Diabetes Care, Vol 17, Issue 9 988-993, Copyright © 1994 by American Diabetes Association
Anti-insulin antibodies are a cause of hypoglycemia following pancreas transplantation
MP Tran, JL Larsen, WC Duckworth, EI Ruby, SA Miller, K Frisbie, RJ Taylor and RJ Stratta
Department of Surgery, University of Nebraska Medical Center, Omaha 68198-3020.
OBJECTIVE--Hypoglycemic symptoms have been reported by more than half of
pancreas transplantation (PTX) recipients. To better understand the
mechanism for the hypoglycemia documented in some of these patients, we
studied the glucose and pancreatic hormone response to Sustacal in patients
with and without hypoglycemia following PTX. RESEARCH DESIGN AND
METHODS--Twelve patients with established, repeated episodes of
hypoglycemia following PTX (hypo) were case-matched to PTX recipients
without hypoglycemic symptoms (control; n = 7). On the day of the study,
fasting glucose, free and total immunoreactive insulin (IRI), C-peptide,
proinsulin, and glucagon were drawn (time 0); Sustacal was administered;
and glucose, free and total IRI, and C-peptide were assayed at 15, 30, 45,
75, 120, 150, 180, and 240 min. Based on the glucose response to Sustacal,
the hypo group was further divided into those whose glucose rose after
Sustacal (hypo-high; n = 7) and those with no increase in glucose from
baseline concentration (hypo-flat; n = 5). RESULTS--Before the
administration of Sustacal, the hypo-high group had a lower fasting
free/total IRI (0.26 +/- 0.06, mean +/- SE) than the hypo-flat (0.51 +/-
0.02) or control (0.52 +/- 0.04) groups (both P < 0.05 compared with
hypo-high). The glucose response to Sustacal was greatest in the hypo-high
group as defined. Area under the curve (AUC) for total IRI following
Sustacal was also greatest in the hypo-high group (P < 0.05 compared
with both control and hypo-flat groups), but there was no significant
difference in free IRI AUC following Sustacal between the three groups. Two
individuals developed hypoglycemia during the Sustacal challenge, both in
the hypo-high group. CONCLUSIONS--The lower fasting free/total IRI ratio
and greater increase in glucose and total IRI in response to Sustacal in
the hypo-high group compared with either the hypo-flat or control groups
are consistent with the presence of significant quantities of anti-insulin
antibodies in the hypo-high group. Because anti-insulin antibodies are, in
turn, an established cause of episodic hypoglycemia, this study provides
the first data to support the hypothesis that significant quantities of
anti-insulin antibodies are a cause of symptomatic hypoglycemia following
PTX in some recipients.