Atherosclerotic oxalosis in coronary arteries

Abstract

Systemic oxalosis may be hereditary or acquired. In these cases, calcium oxalate deposits have been reported in numerous tissues, including the media of arteries. In any category, calcium oxalate deposition has not been described within atherosclerotic plaques in any arteries. As part of a retrospective clinicopathologic study, 80 hearts were obtained from the National Neurological AIDS Bank in an effort to study coronary atherosclerosis in patients infected with HIV. The population consisted of 66 HIV-positive and 14 HIV-negative patients with an average age of 47 years; 79% were males. Proximal coronary arteries were serially sectioned and processed routinely. Sections were studied by hematoxylin and eosin staining and, in selected cases, von Kossa stain and alizarin red S under different conditions, including polarized light, to allow distinction of calcium phosphate from calcium oxalate. Medical histories, autopsy reports, and general autopsy slides were reviewed. In four patients (three with AIDS), calcium oxalate crystals were observed within atherosclerotic plaques in the coronary arteries. Similar deposits were seen in the thyroid gland and other organs but not in the kidneys. None of the patients had chronic renal failure. The calcium oxalate crystal deposits observed in the atherosclerotic plaques in the coronary arteries of these four patients are unique in two ways: (a) these deposits have not previously been described in atherosclerotic plaques; (b) the patients did not demonstrate any of the recognized patterns of oxalosis. We suggest the phrase "atherosclerotic oxalosis" to describe this finding.