Case Control Study
Copyright ©The Author(s) 2015. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Nephrol. May 6, 2015; 4(2): 313-318
Published online May 6, 2015. doi: 10.5527/wjn.v4.i2.313
Histopathology of renal asphyxia in newborn piglets: Individual susceptibility to tubular changes
Clara Gerosa, Nicoletta Iacovidou, Ioanna Argyri, Daniela Fanni, Apostolos Papalois, Filippia Aroni, Gavino Faa, Theodoros Xanthos, Vassilios Fanos
Clara Gerosa, Daniela Fanni, Gavino Faa, Department of Pathology, University of Cagliari, 09124 Cagliari, Italy
Nicoletta Iacovidou, Ioanna Argyri, National and Kapodistrian University of Athens, 10431 Athens, Greece
Apostolos Papalois, Theodoros Xanthos, ELPEN Research - Experimental Center, 10431 Athens, Greece
Filippia Aroni, Laboratory of Experimental Surgery and Surgical Research, University of Athens, 10431 Athens, Greece
Vassilios Fanos, Department of Neonatology, University of Cagliari, 09124 Cagliari, Italy
Author contributions: All authors have contributed equally to the writing of the paper.
Ethics approval: The authors declare that the study protocol has been approved by the institute’s committee on human research.
Informed consent: The research complies with the guidelines for human studies and animal welfare regulations. The authors declare that subjects have given their informed consent.
Conflict-of-interest: No conflict of interest is present.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Dr. Daniela Fanni, MD, PhD, Pathologist, Department of Pathology, University of Cagliari, San Giovanni di Dio Hospital, Via Ospedale n. 54, 09124 Cagliari, Italy. fandan73@yahoo.it
Telephone: +39-7-06092372 Fax: +39-7-06092370
Received: June 11, 2014
Peer-review started: June 12, 2014
First decision: August 14, 2014
Revised: February 3, 2015
Accepted: February 10, 2015
Article in press: February 12, 2015
Published online: May 6, 2015
Processing time: 330 Days and 17.2 Hours
Abstract

AIM: To analyze the effects on the kidney of hypoxia-reoxygenation in an experimental model of normocapnic asphyxia.

METHODS: To this end, 40 newborn Landrace/Large-White piglets aged 1-4 d were studied in this work. Hypoxia was induced by decreasing the inspired fiO2 to 0.06-0.08. Animals were resuscitated with different fiO2 and subdivided into 4 groups: group 1, 2, 3 and 4 received 18%, 21%, 40% and 100% O2 respectively. Macroscopic examination was carried out to evidence possible pathological features. Tissue sample were obtained from both kidneys. Four or five micron paraffin sections were stained with H-E and PAS stain and examined under an optical microscope.

RESULTS: Pathological changes, mainly affecting tubular cells, were observed in the vast majority of kidneys of asphyxiated piglets. The most frequent tubular changes were: tubular casts (95%), tubular dilatation (87.5%), tubular vacuolization (70%), tubular eosinophilia (52.5%), sloughing (50%), fragmentation of the brush border (50%), oedema (32.5%), apoptosis (15%) and glomerular changes (meningeal cell proliferation, capsular adhesion between the flocculus and Bowman’s capsule, glomerulosclerosis and fibrous or cellular crescents associated with collapse of the glomerular tuft). Statistical analysis was carried out on changes observed when the animals were allocated in the 4 groups (χ2-test 0.05). The statistical analysis showed no evidence of differences regarding kidney lesions among the animals groups.

CONCLUSION: Our data show that renal pathology in newborn piglets is characterized by interindividual variability to hypoxia and is not associated with oxygen concentration.

Keywords: Asphyxia; Kidney; Tubular eosinophilia; Tubular dilatation; Vacuolization; Sloughing; Apoptosis; Brush border fragmentation

Core tip: This work studied pathological renal changes following hypoxia-reoxygenation using an established experimental model of normocapnic asphyxia. Tubular dilatation, vacuolization, tubular eosinophilia, sloughing, fragmentation of the brush border and apoptosis were the most frequent changes detected in proximal tubules. Tubular dilatation, vacuolization and sloughing were the earliest lesions, interstitial oedema and apoptosis the late ones. In newborn piglets undergoing asphyxia, renal pathology was not associated with oxygen concentration used during resuscitation.