Placenta, platelets, and podocytes; the triad of renal injury in pregnant women with antiphospholipid syndrome

The intricate triad of placenta, platelets, and podocytes represents a central framework for understanding the multifactorial renal injury associated with antiphospholipid syndrome (APS) during pregnancy. This triadic interaction underscores a pathophysiological continuum driven by thrombosis, inflammation, and endothelial dysfunction that disrupts both placental and renal homeostasis. In pregnant women with APS, the placenta functions as a key initiator of systemic disturbances through procoagulant and proinflammatory mediators that alter vascular tone and promote immune activation. These placental signals propagate into the maternal circulation, stimulating platelet activation and aggregation that intensify microvascular thrombotic damage. Activated platelets further contribute to endothelial injury by releasing cytokines, chemokines, and growth factors that perpetuate inflammatory cascades and coagulative imbalance. At the renal glomerular level, podocytes serve as critical yet vulnerable responders within this network. They experience direct insults from circulating antiphospholipid antibodies and secondary injury from ischemic and hemodynamic stress induced by microthrombi and endothelial derangement. The consequent podocyte depletion and barrier disruption lead to proteinuria and progressive glomerular dysfunction characteristic of APS nephropathy. This integrative model highlights how maternal, hematologic, and renal compartments intersect in a self-reinforcing cycle of injury, illuminating potential therapeutic targets that modulate platelet activation, placental inflammation, and podocyte resilience.