Checkpoint inhibitor associated autoimmune diabetes (CIADM) is a new subtype of type 1 diabetes (T1DM) that arises as a rare complication of immune checkpoint inhibitor (ICI) therapy. Data regarding this condition to date is limited to case reports and small case series.
We systematically review published evidence to identify presentation characteristics and risk factors for CIADM.
From the literature, 220 patients were identified. Mean age was 63.7years (±12.4), mean BMI was 24.7±6.6kg/m2 and 60% of patients were male. Pre-existing type 2 diabetes was present in 8.6%, with 4.5% requiring oral agents. All but 1 patient (99.5%) had prior exposure to either anti-PD1 or anti-PDL1 therapy. One patient had only anti-CTLA4 exposure. Median time from ICI to CIADM onset was 12 weeks (IQR 6-24). At presentation DKA was present in 69.2% and C-peptide was 0.13±0.2nmol/L. Other immune adverse events occurred in 45.4%, with thyroiditis in 18.1%.
T1DM autoantibodies were present in 40.7% (73/179), with anti-GAD being the commonest in 37.4%. T1DM autoantibody positivity was associated with DKA (p=0.003) and faster time to CIADM onset (p=0.002). Of the 88 patients with HLA haplotyping performed, 63.6% had susceptibility haplotypes for T1DM, and 9.0% patients had protective haplotypes.
CIADM commonly presents in DKA and T1DM autoantibody positivity is associated with earlier and more severe presentations.