Determination of Genetic Susceptibility in Severe Recurrences of Ocular Toxoplasmosis (TREXO)

Ocular toxoplasmosis (OT) is a major cause of visual impairment worldwide. OT is responsible for 30 to 50% of posterior uveitis. It is characterized by dormant infections that may reactivate without known reasons, causing severe irreversible visual loss. The overall recurrence rate of OT in Europe is greater than 80% for patients and may range from one episode to 11 episodes (1% of OT) in the most extreme cases. Current treatments do not reduce the risk of recurrences and the risk of toxoplasmosis recurrence cannot be predicted in these immunocompetent patients. These clinical and biological expression changes might be related to an individual genetic susceptibility of each patient. The advanced analysis of the entire genome now possible to consider the project.

Study Overview

• Status: Terminated
• Conditions: Toxoplasmosis Infection; Genotype II; Ocular Toxoplasmosis With Recurrences
• Intervention / Treatment: Biological: seropositive for Toxoplasma gondii

• Study Type: Interventional
• Enrollment (Actual): 16
• Phase: Not Applicable

Contacts and Locations

Study Locations

• France
  • Strasbourg, France, 67000
    • University Hospital, Strasbourg, France

Participation Criteria

Eligibility Criteria

• Ages Eligible for Study: 12 years and older (Child, Adult, Older Adult)
• Accepts Healthy Volunteers: No
• Genders Eligible for Study: All

Description

Inclusion Criteria:

• seropositive for Toxoplasma gondii (for patient and parents)
• Infection with genotype II (for patient and parents)
• ocular toxoplasmosis recurrences >5 (patients only)

Exclusion Criteria:

• Parents seronegative for T. gondii infection
• Infection with others genotypes than type II

Study Plan

How is the study designed?

Design Details

• Primary Purpose: Basic Science
• Allocation: N/A
• Interventional Model: Single Group Assignment
• Masking: None (Open Label)

Number of Arms

1

Arms and Interventions

Participant Group / Arm	Intervention / Treatment
Experimental: seropositive for Toxoplasma gondii	Biological: seropositive for Toxoplasma gondii; blood sample

What is the study measuring?

Primary Outcome Measures

Outcome Measure	Time Frame
Highlighting of genetic mutations associated with the susceptibility to Toxoplasma gondii.severe eye recurrences. Mutation analysis will be done by exome sequencing of the subjects included in this study	This analysis will be performed on a blood sample taken in patients included in the inclusion visit

Collaborators and Investigators

• Sponsor: University Hospital, Strasbourg, France
• Investigators: Principal Investigator: Arnaud SAUER, MD, University Hospital, Strasbourg, France

Study record dates

Study Major Dates

• Study Start (Actual): March 30, 2017
• Primary Completion (Actual): November 11, 2019
• Study Completion (Actual): November 11, 2019

Study Registration Dates

• First Submitted: August 8, 2016
• First Submitted That Met QC Criteria: August 8, 2016
• First Posted (Estimate): August 11, 2016

Study Record Updates

• Last Update Posted (Actual): September 8, 2021
• Last Update Submitted That Met QC Criteria: August 31, 2021
• Last Verified: August 1, 2021

More Information

Terms related to this study

• Additional Relevant MeSH Terms: Pathologic Processes; Infections; Eye Diseases; Disease Attributes; Parasitic Diseases; Coccidiosis; Protozoan Infections; Eye Infections; Disease Susceptibility; Eye Infections, Parasitic; Recurrence; Genetic Predisposition to Disease; Toxoplasmosis; Toxoplasmosis, Ocular
• Other Study ID Numbers: 6433

Plan for Individual participant data (IPD)

• Plan to Share Individual Participant Data (IPD)?: No

Drug and device information, study documents

• Studies a U.S. FDA-regulated drug product: No
• Studies a U.S. FDA-regulated device product: No