A regional study has found that saliva-based screening can be leveraged to determine genetic risk scores for developing type 1 diabetes (T1D). Research results were published in Genome Medicine.
The increased interest in screening for genetic risk for T1D is driven by a variety of factors, including a growing understanding of the genetics associated with T1D, the utility of islet autoantibody screening for risk prediction, and the introduction of immune interventions. The researchers explained that
“early detection” [T1D] Its importance is increasing with the development of immune interventions (e.g., FDA-approved teplizumab in stage 2 disease).Our study shows that T1D [genetic risk score] “This approach is feasible at a population level in the United States, based on the acceptance of saliva sampling as a non-invasive application,” the researchers explained. “In the future, at-home saliva collection kits for DNA/genotyping and minimal blood collection kits for islet autoantibody testing will be available for self-return by medical staff, school staff, or by mail. Adherence to screening guidelines is likely to be enhanced through distribution and use by public health services.”
Type 1 diabetes | Image credit: © Vitalii Vodolazskyi – Stock.adobe.com
Launched at the end of 2016, the Personalized Medicine for Diabetes (PrIMeD) program was launched to pilot population screening for T1D risk. Researchers recruited more than 3,800 children from eight different comprehensive pediatric and specialty centers in Virginia. The group noted that their cohort had diverse ancestry and children ranging in age from 2 to 16 years old.
Genetic risk was determined using minimally invasive saliva screening for each patient. Overall, her 14.2% of patients in the group were considered to be at “high genetic risk.” The majority of these patients (91.1%) were of Caucasian descent, 9.6% were Black or African American, and 1.9% were of Asian descent.
Of the 91 children who already had T1D at the time of the study, about half (52%) had a “high genetic risk.” The researchers say this finding is consistent with previous evidence showing that about 50% of T1D risk is due to genetic factors. The same group found no significant association between genetic risk score and age at onset of T1D.
Of the 494 patients who did not have T1S and had high genetic risk scores, only a minority underwent autoantibody screening. Researchers noted that the test is largely underutilized during the coronavirus pandemic because it requires a blood draw. Of the 28 people who provided samples for islet autoantibody testing, 89.3% were negative for all islet antibodies.
Two patients tested positive for at least two islet autoantibodies (GADA, IAA, ZnT8A) and were recommended to inform their physician and undergo monitoring. Her one other patient tested positive for one islet autoantibody and was recommended to be tested again in 1 year.
“The implementation of PrIMeD was expensive, and so was the cost of clinical research coordinators to staff each clinic. However, there is evidence that investing in T1D screening can be cost-effective. ,” the researchers wrote. “Estimated to cost $4,700 per T1D detection in children and adolescents enrolled in screening programs, and $14,000 per case for routine screening in Denver, Colorado. Together, we saw a 0.1% improvement in T1D, which would require HbA1c levels for this program to reach a value threshold of $50,000 to $150,000 per quality-adjusted life year.”
They note that the current costs of gene panels and islet autoantibody surveillance will need to be lowered for this approach to be cost-effective, but the option of at-home islet autoantibody testing by mail rather than a blood draw It pointed out that the recent introduction of this could increase the cost of testing. Proportion of patients undergoing further evaluation for T1D.
reference
Gartin K, Repaske D, Taylor J et al. Implementing type 1 diabetes genetic risk screening in children from diverse communities: The Virginia PrIMeD project. genome med. Published online on February 14, 2024. doi:10.1186/s13073-024-01305-8