Modern endocrinology is shifting from reactive treatment toward proactive identification of autoimmune diabetes. Clinicians can now detect preclinical type 1 diabetes long before classic symptoms and life-threatening complications emerge. The Spanish Diabetes Society, Spanish Society of Endocrinology and Nutrition, and Spanish Society of Paediatric Endocrinology recently formulated an Integrated Care Pathway. This consensus establishes an evaluable clinical framework for screening, staging, and longitudinal management across pediatric and adult healthcare settings.

Understanding the Staging Framework of Preclinical Type 1 Diabetes

Traditionally, medical teams diagnosed autoimmune diabetes only after severe beta-cell loss triggered classic symptoms or diabetic ketoacidosis. However, contemporary scientific evidence reveals that autoimmunity progresses silently through well-defined preclinical phases. The SED-SEEN-SEEP consensus embraces the established three-stage classification to guide proactive clinical decision-making. Specifically, Stage 1 defines normoglycemic individuals who demonstrate persistent positivity for two or more islet autoantibodies. These individuals maintain normal glucose homeostasis, yet their lifetime progression risk approaches one hundred percent. Subsequently, Stage 2 occurs when persistent islet autoimmunity coincides with dysglycemia. In this phase, patients exhibit impaired fasting glucose, impaired glucose tolerance, or elevated glycated hemoglobin levels. Although patients remain asymptomatic, progressive beta-cell destruction impairs dynamic insulin secretion. Finally, Stage 3 corresponds to traditional clinical onset marked by overt hyperglycemia, weight loss, polyuria, and polydipsia. Therefore, staging preclinical type 1 diabetes provides an actionable window for preventive intervention. Clinicians can identify vulnerable individuals years before metabolic decompensation. By systematically categorizing these stages, healthcare teams can tailor monitoring frequency, deliver targeted education, and evaluate candidates for emerging immunotherapies.

Target Screening Strategies and Autoantibody Profiling

Effective identification of preclinical autoimmunity requires structured and reliable screening methodologies. The consensus defines target population identification as the initial core sub-process. Currently, first-degree relatives of individuals with type 1 diabetes represent the highest-yield target cohort for initial screening. Moreover, individuals with personal histories of autoimmune endocrinopathies or celiac disease warrant heightened clinical suspicion. Testing begins with validated biochemical assays detecting key islet autoantibodies. These include antibodies directed against insulin, glutamic acid decarboxylase, insulinoma-associated protein 2, and zinc transporter 8. Consequently, clinicians must ensure testing occurs in certified laboratories maintaining high analytical specificity. A single positive antibody test does not confirm Stage 1 disease. Instead, the care pathway mandates a confirmatory venous blood sample to rule out transient laboratory positivity. Furthermore, individuals with a confirmed single autoantibody require periodic re-testing, as they may seroconvert to multiple antibodies over time. Conversely, the confirmed presence of two or more autoantibodies indicates irreversible beta-cell autoimmunity. Thus, implementing standardized autoantibody profiling avoids clinical ambiguity. It establishes a definitive baseline for proactive monitoring and prevents unnecessary anxiety through rigorous confirmatory protocols.

Diagnostic Confirmation and Metabolic Staging Protocols

Once clinicians confirm persistent multi-autoantibody positivity, the immediate priority shifts to accurate metabolic staging. The care pathway defines this transition through structured glycemic evaluations. Specifically, clinicians must perform an oral glucose tolerance test alongside baseline glycated hemoglobin measurements. An oral glucose tolerance test remains the gold standard to differentiate Stage 1 from Stage 2 preclinical disease. Patients with normal fasting plasma glucose and two-hour post-load glucose under 140 mg/dL remain in Stage 1. However, individuals showing impaired fasting glucose or two-hour values between 140 and 199 mg/dL progress to Stage 2. Additionally, continuous glucose monitoring plays an expanding role in clinical evaluation. Continuous glucose sensors capture glycemic variability and intermittent postprandial excursions that standard tests might miss. Notably, spending more than ten percent of sensor time above 140 mg/dL strongly correlates with rapid clinical progression. Healthcare professionals must repeat metabolic assessments at structured intervals depending on patient age and specific antibody titers. Younger children, in particular, demonstrate faster progression rates and require closer surveillance. Therefore, systematic metabolic staging prevents sudden symptomatic deterioration, guiding precise clinical interventions.

Clinical Follow-Up and Timely Therapeutic Intervention

Longitudinal clinical follow-up constitutes the third core sub-process within the integrated care pathway. Managing presymptomatic autoimmunity demands multidisciplinary collaboration among pediatric endocrinologists, adult endocrinologists, primary care physicians, and specialized diabetes educators. Furthermore, the consensus emphasizes proactive patient and family education regarding the cardinal signs of hyperglycemia. Families learn to recognize fatigue, unintended weight loss, enuresis, and polydipsia immediately. Consequently, this structured surveillance dramatically reduces diabetic ketoacidosis rates at diagnosis from over forty percent to below five percent. Moreover, early identification enables timely consideration of disease-modifying immunotherapies. Monoclonal anti-CD3 antibodies, such as teplizumab, can delay the onset of Stage 3 clinical diabetes by several years in eligible individuals aged eight and older. Administering these therapies during Stage 2 preserves residual endogenous beta-cell function and extends endogenous insulin production. Additionally, regular follow-up visits allow clinicians to evaluate psychological well-being and provide ongoing psychosocial counseling. Navigating a preclinical diagnosis can cause significant emotional distress for families. Therefore, structured clinical follow-up provides holistic support, balancing vigilant metabolic surveillance with empathetic psychological care.

Information Systems and Pathway Performance Indicators

The consensus establishes a transversal support sub-process to ensure that the clinical care pathway remains scalable, equitable, and measurable. Seamless electronic health record integration connects primary care clinics with tertiary endocrinology referral centers. Specifically, shared registry platforms alert primary care clinicians when high-risk individuals require routine screening or annual follow-up testing. Furthermore, automated tracking systems prevent loss to follow-up, ensuring continuous surveillance during critical transition phases, such as adolescence. To evaluate program success, the pathway incorporates concrete clinical performance indicators. These metrics track the proportion of eligible relatives screened, confirmation rates of positive results, and compliance with staging protocols. Additionally, healthcare institutions must audit the incidence of diabetic ketoacidosis among newly diagnosed Stage 3 patients. A low ketoacidosis rate serves as the ultimate benchmark of pathway effectiveness. Quality audits also assess patient satisfaction, educational retention, and equitable access across socioeconomic backgrounds. Thus, integrating robust information systems transforms screening guidelines into an accountable clinical reality. This structured framework allows healthcare organizations to continuously refine their workflows, optimize resource allocation, and sustain high standards of personalized care.

Frequently Asked Questions

What are the primary stages of preclinical type 1 diabetes?

The classification divides early disease into three distinct clinical stages. Stage 1 involves the detection of two or more islet autoantibodies with strictly normal blood glucose levels. Furthermore, Stage 2 features persistent autoantibodies alongside emerging dysglycemia or impaired glucose tolerance. Stage 3 marks clinical onset with overt symptomatic hyperglycemia. Therefore, structured staging allows clinicians to assess progression risk accurately, initiate timely metabolic monitoring, and offer approved disease-modifying therapies before acute metabolic decompensation occurs.

Who should undergo targeted screening for islet autoantibodies?

Currently, international guidelines recommend targeted screening for individuals at heightened genetic risk. Specifically, first-degree relatives of individuals with established type 1 diabetes represent the primary screening group. Moreover, clinicians can screen children presenting with other autoimmune conditions, such as celiac disease or autoimmune thyroiditis. Emerging population-based programs also evaluate general pediatric cohorts. Identifying these high-risk candidates enables early autoantibody confirmation, structured surveillance, proactive patient education, and prevention of severe diabetic ketoacidosis.

How does early identification prevent diabetic ketoacidosis?

Early identification prevents acute diabetic ketoacidosis through comprehensive patient and family education. When clinicians recognize presymptomatic autoimmunity, they teach families to identify early signs of hyperglycemia promptly. Additionally, routine glycemic surveillance detects rising glucose levels well before severe metabolic crisis develops. Consequently, medical teams can start low-dose insulin therapy or disease-modifying immunotherapies in an elective, controlled outpatient environment, which substantially lowers hospital admissions and long-term neurocognitive complications associated with acute ketoacidosis.

Disclaimer: This content is for informational and educational purposes only... Refer to the latest local and national guidelines for clinical practice.

References

1. Gómez Gila AL et al. Executive summary of the Integrated Clinical care pathway for the detection and management of preclinical stages of type 1 diabetes: SED-SEEN-SEEP consensus. An Pediatr (Engl Ed). 2026 Sep 18. doi: undefined. PMID: 42760247.
2. Martínez-Brocca MA, Bellido V, Cardona-Hernandez R, et al. Screening, staging and follow-up of type 1 diabetes in preclinical stages: consensus of the scientific societies SED, SEEN and SEEP. An Pediatr (Engl Ed). 2025;103(5):503944.
3. Phillip M, Achenbach P, Addala A, et al. Consensus statement on the screening and management of preclinical type 1 diabetes. Diabetologia. 2024;67(12):2580-2601.