Association between alpha 1-antitrypsin levels and intracranial aneurysms: a case-control study

Alpha 1-antitrypsin (A1AT) helps maintain vascular-wall integrity, but its role in the formation and rupture of intracranial aneurysms is unclear.

To compare A1AT levels between patients with ruptured and unruptured intracranial aneurysms and assess the associations with vasospasm and functional outcomes.

We retrospectively analyzed the medical records of patients who had serum A1AT levels measured between 2018 and 2022 during routine outpatient evaluations. The sample included 233 patients with unruptured intracranial aneurysms, 114 with ruptured aneurysms, and 55 controls with intracranial arteriovenous malformations (AVMs), but without aneurysms.

The mean A1AT levels were 134.9 ± 23.3 mg/dL in the unruptured group, 132.1 ± 20.3 mg/dL in the ruptured group, and 132 ± 19 mg/dL in the controls. The A1AT levels did not exhibit a significant association with the presence of intracranial aneurysms when compared to the levels of the control group (odds ratio [OR]: 1.07; 95%CI: 0.93-1.25; p = 0.40) or with aneurysm rupture (OR: 0.94; 95%CI: 0.84-1.04; p = 0.27) when compared to the levels of the unruptured group. Similarly, there were no statistically significant correlations between the protein concentrations and vasospasm (OR: 0.94; 95%CI: 0.69-1.22; p = 0.67) or functional outcomes defined by a score ≤ 2 on the modified Rankin Scale (OR: 0.77; 95%CI: 0.51-1.27; p = 0.23).

The A1AT levels did not differ between the groups with ruptured and unruptured aneurysms, neither were they associated with vasospasm nor functional outcomes.