Nuclear mean gray level and chromatin distribution changes in cardiomyocytes of heart transplant recipients suffering from acute cellular rejection.
BACKGROUND
Distribution and staining of the nuclear chromatin are sensitive indicators of changes in physiology and pathology of cells. However, their use in heart transplant recipients is rare. The aim of this study was to compare cardiomyocyte status in heart transplant recipients suffering from moderate acute cellular rejection and subjects without signs of active cellular rejection.


METHODS
One hundred twenty-nine endomyocardial biopsy samples from 43 heart transplant recipients (no later than 6 months after surgery) were evaluated. Overall, 3235 cardiomyocytic nuclei were analyzed using the Quantimet image analysis system to assess the mean gray level: 1584 nuclei were found in biopsies without signs of rejection or with nonsignificant rejection (ISHLT grades 0, 1A, and 1B), whereas the remaining 1651 nuclei were measured from biopsies showing ISHLT grade 3A (significant rejection). Additionally, the chromatin distribution was assessed in all eligible nuclei.


RESULTS
The mean gray level was markedly increased in nuclei from biopsy samples with significant rejection (182.6 vs 112.5, P < .001, Mann-Whitney U test). Moreover, the analysis of chromatin distribution revealed significantly more frequent chromatin marginalization and irregular distribution in rejecting subjects (P < .001, chi-square test).


CONCLUSIONS
Inflammatory stimulation of cardiomyocytes during acute cellular rejection of the transplanted heart influences the chromatin distribution in the nuclei, which may have an additional value, when assessing the severity of rejection.
Zakliczynski
M
M
Department of Cardiac Surgery and Transplantation, Silesian Center for Heart Diseases, ul. Szpitalna 2, 41-800 Zabrze, Poland. zaklimed@onet.pl
Nozynski
J
J
Lange
D
D
Zembala-Nozynska
E
E
Konecka-Mrówka
D
D
Zembala
M
M
D000208:Acute Disease; D001706:Biopsy; D002467:Cell Nucleus / Q000502:physiology* / Q000648:ultrastructure; D002843:Chromatin / Q000473:pathology* / Q000648:ultrastructure; D006084:Graft Rejection / Q000473:pathology*; D016027:Heart Transplantation / Q000473:pathology*; D006351:Heart Valves / Q000473:pathology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D032342:Muscle Cells / Q000473:pathology* / Q000637:transplantation
D002843:Chromatin