Assessment of Menorrhagia in Females Followed for Bleeding Disorders at the Hemophilia Center of Western New York-Correlation between Clinical Presentation and Laboratory Parameters.

Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 4054-4054
Author(s):  
Eric Bush ◽  
Shannon Smiley ◽  
Linda Belling ◽  
Zale P. Bernstein
Keyword(s):  
New York ◽  
Point System ◽  
Activity Levels ◽  
Blood Samples ◽  
Primary Hemostasis ◽  
Function Analyzer ◽  
Platelet Function Analyzer ◽  
Von Willebrand ◽  
Willebrand Factor ◽  
Summary Data

Abstract Menorrhagia is a common problem among women. The pathophysiology has been attributed to Von Willebrand’s disease in some patients. The lab diagnosis and confirmation of this condition in these women is often difficult. The need for easily reproducible, validated lab investigations is recognized. The platelet function analyzer (PFA-100) (described below) has recently been used as an adjunct for lab diagnosis of this condition. Use of this device is relatively recent, thus clinical correlation with its results have been lacking. Therefore, we initiated a study to determine if a correlation could be established between pictorial blood assessment chart (PBAC), PFA-100, and Von Willebrand’s screening (VWF antigen and co-factor activity levels). Materials and methods: After obtaining informed consent 15 female patients with a diagnosis of von Villebrand’s disease were enrolled in the above study. All received verbal and written instructions of how to record their tampon/pad use on the PBAC. The PBAC was then scored on a validated and well-established point system for lightly (1point), moderately (2points) and heavily (3points) soiled pads or tampons. In addition their blood samples were analyzed for von Willebrand antigen, Ristocetin Co-Factor and on the PFA-100 (pre and post DDAVP). The PFA-100, is a high shear-inducing device which simulates primary hemostasis after injury to small vessel, which consists of a reservoir for whole blood and a small capillary surmounted by a collagen-coated membrane with a central aperture. Platelet agonist which is either epinephrine or ADP is present on the membrane. Closure time is reported as a variable which describes von Willebrand factor function. All blood samples were forwarded to Children’s Hospital of Buffalo Special Coagulation lab for examination of the PFA-100(pre and post DDAVP),and von Willebrand panel. Conclusion: There was correlation between the number of points self-assessed on the PBAC and the PFA-100. Summary Data Patient # Age # points/PBAC VWF Ristocetin Co Factor Factor VIII PFA 100 Pre DDAVP 1 48 10 56 52 70 104 2 47 23 73 53 138 90 3 21 9 69 70 63 151 4 47 180 75 51 120 280 5 44 25 107 68 114 124 6 49 47 102 93 74 63 7 25 12 74 51 84 177 8 26 8 30 28 77 216 9 30 24 47 64 115 125 10 27 11 76 45 60 118 11 25 10 66 49 79 136 12 48 11 51 48 121 117 13 25 9 59 42 44 99 14 23 41 33 11 34 275 15 46 84 3 2 11 300

Lack of association between aspirin responsiveness and seven candidate gene haplotypes in patients with symptomatic vascular disease

2009 ◽  
Vol 101 (01) ◽  
pp. 123-133 ◽  
Author(s):  
Shirley Williams ◽  
Diane Nugent ◽  
Paul Harrison ◽  
Helen Segal ◽  
Anila Syed ◽  
...  
Keyword(s):  
Candidate Genes ◽  
Platelet Function ◽  
Purinergic Receptor ◽  
Blood Platelet ◽  
Function Analyzer ◽  
Prostaglandin H ◽  
Ischemic Attack ◽  
Platelet Function Analyzer ◽  
Von Willebrand ◽  
Willebrand Factor

SummaryWe studied the effect of prophylactic aspirin (ASA) ingestion on platelet function in 463 patients with stroke, transient ischemic attack (TIA) or acute coronary disease (ACD), using the Platelet Function Analyzer-100 (PFA-100). We correlated ASA responsiveness with haplotypes of seven candidate genes, selected for their documented role in platelet function, namely, the genes for integrins α2β1and αIIbβ3 (ITGA2, ITGA2B, and ITGB3), platelet glycoproteins Ibα and VI (GPIBA and GP6), the purinergic receptor P2Y1 (P2RY1), and prostaglandin H synthase 1 (PTGS1 = COX1). Non-responsiveness to ASA was defined as the failure of prior ASA ingestion to prolong the PFA-100 closure time (CT) when blood was perfused through cartridges coated with collagen plus epinephrine (CEPI-CT). ASA non-responsiveness was observed in 114 of 463 patients (24.6 %), but was not associated with haplotypes of any of the seven candidate genes. There was also no association between any haplotypes and the CT when blood was perfused through cartridges coated with collagen plus ADP (CADP-CT). The ASA non-responsive cohort had significantly increased whole blood platelet counts (p = 0.03) and plasma von Willebrand Factor antigen levels (p<0.001), which likely contributes to resistance to the inhibitory effects of ASA in the PFA-100.

Platelet function in cats with hyperthyroidism

2020 ◽  
Vol 22 (12) ◽  
pp. 1214-1218
Author(s):  
Elizabeth C Hiebert ◽  
David L Panciera ◽  
Katie M Boes ◽  
Lara Bartl
Keyword(s):  
Platelet Count ◽  
Platelet Function ◽  
Adenosine Diphosphate ◽  
Control Group ◽  
Closure Time ◽  
Function Analyzer ◽  
The Mean ◽  
Platelet Function Analyzer ◽  
Von Willebrand ◽  
Willebrand Factor

Objectives Cats with hyperthyroidism have been reported to develop thromboembolism, with and without echocardiographic abnormalities consistent with hyperthyroidism. The objective of this study was to compare platelet function in cats with hyperthyroidism with euthyroid age-matched cats. We hypothesized that cats with hyperthyroidism have shortened collagen and adenosine diphosphate (C-ADP) closure times as measured with the platelet function analyzer (PFA-100) in comparison with healthy, age-matched controls. Methods Sixteen hyperthyroid and nine euthyroid healthy cats >7 years of age were recruited from the hospital population. Platelet function, measured using the C-ADP closure times by the PFA-100, and platelet count were measured in healthy euthyroid cats and cats with hyperthyroidism. Results Mean ± SD closure times were not significantly different between control (66.3 ± 9.6 s) and hyperthyroid cats (65.9 ± 11.5 s; P = 0.75). The mean ± SD closure times of hyperthyroid cats that either were untreated or received methimazole for ⩽3 weeks (n = 6; mean 68.5 ± 15.4 s) was not different than that of cats treated for >3 weeks (n = 10; mean 64.3 ± 8.9 s; P = 0.57). The mean automated platelet count was higher in the hyperthyroid group than in the control group ( P = 0.023). Conclusions and relevance Platelet function, as measured by closure time under high shear conditions using C-ADP as an agonist, was not affected by hyperthyroidism in this group of cats. Further research is needed to determine if a hypercoagulable state exists in hyperthyroid cats and the potential roles platelets and von Willebrand factor may have.

Comparison of PFA-100 testing and bleeding time for detecting platelet hypofunction and von Willebrand disease in clinical practice

2003 ◽  
Vol 90 (09) ◽  
pp. 483-490 ◽  
Author(s):  
Emoke Posan ◽  
Robert McBane ◽  
Diane Grill ◽  
Cheri Motsko ◽  
William Nichols
Keyword(s):  
Clinical Practice ◽  
Von Willebrand Factor ◽  
Bleeding Time ◽  
Von Willebrand Disease ◽  
Hemorrhagic Diathesis ◽  
Primary Hemostasis ◽  
Platelet Aggregometry ◽  
Function Analyzer ◽  
Von Willebrand ◽  
Willebrand Factor

SummaryThe PFA-100 instrument (Platelet Function Analyzer, Dade Behring) has been reported to be superior to the bleeding time (BT) as a screening test of primary hemostasis. However evaluation of this device has been principally limited to selected populations.The study’s aim was to determine testing performance in clinical practice, by comparing the PFA-100 to the BT for the identification of von Willebrand disease (VWD) and intrinsic platelet hypofunction.From 1998-2000, PFA-100 closure time (CT) for epinephrine-collagen (EPI) and ADP-collagen (ADP) cartridges and modified Ivy BTs were performed on outpatients referred for testing for suspected or known hemorrhagic diathesis (n=346). Evaluation included assays of von Willebrand factor and platelet aggregometry in addition to platelet flow cytometry and electron microscopy when indicated. The normal distribution of PFA-100 CTs was determined using blood samples from 61 normal donors studied on 155 occasions.Results show that thirty-four patients met the diagnostic criteria for VWD and 31 patients were diagnosed with congenital or acquired intrinsic platelet hypofunction. The sensitivity of the PFA-100 for identification of VWD was significantly better (p<0.01) than the BT with similar specificity. In contrast, the PFA-100 was comparable, but not superior to the BT for detecting platelet hypofunction.We conclude that the PFA-100 performance compares favor-ably to the BT for the identification of intrinsic platelet hypofunction in clinical practice with superior sensitivity for detecting VWD.Therefore, the PFA-100 could replace the BT for purposes of screening for VWD and intrinsic platelet hypofunction. When clinical suspicion is strong, testing should be supplemented with assays of von Willebrand factor and platelet aggregometry.

Sensitive and specific assessment of recombinant von Willebrand factor in platelet function analyzer

Platelets ◽  
2018 ◽  
Vol 30 (2) ◽  
pp. 264-270 ◽  
Author(s):  
Isabell Pekrul ◽  
Thorsten Kragh ◽  
Peter L Turecek ◽  
Aaron R Novack ◽  
Helmut W Ott ◽  
...  
Keyword(s):  
Platelet Function ◽  
Von Willebrand Factor ◽  
Function Analyzer ◽  
Specific Assessment ◽  
Platelet Function Analyzer ◽  
Von Willebrand ◽  
Willebrand Factor

scholarly journals Evaluation of an Automated von Willebrand Factor Activity Assay in von Willebrand Disease

2010 ◽  
Vol 17 (6) ◽  
pp. E25-E29 ◽  
Author(s):  
Marc Trossaërt ◽  
Catherine Ternisien ◽  
Armelle Lefrancois ◽  
Laura Llopis ◽  
Jenny Goudemand ◽  
...  
Keyword(s):  
Von Willebrand Factor ◽  
Screening Strategy ◽  
Von Willebrand Disease ◽  
Activity Assay ◽  
Screening Assay ◽  
Function Analyzer ◽  
Highly Correlated ◽  
Platelet Function Analyzer ◽  
Von Willebrand ◽  
Willebrand Factor

We evaluated the use of the turbidimetric HemosIL von Willebrand Factor (VWF) Activity assay (VWF:Act) on the STA-R automated coagulometer (Stago, Asnières, France) for the diagnosis of von Willebrand disease (VWD). For this, we prospectively screened 268 patients. As a second part, we retrospectively assayed 111 patients with well-defined VWD subtype. In the first prospective study, we demonstrate that in most cases of VWD, VWF ristocetin cofactor activity (VWF:RCo) and VWF:Act are highly correlated but that they both cannot be considered a good screening assay when used alone, since they could miss about 25% of VWF abnormalities. However, the association of VWF:Act analysis and the Platelet Function Analyzer-100 (PFA-100) test constitutes an excellent screening strategy. In our second retrospective study concerning VWD subtypes, VWF:RCo and VWF:Act were well correlated but could be very discrepant, especially for some cases of type 2M VWD. We consider that VWF:RCo remains the “reference assay” for VWD subtype classification.

Assessment of Primary Hemostasis by PFA-100® Analysis in a Tertiary Care Center

2000 ◽  
Vol 84 (07) ◽  
pp. 93-97 ◽  
Author(s):  
Andra James ◽  
Elizabeth Thames ◽  
Karen Moore ◽  
Charles Greenberg ◽  
Thomas Ortel
Keyword(s):  
Platelet Function ◽  
Care Center ◽  
Tertiary Care ◽  
Tertiary Care Center ◽  
Primary Hemostasis ◽  
Platelet Aggregometry ◽  
Function Analyzer ◽  
Platelet Defects ◽  
Platelet Function Analyzer ◽  
Von Willebrand

SummaryWe evaluated the utility of the PFA-100® platelet function analyzer in identifying disorders in platelet function and/or von Willebrand factor (vWF) in patients with various systemic disorders being followed at a tertiary care center. Closure times were determined with collagen/ ADP (CADP) and collagen/epinephrine (CEPI) cartridges for 305 patients, and abnormal results were further evaluated with platelet aggregometry and vWF analysis. Prolonged CADP and/or CEPI closure times were identified in 114 patients (37.3%), but most were isolated prolonged CEPI closure times predominantly due to aspirin therapy (79 patients). Prolonged CADP closure times were most frequently due to qualitative platelet defects and/or decreased vWF levels. Prolonged CADP closure times were encountered most frequently in patients with sickle cell disease and were associated with a decreased hematocrit. This study demonstrated that the PFA-100® analyzer can accurately assess vWF-dependent platelet function and detect other platelet defects under high shear stress in complex patient populations.

Characterization of an In Vitro Platelet Function Analyzer, PFA-100™

1996 ◽  
Vol 2 (4) ◽  
pp. 241-249 ◽  
Author(s):  
Sourav K. Kundu ◽  
Eric J. Heilmann ◽  
Reynaldo Sio ◽  
Carmen Garcia ◽  
Roy A. Ostgaard
Keyword(s):  
Platelet Function ◽  
Rapid Screening ◽  
Closure Time ◽  
Function Analyzer ◽  
Controlled Flow ◽  
Time Required ◽  
Platelet Function Analyzer ◽  
Von Willebrand ◽  
Willebrand Factor

A new in vitro system for the evaluation of platelet function, PFA-100 (currently under evaluation) is characterized. The system monitors platelet aggrega tion on a collagen-epinephrine-coated membrane as whole blood sample is aspirated under controlled flow conditions through a microscopic aperture cut into the membrane. The time required for the platelet plug to oc clude the aperture (closure time) is indicative of the plate let function in the sample. Incubation of normal blood samples with antibodies to glycoprotein (GP) Ib, GPIIb- IIIa, von Willebrand factor, or with the peptide Arg-Gly- Asp-Ser, resulted in a concentration-dependent prolonga tion in closure time. An anti-fibrinogen antibody did not impact the closure time. Closure time was also prolonged when the hematocrit or the platelet count was lowered to pathological values. The study indicates that PFA-100 could detect defects in platelet adhesion or aggregation. The simplicity of the test makes PFA-100 unique for rapid screening of a variety of platelet dysfunction.

scholarly journals Von Willebrand Factor (vWF) Levels and Platelet Counts Showed Strong Inverse Correlation in Calreticulin (CALR) Mutated ET, but Weak in JAK2V617F Mutated PV and ET

Blood ◽  
2018 ◽  
Vol 132 (Supplement 1) ◽  
pp. 4313-4313
Author(s):  
Kazuhide Iizuka ◽  
Noriyoshi Iriyama ◽  
Soji Morishita ◽  
Yoshikazu Iizuka ◽  
Naotake Yanagisawa ◽  
...  
Keyword(s):  
Triple Negative ◽  
Inverse Correlation ◽  
Major Surgery ◽  
Blood Samples ◽  
Allele Burden ◽  
Von Willebrand ◽  
First Time ◽  
Willebrand Factor ◽  
Jak2v617f Allele Burden ◽  
Strong Inverse Correlation

Abstract Background : In myeloproliferative neoplasms, especially essential thrombocythemia (ET), platelet (Plt) counts and von Willebrand factor (vWF):Ristocetin cofactor (RCo) levels have been reported to be inversely correlated. However, there have been no reports of the comparison of high vs. low values of JAK2 allele burden and necessary of Plt counts reduction to achieve vWF:RCo levels ≥50%, which is required for major surgery. We investigated the correlation between vWF level and Plt counts for JAK2V617F mutation positive (JAK2V617F+) polycythemia vera (PV) and ET (allele burdens ≥50% and <50%) and calreticulin mutation-positive (CALR+) ET. Method: We recruited patients with PV and ET who were diagnosed per the 2008 World Health Organization criteria at 3 hospitals since 2011 to 2018. All patients were analyzed at Juntendo University for JAK2 (V617F, exson12), CALR, and MPL mutations. We collected data of JAK2V617F+ or CALR+ patients. Triple-negative mutations of ET were excluded in this study because it is difficult to differentiate between ET and secondary thrombocytosis. We analyzed the correlation between Plt counts and vWF:RCo levels for three mutation groups mutations (JAK2V617F allele burden ≥50%, <50%, CALR+) using Spearman's rank correlation test when blood samples were obtained for the first time from patients after enrolling in this study. In addition, bleeding risk was compared in three mutation groups using Fisher's exact test in patients who were controlled with relatively low Plt counts <600×10⁹/L. Results: We collected 146 PV and ET patients. Among 54 PV patients, 50 had JAK2V617F+, 3 had JAK2 exon 12, and 1 had a triple-negative mutation(s) in PV patients. Among 92 ET patients, 53 had JAK2V617F+, 35 had CALR+ (22 del52, 12 ins5 and 1 del34), and 4 had MPL mutations in ET patients. vWF:RCo levels were weakly inversely correlated with Plt counts in patients with JAK2V617F+ PV and ET from whom blood samples were obtained for the first time after enrolling in this study (Ps=-0.531 and Ps=-0.439, respectively). In contrast, vWF:RCo levels and Plt counts in patients with CALR+ ET showed a strong inverse correlation (Ps=-0.762). Interestingly, 3/50 PV and 4/53 ET patients with JAK2V617F mutations showed vWF:RCo levels >150% (normal vWF:RCo levels range: 50-150%). Furthermore, 3/50 PV and 1/53 ET patients with Plt counts <600×10⁹/L showed vWF: RCo levels <50%. However, none of the patients with CALR+ ET had vWF:RCo levels >150% or <50%. During the entire observation period, 8/50 and 7/53 patients with JAK2V617F+ PV and ET, respectively, and 1/35 patients with CALR+ ET had vWF:RCo levels >150%. One case of JAK2V617F+ ET (allele burden <50%) complicated with deep vein thrombosis; blood sampling data revealed vWF:RCo levels of 200% and a Plt count of 269×10⁹/L. The patient exhibited only age (86 years) as a risk factor for thrombosis and did not have other risk factors (diabetes mellitus, smoking history, hypertension, hyperlipidemia, thrombosis history). When Plt counts were controlled to <600×10⁹/L, all patients with JAK2V617F+ PV and ET and CALR+ ET had vWF:RCo levels >30%. However, 13/86 patients did not achieve 50%, which is the standard for safely performing the major surgical procedures prescribed in most guidelines. In patients whose Plt counts controlled to <600×10⁹/L, vWF:RCo levels <50% was more frequently seen in patients with JAK2V617F allele burden ≥50% than those those with JAK2V617F allele burden <50% (10/32 vs 2/35, p = 0.00956) or CALR mutations (10/32 vs 1/19, p = 0.0373). Conclusion: For patients with CALR+ ET, we propose that vWF:RCo levels can be predicted based on Plt counts; however, it is difficult to predict vWF:RCo levels by Plt counts in JAK2V617F+ PV and ET patients because the inverse correlation between vWF:RCo levels and Plt counts was weak. Overactivation of vWF:RCo levels was often observed in JAK2+ PV and ET. Moreover, in 1 case, the patient exhibited only age as the risk factor for the complication of thrombosis. Because of these findings, overactivation of vWF:RCo levels may be one of the reasons for thrombotic events in JAK2V617F+ PV and ET. In addition, it was also found that cases of JAK2V617F+ allele burden ≥50% in PV and ET should be careful for hemorrhage in major surgery, even if Plt counts were controlled <600×10⁹/L. Disclosures No relevant conflicts of interest to declare.

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