Abstract 2313: Gene Expression Profiling Scores In The Setting Of A Quiescent Biopsy In Chronic, Stable Cardiac Transplant Patients.
BACKGROUND: Gene expression profiling (GEP) scores (Allomap) have been shown to discriminate between quiescence and moderate to severe acute cellular rejection in cardiac transplant (TX) patients (pts). High GEP scores above threshold (≥ 34) with a concurrent quiescent endomyocardial biopsy (BX) have been described, but its clinical significance is unknown.
METHODS: 94 concurrent GEP score and BX grade were analyzed in 42 immunological and clinically stable pts (33 males, 9 females) who were > 1 year post TX. All BX scores were 0R or 1R (defined as quiescent and not treated) with a concurrent index GEP score < or ≥ 34. The BX scores immediately before (30 –90 days) and immediately after (30 –90 days) the index GEP score also confirmed immunologic quiescence (0R or 1R). Demographics, allograft function (hemodynamic, ventricular) and immunosuppression in the two GEP score categories were compared. BX grades were assigned by a single pathologist blinded to the clinical status and GEP score.
RESULTS: There were no statistically significant differences between the two GEP score categories. There was no difference in left ventricular ejection fraction between the 2 groups (63 ± 9 vs 62 ± 7%, p = 0.6). (Remainder of data in Table 1⇓)
CONCLUSION: Post TX pts with quiescent BX may have either high or normal GEP scores in the absence of other clinical discriminators. Perhaps, humoral rejection accounts for this observation. This finding highlights the potential difficulty of using GEP score by itself without allograft BX in the clinical management of TX pts.