Adult-onset Vitamin K-dependent Coagulation Factor Deficiency of Unidentified Etiology

Abstract

Symptoms of bleeding caused by vitamin K-dependent coagulation factor deficiency (VKCFD) are rare in adults. We present two Japanese cases of adult-onset VKCFD, in which the cause of vitamin K deficiency remains unknown despite comprehensive evaluation. Both patients showed markedly decreased levels of coagulation factors (F) VII, FIX, FX, FII, protein C (PC), and protein S (PS), along with elevated levels of protein induced by vitamin K absence/antagonist II (PIVKA-II). The clinical course in both cases ruled out congenital VKCFD. Based on these findings and a similar case in the relevant literature, we propose a new disease entity, idiopathic acquired VKCFD.