The Prevalence of von Willebrand Disease and Significance of in Vitro Bleeding Time (PFA-100) in von Willebrand Disease Screening in the İzmir Region

There is no author summary for this article yet. Authors can add summaries to their articles on ScienceOpen to make them more accessible to a non-specialist audience.

Abstract

Objective: von Willebrand disease (vWD) is the most common hereditary bleeding disorder. The purpose of this investigation was to determine the prevalence of vWD among adolescents in İzmir and to assess the sensitivity and specificity of PFA-100 as a screening method in detecting this disease.

Material and Methods: Our study was conducted on adolescents in the city of İzmir between October 2006 and March 2007. A total of approximately 1500 high school students between 14 and 19 years of age were planned to be included in the investigation. Survey forms prepared for assessing hemorrhagic diathesis were completed by 1339 individuals (512 males, 827 females). The necessary laboratory tests were performed after having obtained written informed consent from 40 individuals suspected to have hemorrhagic diathesis.

Results: Based on the von Willebrand factor antigen (vWF:Ag) and ristocetin cofactor activity (vWF:RCo) levels and bleeding symptoms, vWD type-1 was diagnosed in 14 individuals (4 males, 10 females; prevalence: 1.04%). The most common bleeding symptom in these patients was found to be epistaxis (10/14). Screening with PFA-100 revealed prolongation in both cartridges (Col/ADP and Col/Epi) in 3 of the 14 patients. PFA-100 was determined to exhibit 21.4% sensitivity and 100% specificity in the diagnosis of vWD.

Conclusion: The PFA-100 device was found to have high specificity but to have exhibited low sensitivity. Therefore, its utilization as a screening test may be problematic in patients with mild type-1 vWD. Specific tests (vWF:RCo, vWF:Ag) are required for the definite diagnosis of vWD. However, further studies with a large number of patients are needed.

Conflict of interest:None declared.

Translated abstract

Amaç: von Willebrand hastalığı (vWH) en sık kalıtsal kanama bozukluğudur. Bu çalışmanın amacı, İzmir’de adolesanlarda vWH’nın sıklığını saptamak ve tarama yöntemi olarak PFA-100’ün bu hastalığı saptamada duyarlılık ve özgüllüğünü belirlemektir.

Gereç ve Yöntemler: Çalışmamız İzmir İli’nde adolesanlarda Ekim 2006-Mart 2007 tarihleri arasında yapıldı. Yaşları 14-19 arasında olan yaklaşık 1500 lise öğrencisinin çalışmaya dahil edilmesi planlandı. Kanama diyatezini sorgulamaya yönelik hazırlanan anket formlarının cevapları 1339 (512 erkek, 827 kız) bireyden geri toplanabildi. Muhtemel kanama diyatezi olduğu düşünülen 40 bireyden yazılı onam formları alınarak gerekli laboratuvar testleri alındı.

Bulgular: von Willebrand faktör antijen (vWF:Ag) ve ristosetin kofaktör aktivite (vWF:RCo) düzeyi ve kanama semptomları esas alınarak 14 bireyde (4 erkek, 10 kız) von Willebrand Hastalığı tip-1 tespit edildi (prevalans %1,04). Bu hastalarda saptanan en sık kanama semptomunun burun kanaması olduğu (10/14) görüldü. PFA-100 ile yapılan taramada ise 14 hastadan 3’ünde iki kartuşta da (Col/ADP ve Col/Epi) uzama görüldü. PFA-100’ün von Willebrand Hastalığı’nı saptamadaki duyarlılığı %21,4 ve özgüllüğü %100 olarak bulundu.

Sonuç: Sonuç olarak PFA-100 cihazı yüksek oranda özgül olmakla birlikte düşük oranda duyarlı bulunmuştur. Hafif tip-1 vWH için tarama testi olarak kullanılması sorun yaratabilir. von Willebrand hastalığının mutlak tanısı için spesifik testler (vWF:RCo, vWF:Ag) gerekmektedir. Ancak daha fazla hastayı içeren ileri çalışmalara ihtiyaç vardır.

Related collections

Most cited references 32

Record: found
Abstract: found
Article: not found

Epidemiological investigation of the prevalence of von Willebrand's disease.

F Rodeghiero, G Castaman, E Dini (1987)

To evaluate the prevalence of von Willebrand's disease (vWd) we carried out an epidemiological investigation among school children of the Veneto region in northern Italy. A total of 1,218 of 1,281 possible children participated in the study. They were 11 to 14 years of age, and all attended secondary schools in two distinct small areas, 70 km apart, between which there is no social contact. A blood sample was taken from each subject for determination of the blood group and von Willebrand factor (vWf) level (measured as ristocetin cofactor and expressed in IU/dL after calibration of the internal pool against an international standard), and the parents were given a questionnaire concerning hemorrhagic symptoms in the members of the family in the last three generations. Separate normal ranges were calculated for blood group O and non-O subjects (1,166 children and 289 adults) with a nonparametric method because the distribution curves of the reference values did not fit the gaussian distribution. Diagnoses of vWd were considered only for children who had low vWf levels and were members of a family with a convincing bleeding history (case of "probable vWd"). A final diagnosis was assigned if, in addition to these criteria, at least one other family member on the side with hemorrhagic history had a low vWf level. Of the 1,218 children examined, ten were classified as having vWd (0.82%). Taking into account the 90% confidence interval for the lower limit of the normal range, this figure could range from 7 (0.57%) to 14 (1.15%). All these subjects were mildly to moderately affected and presented features of heterozygous classic vWd (type I). Affected subjects were distributed evenly in the two areas examined. Our results suggest that the prevalence of vWd might be much higher than previously reported and that a different screening approach might be of use for patients with mild bleeding diathesis.

0 comments Cited 86 times – based on 0 reviews      Review now

Bookmark

Record: found
Abstract: found
Article: not found

Prevalence of von Willebrand disease in children: a multiethnic study.

Eric Werner, Emmett H. Broxson, Eathyl Tucker … (1993)

Von Willebrand disease (vWD) was thought to be a rare disorder until a recent survey reported a prevalence of 0.8% in an ethnically homogenous community in northern Italy. The purpose of this study was to determine the prevalence of vWD in an ethnically heterogenous population. Von Willebrand factor (vWF) was measured by the ristocetin cofactor method in 600 healthy children, aged 2 to 18 years, seen for routine school physical examinations in a three-state region. Personal and family bleeding symptoms were determined by questionnaire. The diagnosis of vWD required a personal history of bleeding symptoms, an abnormal vWF activity concentration, and a family history of at least one immediate family member with bleeding symptoms. A total of 315 subjects were white, 212 were black, 16 were Hispanic, 10 were from other groups, and 47 were biracial. Eight subjects (four black, four white) met the criteria for vWD, for a prevalence of 1.3%. Seven subjects with vWD had blood group O (mean vWF = 32 U/dl; range, 10 to 42 U/dl), and one had blood group A (vWF = 41 U/dl). Children who had blood group O had significantly (p < 0.001) lower vWF activities (median, 83 U/dl, range, 43 to 162 U/dl) than those from non-O blood groups (median, 98 U/dl; range, 51 to 190 U/dl). There were no significant differences in vWF activity by ethnicity. The vWF activity was significantly (p < 0.02) greater for boys than girls in both blood groups. Von Willebrand disease is the most common congenital hemostatic disorder; its high prevalence is not limited to one ethnic group.

0 comments Cited 48 times – based on 0 reviews      Review now

Bookmark

Record: found
Abstract: found
Article: not found

Prospective evaluation of the clinical utility of quantitative bleeding severity assessment in patients referred for hemostatic evaluation.

A Tosetto, G Castaman, I Plug … (2011)

Quantitative bleeding assessment tools (BATs) have been used to describe the severity of the bleeding phenotype in patients with von Willebrand disease. To evaluate the clinical usefulness of a BAT for the diagnosis of mild bleeding disorders (MBDs) in previously undiagnosed patients. We prospectively assessed 215 patients who were consecutively referred for evaluation of bleeding symptoms (n=71), abnormal laboratory clotting test results (n=105) or family investigation (n=39) at two second-level centers. The bleeding history was assessed by a young investigator who administered the BAT instrument, and also by a senior physician who independently evaluated the patient and made the final diagnoses. Sensitivity, specificity, negative predictive value (NPV) and positive predictive value (PPV) were computed for a predefined bleeding score (BS) cut-off (BS of >3). Receiver operating characteristic curves were used to establish a diagnostic prediction rule. Assuming the prevalence of MBD in the general population to be ∼1%, a normal BS (≤3) had a very high NPV (99.2%). The PPVs in patients referred for hemostatic or family evaluation at second-level clinics were estimated to be 71.0% and 77.5% (assuming MDB prevalences of 20% and 50%, respectively, in these settings). Measurement of BS in addition to activated partial thromboplastin time significantly increased the diagnostic efficiency of the BAT instrument (NPV of 99.6%). BAT use improves the evaluation of patients with suspected MBD, and we propose its use in a clinical prediction guide based on BAT and activated partial thromboplastin time for the exclusion of patients with suspected MBD in a low-prevalence setting. © 2011 International Society on Thrombosis and Haemostasis.

0 comments Cited 20 times – based on 0 reviews      Review now

Bookmark

All references

Author and article information

Journal

Journal ID (nlm-ta): Turk J Haematol

Journal ID (iso-abbrev): Turk J Haematol

Journal ID (publisher-id): TJH

Title: Turkish Journal of Hematology

Publisher: Galenos Publishing

ISSN (Print): 1300-7777

ISSN (Electronic): 1308-5263

Publication date (Print): March 2013

Publication date (Electronic): 5 March 2013

Volume: 30

Issue: 1

Pages: 40-47

Affiliations

[1 ] Konya Training and Research Hospital, Department of Pediatrics, Konya, Turkey

[2 ] Dr. Behçet Uz Children’s Research and Training Hospital, Department of Pediatrics, İzmir, Turkey

[3 ] Ege University Faculty of Medicine, Department of Pediatric Hematology, İzmir, Turkey

[4 ] Dr. Behçet Uz Children’s Research and Training Hospital, Department of Pediatric Endocrinology, İzmir, Turkey

Author notes

* Address for Correspondence: Konya Training and Research Hospital, Department of Pediatrics, Konya, Turkey Phone: +90 332 323 67 09 E-mail: fatihsap@ 123456gmail.com

Article

Publisher Item ID: 297

DOI: 10.4274/tjh.2011.0020

PMC ID: 3781650

PubMed ID: 24385752

SO-VID: caae7c72-8908-4679-9d9e-b9d79022edbe

License:

This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Read this article at

Abstract

Translated abstract

Related collections

Alternative approaches to Alzheimer's Disease

Most cited references 32

Epidemiological investigation of the prevalence of von Willebrand's disease.

Prevalence of von Willebrand disease in children: a multiethnic study.

Prospective evaluation of the clinical utility of quantitative bleeding severity assessment in patients referred for hemostatic evaluation.

Author and article information

Journal

Affiliations

Author notes

Article

History

Categories

Comments

Comment on this article

Similar content 412

Cited by 2

Most referenced authors 185