PROTON MAGNETIC-RESONANCE SPECTROSCOPY OF BLOOD-PLASMA IN HEART-TRANSPLANT RECIPIENTS TREATED WITH CYCLOSPORINE - AN EARLY PROGNOSIS TEST OF LONG-TERM GRAFT TOLERANCE

Background: Previous results have established the potential interest o f proton magnetic resonance spectroscopy (MRS) of plasma lipoproteins in the detection of rejection processes after heart transplantation. T he aim of this study was to determine whether MRS can provide a releva nt long-term prognosis factor as early as 1 week after transplantation . Methods: Eighteen patients were monitored for a mean period of 16 mo nths after transplantation. The ratio of the sum of the MRS total line widths (TLW) for lipoprotein moieties, obtained 1 week after transpla ntation and cyclosporine administration, over the same sum obtained on the day of transplantation (TLW8/0), as well as the ratio between the corresponding intensities of methyl and methylene moieties (IR) were used to quantify the lipoprotein spectral profile.Results: TLW8/0, wit h a cutoff value of 0.8, seemed to have the most value in predicting r ejection processes (RP) several months later. All six patients with no RP (good prognosis) and all five patients with three or more RPs (poo r prognosis) during the entire 16-month follow-up period were correctl y detected as early as 8 days after transplantation. The seven patient s with only one or two RPs, mainly occurring during the first months a fter transplantation, were usually classified by MRS as having good pr ognosis. Conclusions: The magnetic resonance spectrum depends on both qualitative and quantitative variations in the different lipoprotein f ractions, known to be carriers of cyclosporine. The magnetic resonance spectrum could thus be an early expression of the ability of these Li poproteins to modulate the cyclosporine-mediated immunosuppression.