title: Noninvasive detection of heart transplant rejection with positron emission scintigraphy.
abstract: Positron emission tomography has recently been used to evaluate ischemic heart disease through changes in myocardial blood flow and carbohydrate metabolism. Positron-emitting tracers were evaluated for their ability to detect acute allograft rejection after heterotopic cardiac transplantation in the rat. Sham-operated controls, nonrejecting isografts, and rejecting allografts were evaluated. Decay-corrected uptake of 13NH3 and 18F 2-fluoro 2-deoxyglucose (FDG) reflects blood flow and glucose flux, respectively. Histologic examination of rejecting allografts documented mild rejection at 4 days and severe acute rejection by 8 days. All isografts were free from rejection. Uptake of FDG is greater in rejecting allografts than in nonrejecting isografts during both severe rejection (2.4% +/- 0.8% versus 0.7% +/- 0.4%; p less than 0.02) and mild rejection (2.1% +/- 0.6% versus 0.4% +/- 0.1%; p less than 0.02). Uptake of NH3 in severely rejected grafts is reduced compared with nonrejecting grafts (0.6% +/- 0.3% versus 1.7% +/- 1.1%; p less than 0.02). There is no difference in NH3 uptake during mild rejection (1.8% +/- 0.7% versus 1.3% +/- 0.3%; p greater than 0.05). Uptake of FDG and NH3 in native hearts of animals from all experimental groups is not significantly different from that in sham-operated controls. Glucose may be a preferred metabolic substrate during rejection. Our data support a humoral mechanism for substrate preference during transplant rejection and a potential diagnostic role for positron emission tomography.
authors.affiliation: Department of Cardiac and Thoracic Surgery, Vanderbilt University Medical Center, Nashville, Tennessee.
authors.forename: S J
authors.initials: SJ
authors.lastname: Hoff
authors.forename: J R
authors.initials: JR
authors.lastname: Stewart
authors.forename: W H
authors.initials: WH
authors.lastname: Frist
authors.forename: R M
authors.initials: RM
authors.lastname: Kessler
authors.forename: M P
authors.initials: MP
authors.lastname: Sandler
authors.forename: J B
authors.initials: JB
authors.lastname: Atkinson
authors.forename: J
authors.initials: J
authors.lastname: Votaw
authors.forename: J A
authors.initials: JA
authors.lastname: Carey
authors.forename: M S
authors.initials: MS
authors.lastname: Ansari
authors.forename: W H
authors.initials: WH
authors.lastname: Merrill
mesh_terms: D000641:Ammonia / Q000378:metabolism; D000818:Animals; D003326:Coronary Circulation; D003847:Deoxyglucose / Q000031:analogs & derivatives / Q000378:metabolism; D005462:Fluorine Radioisotopes; D019788:Fluorodeoxyglucose F18; D006084:Graft Rejection; D006207:Half-Life; D016027:Heart Transplantation / Q000000981:diagnostic imaging* / Q000473:pathology / Q000502:physiology; D008297:Male; D009206:Myocardium / Q000378:metabolism / Q000473:pathology; D009590:Nitrogen Radioisotopes; D051381:Rats; D011917:Rats, Inbred Lew; D013997:Time Factors; D014055:Tomography, Emission-Computed; D014184:Transplantation, Homologous; D014185:Transplantation, Isogeneic
chemical_list: D005462:Fluorine Radioisotopes; D009590:Nitrogen Radioisotopes; D019788:Fluorodeoxyglucose F18; D000641:Ammonia; D003847:Deoxyglucose