BACKGROUND: Previous results have established the potential interest of proton magnetic resonance spectroscopy (MRS) of plasma lipoproteins in the detection of rejection processes after heart transplantation. The aim of this study was to determine whether MRS can provide a relevant long-term prognosis factor as early as 1 week after transplantation. METHODS: Eighteen patients were monitored for a mean period of 16 months after transplantation. The ratio of the sum of the MRS total line widths (TLW) for lipoprotein moieties, obtained 1 week after transplantation and cyclosporine administration, over the same sum obtained on the day of transplantation (TLW(8/0)), as well as the ratio between the corresponding intensities of methyl and methylene moieties (IR) were used to quantify the lipoprotein spectral profile. RESULTS: TLW(8/0), with a cutoff value of 0.8, seemed to have the most value in predicting rejection processes (RP) several months later. All six patients with no RP (good prognosis) and all five patients with three or more RPs (poor prognosis) during the entire 16-month follow-up period were correctly detected as early as 8 days after transplantation. The seven patients with only one or two RPs, mainly occurring during the first months after transplantation, were usually classified by MRS as having good prognosis. CONCLUSIONS: The magnetic resonance spectrum depends on both qualitative and quantitative variations in the different lipoprotein fractions, known to be carriers of cyclosporine. The magnetic resonance spectrum could thus be an early expression of the ability of these lipoproteins to modulate the cyclosporine-mediated immunosuppression.
BACKGROUND: Previous results have established the potential interest of proton magnetic resonance spectroscopy (MRS) of plasma lipoproteins in the detection of rejection processes after heart transplantation. The aim of this study was to determine whether MRS can provide a relevant long-term prognosis factor as early as 1 week after transplantation. METHODS: Eighteen patients were monitored for a mean period of 16 months after transplantation. The ratio of the sum of the MRS total line widths (TLW) for lipoprotein moieties, obtained 1 week after transplantation and cyclosporine administration, over the same sum obtained on the day of transplantation (TLW(8/0)), as well as the ratio between the corresponding intensities of methyl and methylene moieties (IR) were used to quantify the lipoprotein spectral profile. RESULTS: TLW(8/0), with a cutoff value of 0.8, seemed to have the most value in predicting rejection processes (RP) several months later. All six patients with no RP (good prognosis) and all five patients with three or more RPs (poor prognosis) during the entire 16-month follow-up period were correctly detected as early as 8 days after transplantation. The seven patients with only one or two RPs, mainly occurring during the first months after transplantation, were usually classified by MRS as having good prognosis. CONCLUSIONS: The magnetic resonance spectrum depends on both qualitative and quantitative variations in the different lipoprotein fractions, known to be carriers of cyclosporine. The magnetic resonance spectrum could thus be an early expression of the ability of these lipoproteins to modulate the cyclosporine-mediated immunosuppression.