Evaluation of Blood Brain Barrier Integrity and Relationship to Structural Brain Abnormalities in MPS IIIB Patients Using Cerebrospinal Fluid/Serum Albumin Index (CSF-AI) and Multimodal Magnetic Resonance Imaging

Recruitment & Eligibility

Status: Withdrawn

Sex: Not specified

Target Recruitment: 6

Inclusion Criteria

A patient must meet all of the following inclusion criteria to be eligible to participate in this study:
1. The patient is *5 years of age.
2. The patient has a definitive diagnosis of MPS IIIB, as determined by the patient meeting the criteria outlined in both (a) and (b):
a. Documented deficiency in alpha-N-acetylglucosaminidase (NAGLU) enzyme activity of *10% of the lower limit of the normal range (Heron, 2011) based on a historical test result from a local laboratory.
and/or
Documented functionally-relevant mutations in both alleles of the NAGLU gene based on a historical test result from a local laboratory.
AND
b. Screening result for NAGLU enzyme activity, performed by a qualified laboratory, confirms the diagnosis of MPS IIIB.
3. The patient or the patient*s parent(s) or legal guardian understands the full nature and purpose of the study, including possible risks of study procedures, and provides informed consent prior to any study procedures being performed.
4. The patient is willing and able to comply with protocol requirements to the extent that may be expected of a patient with cognitive impairment.
5. The Investigator considers the patient to be a suitable candidate based on the patient's clinical status and ability to comply with study procedures.

Exclusion Criteria

A patient who meets any of the following exclusion criteria will be ineligible to participate of this study:
1. The patient has any internal or non-removable external metal items that may present a safety risk (for MRI), or any other medical condition or circumstance in which an MRI is contraindicated according to local institutional policy.
2. The patient has a known or suspected hypersensitivity to anaesthesia, a bleeding disorder, or any other medical condition or circumstance in which a lumbar puncture (for collection of CSF) is contraindicated according to local institutional policy.
3. The patient had a previous allergic reaction to gadolinium-based MRI contrast media.
4. The patient has impaired renal function, i.e., a stable estimated glomerular filtration rate <60% of age-adjusted normal value, as calculated based on the Schwartz formula.
5. The patient has poor venous access or poor tolerance for blood draws that would make multiple venapunctures impractical.
6. In the opinion of the Investigator, the patient has any other prior or ongoing medical condition that may present a safety risk, interfere with study compliance, or confound data interpretation.

Study & Design

Study Type: Observational invasive

Study Design: Not specified

Primary Outcome Measures

Name	Time	Method
<p>The primary objectives are:<br /><br>1. To assess BBB integrity in MPS IIIB patients by estimating the CSF AI.<br /><br>2. To determine the BBB transfer coefficient by DCE-MRI in MPS IIIB patients.</p><br>

Secondary Outcome Measures

Name	Time	Method
<p>The secondary objectives are:<br /><br>1. To describe the relationship between functional/quantitative MRI endpoints<br /><br>and clinical parameters of BBB integrity (e.g., CSF-AI) in MPS IIIB patients<br /><br>2. To estimate the volumes of the plasma and extracellular spaces, using<br /><br>DCE-MRI, in MPS IIIB patients.<br /><br>3. To describe structural brain abnormalities in MPS IIIB patients using<br /><br>structural and diffusion MRI.<br /><br>4. To evaluate biomarkers of neurodegeneration and inflammation related to<br /><br>underlying disease biology in CSF, blood, and urine of MPS IIIB patients.<br /><br>5. To measure heparan sulfate in CSF, blood, and urine of MPS IIIB patients.<br /><br>6. To evaluate the safety and practicality of non-invasive quantitative MRI and<br /><br>related procedures in an MPS IIIB population.</p><br>