Acute biomarker panel changes associated with amphotericin B nephrotoxicity in female Sprague-Dawley rats

To date, eight next‑generation urinary protein kidney safety biomarkers have been qualified to enable monitoring for subclinical drug‑induced kidney injury (DIKI) in rat preclinical studies; however, most DIKI biomarker studies have included only male rats. The objective of this study was to assess the utility of novel DIKI biomarkers, including but not limited to urinary total protein, albumin, cystatin C and osteopontin in female Sprague‑Dawley rats (8/group) that received repeated intravenous injections of amphotericin B (AmpB, 3 mg/kg/day) or vehicle for 10 consecutive days. Serial serum/urine samples were collected on study day (D)4, D8, and D11. Surviving animals were necropsied on D11. The AmpB‑induced kidney histopathology findings were characterized by cortical and medullary tubular alterations, interstitial inflammation, intratubular granular and inflammatory cell casts, acute pelvic inflammation and tubular mineralization. Significant elevations in urinary clusterin on D4, D8 and D11 (3.5 fold, 2.2 fold and 3.3 fold respectively) were observed (versus concurrent controls) following repeated injections of AmpB. In addition, significantly elevated (fold changes) in biomarkers, neutrophil gelatinase‑associated lipocalin (14.6 fold), albumin (13.5 fold), cystatin C (13.5 fold), total protein (3.5 fold), kidney injury molecule 1 (3.0 fold) and osteopontin (2.3 fold) were detected in urine as early as D4. These findings demonstrate the value of early elevations in nephron‑specific DIKI biomarkers for detecting subclinical AmpB nephrotoxicity in female Sprague‑Dawley rats. These findings are anticipated to provide the basis for inclusion of female rats on a case‑by‑case basis in preclinical toxicology studies designed to detect DIKI.