Effect of Monosodium Urate Crystal Deposition on Atherosclerotic Carotid Plaques

Background/Objectives: The accumulation of uric acid in arteriosclerotic plaques has recently attracted attention. Because the interaction between hyperuricemia and atherosclerosis is complex, the details remain obscure. We aimed to elucidate the clinical effect of monosodium urate monohydrate (MSU) deposition on carotid plaques. Methods: This study enrolled 89 patients with carotid plaques. MSU deposits were confirmed using Gomori's methenamine silver staining of carotid endarterectomy (CEA) specimens. To evaluate the macrophage and microvessel marker counts, we used CD68 and CD31. Plaque composition was investigated in carotid plaques with MSU deposition and inflammation. We also examined the use of dual-energy computed tomography (DECT) and compensated for pathological findings to detect MSU crystal deposition in carotid plaques. Results: Of the 89 patients who underwent CEA, 31 (34.8%) had hyperuricemia. Overall, 22 (24.7%) participants had MSU deposits and 67 (75.3%) did not. MSU deposits, CD31-positive microvessels, and CD68-positive cells were observed in shoulder lesions. The number of CD31-positive microvessels and CD68-positive cells was higher in patients with MSU deposits than in those without MSU deposits. Most plaques expressing MSU were plaques with intraplaque hemorrhage. The consistency in MSU deposit identification between histopathology and DECT was poor (kappa = 0.34). Conclusions: MSU deposition may be related to the inflammation of carotid plaques.