Antiphospholipid Syndrome and Antibodies Associated With Malignancy and Older Age: A Retrospective Study.

Background: Antiphospholipid syndrome (APLS) is an established cause of thrombosis and hypercoagulability. However, the clinical characteristics of those with APLS or patients with positive antiphospholipid antibodies (APLA) in the embolic stroke of undetermined source (ESUS) have not been well studied.

Methods: A retrospective analysis was conducted between January 1, 2010, and December 31, 2020, across all three Mayo Clinic sites. Patients who were included in the study were tested for APLA and had a diagnosis of ESUS. Baseline characteristics, radiographic parameters, and outcome data were collected and compared between those who tested positive for APLS or had positive APLA and those who were negative.

Results: A total of 206 patients were included in the study. Eight (4%) patients were diagnosed with APLS, and 21 (10%) patients had positive APLA. On comparing those with a diagnosis of APLS and those without, patients with APLS were found to be significantly older (75 years old ± 9 vs. 58 years old ± 14, p = 0.001) and were more likely to have a history of cancer (50% vs. 13%, p = 0.012). Those with positive APLA had similar findings of being older (67 years old ±13 vs. 58 years old ± 14 p = 0.003) and more likely to have a history of cancer (29% vs. 8.4% p = 0.027). Radiographically, those with APLS had a higher white matter disease burden (Fazekas score median 2 (IQR 1.5-3) vs. median 1 (IQR 1-2), p = 0.028).

Conclusion: Both APLS and positive APLA are associated with older age and a history of malignancy. These findings highlight the importance of considering a hypercoagulable evaluation even in the elderly ESUS population.