Case Report: A case of recurrent thrombosis in pediatric antiphospholipid syndrome associated with pediatric onset systemic lupus

Abstract

Systemic lupus erythematosus (SLE) is an autoimmune disease with multi-system involvement as the main manifestation, and has complex and diverse clinical features. Studies on large samples have revealed that SLE patients have a significantly increased risk of thrombotic events, which are also one of the important causes of morbidity and mortality in SLE patients. Antiphospholipid syndrome (APS) is a rare autoimmune disorder characterized by recurrent arterial and venous thrombosis, pregnancy-related complications, and the persistence of antiphospholipid antibodies at a 12-week interval. There are few reports about SLE coexisting with APS in children. This paper reported a school-age patient who started the disease with gross hematuria after bumping into the waist. The initial diagnosis of renal contusion was then confirmed by color Doppler ultrasound as renal vein and inferior vena cava embolism. She suddenly developed severe chest pain and dyspnea 3 days after hospitalization. And imaging supported pulmonary embolism with massive proteinuria, hypoalbuminemia, and hypercholesterolemia. The initial diagnosis was nephrotic syndrome (NS) with arteriovenous embolization, and popliteal vein embolism occurred again 5 years later, and she was thus diagnosed with SLE coexisting with APS. Afterwards, we discussed the possible mechanism and therapeutic strategies of SLE&APS that started with nephrotic syndrome, in order to achieve early identification and treatment of the disease and improve the prognosis of children.

Keywords: antiphospholipid antibody; antiphospholipid syndrome; gross hematuria; nephrotic syndrome; systemic lupus erythematosus.

Figure 1

Timeline of events.

Figure 2

Clinical features of the current patient. Among auxiliary examinations, color Doppler ultrasound showed hypoechoic masses in the wall of the inferior vena cava (A), and of the right renal vein (B), considering the possibility of thrombosis. Pulmonary artery CT angiography (CTA) showed embolisms of the distal main pulmonary artery, left pulmonary artery trunk and its intrapulmonary branches, and the right lower pulmonary artery (C), considering the possibility of ischemic infarction. The thrombi disappeared after effective treatment (D). Vascular B-ultrasound showed bilateral popliteal vein blood flow, and bilateral mural thrombosis was considered (E-F).

Figure 3

The renal pathology of the current patient. Immunofluorescence showed that IgA, IgG, C3, IgM, Fibrin, C4, C1q, MABα-1, MABα-3, and MABα-5 were all positive (A-E). Under the light microscope, there were 11 glomeruli, 9/11 glomeruli had bulbous sclerosis, the other 2 glomeruli had increased lobulation, mesangial cells (2–4 area) hyperplasia and mesangial matrix, capillaries did not open well, and endothelial proliferation and glomerulus exudation with peribulbar fibrosis and inflammatory cell infiltration were observed. Segmental thickening of the glomerular basement membrane was found, and deposition of polyerythrophilin was observed subcutaneously in the mesangial area. Additionally, there were vacuolar degeneration of renal tubules, abundant protein tubules, and marked edema and fibrosis of renal interstitium with focal inflammatory cell infiltration (F-G). The mesangial cells in 2 glomeruli showed mild to moderate proliferation of matrix with abundant electron deposits. Capillary basement membrane thickness extensively thickened (800–3000 nm). There were large high-density electron deposits on the endothelial side, extensive fusion of microvilli, and partial renal tubular epithelial edema in the foot process (H-I).