Exploration of autoantibody responses in canine diabetes using protein arrays

Abstract

Canine diabetes has been considered a potential model of human type 1 diabetes (T1D), however the detection of autoantibodies common in humans with T1D in affected dogs is inconsistent. The aim of this study was to compare autoantibody responses in diabetic and healthy control dogs using a novel nucleic acid programmable protein array (NAPPA) platform. We performed a cross-sectional study of autoantibody profiles of 30 diabetic and 30 healthy control dogs of various breeds. Seventeen hundred human proteins related to the pancreas or diabetes were displayed on NAPPA arrays and interrogated with canine sera. The median normalized intensity (MNI) for each protein was calculated, and results were compared between groups to identify candidate autoantibodies. At a specificity of 90%, six autoantibodies had sensitivity greater than 10% (range 13–20%) for distinguishing diabetic and control groups. A combination of three antibodies (anti-KANK2, anti-GLI1, anti-SUMO2) resulted in a sensitivity of 37% (95% confidence interval (CI) 0.17–0.67%) at 90% specificity and an area under the receiver operating characteristics curve of 0.66 (95% CI 0.52–0.80). While this study does not provide conclusive support for autoimmunity as an underlying cause of diabetes in dogs, future studies should consider the use of canine specific proteins in larger numbers of dogs of breeds at high risk for diabetes.

Canine diabetes mellitus demonstrates multiple markers of chronic inflammation including Th40 cell increases and elevated systemic-immune inflammation index, consistent with autoimmune dysregulation

“…As reported for laboratory mice and human diabetic subjects, CDM dogs had significantly (p < 0.0001) increased Th40 cell numbers ( Figure 4A ). Unlike the reports for variable and highly inconsistent levels of autoantibodies in CDM ( 3 , 9 ) Th40 cells were universally increased in CDM. PBMC were analyzed for CD3 and then CD4 + CD40 + within the CD3 gated subset ( Figure 4A for controls and 4B for CDM).…”

“…In human disease, GAD and IA-2 auto antibodies are associated with LADA ( 37 ). An exploration of Aab comparing 30 healthy controls and 30 CDM dogs found that at a specificity of 90%, six autoantibodies had sensitivity greater than 10% ( 9 ). To attempt to address the lack of Aab in CDM a novel array technique that queried 1700 pancreatic proteins was only able to identify 6 autoantibodies with sensitivity greater than 10% ( 9 ).…”

“…Studies showed that GAD65 antibodies were detected in 0 -13% of CD, 0 – 10% tested positive for IA2 antibodies and 0% tested positive for Zinc transporter 8 antibodies ( 8 ). A recent study used a nucleic acid programmable protein array platform to query 1700 pancreatic proteins as possible antigens for canine antibodies ( 9 ). In that study 6 autoantibodies were identified that had sensitivity greater than 10% ( 9 ).…”

“…A recent study used a nucleic acid programmable protein array platform to query 1700 pancreatic proteins as possible antigens for canine antibodies ( 9 ). In that study 6 autoantibodies were identified that had sensitivity greater than 10% ( 9 ). Given the difficulty with auto antibody detection in CDM, alternate diagnostic approaches should be developed.…”

Antidiabetic effects of Andrographis paniculata supplementation on biochemical parameters, inflammatory responses, and oxidative stress in canine diabetes

“…Furthermore, the findings of the current study were inconsistent with those of other rodent studies, which reported lowered glucose levels and decreased DM complications after treatment with A. paniculata and andrographolide ( Yu et al, 2003 ; Lee et al, 2010 ; Nugroho et al, 2012 ; Ji et al, 2016 ; Islam, 2017 ; Naik et al, 2017 ; Wediasari et al, 2020 ; Mehta et al, 2021 ; Syukri et al, 2021 ). However, the DM in rodents was chemically induced with streptozotocin or alloxan, which promotes cell death and decreases insulin production; this is different from the canine DM produced by chronic autoantibody destruction over a long period ( Al-awar et al, 2016 ; Furman, 2021 ; O’Kell et al, 2022 ). A. paniculata treatment was reported to lead to beneficial outcomes in insulin-resistant obese mice, a model for type 2 diabetes (T2DM), which is not frequent in dogs ( Catchpole et al, 2005 ; Akhtar et al, 2016 ; Heydemann, 2016 ; Chen et al, 2020 ).…”