Abstract
Platinum is a widely used transition metal in anti-cancer agents, with many reports regarding nephropathy due to severe adverse reactions caused by platinum induced nephrotoxicity. Reports on imaging with metals other than platinum remain limited even in preclinical studies. Furthermore, most of them are case reports, and the relationship between metal distribution and clinical observation in human samples remains room for elucidation. Here we visualized lanthanum (139La) included in Fosrenol, which is usually used for hyperphosphatemia treatment. Gastric inflammation, also known as hemorrhagic gastritis, is the main adverse event of Fosrenol. To conduct this study, gastric biopsy samples obtained from one patient were used to visualize 139La by using quantitative laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). We also compared the 139La distribution and histochemical results. 139La-accumulated areas corresponded to macrophage-positive areas in the immunohistochemistry studies using an anti-CD68 antibody. In contrast, we observed debris-like crystal morphology in hematoxylin and eosin staining tissues. The debris was also associated with 139La accumulation. Abnormal accumulation of 139La crystals caused the observed inflammation. This phenomenon has already been characterized, but this is the first report to compare 139La distribution and histochemical results using LA-ICP-MS.
