Validation Testing for Plasma Oxalate Levels in the Biochemical Laboratory at the Galilee Medical Center, in Collaboration With the Biochemistry Laboratory at CHARITE Hospital in Berlin, and Testing the Relationship Between Oxalate Levels and Vitamin C Levels in Plasma

NCT06578754 | Not Yet Recruiting

• 1 other identifier: 0096-24-NHR
• Study Type: observational
• Target: 50
• Locations: 0 countries
• Sites: N/A

Brief Summary

Background: Elevated plasma oxalate levels in various conditions, including: primary hyperoxaluria due to increased production in the liver, renal failure due to decreased renal excretion, intestinal diseases with fatty diarrhea due to increased intestinal absorption, and increased intake of substances containing oxalate or sources of oxalate. Primary hyperoxaluria type 1 is a rare hereditary disease in which there is an increase in oxalate production in the liver due to a defect in the AGT enzyme in the oxalate metabolism pathway. The disease causes end-stage renal failure, and until recently, the only treatment was liver and kidney transplantation. The disease is more common in our region, and the Pediatric Nephrology Unit is a center of expertise for this disease. In 2022, a new treatment for hyperoxaluria type 1, which is an alternative to liver transplantation (Lomecirane), was added to the health basket. With the introduction of this treatment in Israel, there was a need to test the level of oxalate in plasma in order to monitor the response to treatment and as part of the preparation for kidney transplantation in cases of type 1 hyperoxaluria with end-stage renal failure. There is no laboratory in Israel that performs plasma oxalate testing. The biochemistry laboratory at the Galilee Medical Center performs oxalate testing in urine using an enzymatic method. Testing for oxalate in plasma using this method requires external validation because the manufacturer intends this test for urine only. There are laboratories around the world that use this method to measure oxalate in plasma. Vitamin C is a precursor (source) for oxalate in the body. High vitamin C levels in dialysis may lead to increased oxalate, which is associated with worsening kidney damage and damage to other organs, including an increase in the incidence of cardiovascular disease. Dialysis patients are therefore advised to avoid vitamin C supplements. On the other hand, cases of symptomatic vitamin C deficiency in dialysis patients have been described due to their tendency to have an inadequate diet. One case was described in the literature by the Nephrology Department at our institution. Objectives:

1. 1.To validate the plasma oxalate test by comparing it to an external laboratory that performs the test.
2. 2.To examine the relationship between vitamin C levels and plasma oxalate levels in patients with varying degrees of renal failure.
3. 3.Establishment of a laboratory service that does not currently exist in Israel and is clinically important for treatment decisions.
4. 4.Assessing the relationship between vitamin C levels and oxalate levels in renal failure will help in the tailored treatment of these patients and prevent complications of vitamin C deficiency on the one hand or hyperoxaluria secondary to vitamin C excess on the other.

Conditions

Hyperoxaluria

Keywords

plasma oxalate level, hyperoxaluria

Outcome Measures

Primary Outcomes (1)

• correlation of plasma oxalate between local and external laboratories

  The plasma oxalate results from local and external laboratories will be compared by statistical analysis: Comparison tests for paired samples - to examine the differences between two paired samples using the paired sample T test or the Wilcoxon signed rank test if the distribution of the differences is not normal. A 95% confidence interval will be calculated for the difference between the paired samples. Correlation tests -Pearson's correlation coefficient test or alternatively Spearman's correlation coefficient test Bland-Altman plot and Scatter plot curves will be used to demonstrate the difference between the results. A P value lower than 5% will be considered statistically significant. The investigators aim to to have non significant differences between the results of the laboratories in order to conclude that the results in the local laboratory are valid.

  1 year

Study Arms (4)

Healthy volunteers

About 10 blood samples to be taken from this group

Other: This is an non-interventional study

Dialysis patients without a background of hyperoxaluria

About 10 blood samples to be taken from this group as well as 20 additional blood samples from dialysis patients where oxalate levels and vitamin C levels will be tested

Other: This is an non-interventional study

Hyperoxaluria patients receiving drug treatment or after a liver transplant

About 5 blood samples from this group

Other: This is an non-interventional study

Patients advanced kidney failure not on dialysis

About 5 blood samples from this group

Other: This is an non-interventional study

Interventions

This is an non-interventional study OTHER

Only blood samples will be required in this study. It is noninterventional.

Dialysis patients without a background of hyperoxaluria; Healthy volunteers; Hyperoxaluria patients receiving drug treatment or after a liver transplant; Patients advanced kidney failure not on dialysis

Eligibility Criteria

• Age: 1 Minute - 80 Years
• Sex: all
• Healthy Volunteers: Yes
• Age Groups: Child (0-17), Adult (18-64), Older Adult (65+)
• Sampling Method: Probability Sample

Study Population

Healthy patients Dialysis patients without a background of hyperoxaluria Hyperoxaluria patients receiving drug treatment or after a liver transplant Patients with advanced kidney failure not on dialysis

You may qualify if:

• Signing the informed consent

You may not qualify if:

• Not willing to participate

Sponsors & Collaborators

• Western Galilee Hospital-Nahariya: lead
• Charite University, Berlin, Germany: collaborator

Related Publications (5)

• Pfau A, Ermer T, Coca SG, Tio MC, Genser B, Reichel M, Finkelstein FO, Marz W, Wanner C, Waikar SS, Eckardt KU, Aronson PS, Drechsler C, Knauf F. High Oxalate Concentrations Correlate with Increased Risk for Sudden Cardiac Death in Dialysis Patients. J Am Soc Nephrol. 2021 Sep;32(9):2375-2385. doi: 10.1681/ASN.2020121793. Epub 2021 Jul 19.

  PMID: 34281958 BACKGROUND

• Ikizler TA, Burrowes JD, Byham-Gray LD, Campbell KL, Carrero JJ, Chan W, Fouque D, Friedman AN, Ghaddar S, Goldstein-Fuchs DJ, Kaysen GA, Kopple JD, Teta D, Yee-Moon Wang A, Cuppari L. KDOQI Clinical Practice Guideline for Nutrition in CKD: 2020 Update. Am J Kidney Dis. 2020 Sep;76(3 Suppl 1):S1-S107. doi: 10.1053/j.ajkd.2020.05.006.

  PMID: 32829751 BACKGROUND

• Stokes F, Acquaviva-Bourdain C, Hoppe B, Lieske JC, Lindner E, Toulson G, Vaz FM, Rumsby G. Plasma oxalate: comparison of methodologies. Urolithiasis. 2020 Dec;48(6):473-480. doi: 10.1007/s00240-020-01197-4. Epub 2020 May 29.

  PMID: 32472220 BACKGROUND

• Ladwig PM, Liedtke RR, Larson TS, Lieske JC. Sensitive spectrophotometric assay for plasma oxalate. Clin Chem. 2005 Dec;51(12):2377-80. doi: 10.1373/clinchem.2005.054353. No abstract available.

  PMID: 16306102 BACKGROUND

• Oka Y, Miyazaki M, Matsuda H. Plasma Oxalate Concentration and Patients With CKD. Kidney Int Rep. 2021 Mar 1;6(4):1194. doi: 10.1016/j.ekir.2020.10.041. eCollection 2021 Apr. No abstract available.

  PMID: 33912770 BACKGROUND

MeSH Terms

Conditions

Hyperoxaluria

Condition Hierarchy (Ancestors)

Kidney Diseases; Urologic Diseases; Female Urogenital Diseases; Female Urogenital Diseases and Pregnancy Complications; Urogenital Diseases; Male Urogenital Diseases

Central Study Contacts

Hadas Shasha-Lavsky, MD

CONTACT

+97249107580; hadasl2@gmc.gov.il

Study Design

• Study Type: observational
• Observational Model: COHORT
• Time Perspective: PROSPECTIVE
• Target Duration: 1 Year
• Sponsor Type: OTHER GOV
• Responsible Party: PRINCIPAL INVESTIGATOR
• PI Title: Principle Investigator

Study Record Dates

• First Submitted: August 20, 2024
• First Posted: August 29, 2024
• Study Start: December 31, 2025
• Primary Completion (Estimated): December 31, 2026
• Study Completion (Estimated): December 1, 2027
• Last Updated: December 30, 2025

Record last verified: 2025-12

Data Sharing

• IPD Sharing: Will not share