Cystinuria: clinical practice recommendation.

Area of Science:

• Nephrology
• Urology
• Medical Genetics

Background:

• Cystinuria is an autosomal recessive hereditary disorder characterized by excessive urinary cystine excretion.
• This leads to the formation of cystine stones due to cystine's low solubility at physiological urinary pH.
• The rarity of cystinuria and limited evidence necessitate clear clinical guidance.

Purpose of the Study:

• To develop comprehensive clinical practice recommendations for the diagnosis, treatment, and follow-up of patients with cystinuria.
• To provide expert consensus on managing this rare kidney stone disease in both pediatric and adult populations.
• To consolidate current knowledge and best practices for cystinuria management.

Main Methods:

• A consensus conference was held from January 2019, following a period of recommendation development from June 2018 to December 2019.
• Working groups conducted systematic literature reviews (MEDLINE) on specific cystinuria management topics.
• Recommendations were drafted, discussed, and finalized by a multidisciplinary expert panel.

Main Results:

• Twenty key statements were produced, offering guidance on diagnosis, genetic analysis, and imaging techniques.
• Recommendations cover surgical treatment indications and modalities, conservative management (hydration, diet, alkalinization, cystine-binding drugs), and follow-up protocols.
• Guidance addresses self-monitoring, complications like renal failure and hypertension, and quality of life impacts.

Conclusions:

• These clinical practice recommendations offer comprehensive guidance for managing cystinuria in adults and children.
• The recommendations address all facets of cystinuria care, from initial diagnosis through long-term management and complication monitoring.
• Despite limitations in evidence grading due to disease rarity, these statements provide essential direction for clinicians.