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Comprehensive re‐evaluation of historical von Willebrand disease diagnosis in association with whole blood platelet aggregation and function
Author(s) -
Nummi V.,
Lassila R.,
JoutsiKorhonen L.,
Armstrong E.,
Szanto T.
Publication year - 2018
Publication title -
international journal of laboratory hematology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.705
H-Index - 55
eISSN - 1751-553X
pISSN - 1751-5521
DOI - 10.1111/ijlh.12785
Subject(s) - von willebrand disease , platelet , von willebrand factor , medicine , ristocetin , gastroenterology , immunology
Diagnosis of von Willebrand disease ( VWD ) is challenging, particularly for type 1. The current diagnostic guidelines emphasize simultaneous bleeding symptoms and von Willebrand factor ( VWF ) levels of <30‐40 IU / dL . Historical diagnoses require updated evaluation. We assessed the accuracy of past VWD diagnoses in our comprehensive care center with the standardized bleeding score ( BS ) and central laboratory analysis, focusing on VWF ‐dependent platelet functions in whole blood. Methods Our study comprised 83 adults with prior VWD who were diagnosed a median of 20 years ago. We assessed BS , VWF antigen and activity (minimum of 3 measurements), FVIII , PFA ‐100 ® , and platelet aggregation via Multiplate ® . Genetic testing was targeted to types 3, 2N, 2B, and equivocal cases. Results All 13/13 (100%) type 3 and 29/32 (90%) type 2, but only 10/38 (26%) of type 1 (overall 52/83 (63%)) patients met the current criteria for VWD . All confirmed cases had abnormal BS , impaired PFA ‐100 ® , and decreased or absent ristocetin‐induced platelet aggregation ( RIPA ), except subtype 2B. VWF , FVIII , RIPA , and PFA correlated with BS including all study subjects. Ten of the 38 patients with previous type 1 had low VWF (35‐50 IU / dL ) and variable VWF ‐dependent platelet function. Altogether, 21/83 patients (25%) had repeatedly normal VWF : RC o (>50 IU / dL ). Conclusion von Willebrand disease is associated with impaired VWF ‐dependent whole blood platelet functions that match traditional VWF measurements. We detected normal VWF in 25% of historically diagnosed patients, mainly type 1 patients, implying that there is a need to systematically re‐evaluate historical VWD diagnoses.