Prevalence of inherited antithrombin, protein C , and protein S deficiencies in portal vein system thrombosis and B udd‐ C hiari syndrome: A systematic review and meta‐analysis of observational studies

Abstact Background and Aim The prevalence of inherited antithrombin ( AT ), protein C ( PC ), and protein S ( PS ) deficiencies in portal vein system thrombosis ( PVST ) and B udd‐ C hiari syndrome ( BCS ) are substantially varied in different studies. No quantitative syntheses of these studies have been performed. A systematic review and meta‐analysis were conducted to examine the prevalence of inherited AT , PC , and PS deficiencies in these patients and to compare the prevalence with healthy subjects. Methods PubMed , EMBASE , and C ochrane L ibrary databases were employed to identify all studies in which inherited AT , PC , and PS deficiencies in PVST and/or BCS were evaluated by family study or gene analysis. Prevalence and odds ratios of these inherited deficiencies were pooled; heterogeneity among studies was evaluated. Results Nine studies were included in our meta‐analysis. The pooled prevalence of inherited AT , PC , and PS deficiencies were 3.9%, 5.6%, and 2.6% in PVST , and 2.3%, 3.8%, and 3.0% in BCS , respectively. Heterogeneity among studies was not significant except for the analysis of inherited PC deficiency in BCS . Three studies compared the prevalence of these inherited deficiencies between PVST patients and healthy subjects. The pooled odds ratios of inherited AT , PC , and PS deficiencies for PVST patients were 8.89 (95% confidence interval [ CI ] 2.34–33.72, P  = 0.0011), 17.63 (95% CI 1.97–158.21, P  = 0.0032), and 8.00 (95% CI 1.61–39.86, P  = 0.011), respectively. Only one study demonstrated that no inherited deficiency was found in both BCS patients and healthy subjects. Conclusions Inherited AT , PC , and PS deficiencies are rare in PVST and BCS . These inherited deficiencies increase the risk of PVST .