A novel whole blood assay was unable to predict clinical severity in patients with type 1 von Willebrand disease (VWD).
The whole blood ristocetin-induced platelet agglutination (WB-RIPA) assay has shown potential for use as a diagnostic test for patients with type 1 VWD. However, the ability of the assay to predict clinical severity of the disease is unknown.
Yuto Nakajima, MD, of the Nara (Japan) Medical University and his colleagues studied the diagnostic and clinical capabilities of the assay in 55 patients with type 1 VWD and 20 healthy controls. The results of the study were published in Haemophilia.
The team examined relationships between WB-RIPA levels, VWF-associated measurements, and bleeding scores using whole blood samples. Bleeding severity was assessed using scores from a standardized assessment tool.
After analysis, the team found that assay values were significantly lower in patients with type 1 VWD versus healthy controls (P less than .0001), which validated the detection abilities of the test.
However, correlations between WB-RIPA levels and specific VWF-associated measurements were found to be weak. Similar results were reported with assay levels and bleeding scores. There were no significant differences seen in WB-RIPA between patients with a bleeding score of 4 or greater (abnormal bleeding tendency) and less than 4 (no abnormal bleeding tendency).
“Our study indicated that the WB-RIPA assay would not be useful for assessing and predicting the clinical severity in type 1 VWD,” they wrote.
The authors acknowledged that a key limitation was that the definition of type 1 VWD used in the study was not based on the most current classification.
The study was supported by grant funding from the Ministry of Education, Culture, Sports, Science and Technology (Japan). The authors reported having no conflicts of interest.
SOURCE: Nakajima Y et al. Haemophilia. 2019 Mar 13. doi: 10.1111/hae.13725.