An observational study in Autoimmune Thyroiditis, sponsored by Sehit Prof. Dr. Ilhan Varank Sancaktepe Training and Research Hospital. Completed at 1 site in Turkey (Türkiye). Open to participants aged 18 Years to 80 Years. Per ClinicalTrials.gov, last updated 2026-11-05.
Sponsored by Sehit Prof. Dr. Ilhan Varank Sancaktepe Training and Research Hospital · Observational
Hashimoto's thyroiditis (HT) is the most common autoimmune thyroid disease and is increasingly recognized as a condition associated with chronic low-grade systemic inflammation beyond thyroid hormone dysfunction. The soluble α-Klotho-fibroblast growth factor 23 (FGF23) axis plays a central role in mineral metabolism, inflammation, and aging-related pathways; however, its involvement in HT has not been adequately characterized.
This prospective case-control study aims to compare serum soluble α-Klotho and FGF23 levels between adults with Hashimoto's thyroiditis and age- and sex-matched healthy controls, and to investigate their associations with thyroid function parameters, inflammatory markers, and autoimmune burden. In addition, the FGF23/sKlotho ratio will be evaluated as an integrated marker of functional imbalance within the Klotho-FGF23 axis.
The study seeks to determine whether Hashimoto's thyroiditis is associated with systemic dysregulation of the Klotho-FGF23 pathway independent of renal function and mineral metabolism.
Hashimoto's thyroiditis (HT) is a chronic autoimmune disease characterized by lymphocytic infiltration of the thyroid gland and the presence of anti-thyroid peroxidase (anti-TPO) and anti-thyroglobulin (anti-TG) antibodies. While traditionally defined by thyroid hormone dysfunction, emerging evidence suggests that HT is associated with persistent immune activation, oxidative stress, and low-grade systemic inflammation.
The α-Klotho-FGF23 axis is an endocrine pathway involved in phosphate metabolism, vitamin D regulation, inflammation, and aging-related biological processes. Soluble α-Klotho (sKlotho) exerts anti-inflammatory and anti-oxidative effects, whereas FGF23 is increasingly recognized as a hormone influenced by inflammatory stimuli. Dysregulation of this axis has been reported in various chronic inflammatory conditions; however, data in autoimmune thyroid disease are limited.
This prospective, single-center case-control study will include adult patients with Hashimoto's thyroiditis and healthy controls without thyroid or systemic autoimmune disease. Serum soluble α-Klotho and FGF23 levels will be measured using enzyme-linked immunosorbent assay (ELISA). Clinical data including thyroid function tests (TSH, free T4), thyroid autoantibodies (anti-TPO, anti-TG), renal function parameters, mineral metabolism markers (calcium, phosphorus, 25-hydroxyvitamin D), and C-reactive protein (CRP) will be recorded.
Primary analyses will compare sKlotho and FGF23 levels between groups. Secondary analyses will evaluate associations between these biomarkers and autoimmune burden (anti-TG levels), inflammatory status (CRP), and thyroid function. Multivariable regression models will be used to determine independent associations after adjustment for potential confounders.
The study also aims to evaluate the FGF23/sKlotho ratio as an integrated indicator of functional imbalance within the Klotho-FGF23 axis in Hashimoto's thyroiditis.
27 studies on the registry are indexed under Thyroiditis, Autoimmune; 4 are open to participants now.
Browse Thyroiditis, Autoimmune studies →Sehit Prof. Dr. Ilhan Varank Sancaktepe Training and Research Hospital is the lead sponsor of 41 studies on the registry; 14 are open to participants now.
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The criteria were revised on the registry on Nov 5, 2026. See what changed
Adult participants aged 18-65 years will be recruited from the endocrinology outpatient clinic of a tertiary care center. The study population will consist of patients diagnosed with Hashimoto's thyroiditis and age- and sex-matched healthy controls without thyroid or systemic autoimmune disease. All participants will undergo baseline clinical evaluation and venous blood sampling for measurement of soluble α-Klotho and FGF23 levels, along with routine laboratory parameters.
Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Autoimmune disease
A condition in which the immune system attacks the body’s own tissues, such as rheumatoid arthritis, lupus, psoriasis, type 1 diabetes or inflammatory bowel disease.
Immunotherapy studies often leave out active autoimmune disease, and some name exceptions, such as thyroid disease on replacement hormone. Check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
GFR and eGFR (kidney filtering)
GFR (glomerular filtration rate) is how much blood the kidneys filter each minute. It is usually estimated from a blood test — eGFR, by formulas such as CKD-EPI or MDRD — and some studies ask for it to be measured directly instead. Usually given in mL/min/1.73 m².
Check the method, the units and the minimum the study states. A value of 90 or above is in the normal-or-high range, but kidney damage can show in other tests too.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Cancer (malignancy)
Malignancy means cancer. Criteria about another or earlier malignancy ask whether you have had a different cancer, usually within a set number of years.
Some are commonly allowed, such as treated skin cancers other than melanoma and early cancers removed completely — check the exceptions this study lists.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Corticosteroids (steroids)
Anti-inflammatory medicines such as prednisone, prednisolone and dexamethasone — not the anabolic steroids used for muscle.
Studies differ in what they allow: check which steroid medicines, routes (tablets, injections, creams, inhalers, eye drops) and doses this study accepts.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Immunosuppression
A weakened immune system. It can come from an illness, such as HIV or some blood cancers, or from medicines that turn the immune system down, for example after an organ transplant or for an autoimmune disease; steroids at higher doses count.
Read whether the line is about a condition or about medicines, and which medicines and doses it means.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Adults aged 18-65 years diagnosed with Hashimoto's thyroiditis based on clinical evaluation, thyroid function tests, and positive anti-thyroid peroxidase (anti-TPO) and/or anti-thyroglobulin (anti-TG) antibodies. Participants may be euthyroid or hypothyroid. Serum soluble α-Klotho and FGF23 levels will be measured. Clinical, inflammatory, renal, and mineral metabolism parameters will be recorded.
Other: Blood Sampling and Biomarker Measurement
Age- and sex-matched adults without a history of thyroid disease, autoimmune disorders, chronic kidney disease, or chronic systemic illness. Participants will have normal thyroid function tests. Serum soluble α-Klotho and FGF23 levels will be measured, and clinical laboratory parameters will be recorded for comparison.
Other: Blood Sampling and Biomarker Measurement
Venous blood sampling for measurement of serum soluble α-Klotho and fibroblast growth factor 23 (FGF23) levels using enzyme-linked immunosorbent assay (ELISA). No therapeutic intervention is administered.
Difference in Serum Soluble α-Klotho Levels Between Hashimoto's Thyroiditis and Healthy Controls
Time frame: Baseline
Plan to share: No
No publications or documents are linked to this record.
Ran from Mar 2026 to primary completion in May 2026, 2 months.
How these figures are worked out, and which studies are left out of them.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
This study is completed, as verified in Nov 2026. You cannot join it, but the record below documents what was studied.
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Sehit Prof. Dr. Ilhan Varank Sancaktepe Training and Research Hospital