moroff, S Murphy for the Biomedical Excellence for Safer
Transfusion Working Party of the International Society of Blood
Transfusion
BACKGROUND: There is no consensus regarding the use of specific in
vitro tests for the assessment of the quality of platelet components.
A literature review found that the platelet discoid shape as measured
photometrically by the extent of shape change (ESC) and hypotonic shock
response (HSR) correlated well with in vivo viability. The purpose of
this study was to determine whether multiple research laboratories can
perform the ESC and HSR assays in an accurate, reproducible manner,
with acceptable sensitivity and comparable results.
STUDY DESIGN AND METHODS: Eleven laboratories conducted five identical
experiments, each with a different unit of platelet-rich-plasma (PRP).
For each experiment, 2 half-units of PRP were prepared and stored
overnight: 1 half-unit at 20 to 24 deg. C. in CPD (CPD-PRP) and the
other at 1 to 6 deg. C. with 2 mg per mL of EDTA (cold EDTA-PRP)
added to produce spherical platelets with reduced HSR. Platelet
suspensions having different proportions of the two PRP's were prepared
and evaluated in duplicate by ESC and HSR assays, and morphologically
scored by microscopy. One-way ANOVA and Duncan multiple-range tests
were performed to determine significant differences in assay results
for suspensions having different proportions of CPD-PRP.
RESULTS: Comparable ESC (mean range; 20-28% for CPD-PRP and 1-6% for
cold EDTA-PRP) and HSR (mean range: 58-81% for CPD-PRP and 12-31% for
cold EDTA-PRP) measurements were obtained by nine laboratories.
Duplicate testing showed high reproducibility of ESP and HSR results in
all laboratories. A 25-percent difference in the proportion of CPD-PRP
(indicative of a difference of approximately 25% in the proportions of
discoid and spherical platelets) was detected with a sample size of
five (p<0.05) for both the ESC and HSR assays. A high correlation was
found for the ESC assay and morphology score (r = O.93, n =m 345).
CONCLUSION: Multiple laboratories were able to obtain comparable
results with the ESC and HSR tests. They were able to show that the
tests can be performed in an accurate, reproducible manner and with
acceptable sensitivity.
(Transfusion 1998:38:31-40)
OTHER TITLES OF INTEREST
CANCER RESEARCH with CHRONO-LOG PLATELET AGGREGATION
SYSTEMS
A Sensitive Platelet Activation-based Functional Assay for the
Antileukemic Agent Bryostatin 1
Marcus E Carr Jr, Sheryl L Carr and Steven Grant
Anti-Cancer Drugs 1995,6, pp 384-391
Functional Assay for the Antileukemic Agent Bryostatin 1
M E Carr Jr., S L Carr and S Grant
BLOOD, Journal of the American Society of Hematology, Vol
84, No. 10, Suppl 1 (pp 1a-840a)
Inhibition of Human Platelet Glycoprotein IIB/IXIA Binding to
Fibrinogen by Tumor Cell Membrane Proteins
Mikio Kamiyama, Karen Chen, Jean Lynch and Yale S. Arkel
Cancer Research 53, 221-223, January 15, 1993
Elevated Production of Active Oxygen in Bloom's Syndrome Cell
Lines
Thomas Nicotera, Kuldip Thusu and Paresh Dandona
Cancer Research 53, 5104-5107, November 1, 1993
Tumor Cells Induce Platelet Aggregation and Intraplatelet
Calcium Ion Movements
L Pacchiarini, M Zucchella, A R Eynard, G Grignani
PLATELETS (1993) 4, 275-279
Interactions of Tumors with the Hemostatic System: Role of
Calcium Fluxes in Platelets and in Cancer Cells
G. Grignani, A Brocchieri, A Saporiti, L Pacchiarini, M Zucchella
The Cancer Journal, September-October 1994, vol. 7, no. 5
Effect of Different Platelet Agonists on Intracellular Free
Ca++ Concentrations in Human Tumor Cells: Possible Role in Tumor
Growth
A Saporita, A Brocchieri, C Porta, M Moroni, G Grignani
Int. J. Cancer:(1995) 62, 291-296
Granylocyte Function in Coronary Artery Disease
de Servi S, Ricevuti G, Mazzone A, Ghio S, Zita A,
Raffaghello S, Specchia G.
Am J Cardiol 1991, Vol 68, 9/03/91
Chemiluminescence of Phagocytic Cells
Schadelin J, Schadelin R
Critical Reviews in Clin Lab Sci. 1-19, 11/01/80
A Microtechnique for Studying Chemiluminescence Response of
Phagocytes Using Whole Blood and Its Applications to the
Evaluation of Phagocytes in Pregnancy
Selvaraj RJ, Sbarra AJ, Thomas GB, Cetrulo CL, Mitchell
GW
Res: Jnl of the Reticuloendo Soc 31:3-16 1/1/82
IL-Arginine-Nitric Oxide Pathway as a Key Regulatory
Mechanism in Cell-to-Cell Communication
Lefer AM, Lefer DJ.
Biomol Res News, Vol 4, No 1, ppg 1-3, 3/01/93
Free Radical-Mediated Platelet Activation by Hemoglobin
Released from Red Blood Cells
Iuliano L, Violi, F, Pedersen JZ, Pratico D, Rotilio G,
Balsano F.
Arch Biochem & Biophy. Vol 299, No 2, ppg 220-224.
12/01/92
Calcium-Calmodulin Dependence of Oxygen Free Radical
Production by Leukocytes in Whole Blood
Brian D. Snyder, Ahmad Aljada, Usha Khurana, Kuldip
Thusu, Joseph L. Izzo Jr and Paresh Dandona
Abstracts of the Sci Confer on Atherosclerosis,
Thrombosis and Proliferation, Feb 23-26, 1994
Elevated Production of Active Oxygen in Bloom's Syndrome
Cell Lines
Thomas Nicotera, Kuldip Thusu and Paresh Dandona
Cancer Research 53, 5104-5107, Nov 1, 1992
CHEMILUMINESCENCE with CHRONO-LOG LUMI-AGGREGOMETERS
Pentoxifylline Modulates Activation of Human Neutrophils by
Amphotericin B in vitro
Gail W. Sullivan, Holliday T. Carper, and Gerald L. Mandell
Antimicrobial Agents and Chemotherapy, Feb. 1992, p. 408-416
Lipid Complexing Decreases Amphotericin B Inflammatory Activation of
Human Neutrophils Compared with That of a Desoxycholate-Suspended
Preparation of Amphotericin B (Fungizone)
Gail W. Sullivan, Holliday T. Carper, and Gerald L. Mandell
Antimicrobial Agents and Chemotherapy, Jan. 1992, p. 39-45
The Effect of Three Human Recombinant Hematopoietic Growth Factors
(Granulocyte-Macrophage Colony-Stimulating Factor, Granulocyte Colony-
Stimulating Factor, and Interleukin-3) on Phagocyte Oxidative
Activity
Gail W. Sullivan, Holliday T. Carper, and Gerald L. Mandell
Blood, Vol 81, No 7 (April 1), 1993; pp 1863-1870
N,N,N-Trimethylsphingosine Modifies Aggregometry Response and ATP
Release from Platelets in Whole Blood
Ralf Knofler, Tetsumei Urano, Yumiko Takada and Akikazu Takada
Thrombosis Research, Vol 76, No 4, 1994, pp 323-332.
