Effect of Urine Alkalinazation on Urinary Inflammatory Markers in Patients With Cystinuria
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ClinicalTrials.gov Identifier: NCT03836144 |
Recruitment Status :
Completed
First Posted : February 11, 2019
Last Update Posted : March 22, 2022
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It has recently been described the presence of a urinary inflammatory signature in patients with cystinuria, the most common cause of renal lithiasis of genetical origin. These data are very innovative in this pathology but deserve further studies to establish the specificity of this inflammatory signature in patients with cystinuria compared to other nephropathies and other renal lithiasis diseases. Moreover, the effect of the usual treatment of cystinuria (namely urine alkalanization) on urinary inflammatory biomarkers deserves to be tested.
The objectives of the present study are: i) To study the urinary inflammatory profile by mass spectrometry (a very efficient tool to detect and identify proteins) in patients with cystinuria and in patients with lithiasis of other origin and in patients with inflammatory renal disease ; ii) To study the potential effect of urine alkalinazation with potassium citrate (usual treatment according to European recommendations) on the inflammatory signature of patients with cystinuria. To this aim, urine of non treated cystinuric patients will be collected before treatement initiation and 3 months after the start of the alkalizing treatment.
Condition or disease | Intervention/treatment |
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Cystinuria Renal Lithiasis Glomerulonephritis Interstitial Nephritis | Dietary Supplement: Potassium citrate |
Study Type : | Observational |
Actual Enrollment : | 63 participants |
Observational Model: | Case-Control |
Time Perspective: | Prospective |
Official Title: | Effect of Urine Alkalinazation on Urinary Inflammatory Markers Analyzed Using Mass Spectrometry in Patients With Cystinuria |
Actual Study Start Date : | April 2, 2015 |
Actual Primary Completion Date : | January 31, 2020 |
Actual Study Completion Date : | December 31, 2020 |

Group/Cohort | Intervention/treatment |
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Cystinuria
10 patients with cystinuria. Experimental. Urine collected before treatment initiation and 3 months after. Treatment: Usual alkalizing treatment using oral potassium citrate. The initial dosage will be 4 g/day divided into 3 to 4 oral daily doses. If the objective of urinary pH is not reached after the first two weeks of treatment, the dose will be increased by 2 grams (6 grams total). If the urinary pH remains below 7.5 after 2 weeks with 6 grams of potassium citrate per day, the alkalizing treatment will then be supplemented with oral sodium bicarbonate in the form of Vichy water or officinal preparation. This treatment is the usual treatment recommended for cystinuria .
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Dietary Supplement: Potassium citrate
Other Name: Sodium bicarbonate |
Non cystinuria nephrolithiasis
20 patients with a nephrolithiasis not due to cystinuria. Control group. Urine collected once to study biomarkers of inflammation No intervention.
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Inflammatory nephropathy
10 patients with an inflammatory nephropathy of glomerular or tubulo interstitial origin (confirmed by renal biopsy). Control group. Urine collected once to study biomarkers of inflammation. No intervention. |
- Change from baseline urine inflammatory profile after 3 months of alkalizing treatment using mass spectrometry in patients with cystinuria. [ Time Frame: at inclusion and after three months of the usual alkalizing treatment for the patients with cystinuria ]Study of urine inflammatory biomarkers profile using mass spectrometry to determine if the alkalizing treatment is susceptible to modify the urine inflammatory profile. Proteases inhibitors will be added to the urine sample immediately after urination. Urine will then be frozen at -80°C until mass spectrometry analysis. Mass spectrometry will determine the differential expression of all the proteins present the urine sample. For the purpose of the present study, the investigators will focus on the expression of inflammatory biomarkers among them MMP9 (matrix metallopeptidase), Myeloperoxydase, Proteinase 3, Neutrophil Elastase, Cathepsine G, LSP1 (lymphocyte specific protein), Fibrinogen beta and gamma chains. The aim of mass spectrometry is to detect the presence of proteins in the urine sample and to assess the differential levels of expression of the detected proteins but not to precisely measure the urine concentration of the detected proteins.
- Assessment of urine inflammatory profile in controls groups using mass spectrometry. [ Time Frame: at inclusion for patients with a nephrolithiasis not due to cystinuria and in patients an inflammatory nephropathy of glomerular or tubulo interstitial origin ]Study of urine inflammatory biomarkers with mass spectrometry in control groups to determine if the urine inflammatory profile is specific to cystinuria. Proteases inhibitors will be added to the urine sample immediately after urination. Urine will then be frozen at -80°C until analysis. Mass spectrometry will determine the differential expression of all the proteins present the urine sample. For the purpose of the present study, the investigators will focus on the expression of inflammatory biomarkers. The aim of mass spectrometry is to detect the presence of proteins in the urine sample and to assess the differential levels of expression of the detected proteins but not to precisely measure the urine concentration of these proteins. Moreover, urine analysis by mass spectrometry will detect all urinary proteins and the investgators do exclude to find unexpected proteins. For those reasons, urine analysis by mass spectrometry is a unique outcome.
- Study of crystalluria (presence of crystals in urine) to assess nephrolithiasis activity. [ Time Frame: at inclusion for these two groups and after three months of the usual alkalizing treatment for the patients with cystinuria ]Assessment of the presence of crystals in the second morning urine sample in patients with cystinuria and in patients with a nephrolithiasis not due to cystinuria, to assess nephrolithiasis activity.
- Presence of stones in the renal cavities or in the urinary tract using ultrasonograhy. [ Time Frame: at inclusion for these two groups and after three months of the usual alkalizing treatment for the patients with cystinuria ]assessment of the presence of urinary stones using ultrasonogrpahy in patients with cystinuria and in patients with a nephrolithiasis not due to cystinuria.
- Blood CRP concentrations to assess systemic inflammation [ Time Frame: at inclusion for all groups and and after three months of the usual alkalizing treatment for the patients with cystinuria ]Blood CRP concentration (mg/L)
Biospecimen Retention: Samples Without DNA

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Ages Eligible for Study: | 18 Years and older (Adult, Older Adult) |
Sexes Eligible for Study: | All |
Accepts Healthy Volunteers: | No |
Sampling Method: | Non-Probability Sample |
Patients with cystinuria, as well as patients with renal lithiasis not due to cystinuria and patients with an inflammatory renal pathology will be selected by the investigators of the study during their usual medical consultation.
At that time, patients will be given the information note and will be asked to sign the written informed consent.
Inclusion Criteria:
- age superior or equal to 18 years
- patient able to understand the information note and to sign the informed consent
- patient with an Health coverage
- no current urinary tract infection (assessed by a cytobacteriological examination of the urine)
- For the cystinuria group: patient with cystinuria not yet treated or for whom the alkalizing treatment or the cystein binding thiol agents have been discontinuated for at least 3 months AND with an estimated GFR (using the MDRD formula) greater than 60 ml/min/1.73m2.
- For the control groups: patient presenting either a renal lithiasis not due to cystinuria, or an inflammatory renal pathology confirmed by an anterior renal biopsy (glomerulonephritis or interstitial nephritis) AND with an estimated GFR (using the MDRD formula) greater than 30 ml/ min/1.73m2.
Exclusion Criteria:
- Cystinuric patient already treated (whatever the treatment)

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): NCT03836144
France | |
Eurpean Georges Pompidou Hospital | |
Paris, Ile-de-France, France, 75015 |
Responsible Party: | Marie Courbebaisse, Associate Professor, MD, PhD, European Georges Pompidou Hospital |
ClinicalTrials.gov Identifier: | NCT03836144 |
Other Study ID Numbers: |
EuropeanGPH |
First Posted: | February 11, 2019 Key Record Dates |
Last Update Posted: | March 22, 2022 |
Last Verified: | March 2022 |
Individual Participant Data (IPD) Sharing Statement: | |
Plan to Share IPD: | No |
Studies a U.S. FDA-regulated Drug Product: | No |
Studies a U.S. FDA-regulated Device Product: | No |
Mass spectrometry Cystinuria Inflammation Nephrolithiasis |
Cystinuria Nephritis Glomerulonephritis Nephritis, Interstitial Lithiasis Kidney Diseases Urologic Diseases Renal Aminoacidurias Renal Tubular Transport, Inborn Errors |
Genetic Diseases, Inborn Pathologic Processes Potassium Citrate Diuretics Natriuretic Agents Physiological Effects of Drugs Expectorants Respiratory System Agents |