Renal Uptake of Fatty Acids (FFA) in Patients With Idiopathic Uric Acid Nephrolithiasis (IUAN) (IUAN)
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|ClinicalTrials.gov Identifier: NCT02975986|
Recruitment Status : Withdrawn
First Posted : November 29, 2016
Last Update Posted : October 5, 2020
The investigators will test the hypothesis that renal uptake of free (i.e. non-esterified) fatty acids (FFa) is increased in iuan. To accomplish this goal the investigators will measure renal FFa uptake FFa uptake in vivo in patients with iuan and matched non-stone forming subjects via single-photon emission computed tomography (SPeCT)/CT imaging.
The definitive proof of the hypothesis rests on whether increased renal FFa uptake is demonstrable in humans with iuan.
|Condition or disease||Intervention/treatment||Phase|
|Uric Acid Nephrolithiasis||Other: 123I-BMIPP Other: 99mTc-MAG3||Not Applicable|
This is a cross-sectional study of patients with iuan and matched non-stone formers to test the hypothesis that renal FFa uptake is increased in iuan, using noninvasive 123i-labeled [MiCRo-SYMBoL]-methyl-p-iodo-phenyl-pentadecanoic acid(123i-BMiPP) SPeCT/CT imaging, an established FFa analog approved for human studies.
Participants will be placed on an instructed controlled metabolic diet (30% fat, 15% protein, 55% carbohydrate, 300 mg cholesterol per day, 400 mg calcium, 800mg phosphorus, 100 meq sodium, with low acid ash content, and 3000 cc distilled water) for 5 days to exclude dietary confounders (3 days as outpatient and the final 2 days as inpatient). On days 4 and 5, two fasting blood samples will be collected for the measurement of CMP, insulin, FFa and two 24-h urine samples will be collected under mineral oil to be analyzed for total volume, pH, Cr, na, K, Ca, Mg, Cl, P, uric acid, nH4+, titratable acidity (Ta), sulfate, HCo3- and citrate. The morning of day 6, patients will undergo dual 123i-BMiPP and 99mTc-MaG3 (99mTc mercaptoacetyltriglycine mertiatide) SPeCT/CT imaging after 12 hrs of fasting. 99mTc-MaG3 (8-10mCi) will be injected intravenously for the flow phase of a standard renal scan which includes dynamic imaging for 2 minutes. an additional 1 minute image will be acquired (the 2-3 minute image on a standard renal scan). acquisition will then stop. immediately afterward 123i-BMiPP (4-5mCi) will be injected intravenously for a 1hour uptake period. after the 1 hour uptake dual isotope (Tc-99m and i-123) SPeCT/CT images of the kidney will be acquired on a clinical Siemens Symbia dual head SPeCT/CT system. The 99mTc-MaG3 flow image data will be used to measure renal plasma flow,12 using the Ge Xeleris renal analysis software package already installed on the clinical SPeCT/CT system. The 123i-BMiPP, a gamma emitter with a half-life of 13.13 hours, is to measure renal 123i-BMiPP (FFa) uptake 13 123i-BMiPP uptake will be corrected for effective renal plasma flow (mL/min) measured with 99mTc-MaG3, using the Ge Xeleris renal analysis software package.
Expected findings: If the hypothesis is correct, the investigators expect increased FFa uptake as measured by 123i-BMiPP SPeCT/CT corrected for renal effective plasma flow in the kidney cortex of iuan patients vs. matched controls.
|Study Type :||Interventional (Clinical Trial)|
|Actual Enrollment :||0 participants|
|Intervention Model:||Single Group Assignment|
|Masking:||None (Open Label)|
|Primary Purpose:||Basic Science|
|Official Title:||Renal Uptake of Fatty Acids (FFA) in Patients With Idiopathic Uric Acid Nephrolithiasis (IUAN)|
|Study Start Date :||January 2017|
|Estimated Primary Completion Date :||September 2020|
|Estimated Study Completion Date :||December 2021|
Controlled metabolic diet
All study patients will be placed on an instructed controlled metabolic diet. Intervention: Uptake of radioactive isotope by the kidney Radiotracer: 123I-BMIPP, 99mTc-MAG3
Uptake of radioactive isotope by the kidney
Uptake of radioactive isotope by the kidney
- Increased FFA uptake as measured by 123I-BMIPP SPECT/CT corrected for renal effective plasma flow in the kidney cortex of IUAN patients vs. matched controls [ Time Frame: 6 days ]Based on preliminary animal study, we anticipate a mean difference of approximately 26% between IUAN and control non-stone forming subjects, but with a higher CV of 20%. For 80% power (=0.05), will be able to detect at 1.5 standardized effect size (%change/CV) with n=10 per group. Comparisons between IUAN and non-stone former groups will be made with two-sample t-tests or Wilcoxon Rank Sum tests.
To learn more about this study, you or your doctor may contact the study research staff using the contact information provided by the sponsor.
Please refer to this study by its ClinicalTrials.gov identifier (NCT number): NCT02975986
|United States, Texas|
|UT Southwestern Medical Center - Center for Mineral Metabolism|
|Dallas, Texas, United States, 75390-8885|
|UT Southwestern Medical Center|
|Dallas, Texas, United States, 75390|
|Principal Investigator:||Khashayar Sakhaee, MD||UT Southwestern|