BACKGROUND: Acute rejection is one of the most important direct contributors to mortality after heart transplantation. Advances in the development of novel non-invasive approaches for the early identification of allograft rejection are necessary. We conducted a non-targeted proteome characterization focused on identifying multiple plasmatic protein differences to evaluate their diagnostic accuracy for rejection episodes. METHODS: We included consecutive plasma samples from transplant recipients undergoing routine endomyocardial biopsies. A liquid chromatography−tandem mass spectrometry analysis using isobaric tags (tandem mass tag 10-plex) was performed and concentrations of CD5L were validated using a specific sandwich enzyme-linked immunosorbent assay. RESULTS: A total of 17 altered proteins were identified as potential markers for detecting heart transplant rejection, most involved in inflammation and immunity. CD5L, an apoptosis inhibitor expressed by macrophages, showed the best results in the proteomic analysis (n = 30). We confirm this finding in a larger patient cohort (n = 218), obtaining a great diagnostic capacity for clinically relevant rejection (≥Grade 2R: area under the curve = 0.892, p < 0.0001) and preserving the accuracy at mild rejection (Grade 1R: area under the curve = 0.774, p < 0.0001). CD5L was a strong independent predictor, with an odds ratio of 14.74 (p < 0.0001), for the presence of rejection. CONCLUSIONS: Episodes of acute cardiac allograft rejection are related to significant changes in a key inhibitor of apoptosis in macrophages, CD5L. Because of its precision to detect acute cellular rejection, even at mild grade, we propose CD5L as a potential candidate to be included in the studies of molecule combination panel assays. This finding could contribute to improving the diagnostic and preventive methods for the surveillance of cardiac transplanted patients.

No abstract

Objective: Severe pressure ulcers (PUs) do not respond to conservative wound therapy and need surgical repair. To better understand the pathogenesis and to advance on new therapeutic options, we focused on the proteomic analysis of PU, which offers substantial opportunities to identify significant changes in protein abundance during the course of PU formation in an unbiased manner. Approach: To better define the protein pattern of this pathology, we performed a proteomic approach in which we compare severe PU tissue from spinal cord injury (SCI) patients with control tissue from the same patients. Results: We found 76 proteins with difference in abundance. Of these, 10 proteins were verified as proteins that define the pathology: antithrombin-III, alpha-1-antitrypsin, kininogen-1, alpha-2-macroglobulin, fibronectin, apolipoprotein A-I, collagen alpha-1 (XII) chain, haptoglobin, apolipoprotein B-100, and complement factor B. Innovation: This is the first study to analyze differential abundance protein of PU tissue from SCI patients using high-throughput protein identification and quantification by tandem mass tags followed by liquid chromatography tandem mass spectrometry. Conclusion: Differential abundance proteins are mainly involved in tissue regeneration. These proteins might be considered as future therapeutic options to enhance the physiological response and permit cellular repair of damaged tissue.