MOLECULAR PROFILING IMPROVES DIAGNOSES OF REJECTION AND INFECTION IN TRANSPLANTED ORGANS. The monitoring of transplanted hearts is currently based on histological evaluation of endomyocardial biopsies, a method that is fairly insensitive and that does not always accurately discriminate between rejection and infection in the heart. Accurate diagnosis of rejection and infection is absolutely crucial, however, as the respective treatments are completely different. Using microarrays we analyzed gene expression in 76 cardiac biopsies from 40 heart recipients undergoing rejection, no rejection, or T. cruzi infection. We found a set of 98 genes whose expression patterns were typical of acute rejection, and 87 genes that discriminated between rejection and T. cruzi infection. These sets revealed acute rejection episodes up to two weeks earlier, and trypanosome infection up to two months earlier than did histological evaluation. When applied to raw data from other institutions, the two sets of predictive genes were also able to accurately pinpoint acute rejection of lung and kidney transplants, as well as bacterial infections in kidneys. In addition to their usefulness as diagnostic tools, the data suggest that there are similarities in the biology of the processes involved in rejection of different grafts and also in the tissue responses to pathogens as diverse as bacteria and protozoa. Keywords: disease state analysis
This series includes 24 samples that were used to validate acute rejection profile descovered previously (GSE2596). This set of hybridizations was done using different from GSE2596 reference RNA (Cy5-labeled). Therefore, Cy3/Cy5 log-ratios could not be compared between these two series. There are 27 arrays in this series because 3 samples were done in duplicates that can be identified by first numbers in the title of the sample.