USF Health-led TEDDY analysis focuses on development of multiple distinct autoantibodies targeting insulin-producing cells, from initial autoimmunity to symptomatic disease

TAMPA, Fla. — Children with multiple islet autoantibodies – biological markers of autoimmunity – are more likely to progress to symptomatic type 1 diabetes (T1D) than those who remain positive for a single autoantibody.

Now, new findings from The Environmental Determinants of Diabetes in the Young (TEDDY) study in the U.S. and Europe show that detailed information about the order, timing and type of autoantibodies appearing after the first autoantibody can significantly improve prediction of which children are most likely to progress to type 1 diabetes more rapidly.

The TEDDY analysis was published in the September 2020 issue of Diabetes Care.

“A better understanding of distinct autoantibody spreading is important, because it will allow us to identify at-risk children earlier in the disease process,” said the study’s lead author Kendra Vehik, PhD, a professor of epidemiology at the University of South Florida Health (USF Health) Morsani College of Medicine’s Health Informatics Institute. “That means while children are still asymptomatic, we can start to look at interventions and strategies that may reduce, delay or stop the progression of type 1 diabetes.”

While antibodies are molecules produced by the body’s immune system to detect and destroy specific viruses, bacteria and other harmful substances, autoantibodies are antibodies that target a person’s own healthy tissue. In the case of T1D, a misdirected autoimmune response attacks the pancreas and gradually destroys the organ’s insulin-producing beta cells.

Without the hormone insulin the body cannot regulate its blood sugar levels, which can cause serious, long-term medical complications such as cardiovascular disease, nerve and kidney damage, and vision loss. Children (and adults) with T1D must monitor their dietary intake and exercise and take insulin injections, or use an insulin pump, daily to help control their blood sugar levels.

“Physically and psychologically, it’s a very burdensome disease that needs to be managed every day over a lifetime,” Dr. Vehik said.

Kendra Vehik, PhD, an epidemiologist at the USF Health Informatics Institute, led the TEDDY analysis.

For this TEDDY analysis, eligible children with increased genetic risk for T1D, were followed every three months, from the age of 3 months up to 15 years, for the development of a first-appearing autoantibody directed against pancreatic insulin-producing cells: glutamic acid decarboxylase antibody (GADA), insulin autoantibody (IAA), or insulinoma-associated-protein-2 autoantibody (IA2-2A). The researchers also looked for the subsequent appearance of a second autoantibody and further progression to T1D. Zinc transporter 8 autoantibody(ZnT8A) was only measured in children who developed an IAA, GADA, or IA-2A. These four different autoantibodies are so far the most reliable biological indicators of early T1D, before symptoms become apparent.

Of the 608 study participants – all testing positive for either a first-appearing IAA or GADA — more than half (336) developed a second autoantibody. Furthermore, 53% of these 336 children with a second antibody progressed to T1D within about 3.5 years.  Only about 10% of the 272 children testing positive for a single autoantibody at the end of the follow-up for this study (Dec. 31, 2019) had transitioned to T1D.

Among the key study findings:

• All study participants had high-risk genotypes for T1D. However, those increased-risk children who also had a parent or sibling with T1D were more likely to develop a second-appearing autoantibody than those without a family history.
• The younger the child at the time they tested positive for a first autoantibody, the greater their risk for developing a second autoantibody. Conversely, the risk for T1D decreased if the first autoantibody appeared when the child was older.
• Children testing positive for a second autoantibody, regardless of the type, had at least a five-fold increased risk of progressing to T1D, compared to children who stayed single autoantibody positive. IA-2A, as a second autoantibody, conferred the highest risk, compared with GADA, IAA, or ZnT8A.
• Risk of progression to T1D was influenced by how quickly the second autoantibody appeared. Emergence of a second autoantibody within a year of the first doubled the risk of progression to T1D. Children’s likelihood of developing T1D declined as the months between the first and second-appearing autoantibodies increased.

Better stratifying the risk of progression from the start of autoimmunity to symptomatic disease could help diagnose T1D earlier and offers the opportunity to prevent diabetic ketoacidosis (DKA) and its serious complications by educating parents to watch for early signs, Dr. Vehik said.

“For instance, if a clinician knows that a young child testing positive for IA-2A as their second-appearing autoantibody will be at a higher risk to more rapidly progress to type 1 diabetes, they can reduce the risk of symptomatic onset of disease. Clinicians can also educate the parents about the early signs of disease, such as, weight loss, extreme thirst, more frequent urination, or other DKA symptoms,” she said. “If that happens, the parents will know they should get their child to a doctor or hospital as soon as possible.”

Specific antibody risk profiling can also help identify those at-risk children most likely to benefit from recruitment for T1D prevention trials, Dr. Vehik added.

Dr. Vehik next plans to build upon a previous TEDDY study linking viral behavior with T1D diabetes to test whether prolonged viral infections may environmentally trigger the transition from first- to second-appearing islet autoantibodies in children genetically susceptible to diabetes.

The recently published autoantibody analysis by Dr. Vehik and TEDDY colleagues was funded by National Institute of Diabetes and Digestive and Kidney Diseases grants. USF Health’s Dr. Jeffrey Krischer is the study chair and director of the data coordinating center for the NIH-sponsored TEDDY international multicenter study.

ABOUT TEDDY
The Environmental Determinants of Diabetes in the Young (TEDDY) study is a longitudinal, multinational study examining genetic-environmental causes of type 1 diabetes (T1D). The study follows children at high genetic risk for T1D from birth to 15 years of age at 6 clinical centers in the U.S. and Europe. TEDDY is funded by the National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institute of Allergy and Infectious Diseases (NIAID), Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), National Institute of Environmental Health Sciences (NIEHS), Centers for Disease Control and Prevention (CDC), and JDRF. More information can be found on the TEDDY study website.

The USF-led study may lead to drug therapies to replenish cells destroyed or damaged by diabetes

Tampa, FL (Sept. 23, 2015) — Cells that express neurogenin 3 (NGN3) may one day be harnessed to create a plentiful supply of insulin-producing beta cells for the treatment of diabetes, a study led by researchers at the University of South Florida suggests.

NGN3 is the master gene driving development of the human endocrine pancreas, including the beta cells that make and secrete the hormone insulin, which helps control blood sugar levels. In type 1, or juvenile, diabetes, insulin-producing beta cells are destroyed by the person’s immune system, and patients need insulin injections to survive. Patients with the more common type 2 diabetes, referred to as adult-onset diabetes, produce insulin but their bodies cannot use it properly, and they often require extra insulin.

In a study recently published in the journal PLOS ONE, researchers from the Children’s Research Institute, USF Health Morsani College of Medicine; Johns Hopkins University School of Medicine; and the University of Illinois at Chicago, detected the NGN3 protein in histologically normal pancreatic biopsies from two sources — cadavers and patients requiring biopsy for diagnostic purposes.

Michael Shamblott, PhD

“NGN3 expression in the adult pancreas was unexpected, because it cannot be detected in the adult rodent pancreas – only during fetal development,” said the study’s principal investigator Michael Shamblott, PhD, an endowed chair of pediatrics at the Children’s Research Institute, USF Health Morsani College of Medicine, whose research focuses on regenerative cell therapies to replenish the insulin-producing cells destroyed or damaged by diabetes.

The researchers found NGN3-expressing cells in the exocrine pancreas, the part of the pancreas that produces digestive enzymes.  NGN3-expressing cells closely match the characteristics of both mouse and human endocrine “progenitor” cells that give rise to all and only cells in pancreatic tissue known as islets.  These cells can be collected from cadaveric pancreas tissue or from the patient’s own pancreas and coaxed to resemble beta cells that produce and secrete insulin.

Islet transplantation as a means of reversing diabetes has been hampered by the limited durability of grafts and scarcity of pancreas donors. It can take multiple donors to yield enough islet cells for one recipient and donor tissue is not matched to the recipient so strong immunosuppressive drugs are required to avoid rejection.

“Now that we know these NGN3 cells are a normal part of adult human pancreas biology, we can learn to increase them and to coax them towards becoming differentiated pancreatic endocrine cells by using specific drugs,” Dr. Shamblott said.  “Our goal is to regenerate functional beta cells that can cure diabetes.”

The researchers have also discovered several pathways regulating NGN3 in the adult pancreas, which may be targets of future drug treatments of diabetes, Dr. Shamblott said.

Article citation:
Danielle L. Gomez, Marci O’Driscoll, Timothy P. Sheets, Ralph H. Hruban, Jose Oberholzer, James J. McGarrigle, Michael J. Shamblott, “Neurogenin 3 Expressing Cells in the Human Exocrine Pancreas Have the Capacity for Endocrine Cell Fate,” PLOS ONE, Aug. 19, 2015, DOI: 10.1371/journal.pone.0133862.

About USF Health

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