Comparison of type I, type III and type VI collagen binding assays in diagnosis of von Willebrand disease

• Published in: Journal of thrombosis and haemostasis Vol. 10; no. 7; pp. 1425 - 1432
• Main Authors: FLOOD, V. H., GILL, J. C., CHRISTOPHERSON, P. A., WREN, J. S., FRIEDMAN, K. D., HABERICHTER, S. L., HOFFMANN, R. G., MONTGOMERY, R. R.
• Format: Journal Article
• Language: English
• Published: Oxford, UK Blackwell Publishing Ltd 01.07.2012; Elsevier Limited
• Subjects: Binding sites; Case-Control Studies; Collagen; Collagen - chemistry; Collagen - metabolism; Enzyme-Linked Immunosorbent Assay; Humans; Protein Binding; Protein Isoforms - chemistry; Protein Isoforms - metabolism; von Willebrand disease; von Willebrand Diseases - diagnosis; von Willebrand Diseases - metabolism; von Willebrand factor
• ISSN: 1538-7933; 1538-7836; 1538-7836
• DOI: 10.1111/j.1538-7836.2012.04747.x

Background:  von Willebrand factor (VWF) plays a key role in coagulation by tethering platelets to injured subendothelium through binding sites for collagen and platelet GPIb. Collagen binding assays (VWF:CB), however, are not part of the routine work‐up for von Willebrand disease (VWD). Objectives:  This study presents data on collagen binding for healthy controls and VWD subjects to compare three different collagens. Patients/Methods:  VWF antigen (VWF:Ag), VWF ristocetin cofactor activity and VWF:CB with types I, III and VI collagen were examined for samples obtained from the Zimmerman Program. Results:  Mean VWF:CB in healthy controls was similar and highly correlated for types I, III and VI collagen. The mean VWF:CB/VWF:Ag ratios for types I, III and VI collagen were 1.31, 1.19 and 1.21, respectively. In type 1 VWD subjects, VWF:CB was similar to VWF:Ag with mean VWF:CB/VWF:Ag ratios for types I, III and VI collagen of 1.32, 1.08 and 1.1, respectively. For type 2A and 2B subjects, VWF:CB was uniformly low, with mean ratios of 0.62 and 0.7 for type I collagen, 0.38 and 0.4 for type III collagen, and 0.5 and 0.47 for type VI collagen. Conclusions:  Normal ranges for type I, III and VI collagen are correlated, but higher values were obtained with type I collagen as compared with types III and VI. The low VWF:CB in type 2A and 2B subjects suggests that VWF:CB may also supplement analysis of multimer distribution. However, these results reflect only one set of assay conditions per collagen type and therefore may not be generalizable to all collagen assays.