Hydroxyproline Influence on Oxalate Metabolism

  • Study type:

    Interventional What is this?

    Describes the nature of a clinical study. Types include:

    • Observational study — observes people and measures outcomes without affecting results.
    • Interventional study (clinical trial) — studies new tests, treatments, drugs, surgical procedures or devices.
    • Medical records research — uses historical information collected from medical records of large groups of people to study how diseases progress and which treatments and surgeries work best.
  • Study phase:

    I/II What is this?

    During the early phases (phases 1 and 2), researchers assess safety, side effects, optimal dosages and risks/benefits. In the later phase (phase 3), researchers study whether the treatment works better than the current standard therapy. They also compare the safety of the new treatment with that of current treatments. Phase 3 trials include large numbers of people to make sure that the result is valid. There are also less common very early (phase 0) and later (phase 4) phases. Phase 0 trials are small trials that help researchers decide if a new agent should be tested in a phase 1 trial. Phase 4 trials look at long-term safety and effectiveness, after a new treatment has been approved and is on the market.

Study IDs

  • Site IRB:

    • Rochester, Minnesota: 13-000150
  • NCT ID:

  • Sponsor Protocol Number:

    RDCRN 6405

About this study

Primary hyperoxaluria is an inborn error of metabolism that results in marked overproduction of oxalate by the liver. The excess oxalate causes kidney failure and can cause severe systemic disease due to oxalate deposition in multiple body tissues.

Metabolic pathways that lead to oxalate are poorly understood, but recent evidence suggests that hydroxyproline may play a role. Sources of hydroxyproline include the diet and bone turnover. If hydroxyproline can be confirmed as a signficant factor in primary hyperoxaluria, diet modification might be of value in reducing the severity of disease.

This protocol, in which hydroxyproline labelled with a cold isotope is infused intravenously in patients with primary hyperoxaluria, will allow us to measure the amount of oxalate produced from hydroxyproline. The contribution of hydroxyproline metabolism to the amount of oxalate excreted in urine in will be able to be determined for patients with each of the known types of primary hyperoxaluria.

Participation eligibility

Participant eligibility includes age, gender, type and stage of disease, and previous treatments or health concerns. Guidelines differ from study to study, and identify who can or cannot participate. If you need assistance understanding the eligibility criteria, please contact the study team.

See eligibility criteria

Inclusion criteria:

  • Confirmed diagnosis of primary hyperoxaluria
  • eGFR (by serum creatinine) > 50ml/min/1.73m2

Exclusion criteria:

  • eGFR < 50 ml/min/1.73m2
  • History of liver or kidney transplant
  • Primary hyperoxaluria patients who have responded to pyridoxine therapy with reduction of urine oxalate excretion to < 0.45 mmol/1.73m2/day.
  • Pregnancy

Participating Mayo Clinic locations

Study statuses change often. Please contact us for help.

Mayo Clinic Location Status Contact

Rochester, Minn.

Mayo Clinic principal investigator

Dawn Milliner, M.D.

Contact us for the latest status

Julie Olson R.N., CCRP