Glutamine therapy of cystinuria

Area of Science:

• Nephrology
• Metabolic Disorders
• Urology

Background:

• Cystinuria is a rare genetic disorder characterized by excessive cystine excretion in urine.
• Homozygous cystinuria leads to the formation of cystine stones in the urinary tract.
• Current treatments aim to reduce cystine supersaturation in urine.

Purpose of the Study:

• To investigate the effect of oral glutamine on urinary cystine excretion and crystalluria in patients with homozygous cystinuria.
• To assess changes in urinary pH and fractional cystine excretion during glutamine therapy.

Main Methods:

• Studied five patients with homozygous cystinuria.
• Collected urine samples before and during oral glutamine therapy.
• Analyzed urinary cystine, acids, and cystine crystalluria.
• Measured urinary pH and fractional excretion of cystine.

Main Results:

• Oral glutamine did not change absolute urinary cystine excretion.
• Fractional excretion of cystine remained unaffected by glutamine therapy.
• Urinary pH was not significantly altered by oral glutamine.
• Cystine crystalluria persisted both before and during glutamine treatment.

Conclusions:

• Oral glutamine therapy is ineffective in reducing urinary cystine excretion or preventing cystine crystalluria in homozygous cystinuria.
• Glutamine does not appear to be a viable therapeutic option for managing cystine stone formation in this condition.