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Apoptosis in acute pulmonary allograft rejection and cytomegalovirus infection

P R Hansen1, A M Holm, U G Svendsen

  • 1The Heart Center, Rigshospitalet, Copenhagen, Denmark.

APMIS : Acta Pathologica, Microbiologica, Et Immunologica Scandinavica
|May 21, 1999
PubMed

Insights

Apoptosis, programmed cell death, is increased in acute pulmonary allograft rejection and cytomegalovirus (CMV) pneumonitis. This finding suggests apoptosis plays a key role in lung transplant complications.

Area of Science:

  • Immunology
  • Cell Biology
  • Pulmonary Medicine

Background:

  • Apoptosis, or programmed cell death, involves DNA fragmentation identifiable by in situ terminal deoxyribonucleotide transferase-mediated dUTP nick-end labeling (TUNEL).
  • Apoptosis has been linked to cardiac and hepatic allograft rejection.

Purpose of the Study:

  • To investigate the role of apoptosis in acute pulmonary allograft rejection.
  • To determine the contribution of apoptosis to cytomegalovirus (CMV) pneumonitis in lung transplant recipients.

Main Methods:

  • In situ TUNEL staining was performed on 70 transbronchial biopsy specimens from 25 pulmonary allograft recipients.
  • The density of apoptotic nuclei was quantified and correlated with rejection grade (ISHLT classification) and CMV infection.

Main Results:

  • Apoptotic cells were found in pulmonary parenchymal and infiltrating mononuclear cells during acute rejection.
  • A positive correlation existed between apoptotic cell numbers and the severity of acute pulmonary allograft rejection.
  • Elevated apoptotic cell density was observed in pulmonary allografts with CMV pneumonitis.

Conclusions:

  • Apoptosis significantly contributes to cell death in acute pulmonary allograft rejection.
  • Apoptosis is implicated in the pathogenesis of CMV pneumonitis following lung transplantation.

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