Uric Acid and Preeclampsia: Pathophysiological Interactions and the Emerging Role of Inflammasome Activation

Abstract

Preeclampsia (PE) is a multifactorial hypertensive disorder unique to pregnancy and a leading cause of maternal and fetal morbidity and mortality worldwide. Its pathogenesis involves placental dysfunction and an exaggerated maternal inflammatory response. Uric acid (UA), traditionally regarded as a marker of renal impairment, is increasingly recognized as an active contributor to the development of PE. Elevated UA levels are associated with oxidative stress, endothelial dysfunction, immune activation, and reduced renal clearance. Clinically, UA is measured in the second and third trimesters to assess disease severity and guide obstetric management, with higher levels correlating with early-onset PE and adverse perinatal outcomes. Its predictive accuracy improves when combined with other clinical and biochemical markers, particularly in low-resource settings. Mechanistically, UA and its monosodium urate crystals can activate the NLRP3 inflammasome, a cytosolic multiprotein complex of the innate immune system. This activation promotes the release of IL-1? and IL-18, exacerbating placental, vascular, and renal inflammation. NLRP3 inflammasome activation has been documented in placental tissues, immune cells, and kidneys of women with PE and is associated with hypertension, proteinuria, and endothelial injury. Experimental studies indicate that targeting UA metabolism or inhibiting NLRP3 activation, using agents such as allopurinol, metformin, or MCC950, can mitigate the clinical and histopathological features of PE. These findings support the dual role of UA as both a biomarker and a potential therapeutic target in the management of the disease.