Autoimmune hemolytic anemia and venous thromboembolism: A systematic review and meta-analysis

- Patients with AIHA have a higher risk of venous thromboembolism.
- The pooled risk ratio is 2.63 (95% 1.37-5.05).
- Mechanism behind this association is unclear and merits further study.

ObjectiveTo investigate the risk of venous thromboembolism (VTE) among patients with autoimmune hemolytic anemia (AIHA).MethodsWe conducted a systematic review and meta-analysis of observational studies that reported odds ratio, relative risk, hazard ratio or standardized incidence ratio comparing the risk of VTE in patients with AIHA versus participants without AIHA. Pooled risk ratio and 95% confidence intervals were calculated using a random-effect, generic inverse variance method of DerSimonian and Laird.ResultsOut of 592 potentially relevant articles, four studies (three cohort studies and one cross-sectional study) met our inclusion criteria and were included in the data analysis. The pooled risk ratio of VTE in patients with AIHA was 2.63 (95% CI, 1.37-5.05). The statistical heterogeneity of this study was high with an I2 of 97%.ConclusionsOur study demonstrated a significantly increased risk of VTE among patients with AIHA.