Need to identify risk of developing type 1 diabetes? Test for autoantibodies!

Key Takeaway

Screening for risk of T1D provides an opportunity to intervene with therapy to delay the onset of clinical symptoms^2-5

The ability to detect and quantify the risk of developing T1D allow predicting the rate of progression to symptomatic disease with considerable accuracy.²

The risk of T1D is 15-fold higher among relatives of people with T1D compared to those without a family history of the disease.⁵

About 95% relatives of individuals with T1D often test negative after screening for autoantibodies, providing reassurance to families.⁵

Why screen for autoantibodies?

T1D is associated with the appearance of autoantibodies many months or years before symptom onset.¹ Decline in beta-cell function occurs in four distinct stages and by the time clinical symptoms manifest, significant beta-cell loss has typically occurred.^1,2 Screening for autoantibodies is important for early detection of beta-cell destruction and provides patients/caregivers with opportunity to access healthcare providers to help them prepare and develop skills for better management of T1D.^2,5,6

The autoantibodies detected in T1D include:^1,2

• Glutamic acid decarboxylase autoantibodies (GADA)
• Insulinoma-associated-2 autoantibodies (IA-2A)
• Insulin autoantibodies (IAA)
• Zinc transporter 8 autoantibodies (ZnT8A) 

Stages of T1D depicting progressing beta-cell function decline²

How the presence of islet autoantibody determines risk of T1D?

The number of detectable autoantibodies through screening correlates with risk of developing T1D.^2,6 The majority of individuals with a single autoantibody do not progress to T1D.⁷ However, presence of two or more autoantibodies increases the risk of progression to clinical T1D to 70% over 10 years and 100% over lifetime.⁶

Risk of progression to autoimmune T1D after seroconversion to islet autoantibody positivity⁶

Who should be screened for islet autoantibodies?

Individuals with a family history of T1D are at greater risk of developing the disease, with up to a 15-fold increased risk if a first-degree relative has T1D.⁵ Additionally, individuals with certain other associated autoimmune diseases (e.g., coeliac disease and autoimmune thyroiditis) and adults with abnormal glucose levels with a low BMI (<25 kg/m2) or aged <35 years are also likely to develop T1D.^9,10.
 

Explore the connection between T1D and other associated autoimmune conditions in this article.

BMI, body mass index; FDR, first-degree relative; HLA, human leukocyte antigen; T1D, type 1 diabetes.

Figure adapted from Sims EK, Besser REJ, Dayan C, et al; NIDDK Type 1 Diabetes TrialNet Study Group. Screening for type 1 diabetes in the general population: A status report and perspective. Diabetes. 2022;71(4):610-623.

What is the right age for screening for T1D?

Although T1D can manifest at any age, it most commonly occurs in children, teenagers, or young adults.^1,11 Autoantibodies often emerge before the age of 6, even in cases where T1D is diagnosed much later in childhood. Screening for islet autoantibodies at ages of 2 and 6 has proven to be sensitive and efficient in predicting T1D.¹²

What are the benefits of screening for T1D?

Screening individuals shows that approximately 95% of relatives of individuals with T1D test negative for autoantibodies, which can provide reassurance, especially to families with an affected member.⁵

In individuals who test positive for autoantibodies, screening leads to early detection of T1D, which in turn:⁶

• Can prevent diabetes ketoacidosis, a life-threatening complication of diabetes.
• Provide preparation time to patients and caregivers to develop skills to manage T1D.
• Enable access to medical care to provide ongoing education and monitoring.

Know more about the monitoring of people screened positive for ≥1 islet autoantibodies in this article.