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Abstract: SA-PO1096

Kidney Injury Molecule-1 (KIM-1) Identifies Antemortem Injury in Fetal Postmortem Kidney

Session Information

Category: Pathology and Lab Medicine

  • 1502 Pathology and Lab Medicine: Clinical

Authors

  • Yin, Wenqing, Brigham and Women's Hospital, Boston, Massachusetts, United States
  • Zhang, Ping L., William Beaumont Hospital, Royal Oak, Royal Oak, Michigan, United States
  • Macknis, Jacqueline K., Beaumont Health, Royal Oak, Michigan, United States
  • Bonventre, Joseph V., Brigham and Women's Hospital, Boston, Massachusetts, United States
Background

KIM-1, a type I transmembranous protein, is a specific and stable protein marker for identifying injury in proximal tubules during acute kidney injury. There is currently no technique to unambiguously diagnose antemortem kidney injury on postmortem examination since postmortem tissue damage and autolysis are common. We hypothesized that KIM-1 could be very useful for detecting antemortem proximal tubular injury in autolyzed kidneys upon postmortem examination.

Methods

A total of 52 fetal/neonatal autopsy kidneys, from 30 stillborns and 22 liveborns, were assessed for KIM-1 staining. Kidney autolysis was evaluated by light microscopy and disappearance of CD133 expression. The autolysis was graded from 0 (no autolysis) to 3+ (entire loss of chromatin staining). Correlation between KIM-1 and autolysis scores was evaluated by linear regression analysis. Given that serum creatinine is unreliable in neonates, we assessed pre-terminal hypoxia in fetuses by the presence of squames in pulmonary alveoli and/or the need for intubation.

Results

The expression of KIM-1 was seen in a majority of the fetal and neonatal autopsy kidneys (77%, 40/52) as early as 16 weeks of gestation, even in the presence of autolysis. There was no significant correlation between KIM-1 scores and autolysis scores (r = 0.201 and p = 0.1521). There was a high correlation between KIM-1 expression and these clinical indices of hypoxia, either presence of aspirated amniotic fluid contents in stillborn or need for intubation in liveborn.

Conclusion

Our data suggest that KIM-1 is a specific and stable marker of antemortem tubular injury in fetuses, despite postmortem autolysis. A high correlation between KIM-1 expression and these clinical indices of hypoxia implies that KIM-1 may be a reliable marker to indicate the hypoxic state in pediatric autopsies.

Funding

  • Other U.S. Government Support