Association Between Systemic Inflammation Indices and Recurrence Risk in Primary Budd-Chiari Syndrome.

Background: Budd-Chiari syndrome (BCS) is a rare thrombotic liver disorder with a substantial risk of recurrence, even after treatment. Inflammation-based markers such as the neutrophil-to-lymphocyte ratio (NLR), platelet-to-lymphocyte ratio (PLR), and lymphocyte-to-monocyte ratio (LMR) have been associated with thrombotic diseases, but their predictive value for BCS recurrence remains unclear. Methods: This retrospective cohort study included 708 (median 51 y, male: 57.8%) patients diagnosed with primary BCS between January 2015 and July 2022. Nine systemic inflammatory indices were calculated from baseline and biochemical parameters. The primary outcome was recurrence, defined by clinical symptoms and imaging-confirmed re-obstruction or thrombosis. Associations were evaluated using logistic regression models, quartile-based logistic regression, and weighted quantile sum (WQS) regression. Subgroup and interaction analyses were also performed. Results: During follow-up, 226 patients (31.9%) experienced post-treatment recurrence. Elevated NLR and PLR were associated with increased recurrence risk, while higher LMR was protective. WQS regression identified novel indices such as the neutrophil-to-albumin ratio (NAR) and monocyte-to-albumin ratio (MAR) as top contributors. Subgroup analyses showed consistent associations, especially in IVC-type BCS and cirrhotic patients. Conclusion: Several inflammation-based indices were independently associated with recurrence risk in primary BCS. These findings highlight the potential utility of inflammatory markers in recurrence surveillance.