Review article: the aetiology of primary Budd–Chiari syndrome – differences between the West and China

Background: China may have the largest number of Budd–Chiari syndrome (BCS) cases in the world (at least 1914 original papers were published, and at least 20 191 BCS patients were reported). Considering the discrepancy in the clinical profiles and preferred treatment selection of primary BCS between the West and China, understanding its aetiology in these two different regions is very important. Aim: To review the data from large cohort studies and meta-analyses to illustrate the epidemiology of risk factors for BCS in the West and China. Methods: Relevant papers were identified by major English- and Chinese-language databases, conference abstracts, and by manual search. Results: Risk factors reviewed include myeloproliferative neoplasms (MPNs) and their related gene mutations, anti-phospholipid syndrome, paroxysmal nocturnal haemoglobinuria (PNH), hyperhomocysteinaemia and 5,10-methylenetetrahydrofolate reductase (MTHFR) C677T mutation, factor V Leiden (FVL) and prothrombin G20210A mutations, inherited anti-thrombin, protein C and protein S deficiencies, pregnancy and puerperium, poverty, and family history. Conclusions: We examined the differences in the aetiological distribution of BCS between the West and China. Several recommendations should be considered in Chinese BCS patients: (i) screening for hyperhomocysteinaemia and MTHFR mutation should be regularly performed; (ii) screening for MPNs, PNH, and anti-phospholipid syndrome should be selectively performed; (iii) inherited anti-thrombin, protein C, and protein S deficiencies should be actively explored; (iv) screening for FVL and prothrombin G20210A mutations may be unnecessary; and (v) the clinical significance of pregnancy and puerperium, poverty with bacterial infections and unsanitary environments, and family history as possible risk factors should never be neglected.