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  1. Laffan M, Sathar J, Johnsen JM
    Haemophilia, 2021 Feb;27 Suppl 3:66-74.
    PMID: 32578345 DOI: 10.1111/hae.14050
    von Willebrand disease (VWD) is the most common inherited bleeding disorder. VWD is caused by deficiencies in von Willebrand factor (VWF), a critical adhesive haemostatic protein. This review provides an overview of VWD diagnosis and treatment, special considerations in treating women with VWD, and current genomic approaches to VWD. For diagnosis and treatment in VWD, an accurate diagnosis is critical to providing effective treatments, determining appropriate laboratory monitoring and for counselling the patient and family. Diagnosis of VWD begins with the clinical assessment for the bleeding phenotype, which is usually characterized by mucocutaneous and provoked bleeding. The diagnosis of VWD is then made by laboratory investigation. Multiple assays are used to assess VWF levels and functions. The mainstays of VWD treatment are tailored by VWD type and symptoms, and can include antifibrinolytic treatment, desmopressin and VWF replacement treatment. Women with VWD are also at risk for excessive uterine bleeding, such as with menses and childbirth. In addition to standard VWD treatments, heavy menstrual bleeding can be treated with hormones. Interdisciplinary management of childbirth and prophylaxis in the postpartum period are needed to reduce the risk of postpartum haemorrhage. Genomic approaches to VWD can inform VWD diagnosis, treatment, test assay selection, reproductive planning and family counselling. Most VWD patients have an identifiable VWF gene DNA variant. Next-generation sequencing is rapidly being adopted to provide more comprehensive VWF sequence information for patients with known or suspected VWD.
    Matched MeSH terms: von Willebrand Factor/genetics
  2. Marianor M, Zaidah AW, Maraina ChC
    Biomark Insights, 2015;10:75-9.
    PMID: 26339184 DOI: 10.4137/BMI.S24353
    Epidemiological studies have shown that vascular-related disorders are associated with high von Willebrand factor antigen (VWF:Ag) and VWF propeptide (VWFpp). VWFpp is secreted together with VWF:Ag upon endothelial cell activation, hence it could be a potential biomarker. This study was conducted to compare between VWF:Ag and VWFpp levels among 30 healthy individuals and 42 patients with high levels of VWF:Ag in different medical conditions and ABO blood groups. VWFpp levels were strongly correlated with VWF:Ag. VWF:Ag and VWFpp levels were significantly increased in patients compared to healthy individuals. VWFpp is not affected by ABO blood group in both healthy individual and patient groups unlike VWF:Ag. As expected, this study showed that VWFpp levels increased in parallel with VWF:Ag levels in patients with diseases associated with endothelial activation. VWFpp though nonspecific is a potential biomarker reflecting underlying pathophysiological changes in various medical conditions with an additional advantage of not being influenced by ABO blood groups.
    Matched MeSH terms: von Willebrand Factor
  3. Mahat M, Abdullah WZ, Hussin CM
    J Immunol Res, 2014;2014:850810.
    PMID: 25759835 DOI: 10.1155/2014/850810
    Measurement of von Willebrand factor antigen (VWF : Ag) levels is usually performed in a specialised laboratory which limits its application in routine clinical practice. So far, no commercial rapid test kit is available for VWF : Ag estimation. This paper discusses the technical aspect of latex agglutination method which was established to suit the purpose of estimating von Willebrand factor (VWF) levels in the plasma sample. The latex agglutination test can be performed qualitatively and semiquantitatively. Reproducibility, stability, linearity, limit of detection, interference, and method comparison studies were conducted to evaluate the performance of this test. Semiquantitative latex agglutination test was strongly correlated with the reference immunoturbidimetric assay (Spearman's rho = 0.946, P < 0.001, n = 132). A substantial agreement (κ = 0.77) was found between qualitative latex agglutination test and the reference assay. Using the scoring system for the rapid latex test, no agglutination is with 0% VWF : Ag (control negative), 1+ reaction is equivalent to <20% VWF : Ag, and 4+ reaction indicates >150% VWF : Ag (when comparing with immunoturbidimetric assay). The findings from evaluation studies suggest that latex agglutination method is suitable to be used as a rapid test kit for the estimation of VWF : Ag levels in various clinical conditions associated with high levels and low levels of VWF : Ag.
    Matched MeSH terms: von Willebrand Factor/metabolism*
  4. Faiz ZM, Mardhiyyah MP, Mohamad A, Hidir A, Nurul-Hidayah A, Wong L, et al.
    Anim. Reprod. Sci., 2019 Oct;209:106143.
    PMID: 31514941 DOI: 10.1016/j.anireprosci.2019.106143
    Understanding Macrobrachium rosenbergii ovarian maturation control at the genome level is an important aspect for increasing larvae production. In this study, an ovarian maturation related gene, M. rosenbergii vWD domain and three Kazal-type domains of a gene (MrvWD-Kazal) have been studied. The MrvWD-Kazal gene was isolated using a rapid amplification of cDNA end (RACE) method and the relative abundances of MrvWD-Kazal mRNA in the ovary, hepatopancreas, stomach, intestine and gill were determined by using the quantitative PCR technique. The MrvWD-Kazal gene is composed of 2194 bp with an open reading frame (ORF) of 1998 bp encoding 665 amino acids and has great similarity to the M. nipponense vWD-Kazal gene (91%). The qPCR analyses indicated the relative abundance of MrvWD-Kazal mRNA transcript varied among different stages of ovarian function (P < 0.05), but there were no differences abundance in hepatopancreas, stomach, intestine and gill (P> 0.05). In the ovary, relative abundance of MrvWD-Kazal mRNA transcript gradually increased with ovarian maturation from Stages 1 (Spent; 1.00-fold), to 2 (Proliferative; 3.47-fold) to 3 (Premature; 6.18-fold) and decreased at Stage 4 (Mature; 1.31-fold). Differential relative abundances of MrvWD-Kazal mRNA transcript in the ovary indicate the MrvWD-Kazal protein may have an important function in ovarian maturation of M. rosenbergii. The results of this study also indicate the MrvWD-Kazal is not involved in regulation of the reproductive related function of the hepatopancreas, digestive system (stomach and intestine) and respiratory system (gill).
    Matched MeSH terms: von Willebrand Factor/genetics; von Willebrand Factor/chemistry*
  5. Periayah MH, Halim AS, Saad AZ, Yaacob NS, Karim FA
    Open Access Maced J Med Sci, 2016 Mar 15;4(1):112-7.
    PMID: 27275342 DOI: 10.3889/oamjms.2016.030
    BACKGROUND: Von Willebrand disease (vWD) is an inherited hemostatic disorder that affects the hemostasis pathway. The worldwide prevalence of vWD is estimated to be 1% of the general population but only 0.002% in Malaysia.

    AIM: Our present paper has been written to disclose the statistical counts on the number of vWD cases reported from 2011 to 2013.

    MATERIAL AND METHODS: This article is based on sociodemographic data, diagnoses and laboratory findings of vWD in Malaysia. A total of 92 patients were reported to have vWD in Malaysia from 2011 to 2013.

    RESULTS: Sociodemographic-analysis revealed that 60% were females, 63% were of the Malay ethnicity, 41.3% were in the 19-44 year old age group and 15.2% were from Sabah, with the East region having the highest registered number of vWD cases. In Malaysia, most patients are predominately affected by vWD type 1 (77.2%). Factor 8, von Willebrand factor: Antigen and vWF: Collagen-Binding was the strongest determinants in the laboratory profiles of vWD.

    CONCLUSION: This report has been done with great interest to provide an immense contribution from Malaysia, by revealing the statistical counts on vWD from 2011-2013.

    Matched MeSH terms: von Willebrand Factor
  6. Noordin SS, Karim FA, Mohammad WMZBW, Hussein AR
    Indian J Hematol Blood Transfus, 2018 Jul;34(3):510-516.
    PMID: 30127563 DOI: 10.1007/s12288-017-0879-8
    Thawed plasma is fresh frozen plasma (FFP) that has been stored for 5 days at 1-6 °C. Duration of storage and different storage temperatures might affect the coagulation factor activity in thawed FFP. This study measured the changes of coagulation factor activities over 5 days in thawed FFP and stored at two different initial storage temperatures. Thirty-six units of FFP, which consisted of nine units each from blood groups A, B, AB, and O, were thawed at 37 °C. Each unit was divided into two separate groups (Group A and Group B) based on initial storage temperature. The first group was stored at 2-6 °C for 5 days (Group A). The second group was stored at 20-24 °C for initial 6 h followed by 2-6 °C for 5 days (Group B). Prothrombin time (PT), activated partial thromboplastin time (APTT), coagulation factor activities of fibrinogen, factor (F) II, FV, FVII, FVIII, FIX, FX, and von Willebrand factor antigen (vWF Ag) were assessed at baseline after thawing, at 6 h, and on days 1, 3, and 5 of storage for both groups. All coagulation factors mean activities in both storage groups decreased significantly over 5 days of storage. The mean FVIII activity at day 5 of storage was 36.9% in Group A and 39.8% in Group B. The other coagulation factors mean activities were > 50% on day 5 of storage in both groups. The coagulation factor activities of thawed FFP stored for 5 consecutive days were reduced in the two storage groups but most of the activities were still above 30%. This study suggests that thawed FFP stored for 5 days has the potential to ameliorate coagulation factor deficiencies in affected patients.
    Matched MeSH terms: von Willebrand Factor
  7. Yeap SK, Beh BK, Kong J, Ho WY, Mohd Yusof H, Mohamad NE, et al.
    PMID: 25031606 DOI: 10.1155/2014/707829
    Fermented red yeast rice has been traditionally consumed as medication in Asian cuisine. This study aimed to determine the in vivo hypocholesterolemic and antioxidant effects of fermented red yeast rice water extract produced using Malaysian Agricultural Research and Development Institute (MARDI) Monascus purpureus strains in mice fed with high cholesterol diet. Absence of monacolin-k, lower level of γ-aminobutyric acid (GABA), higher content of total amino acids, and antioxidant activities were detected in MARDI fermented red yeast rice water extract (MFRYR). In vivo MFRYR treatment on hypercholesterolemic mice recorded similar lipid lowering effect as commercial red yeast rice extract (CRYR) as it helps to reduce the elevated serum liver enzyme and increased the antioxidant levels in liver. This effect was also associated with the upregulation of apolipoproteins-E and inhibition of Von Willebrand factor expression. In summary, MFRYR enriched in antioxidant and amino acid without monacolin-k showed similar hypocholesterolemic effect as CRYR that was rich in monacolin-k and GABA.
    Matched MeSH terms: von Willebrand Factor
  8. Looi LM, Cheah PL, Lin HP
    Pathology, 1992 Jan;24(1):34-6.
    PMID: 1374551
    Clear cell sarcoma of kidney (CCSK) is a rare but distinct tumor of childhood frequently confused with Wilms' tumor (nephroblastoma). It has a characteristic histology, a marked predilection for metastasis to bone, and an aggressive clinical course with a high relapse rate in spite of surgical excision, chemotherapy and radiotherapy. We report the first histologically proven CCSK in a Malaysian patient. This was an 8-mth-old Malay boy who was clinically diagnosed to have stage I Wilms' tumor. Despite treatment, he developed multiple metastases 10 mths after initial presentation and died soon after. Emphasis is placed on recognizing this entity in view of (1) its naturally aggressive behaviour and (2) the prospect of improving prognosis with currently recommended intensified chemotherapeutic regimes. Its immunohistochemical profile of vimentin-positivity and negativity for epithelial membrane antigen, cytokeratin and Factor-8 related antigen is more in favour of a mesenchymal or glomerular origin than a tubular or vascular origin.
    Matched MeSH terms: von Willebrand Factor/analysis
  9. Wong KT, Shamsol S
    J Cutan Pathol, 1999 Jan;26(1):13-6.
    PMID: 10189239
    The association of mast cells with typical lesions of Kimura's disease was investigated by quantitative methods after immunohistochemical staining for Factor VIII-related antigen and counterstaining with toluidine blue. Formalin-fixed, paraffin-embedded, tissue sections from 9 confirmed cases of Kimura's disease were examined after staining to estimate mast cell and blood vessel densities by counting 100 random fields under oil immersion. There was a statistically significant increase of both mast cells and blood vessels in Kimura's disease (p<0.01) compared with normal skin and reactive lymph node controls. However, as far as the individual Kimura's disease lesion is concerned, there was generally no correlation between areas with mast cell increase and the degree of vascularity. Moreover, when lesions of less than 1 year's duration were compared with older lesions, there appeared to be a relative decrease in mast cells and a concomitant increase in vascularity in the latter. These results confirmed that mast cells are associated with Kimura's disease, and suggest that they may be involved in its early pathogenesis, although its possible role in angiogenesis may not be direct.
    Matched MeSH terms: von Willebrand Factor/analysis
  10. Nur Fariha MM, Chua KH, Tan GC, Lim YH, Hayati AR
    Cell Biol Int, 2012;36(12):1145-53.
    PMID: 22957758 DOI: 10.1042/CBI20120044
    Cell-based therapy using stem cells has emerged as one of the pro-angiogenic methods to enhance blood vessel growth and sprouting in ischaemic conditions. This study investigated the endogenous and induced angiogenic characteristics of hCDSC (human chorion-derived stem cell) using QPCR (quantitative PCR) method, immunocytochemistry and fibrin-matrigel migration assay. The results showed that cultured hCDSC endogenously expressed angiogenic-endogenic-associated genes (VEGF, bFGF, PGF, HGF, Ang-1, PECAM-1, eNOS, Ve-cad, CD34, VEGFR-2 and vWF), with significant increase in mRNA levels of PGF, HGF, Ang-1, eNOS, VEGFR-2 and vWF following induction by bFGF (basic fibroblast growth factor) and VEGF (vascular endothelial growth factor). These enhanced angiogenic properties suggest that induced hCDSC provides a stronger angiogenic effect for the treatment of ischaemia. After angiogenic induction, hCDSC showed no reduction in the expression of the stemness genes, but had significantly higher levels of mRNA of Oct-4, Nanog (3), FZD9, ABCG-2 and BST-1. The induced cells were positive for PECAM-1 (platelet/endothelial cell adhesion molecule 1) and vWF (von Willebrand factor) with immunocytochemistry staining. hCDSC also showed endothelial migration behaviour when cultured in fibrin-matrigel construct and were capable of forming vessels in vivo after implanting into nude mice. These data suggest that hCDSC could be the cells of choice in the cell-based therapy for pro-angiogenic purpose.
    Matched MeSH terms: von Willebrand Factor/analysis; von Willebrand Factor/genetics
  11. Camalxaman SN, Zeenathul NA, Quah YW, Loh HS, Zuridah H, Hani H, et al.
    In Vitro Cell Dev Biol Anim, 2013 Mar;49(3):238-44.
    PMID: 23435855 DOI: 10.1007/s11626-012-9553-5
    Endothelial cells have been implicated as key cells in promoting the pathogenesis and spread of cytomegalovirus (CMV) infection. This study describes the isolation and culture of rat brain endothelial cells (RBEC) and further evaluates the infectious potential of a Malaysian rat CMV (RCMV ALL-03) in these cultured cells. Brain tissues were mechanically fragmented, exposed to enzymatic digestion, purified by gradient density centrifugation, and cultured in vitro. Morphological characteristics and expression of von Willebrand factor (factor VIII-related antigen) verified the cells were of endothelial origin. RBEC were found to be permissive to the virus by cytopathic effects with detectable plaques formed within 7 d of infection. This was confirmed by electron microscopy examination which proved the existence of the viral particles in the infected cells. The susceptibility of the virus to these target cells under the experimental conditions described in this report provides a platform for developing a cell-culture-based experimental model for studies of RCMV pathogenesis and allows stimulation of further studies on host cell responses imposed by congenital viral infections.
    Matched MeSH terms: von Willebrand Factor/metabolism
  12. Jackson N, Hashim ZA, Zainal NA, Jamaluddin N
    Singapore Med J, 1995 Apr;36(2):230-1.
    PMID: 7676276
    A 30-year-old Malay lady, with no previous or family history of bleeding, presented with severe gum bleeding 25 days post-partum. The factor VIII:c was 0.03 iu/ml with evidence of a slow-acting factor VIII inhibitor. Von Willebrand factor antigen (VWF:age) varied from less that 0.05 to 0.17 iu/ml, and there was absent ristocetin-induced platelet aggregation. Anti-nuclear and anti-DNA antibodies were present, but there were no other features of systemic lupus erythematosus. There was some clinical response to cryoprecipitate and tranexamic acid, and slight improvement with corticosteroid. Fifteen months later, the patient has no active bleeding problem, and her VWF-ag is increasing spontaneously. However, factor VIII:c is less than 0.01 iu/ml and her factor VIII inhibitor titre is still > 20 Bethesda units/ml.
    Matched MeSH terms: von Willebrand Factor/analysis
  13. Stasyshyn O, Djambas Khayat C, Iosava G, Ong J, Abdul Karim F, Fischer K, et al.
    J Thromb Haemost, 2017 Apr;15(4):636-644.
    PMID: 28166608 DOI: 10.1111/jth.13647
    Essentials rVIII-SingleChain is a novel recombinant factor VIII with covalently bonded heavy and light chains. Efficacy, safety and pharmacokinetics were studied in pediatric patients with severe hemophilia A. Across all prophylaxis regimens, the median annualized spontaneous bleeding rate was 0.00. rVIII-SingleChain showed excellent hemostatic efficacy and a favorable safety profile.

    SUMMARY: Background rVIII-SingleChain is a novel B-domain truncated recombinant factor VIII (rFVIII) comprised of covalently bonded FVIII heavy and light chains, demonstrating a high binding affinity to von Willebrand factor. Objectives This phase III study investigated the safety, efficacy and pharmacokinetics of rVIII-SingleChain in previously treated pediatric patients < 12 years of age with severe hemophilia A. Patients/Methods Patients could be assigned to prophylaxis or on-demand therapy by the investigator. For patients assigned to prophylaxis, the treatment regimen and dose were based on the bleeding phenotype. For patients receiving on-demand therapy, dosing was guided by World Federation of Hemophilia recommendations. The primary endpoint was treatment success, defined as a rating of 'excellent' or 'good' on the investigator's clinical assessment of hemostatic efficacy for all treated bleeding events. Results The study enrolled 84 patients (0 to < 6 years, n = 35; ≥ 6 to < 12 years, n = 49); 81 were assigned to prophylaxis and three to an on-demand regimen. Patients accumulated a total of 5239 exposure days (EDs), with 65 participants reaching > 50 EDs. In the 347 bleeds treated and evaluated by the investigator, hemostatic efficacy was rated as excellent or good in 96.3%. The median annualized spontaneous bleeding rate was 0.00 (Q1, Q3: 0.00, 2.20), and the median annualized bleeding rate was 3.69 (Q1, Q3: 0.00, 7.20) across all prophylaxis regimens. No participant developed an inhibitor. Conclusions rVIII-SingleChain is a novel rFVIII molecule showing excellent hemostatic efficacy and a favorable safety profile in a clinical study in children < 12 years of age with severe hemophilia A.

    Matched MeSH terms: von Willebrand Factor/chemistry
  14. Rohaida Abd Rahman, Faridah Afandi, Tun Maizura Mohd Fathullah, Rafeezul Mohamed
    MyJurnal
    The National Blood Center, Kuala Lumpur interprets laboratory results for the von Willebrand factor (vWF) profile based on guidelines provided by the U.S. National Heart, Lung, and Blood Institute, which were established based on the Caucasian population [1-2]. The vWF profiles among the Malay population has not yet been established.

    The goals of this study were to determine the vWF profiles of the different ABO blood types among Malays and to evaluate their association with demographic characteristics and smoking habits.

    One hundred and forty Malay donors participated in this study. Factor VIII (FVIII), vWF antigen, and ristocetin cofactor (RiCof) levels and collagen binding activity (CBA) were measured by coagulometric clot detection, latex agglutination, and enzyme-linked immunosorbent assay.
    Matched MeSH terms: von Willebrand Factor
  15. Husain NN, Hairon SM, Zain RM, Bakar M, Bee TG, Ismail MS
    Oman Med J, 2020 Mar;35(2):e108.
    PMID: 32257417 DOI: 10.5001/omj.2020.26
    Objectives: Despite being recognized worldwide as an alternative therapy in treating various chronic diseases and pain, the mechanism of wet cupping is still not well understood. The purpose of this study was to evaluate fasting blood sugar (FBS), renal function parameters, and endothelial function changes following wet cupping in healthy individuals.

    Methods: We conducted a single-arm intervention study at the Clinical Lab of Community Medicine, Universiti Sains Malaysia, and included 31 healthy individuals aged between 30 and 60 years old. Wet cupping therapy was performed at five treatment points at the beginning of the study and repeated after three months. Health outcomes at baseline, one, three, and four months were assessed for FBS, renal function parameters (urea, creatinine, and uric acid), systolic blood pressure (SBP), and von Willebrand factor (vWF).

    Results: Forty-five percent of participants were female, and the mean age of study participants was 44.9±6.4 years. Wet cupping therapy significantly reduced FBS, serum urea, and serum creatinine at one, three, and four months compared with baseline values. Serum uric acid and SBP showed a significant reduction at one and four months compared with baseline. The vWF (a measure of endothelial function) had a 4.0% reduction at four months compared to baseline, with a mean difference of 5.3 (95% confidence interval (CI): 2.20 = 8.55; p = 0.002).

    Conclusions: This study provides preliminary support that repeated wet cupping therapy enhances body health status; thus, it could be an effective complementary medicine in disease prevention.

    Matched MeSH terms: von Willebrand Factor
  16. Liew SC, Das-Gupta E, Chakravarthi S, Wong SF, Lee N, Safdar N, et al.
    BMC Res Notes, 2012;5:201.
    PMID: 22537619 DOI: 10.1186/1756-0500-5-201
    Angiogenesis has been reported to be one of the contributory factors to the pathogenesis of psoriasis vulgaris. This study aims to compare the expression of different angiogenesis growth factors namely (1) the vascular endothelial growth factor (VEGF) subfamily: A, B, C, D and placenta growth factor (PlGF); (2) nerve growth factor (NGF) and (3) von Willebrand factor (vWFr) in the skins of patients with psoriasis vulgaris and non-psoriatic volunteers.

    Study site: Dermatology Department of Hospital Kuala Lumpur, Kuala Lumpur and Tuanku Ja’afar Hospital, Seremban, Malaysia
    Matched MeSH terms: von Willebrand Factor/biosynthesis
  17. Rahman NA, Sharudin A, Diah S, Muharram SH
    Microb Pathog, 2017 Sep;110:352-358.
    PMID: 28711510 DOI: 10.1016/j.micpath.2017.07.021
    INTRODUCTION: Pneumococcal infections have caused morbidity and mortality globally. Streptococcus pneumoniae (pneumococci) are commensal bacteria that colonize the nasopharynx, asymptomatically. From there, pneumococci can spread in the lungs causing pneumonia and disseminate in the bloodstream causing bacteremia (sepsis) and reach the brain leading to meningitis. Endothelial cells are one of the most important components of the blood-brain barrier that separates the blood from the brain and plays the first protective role against pneumococcal entry. Thus this study aimed to investigate on the ability of non-meningitis pneumococcal clinical strains to adhere and invade a brain endothelium model.

    METHODS: Two pneumococcal Brunei clinical strains were serotyped by multiplex PCR method using oligonucleotide sequences derived from Centers for Disease Control and Prevention. A validated immortalised mouse brain endothelial cell line (bEnd.3) was used as a brain endothelium model for the study of the pneumococcal breach of the blood-brain barrier using an adherence and invasion assay.

    RESULTS: Both of the pneumococcal clinical strains were found to be serotype 19F, a common circulating serotype in Southeast Asia and globally and possess the ability to adhere and invade the brain endothelial cells.

    CONCLUSION: In addition, this is the first report on the serotype identification of pneumococci in Brunei Darussalam and their application on a brain endothelium model. Further studies are required to understand the virulence capabilities of the clinical strains.

    Matched MeSH terms: von Willebrand Factor/metabolism
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