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T and B Cells in Graves' Orbitopathy

NCT03195296 · Status: COMPLETED · Type: OBSERVATIONAL · Enrollment: 20

Last updated 2018-02-12

No results posted yet for this study

Summary

Graves orbitopathy (GO) is an inflammatory eye disease associated in 95% of patients with Graves' hyperthyroidism (GH), in \~3-4% with hypothyroid autoimmune thyroiditis, and in \~1-2% with thyroid autoimmunity in the absence of thyroid dysfunction, the former known as euthyroid GO. The pathogenesis of GO is autoimmune, with the TSH-receptor being considered the major autoantigen, thereby establishing a pathogenetic link between the thyroid and orbital tissue. Thus, TSH-receptor is expressed by orbital fibroblasts, where it forms a complex with the IGF-1 receptor. Unlike GH, which is notoriously caused by TSH-receptor stimulating autoantibodies, GO is believed to reflect cell-mediated autoimmunity, as suggested by studies showing a Th1-like pattern of cytokine release by primary cultures of orbital infiltrating lymphocytes from GO patients. On the other hand, a role of B lymphocytes has emerged in recent years based on the observation that the anti-CD20 monoclonal antibody rituximab has a beneficial effect on GO activity, as demonstrated by a recent randomized clinical trial in which rituximab was compared with intravenous glucocorticoids (GC), being the former the standard treatment of moderately-severe GO. The explanation for the findings was that B lymphocytes are involved in the pathogenesis of GO as antigen-presenting cells. However, in spite of the above mentioned promising observations, another randomized clinical trial in which rituximab was compared with placebo provided opposite results. Thus, rituximab had no effect at all on GO. Data from the two studies were confronted and major differences between the two cohorts emerged, especially concerning GO activity, leading to the conclusion that rituximab may be effective for active, but not for inactive GO. Rituximab has been employed also for autoimmune diseases other than GO, including type 1 diabetes. In the former, it was shown that the effectiveness of rituximab paralleled the presence of CD20-positive infiltrating lymphocytes in pancreas islets. We therefore postulated that something similar may occur in GO, because of which we planned the present, perspective, observational study, aimed at determining the presence and immunohistochemical features of lymphocytes infiltrating orbital tissues in patients with GO and to relate them with the clinical features of GO.

Conditions

  • Graves Ophthalmopathy

Interventions

OTHER

No intervention

No intervention related to the study is foreseen

Sponsors & Collaborators

  • University of Pisa

    lead OTHER

Principal Investigators

  • Michele Marinò, MD · University of Pisa

Eligibility

Min Age
18 Years
Max Age
80 Years
Sex
ALL
Healthy Volunteers
No

Timeline & Regulatory

Start
2017-01-01
Primary Completion
2017-05-31
Completion
2017-05-31

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Read the full study record

This page highlights key information. For complete eligibility criteria, study locations, investigator contacts, and the full protocol, visit the original record on ClinicalTrials.gov.

View NCT03195296 on ClinicalTrials.gov