Retroperitoneal and lower extremities muscle bleeding in acquired haemophilia A (AHA): Risk factors and implications in disability and survival

Aim

To assess risk factors of retroperitoneal and lower extremity musculoskeletal bleed in acquired haemophilia (AHA) and perform an objective assessment of disability and influence on survival.

Methods

We included 49 patients with AHA from November 2017 to May 2023. The occurrence of any retroperitoneal or/and lower extremities bleeding manifestation was investigated. On clinical follow-up, we search for compressive femoral neuropathy and quadriceps amyotrophy. The lower extremity functional scale (LEFS) was carried out one year after the last bleeding event in all AHA patients.

Results

A 61.2% of patients in our AHA cohort presented with any retroperitoneal and/or lower extremities musculoskeletal manifestation. Those patients had higher percentage of major bleeding EACH2/ISTH criteria (90% vs. 57%, p = .01), needs of blood transfusions (86% vs. 57% of patients, p = .03), and haemostatic by-pass products (90% vs. 63%, p = .02). Hypertension (HR 2.6, 95% CI 1.1–5.9, p = .02), presence of autoimmune disease (HR 13, 95% CI 1.7–99, p = .01), and inhibitor level > 20 BU (HR 2.6 95% CI 1.0–6.8, p = .04) significantly predicted retroperitoneal/lower extremities clinical manifestations. Most frequent sequelae were quad atrophy (30.6%) and femoral nerve palsy (20.4%). Quad atrophy and LEFS scores under 50 were associated with increased mortality (HR 3, 95% CI 1.1–8.6 and HR 12, 95% CI 3.3–45, respectively).

Conclusion

AHA with retroperitoneal/lower extremities bleeding involvement is of greater severity and shows high disability and worst survival outcomes. Quadriceps atrophy and LEFS scale scoring under 50 predicted mortality in our AHA patients.