Antiphospholipid Syndrome in a Patient With IgA Nephropathy: A Rare and Challenging Clinical Overlap

Abstract

Antiphospholipid syndrome (APS) is a rare autoimmune condition associated with a heightened risk of blood clots in arteries and veins due to the presence of specific antibodies. IgA nephropathy (IgAN), a kidney disorder involving immune complex deposition, is another immune-mediated disease. The coexistence of APS and IgAN is highly uncommon. We describe a young adult male with biopsy-confirmed kidney involvement who developed a significant clot in the lower limb. Despite appropriate treatment, the clot progressed, leading to complications in the lungs. Further investigation revealed laboratory findings consistent with APS. The patient underwent advanced interventions including clot removal and vascular procedures, followed by long-term treatment to prevent further clotting. This study emphasizes the clinical complexity when these two immune-mediated conditions overlap and underscores the importance of early detection and collaborative care in managing such rare and serious presentations.

Keywords: anticoagulation; antiphospholipid syndrome (aps); case report; deep venous thrombosis (dvt); iga nephropathy (igan); pulmonary embolism (pe); thrombectomy.

Figure 1. Color Doppler ultrasound showing deep vein thrombosis in the left common femoral vein.

Color Doppler ultrasound image demonstrating thrombosis (arrow) in the left common femoral vein, consistent with deep vein thrombosis (DVT). The absence of flow within the vein and intraluminal echogenic material are characteristic findings. LT CFV: left common femoral vein

Figure 2. PET scan indicating thrombophlebitis of the left external iliac and femoral veins.

Positron emission tomography (PET) scan image demonstrating increased radiotracer uptake along the dilated left external iliac and femoral veins (arrow), consistent with thrombophlebitis secondary to venous thrombosis. The localized uptake reflects the inflammatory response associated with the thrombotic process.

Figure 3. Doppler ultrasound revealing deep vein thrombosis of the left superficial femoral vein.

Doppler ultrasound image showing deep vein thrombosis (DVT) of the left superficial femoral vein (arrow), characterized by intraluminal echogenic material and disturbed blood flow. The abnormal Doppler signal pattern indicates impaired venous return due to thrombosis. SFV: superficial femoral vein

Figure 4. Computed tomography pulmonary angiography revealing pulmonary embolism.

Axial view of a computed tomography (CT) pulmonary angiography image demonstrating a filling defect within the pulmonary artery (arrow), indicative of acute pulmonary embolism. The defect represents an intravascular thrombus obstructing pulmonary blood flow.