Factors of islet transplant success: results from the Collaborative Islet Transplant Registry 1999-2010

M. Rickels¹, F.B. Barton², R. Alejandro³, F. Pattou⁴, T. Berney⁵, P. Senior⁶, S. Messinger^3
1 University of Pennsylvania School of Medicine, Philadelphia, PA, USA; ² The EMMES Corporation, Rockville, MD, USA; ³ University of Miami, Miami, FL, USA; ⁴ Lille University, Lille, France; ⁵ Geneva University, Geneva, Switzerland; ⁶ University of Alberta, Edmonton, Canada

Objective: Identifying factors that predict successful outcomes of allogeneic islet transplantation can guide patient selection and management. Data from the Collaborative Islet Transplant Registry (CITR), was used to identify factors of successful outcomes.

Methods:. As of November 2010, 408 islet alone and 73 islet-after-kidney or simultaneous-islet-kidney with 1-6 infusions in 1999-2009 and >1 year follow-up were analyzed by Cox proportional hazards for all available patient, donor, islet and immunosuppression factors on retention of insulin independence >14 days (II), and sustained C-peptide levels >0.3 ng/mL, multivariately at p<0.15.

Results: The favorable factors for II yield an estimated 65% retaining II 5 years post last infusion, compared with 20% of those without (Table 1 and Figure 1). For retention of C-peptide>0.3 ng/mL, favorable factors can effect an 85% rate of C-peptide retention at 5 years (Table 2 and Figure 2) compared to nearly 0% with unfavorable factors.

Conclusions: Patient characteristic selection and carefully selected immunosuppression can effectuate remarkable improvements in outcomes of islet transplantation. Some factors that may favorable for one outcome may not be favorable for others.

Table 1. Final Cox model for retention of insulin independence post last infusion

ITA = islet transplant alone

IAK = islet after kidney / simultaneous islet-kidney

Figure 1. Retention of II (95%CI) with favorable factors (see Table 1) vs. unfavorable factors.

Table 2. Final Cox model for retention of C-peptide>0.3 ng/mL

Figure 2. Retention of C-peptide>0.3 ng/mL (95% CI) with favorable factors (see Table 2) vs. unfavorable factors.