Positron Emission Tomography to Assess the Outcome of Intraportal Islet Transplantation.

Eriksson O, Selvaraju R, Eich T, Willny M, Brismar TB, Carlbom L, Ahlström H, Tufvesson G, Lundgren T, Korsgren O

Diabetes 65 (9) 2482-2489 [2016-09-00; online 2016-06-20]

No imaging methodology currently exists to monitor viable islet mass after clinical intraportal islet transplantation. We investigated the potential of the endocrine positron emission tomography (PET) marker [(11)C]5-hydroxytryptophan ([(11)C]5-HTP) for this purpose. In a preclinical proof-of-concept study, the ex vivo and in vivo [(11)C]5-HTP signal was compared with the number of islets transplanted in rats. In a clinical study, human subjects with an intraportal islet graft (n = 8) underwent two [(11)C]5-HTP PET and MRI examinations 8 months apart. The tracer concentration in the liver as a whole, or in defined hotspots, was correlated to measurements of islet graft function. In rat, hepatic uptake of [(11)C]5-HTP correlated with the number of transplanted islets. In human subjects, uptake in hepatic hotspots showed a correlation with metabolic assessments of islet function. Change in hotspot standardized uptake value (SUV) predicted loss of graft function in one subject, whereas hotspot SUV was unchanged in subjects with stable graft function. The endocrine marker [(11)C]5-HTP thus shows a correlation between hepatic uptake and transplanted islet function and promise as a tool for noninvasive detection of viable islets. The evaluation procedure described can be used as a benchmark for novel agents targeting intraportally transplanted islets.

Olof Eriksson

SciLifeLab Fellow

PubMed 27325286

DOI 10.2337/db16-0222

Crossref 10.2337/db16-0222

pii: db16-0222
pmc: PMC5001185
ClinicalTrials.gov: NCT02689479

Publications 9.5.0