scholarly journals Is ≥100% the magic number to rule out the laboratory diagnosis of von Willebrand disease based on initial testing?

2021 ◽  
Author(s):  
Angela C. Weyand ◽  
Peter Kouides ◽  
Jemily Malvar ◽  
Julie Jaffray
Keyword(s):  
Magic Number ◽  
Laboratory Diagnosis ◽  
Von Willebrand Disease ◽  
Initial Testing ◽  
Von Willebrand ◽  
Rule Out

Screening for haemorrhagic disorders in paediatric patients by means of a questionnaire

2009 ◽  
Vol 29 (S 01) ◽  
pp. S87-S89 ◽  
Author(s):  
I. Music ◽  
M. Novak ◽  
B. Acham-Roschitz ◽  
W. Muntean
Keyword(s):  
Predictive Value ◽  
Laboratory Diagnosis ◽  
Von Willebrand Disease ◽  
Control Group ◽  
Older Children ◽  
Mild Disease ◽  
History Of ◽  
Von Willebrand ◽  
Specific Symptoms ◽  
Infants And Young Children

SummaryAim: In children, screening for haemorrhagic disorders is further complicated by the fact that infants and young children with mild disease in many cases most likely will not have a significant history of easy bruising or bleeding making the efficacy of a questionnaire even more questionable. Patients, methods: We compared the questionnaires of a group of 88 children in whom a haemorrhagic disorder was ruled out by rigorous laboratory investigation to a group of 38 children with mild von Willebrand disease (VWD). Questionnaires about child, mother and father were obtained prior to the laboratory diagnosis on the occasion of routine preoperative screening. Results: 23/38 children with mild VWD showed at least one positive question in the questionnaire, while 21/88 without laboratory signs showed at least one positive question. There was a trend to more specific symptoms in older children. Three or more positive questions were found only in VWD patients, but only in a few of the control group. The question about menstrual bleeding in mothers did not differ significantly. Sensitivity of the questionnaire for a hemostatic disorder was 0.60, while specifity was 0.76. The negative predictive value was 0.82, but the positive predictive value was only 0.52. Conclusions: Our small study shows, that a questionnaire yields good results to exclude a haemostatic disorder, but is not a sensitive tool to identify such a disorder.

scholarly journals Quantitative impact of using different criteria for the laboratory diagnosis of type 1 von Willebrand disease

2014 ◽  
Vol 12 (8) ◽  
pp. 1238-1243 ◽  
Author(s):  
T. Quiroga ◽  
M. Goycoolea ◽  
S. Belmont ◽  
O. Panes ◽  
E. Aranda ◽  
...  
Keyword(s):  
Laboratory Diagnosis ◽  
Von Willebrand Disease ◽  
Von Willebrand ◽  
Quantitative Impact

Severe nose bleeding after intake of acetylsalicylic acid: von Willebrand disease type 2A

2003 ◽  
Vol 23 (03) ◽  
pp. 135-137
Author(s):  
B. Mansouri Taleghani ◽  
W. A. Wuillemin ◽  
N. X. von der Weid
Keyword(s):  
Acetylsalicylic Acid ◽  
Laboratory Diagnosis ◽  
Inhibitory Effect ◽  
Von Willebrand Disease ◽  
Bleeding Disorders ◽  
Laboratory Findings ◽  
History Of ◽  
Inflammatory Drugs ◽  
Von Willebrand

SummaryThis case report of a school boy with a history of severe and repeated episodes of epistaxis presents a short overview of the clinical and laboratory findings which lead to confirm the suspected diagnosis of von Willebrand disease (vWD). Suspicion of defective primary haemostasis should arise when unusual (because of their number or duration) mucosal bleeds appear in an otherwise normal and healthy patient. Because of its definitive inhibitory effect on platelet aggregation, acetylsalicylic acid (more than other non-steroidal anti-inflammatory drugs exerting unselective inhibition of cyclooxygenase) is a strong factor in triggering or sustaining the bleeding disorders in these patients. Among the congenital disorder of primary haemostasis, vWD is by far the most frequent one.The difficulties of laboratory diagnosis of vWD are stressed; the promises and pitfalls of new in vitro methods for measuring primary haemostasis (PFA-100® analyzer) are discussed. An accurate diagnosis of the specific type of vWD is of critical importance for correct patient management as well as for genetic counseling.

Ristocetin Induced Platelet Factor 3 Availability, A Possible New Tool In The Diagnosis Of Von Willebrand’S Disease

1981 ◽  
Author(s):  
L Muszbek ◽  
H Losonczy ◽  
B Hársfalvi ◽  
I Nagy
Keyword(s):  
Bleeding Time ◽  
Laboratory Diagnosis ◽  
Von Willebrand Disease ◽  
Platelet Factor ◽  
Von Willebrand's Disease ◽  
Von Willebrand’S Disease ◽  
Total Inhibition ◽  
Plasma Factor ◽  
Von Willebrand ◽  
Normal Controls

Ristocetin induced platelet aggregation (RIPA) is a highly valuable technique in the laboratory diagnosis of von Willebrand’s disease (vWD) and together with the estimation of bleeding time, F VIII procoagulant activity and F VIII related antigen in most cases it makes also division of vWD into phenotypic subgroups possible. We have shown that ristocetin makes platelet factor 3 available and ristocetin induced platelet factor 3 availability (RIPF3) similarly to RIPA also depends on a plasma factor. In the present paper it was examined if RIPF3 can be applied as a laboratory test in the diagnosis of vWD. PRP from normal controls, patients with various release defects and von Willebrand patients was incubated and continuously stirred with ristocetin or phys. saline and after 20 min the RW clotting times were determined. RIPF3 activity was expressed as the ratio of the clotting times obtained following incubation with phys. saline and ristocetin.In healthy controls and patients with release defect (n=21) this ratio was higher than 1.5, and in most cases between 1.8-2.5. In patients with vWD (n=10) the ratio was well below 1.5 (with one exception it ranged between 0.95-1.2). In 9 of the lO patients the absence or strong diminution of RIPA and RIPF3 showed close paralellism. In one patient only the slope of first vawe of ristocetin aggregation was decreased while at the same time an almost total inhibition of RIPF3 could be observed. The results indicate that RIPF3 is a valuable quantitative diagnostic test in von Willebrand disease. It can be used if expensive aggregometer is not available and it may also have an importance as additional test to RIPA in the division of vWD into subgroups. An attempt was made to develop this test further by using chromogenic substrate for the measurement of RIPF3.

Laboratory Diagnosis of von Willebrand Disease

2009 ◽  
Vol 03 (01) ◽  
pp. 33 ◽  
Author(s):  
Muriel Meiring ◽  
Philip N Badenhorst ◽  
Mareli Kelderman ◽  
◽  
◽  
...  
Keyword(s):  
Factor Viii ◽  
Correct Diagnosis ◽  
Laboratory Diagnosis ◽  
Binding Activity ◽  
Von Willebrand Disease ◽  
Coagulant Activity ◽  
Low Sensitivity ◽  
Von Willebrand ◽  
Willebrand Factor

von Willebrand disease (VWD) is a bleeding disorder caused by either quantitative (type 1 and 3) or qualitative (type 2) defects of von Willebrand factor (VWF). No single available test provides appropriate information about the various functions of VWF, and the laboratory diagnosis of VWD is based on a panel of tests, including the measurement of factor VIII coagulant activity (FVIIIC), VWF antigen levels (VWF:Ag), VWF activity as measured by the ristocetin co-factor activity (VWF:RCo), the collagen-binding activity of VWF (VWF:CB), VWF multimer analysis, ristocetininduced platelet agglutination (RIPA), the factor-VIII-binding assay of plasma VWF and VWF propeptide levels. Due to the heterogeneity of VWF defects and the variables that interfere with VWF levels, a correct diagnosis of types and subtypes may sometimes be difficult, but is very important for therapy. Furthermore, the RCo assay and the RIPA test are based on platelet agglutination in reaction with the non-physiological antibiotic ristocetin. These tests also have low sensitivity and are difficult to standardise. Therefore, several analyses (tests) are required to diagnose VWD and it is important to be aware of the pitfalls to which these tests are subjected in terms of the diagnosis. In this article, the laboratory diagnosis of patients with type 1, 2A, 2B, 2M, 2N and 3 VWD will be explained by using a modified algorithm that was first proposed by the guidelines for diagnosis and treatment of VWD in Italy.

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