Non-Invasive Diagnostic Panel for MASLD in Children With Obesity

Metabolic dysfunction-associated steatotic liver disease (MASLD) is the most common chronic liver disease of childhood and is closely associated with obesity. Liver biopsy, the histological reference standard, is not ethically acceptable as a routine screening tool in children because it requires general anaesthesia and carries procedural risk and sampling error. The currently used non-invasive screening tools, alanine aminotransferase and ultrasonography, have limited diagnostic accuracy when used alone. An accurate, non-invasive diagnostic approach for pediatric MASLD is therefore needed.

This single-center, prospective, two-group, exploratory pilot diagnostic classification study is conducted at Kayseri City Hospital, Kayseri, Türkiye. Children aged 8 to 18 years with a body mass index at or above the 85th percentile for age and sex, according to Turkish national growth references, are screened consecutively in the pediatric endocrinology outpatient clinic. Enrollment of 180 participants is planned, balanced by sex.

Each participant attends a single study visit of approximately three hours. After a 12-hour fast, a single venous blood sample is obtained for routine biochemistry, insulin, and the serum biomarker panel; serum and plasma aliquots are stored at -80 °C until batched analysis by enzyme-linked immunosorbent assay in duplicate with blinded internal controls. Abdominal ultrasonography is performed for hepatic steatosis grading, and liver stiffness is measured by two-dimensional shear wave elastography. A separate whole-blood sample is used for DNA isolation and genotyping of three MASLD-associated variants, from which a three-variant polygenic risk score is derived. Anthropometric measurements including waist circumference percentile, blood pressure, pubertal staging, and questionnaire-based nutritional and physical activity assessment are recorded at the same visit. No therapeutic intervention is assigned by the study protocol.

Participants are classified as MASLD-positive or MASLD-negative using a composite reference standard based on ultrasonographic steatosis grading together with cardiometabolic risk factor criteria, in accordance with current pediatric guidelines. To avoid incorporation bias, two-dimensional shear wave elastography is used only as a candidate predictor and does not contribute to the reference standard; reference standard assessment is performed blinded to biomarker and genotype results.

The analysis develops a LASSO-regularized logistic regression model combining serum biomarkers, liver stiffness, and the polygenic risk score, with internal validation by bootstrap resampling. Model discrimination is compared with alanine aminotransferase alone and with ultrasonography alone. Reporting will follow the STARD 2015 statement.

Inclusion criteria

• Age 8 to 18 years.
• Body mass index at or above the 85th percentile for age and sex according to Turkish national growth references.
• Hepatic steatosis of grade 1 or higher on abdominal ultrasonography and/or alanine aminotransferase at or above the biology-based upper limit of normal (26 U/L for boys; 22 U/L for girls), or persistent alanine aminotransferase elevation at or above twice the upper limit of normal (50 U/L for boys; 44 U/L for girls).
• At least one cardiometabolic risk factor.
• Written informed consent provided by a parent or legal guardian, with simplified assent for children aged 8 to 11 years and standard assent for children aged 12 years and older.

Exclusion criteria

• Viral hepatitis.
• Autoimmune liver disease.
• Wilson disease, alpha-1 antitrypsin deficiency, or hereditary hemochromatosis.
• Use of hepatotoxic medication, including corticosteroids, methotrexate, valproate, amiodarone, or tamoxifen.
• Fasting duration shorter than 12 hours.
• Active infection, defined as C-reactive protein above 10 mg/L.
• Untreated thyroid disorder, defined as thyroid-stimulating hormone below 0.5 or above 5.
• Total parenteral nutrition.
• Diabetic ketoacidosis.
• Inability to obtain informed consent.