Evaluation of ProC Global assay in women with a history of venous thromboembolism on hormonal therapy

The risk of thrombosis in women increases significantly during treatment with hormonal therapy (HT). The aim of this study was to evaluate ProC Global assay in women with a history of venous thromboembolism (VTE) while using HT. Protein C activation time normalized ratio (PCAT-NR) levels were significantly lower in 32 women with a history ofVTE while using HT (0.72 ± 0.1) compared with 56 healthy controls without HT, matched by age at blood sampling (0.99 ± 0.2) and 40 healthy controls with HT, matched by age and HT at VTE event (0.94 ± 0.2) (P<0.001 for both).PCAT-NR lower than the cut-off level of 0.8 was found in 23/32 (72%) patients compared with 5/56 (9%) age-matched controls (OR=26, 95%CI: 7–106, P<0.001) and 9/40 (22.5%) of HT-matched controls (OR=9, 95%CI: 2.7–30, P<0.001). Any thrombophilic risk factor was found in 20/32 (62.5%) of patients compared with 12/56 (21.4%) of agematched controls (OR=6, 95%CI: 2.1–10, P<0.001) and 12/40 (30%) of HT-matched controls (OR=4, 95%CI: 1.3–11.8, P=0.006).Out of the variables that are risk factors of VTE as age, HT or thrombophilic risk factor, ProC Global assay was found in the multivariate analysis – logistic regression, as the parameter that was the most associated with patient group [Exp(B)=15.8, 95% CI: 4.2–59.0, P<0.001]. In conclusion, abnormal PCAT-NR is associated with VTE in women using HT. ProC Global assay may potentially serve as a diagnostic tool for evaluating the risk of VTE in women prior to administration of HT.