Seronegative Catastrophic Antiphospholipid Syndrome: A Case Report of a Deadly Diagnosis

Catastrophic antiphospholipid syndrome (CAPS) is a rare autoimmune condition that causes diffuse hypercoagulability affecting multiple organ systems. Typically, CAPS is diagnosed via serological workup, clinical findings, or histopathological findings. However, patients with clinical features of CAPS have been found to be seronegative. This case report aims to inform clinicians of the growing array of CAPS serological markers and the need for further research into these markers to assess clinical viability. Here, we present a case of a 51-year-old female who presented with multi-system thrombosis and was diagnosed with seronegative CAPS (SN-CAPS). Given the significant mortality rate associated with CAPS, it is imperative that an early diagnosis is established, and treatment is initiated. Thus, continued serological research for CAPS is required to aid in this effort.