Kidney Week

Abstract: FR-PO021

Histopathological Features of Acute Tubular Necrosis in Native Kidney Correlate with Clinical Outcomes

Session Information

• AKI: Clinical, Outcomes, Trials - I
  October 26, 2018 | Location: Exhibit Hall, San Diego Convention Center
  Abstract Time: 10:00 AM - 12:00 PM

Category: Acute Kidney Injury

• 102 AKI: Clinical, Outcomes, and Trials

Authors

• Chen, Joy C. Y., Mayo Clinic, Rochester, Minnesota, United States

Joy C. Y. Chen,

• Ravindran, Aishwarya, Mayo Clinic, Rochester, Minnesota, United States

Aishwarya Ravindran,

• Sethi, Sanjeev, Mayo Clinic, Rochester, Minnesota, United States

Sanjeev Sethi,

• Kashani, Kianoush, Mayo Clinic, Rochester, Minnesota, United States

Kianoush Kashani,

Background

Acute kidney injury (AKI) is a life-threatening complication of critical illnesses and is associated with increased morbidity and mortality. Acute tubular necrosis (ATN) is a frequent cause of AKI; however, few studies have examined the histopathological features of ATN as prognostic factors of kidney function recovery in native kidneys. Our aim is to describe histopathological features of ATN systematically and correlate with clinical outcomes.

Methods

Analyses included adult patients who underwent kidney biopsy for AKI unrelated to kidney transplantation at Mayo Clinic Rochester from January 1^st, 2000 through December 31^st, 2015 and ATN was the primary histological diagnosis (n = 46). Biopsies were reviewed by a kidney pathology consultant (SS) semi-quantitatively. Features of ATN included vacuolization, the presence of tubular debris, tubular distension, tubular cell flattening, and the extent of interstitial fibrosis and tubular atrophy (IFTA). To evaluate the factors associated with kidney recovery, patients were divided into two groups: recovery (n = 28, serum creatinine (SCr) level at 30 days decreased by 0.3 mg/dL and renal replacement therapy (RRT) liberated) vs. no recovery (n = 18).

Results

The median age at time of biopsy was 67 [IQR 58, 75] years old; of which 50% were males, 91% Caucasian, with Charlson comorbidity index of 5 [IQR 4, 7], and SCr 3.9 mg/dL [IQR 2.2, 5.2] at the time of biopsy. 35 (76%) patients were inpatient, 9 (20%) required intensive care unit (ICU) admission, and 10 (22%) required RRT at time of biopsy. Twenty eight (61%) patients recovered kidney function within 30 days of biopsy. The presence of 3+ debris on biopsy was associated with a higher chance of recovery (Figure 1).

Conclusion

Among patients with AKI with biopsy-confirmed ATN, 61% recovered kidney function within 30 days of biopsy and recovery was associated with increased presence of tubular debris.

Figure 1 Histopathologic features of ATN in patients with and without recovery. *P-value <0.05.