Clinicopathologic Appearance of Advanced Ketoacidosis With Basal Vacuolation in Renal Tubules

Abstract

Context.— Basal vacuolization (BV) in renal tubules is a histopathologic hallmark of advanced ketoacidosis that enables us to retrospectively diagnose these cases. Objective.— To clarify the pathologic background and serologic findings of ketoacidosis with BV, and to reveal the pathologic findings by each pathologic background. Design.— We examined 664 serial autopsy cases. A systemic histopathologic examination and measurement of serum β-hydroxybutyrate concentration were performed for the cases with BV. The extent of steatosis and fibrosis in the organs and the degree of coronary artery stenosis were semiquantitatively investigated. Immunohistochemistry for adipophilin was also performed to analyze its usefulness for the pathologic diagnosis. Results.— Basal vacuolization was found in 16 cases, all of which showed a pathologic serum β-hydroxybutyrate concentration. The main background of ketoacidosis was considered as alcohol abuse in 6 cases, diabetes in 5, malnutrition in 3, and hypothermia and infection in 1 case each. Severe hepatic fibrosis was observed only in the alcohol-abuser group. Moreover, cardiac steatosis was more severe in patients with possible alcohol abuse than in those with other causes. Immunohistochemistry for adipophilin showed immunoreactivity consistent with BV in 13 of 16 cases. There was no correlation between β-hydroxybutyrate concentration and either the postmortem or storage interval. Conclusions.— Basal vacuolization may be a useful finding for detecting ketoacidosis cases in a postmortem investigation. Serum β-hydroxybutyrate was a stable and reliable compound for the definitive diagnosis of ketoacidosis in such cases. The present study showed that pathologic changes in some organs may vary by each pathologic background of ketoacidosis with BV.