Barriers to Implementation of Teleretinal Diabetic Retinopathy Screening Programs Across the University of California

Aim: To describe barriers to implementation of diabetic retinopathy (DR) teleretinal screening programs and artificial intelligence (AI) integration at the University of California (UC). Methods: Institutional representatives from UC Los Angeles, San Diego, San Francisco, Irvine, and Davis were surveyed for the year of their program's initiation, active status at the time of survey (December 2021), number of primary care clinics involved, screening image quality, types of eye providers, image interpretation turnaround time, and billing codes used. Representatives were asked to rate perceptions toward barriers to teleretinal DR screening and AI implementation using a 5-point Likert scale. Results: Four UC campuses had active DR teleretinal screening programs at the time of survey and screened between 246 and 2,123 patients at 1-6 clinics per campus. Sites reported variation between poor-quality photos (<5% to 15%) and average image interpretation time (1-5 days). Patient education, resource availability, and infrastructural support were identified as barriers to DR teleretinal screening. Cost and integration into existing technology infrastructures were identified as barriers to AI integration in DR screening. Conclusions: Despite the potential to increase access to care, there remain several barriers to widespread implementation of DR teleretinal screening. More research is needed to develop best practices to overcome these barriers

Vesicular monoamine transporter, type 2 (vmat2) expression as it compares to insulin and pancreatic polypeptide in the head, body and tail of the human pancreas

The vesicular monoamine transporter, type 2 (VMAT2) is responsible for sequestering monoamine neurotransmitters into exocytic vesicles in neurons, enterochromaffin-like cells of the stomach and cells arising from the common myeloid progenitor. VMAT2 is also present in the pancreas and is expressed by insulin producing β cells, but not by glucagon or somatostatin expressing islet cells. Positron emission tomography (PET) targeting of VMAT2 is currently being evaluated as a non-invasive tool to measure β cell mass (BCM) in living humans. In recent trials, PET measurements of VMAT2 in the pancreas overestimated BCM in type 1 diabetes (T1D) patients predicted to have little to no BCM by metabolic measures. Recently, tissue immunohistochemistry studies suggested that VMAT2 staining may also co-localize with pancreatic polypeptide (PP) staining cells in pancreas tissue, but these studies were not quantitative. In this report, we evaluated VMAT2 specificity for β cells in sub-regions of the human pancreas using antibodies targeting VMAT2, insulin and PP by double-label immunofluorescence. Immunostaining for VMAT2 and insulin demonstrated 89 ± 8% overlap in the body and tail of the pancreas. However, 44 ± 12% and 53 ± 15% of VMAT2 cells co-stained with PP- and insulin-staining cells, respectively in the pancreatic head. Significant co-staining for VMAT2 and PP cells in the head of the pancreas may partly explain the apparent overestimation of BCM in T1D by PET. Specific targeting of the pancreatic body and tail using VMAT2 PET scanning may reflect BCM more accurately

Anti-PD-L1 therapy and the onset of diabetes mellitus with positive pancreatic autoantibodies.

An 84-year-old woman with metastatic squamous cell carcinoma of the nasopharynx and no history of diabetes was started on the antiprogrammed cell death ligand-1 (anti-PD-L1) antibody durvalumab. Four months later, she presented in diabetic ketoacidosis with glucose 488 mg/dL, anion gap 16, positive serum ketones and A1C9.1%. Antiglutamic acid decarboxylase 65 (GAD) antibody was 13 U/mL (normal, <0.5 U/mL), c-peptide 0.4 ng/dL (normal, 1.1-4.3 ng/mL) and glucose 142 mg/dL. A man with metastatic papillary urothelial carcinoma was treated with the PD-L1 inhibitor atezolizumab. He had no history of diabetes. Nine weeks after initiation, he developed fatigue and polyuria with blood glucose 336 mg/dL, c-peptide 0.6 ng/mL, A1C8.2% and GAD antibodies 28.4 U/mL (normal, <1 U/mL). Due to the diagnosis of autoimmune diabetes, both patients were treated with insulin. Autoimmune diabetes is a rare immune-related adverse effect of PD-L1 inhibitors. We present the first two cases with documented positive pancreatic autoantibodies

MON-345 Hypercalcemia After Placement of Antibiotic-Loaded Calcium Sulfate Beads

Abstract Calcium sulfate beads are used to fill bone voids in bone loss and nonunion, as well as in the management of bone and joint infections.1 Specifically, Stimulan® is an absorbed form of antibiotic-loaded calcium sulfate beads which delivers high local antibiotic concentrations for treatment of infection, but has also been associated with hypercalcemia in 5.4% of cases.1 Despite the significant morbidity associated with hypercalcemia, there is little published literature describing this important complication. In our institution, five patients hospitalized between March 2019 and September 2019 with normal baseline calcium levels developed hypercalcemia as a complication of Stimulan® placement. Typically, 10 to 60 cc of Stimulan® were inserted in each surgery, with the exception of 120cc in one surgery. Three patients required a second surgery with antibiotic bead placement, and hypercalcemia occurred with both initial and subsequent surgeries. The onset of hypercalcemia varied from post-operative day one to four. The peak corrected calcium was 10.7-16.1 mg/dL which corresponded to ionized calcium of 1.57 to &amp;gt;2.20 mmol/L (normal 1.09-1.29 mmol/L). The patient with the highest bead volume had the highest calcium. Calcium peaked on post-operative days three to five. Patients were treated with intravenous fluids, furosemide, calcitonin and anti-resorptives including denosumab and zoledronic acid. Four patients required hemodialysis. Three patients required dialysis for symptomatic hypercalcemia and in one patient the indication was multifactorial. Calcium typically normalized by post-operative day 14 to 21, but hypercalcemia duration was unknown in two patients (one died; one had hypercalcemia on hospital discharge). As illustrated in our cases, patients who develop hypercalcemia after their initial antibiotic bead placement may be at risk for recurrent hypercalcemia if additional surgeries use antibiotic beads. Higher bead volume may be associated with more significant hypercalcemia.1 Although previous cases have reported milder hypercalcemia, our cases demonstrate that hypercalcemia can be more severe and prolonged, necessitating dialysis in addition to traditional therapies. 1-3 References: 1.Kallala R, Harris WE, Ibrahim M, Dipane M, McPherson E. Use of Stimulan absorbable calcium sulphate beads in revision lower limb arthroplasty: Safety profile and complication rates. Bone Joint Res. 2018 Nov 3;7(10):570-579. 2.Kallala R, Haddad FS. Hypercalcaemia following the use of antibiotic-eluting absorbable calcium sulphate beads in revision arthroplasty for infection. Bone Joint J. 2015 Sep;97-B(9):1237-41. 3.Carlson Jr. CR, Markulis E, Thompson E, Havill J. A novel case of hypercalcemia following the use of calcium sulfate beads. Nephrol Open J. 2015; 1(1): 17-19.</jats:p