Identify literature describing transverse myelitis in primary antiphospholipid syndrome, aiming to characterize its clinical spectrum, immunological features, and therapeutic responses.

Antiphospholipid syndrome (APS) is a prothrombotic autoimmune disease with heterogeneous clinicopathological manifestations. Several neurological manifestations have been described in past decades. Transverse myelitis is the least explored due to its rare incidence (0.4% to 4%). Although clinical manifestations typically include motor, sensory, and sphincter dysfunction, the immunological link to APS remains poorly understood.

A systematic review of APS case reports on patients who developed transverse myelitis, PRISMA guidelines were followed. Cases of seropositive APS without clinical manifestations were included. A database search was conducted across PubMed, Scopus, Web of Science, and Embase from inception to September 2025. Covidence was used for screening and for data extraction using a standardized form. The Joanna Briggs Institute (JBI) Checklist for Case Reports and Case Series was used to assess risk of bias. Data were analyzed in Stata BE version 19.5.

Twelve publications met the inclusion criteria, compiling 14 cases. Median age 34.5 years (IQR 18.2), male (8, 57.1%), classic primary APS (7, 50%), asymptomatic seropositive (7, 50%), anticardiolipin antibodies (14, 100%), lupus anticoagulant (7, 50%), and anti-β2 glycoprotein I antibodies (7, 50%). MRI imaging revealed Longitudinal Extensive Transverse Myelitis (LETM) in 7 (50%). CSF was normal in 71.4%, pleocytosis in 28.6%, and hyperproteinorachia in 21.4%. All patients (14, 100%) received corticosteroids; additional therapies included PLEX, IVIG, Cytoxan, Azasan, and anticoagulants. The median time to recovery was 26 weeks (IQR 15.5).

The heterogeneity of transverse myelitis in primary APS underscores the need for predictive biomarkers and personalized treatment approaches. Variable responses to corticosteroids emphasize the need for novel therapeutic strategies. Ongoing research is crucial to improving early diagnosis and investigating the potential of targeted therapies to mitigate the morbidity associated with this rare complication.