Effect of Semet (80 and 160 mcg) Versus Placebo in Euthyroid Patients With AIT

Study Overview
=================
Brief Summary
-----------------
Over the past 10 years, several clinical studies have suggested that selenium supplementation may influence the natural history of AIT. Recently, Interferon gamma (IFNγ)-inducible chemokines (CXCL-9, -10 and -11) were shown to be elevated in the AIT patients. The aim of this prospective, randomized, controlled study is to evaluate the effect of two different doses of selenomethionine (80 or 160 mcg) versus placebo in euthyroid women with AIT, in terms of reduction of anti-thyroid antibodies and improvement of thyroid hypoechogenicity, over 24 months. Serum levels of selenium, CXCL-9, -10 and -11 and their regulators, Tumor necrosis factor alpha (TNFα) and INFγ, thyroid function and volume and the quality of life of AIT patients are also evaluated.

Official Title
-----------------
Effect of Supplementation of Two Doses of L-selenomethionine (Semet; 80 and 160 mcg) Versus Placebo in Patients With Chronic Autoimmune Thyroiditis (AIT) With Normal Thyroid Function.

Conditions
-----------------
Thyroiditis Autoimmune

Intervention / Treatment
-----------------
* Dietary Supplement: Selenomethionine
* Other: Placebo


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: Diagnosis of chronic autoimmune thyroiditis defined by positivity of anti thyroperoxidase and/or anti thyroglobulin antibodies (> or = 100 U/l) and thyroid hypoechogenicity Exclusion Criteria: Presence of other thyroid disease but micronodules History of the malignancy in the past 5 years Drugs affecting immune system and/or thyroid function Pregnancy detected during screening or follow-up.

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 65 Years

Sexes Eligible for Study
-----------------
Female

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Treatment
Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Placebo Comparator: Placebo<br>Patients randomized to receive same pharmaceutical form (capsule) used for the two Semet groups, with the same excipients but the active drug. | Other: Placebo<br> <br> |
| Active Comparator: 80-Semet<br>Patients randomized to receive selenomethionine at 80 mcg per day. | Dietary Supplement: Selenomethionine<br> <br> |
| Active Comparator: 160-Semet<br>Patients randomized to receive selenomethionine at 160 mcg per day. | Dietary Supplement: Selenomethionine<br> <br> |

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Reduction of anti-thyroid antibodies | Anti thyroperoxidase and thyroglobulin antibodies are measured by a chemiluminescent assay. Any statistically significant decrease of one or both antibody values compared to the baseline is considered a reduction relevant to the study outcome. | 12 months | 
| Improvement of thyroid echogenicity | High-resolution sonograhic images are captured, converted into a spectrum of gray-scale pixels (gsp) ranging from 0 (lowest echogenicity) to 255 (highest echogenicity) and a mean value is then obtained. Any statistically significant increase of the gsp compared to the baseline is considered an improvement relevant to the study outcome. | 12 months | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Prevention or reduction of the incidence of hypothyroidism | Defined by a significant lower number of new subclinical or overt hypothyroidism cases in the two Semet groups compared to the placebo group. | 24 months |