Relapsing polychondritis in a patient with suspected antiphospholipid syndrome presenting with inferior vena cava thrombosis: Palestinian case report

Antiphospholipid syndrome (APS) is an autoimmune thrombophilia characterized by arterial and venous thrombosis that commonly affects the deep veins of the lower extremities and cerebral vasculature. Inferior vena cava (IVC) thrombosis is an extremely rare manifestation of APS and is often associated with hypercoagulable states. Relapsing polychondritis (RPC) is an autoimmune disorder affecting cartilaginous structures, sometimes occurring alongside APS. However, the coexistence of primary suspected APS and RPC has rarely been reported. A 33-year-old previously healthy male who presented with fever, acute right-sided flank pain, and systemic symptoms. Initial evaluation revealed urolithiasis, but persistent pain and elevated inflammatory markers prompted further imaging, which revealed IVC thrombosis. This case highlights the importance of recognizing suspected APS in patients presenting with unprovoked IVC thrombosis and highlights RPC as a potential autoimmune comorbidity. Although APS is a well-established prothrombotic disorder, its coexistence with RPC remains uncommon and poorly understood. The presence of antiphospholipid antibodies may contribute to the vascular inflammation observed in RPCs, suggesting a possible pathogenic link between these two conditions. Further studies are needed to explore the relationship between APS and RPC and refine diagnostic and therapeutic approaches.