Quantitative short-tandem repeat analysis of recipient-derived cells as an additional tool for diagnosing cardiac allograft rejection.
BACKGROUND
Diagnosis of cardiac allograft rejection is currently based on histologic exploration of endomyocardial biopsies. Moderate interobserver reproducibility in the estimation of number and distribution of inflammatory cells leads to disagreements in the assignment of rejection grades. Short-tandem repeat (STR) analysis is routinely used after hematopoietic stem-cell transplantation to determine the proportions of donor cells. We compared the amount of recipient-derived cells with the histopathologic grade of rejection in cardiac allografts to determine whether this method might be useful for the assessment of rejection episodes.


METHODS
One hundred forty-three endomyocardial biopsies from 18 patients were investigated for the percentage of recipient-derived cell content by polymerase chain reaction-based STR analysis and correlated with rejection grades determined according to the International Society for Heart and Lung Transplantation grading system. Y-chromosome chromogene in situ hybridization was performed in gender-mismatched (female-to-male) heart transplants to explore the influence of cardiomyocyte cell chimerism.


RESULTS
The mean percentages of recipient-derived cells associated with various degrees of rejection were 13% in grade 0, 24% in grade 1A, 29% in grade 1B, 35% in grade 2, and 50% in grade > or =3A. Samples lacking signs of rejection (grade 0) had a significantly lower (P<0.001) amount of recipient-derived cells than higher degrees of rejections. Chromogene in situ hybridization analysis revealed that the recipient-derived cells were mainly inflammatory.


CONCLUSIONS
The results of STR-analysis indicate that rejection is correlated with a higher proportion of recipient-derived cells. This assessment is observer independent and may thus represent an additional diagnostic tool for the assessment of rejection and management of immunosuppressive treatment.
Pichler
Martin
M
Department of Oncology, University Clinic of Internal Medicine, Medical University of Graz, Graz, Austria.
Beckendorf
Jan
J
Winter
Elke
E
Kleinert
Reinhold
R
Kniepeiss
Daniela
D
Hoefler
Gerald
G
D000208:Acute Disease; D000328:Adult; D000368:Aged; D041322:Chromosomes, Human, Y; D004699:Endocardium / Q000473:pathology; D005260:Female; D005819:Genetic Markers; D005820:Genetic Testing / Q000379:methods*; D006084:Graft Rejection / Q000175:diagnosis* / Q000209:etiology / Q000235:genetics / Q000473:pathology / Q000517:prevention & control; D016027:Heart Transplantation / Q000009:adverse effects*; D006801:Humans; D007166:Immunosuppressive Agents / Q000627:therapeutic use; D017403:In Situ Hybridization; D008297:Male; D018895:Microsatellite Repeats; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology; D015588:Observer Variation; D016133:Polymerase Chain Reaction; D011237:Predictive Value of Tests; D012372:ROC Curve; D015203:Reproducibility of Results; D012189:Retrospective Studies; D013997:Time Factors; D018183:Transplantation Chimera; D014184:Transplantation, Homologous; D016896:Treatment Outcome; D055815:Young Adult
D005819:Genetic Markers; D007166:Immunosuppressive Agents