Effect of Blood Group on von Willebrand Factor Antigen Levels in Compensated Advanced Chronic Liver Disease and Utility of von Willebrand Factor-Platelet Ratio for Detecting Clinically Significant Portal Hypertension.

BACKGROUND/PURPOSE: In the general population, von Willebrand Factor (vWF) antigen levels are 20-30% lower in blood group O. However, the effect of blood group O on vWF antigen in compensated advanced chronic liver disease (cACLD) is unknown. Furthermore, there are limited data comparing vWF with elastography for assessment of clinically significant portal hypertension (CSPH). We assessed the effect of blood group O on vWF antigen levels, and the discriminative ability of vWF-platelet ratio (VITRO) for assessment of CSPH in comparison to liver stiffness measurement (LSM) on elastography in cACLD.

METHODS

One hundred patients with cACLD were prospectively included. Hemogram, blood biochemistry, plasma vWF antigen levels, computed tomography abdomen, LSM with vibration-controlled transient elastography and endoscopic screening for varices were performed. CSPH was defined by the presence of collaterals on imaging, varices on endoscopy or portosystemic pressure gradient >10 mmHg.

RESULTS

vWF antigen levels were comparable between blood group O and non-O (282.9 ± 44.6% vs 289.9 ± 86.3%, P = 0.60). vWF: antigen had significant correlation with LSM [rho:0.65 (95% confidence interval (CI): 0.48-0.75, P < 0.001)] and portosystemic pressure gradient [rho = 0.60 (95% CI: 0.27-0.81, P < 0.001)].Areas under the curves (AUROCs) of LSM (0.878, 95% CI: 0.747-0.980) and VITRO (0.881, 95% CI: 0.745-0.982, P = 0.95) were comparable for detecting CSPH. Optimal VITRO rule-out and rule-in cut-offs for CSPH were <1.14 [sensitivity 95%, negative predictive value 74.83%] and >1.93 [specificity 90%, positive predictive value 95.85%)]. The proportion of patients in the indeterminate -zone using BAVENO VII criteria (48%) was significantly higher than that with VITRO (22%, P < 0.001). As many as 81.3% patients lying in the intermediate zone using BAVENO VII criteria could be recategorized as ruled-out or ruled-in using VITRO.

CONCLUSION

Blood group O did not affect vWF levels in our cohort of cACLD patients. VITRO holds promise as potential blood-based adjunct to elastography for assessment of CSPH and varices in cACLD.

CLINICAL TRIAL REGISTRATION: Not applicable.