C-peptide and glucose values in the peritransplant period after intraportal islet infusions in type 1 diabetes.
BACKGROUND
Successful islet allograft transplantation has been achieved worldwide. This study aimed at evaluating the relationship between peritransplant C-peptide (CP) values and long-term allograft function.


METHODS
We measured CP-to-glucose ratio (CPGR) in intraportal samples pre- and postinfusion, and in peripheral circulation at baseline pretransplant and at 1, 3, 6, 12, 72 hours, 1 week, and 15 and 30 days after first and second infusion in 13 islet allograft recipients. Peritransplant treatment included intravenous (IV) 5% dextrose in saline in all patients. We compared portal CPGR to insulin reduction (%) at 30 days after each infusion, and at 1 year after second infusion.


RESULTS
CPGR peaked between the immediate postinfusion and 3 hours and decreased at 12 hours. At 1 week, CPGR was 0.76 +/- 0.45 and 1.44 +/- 0.37 after first and second infusion, respectively. CPGR at 30 days after second infusion doubled compared to first infusion (P < .001). There was no correlation between peak CPGR and insulin reduction percent at any time point. One patient experienced hypoglycemia (47 mg/dL) 1 hour after second infusion.


CONCLUSIONS
There was no relationship between the CP values in the peritransplant period and long-term graft function or success rate. The early peak in the C-peptide levels is indicative of a significant insulin release after each islet infusion. For this reason, it is important to carefully monitor serum glucose levels in the peritransplant period (hourly for the first 6 hours) and to maintain an IV glucose infusion to avoid hypoglycemia.
Faradji
R N
RN
Department of Medicine, University of Miami Miller School of Medicine, Miami, FL 33136, USA.
Monroy
K
K
Cure
P
P
Froud
T
T
Baidal
D
D
Pileggi
A
A
Messinger
S
S
Ricordi
C
C
Alejandro
R
R
D000328:Adult; D001786:Blood Glucose / Q000378:metabolism; D002096:C-Peptide / Q000097:blood*; D003922:Diabetes Mellitus, Type 1 / Q000097:blood / Q000601:surgery*; D006801:Humans; D016381:Islets of Langerhans Transplantation / Q000379:methods* / Q000502:physiology*; D011168:Portal System; D014184:Transplantation, Homologous; D016896:Treatment Outcome
D001786:Blood Glucose; D002096:C-Peptide