Effect of Urine Alkalinazation on Urinary Inflammatory Markers in Patients With Cystinuria

European Georges Pompidou Hospital

Status: Completed

Conditions: Glomerulonephritis; Renal Lithiasis; Cystinuria; Interstitial Nephritis

Treatments: Dietary Supplement: Potassium citrate

Study type: Observational

Funder types: Other; Industry

Identifiers

NCT03836144

EuropeanGPH

Details and patient eligibility

About

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.

Enrollment: 63 patients

Sex: All

Ages: 18+ years old

Volunteers: No Healthy Volunteers

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)

Trial design

63 participants in 3 patient groups

Cystinuria

Description:

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 .

Treatment:

Dietary Supplement: Potassium citrate

Non cystinuria nephrolithiasis

Description:

20 patients with a nephrolithiasis not due to cystinuria. Control group. Urine collected once to study biomarkers of inflammation No intervention.

Inflammatory nephropathy

Description:

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.