Prevalence and clinical impact of gastrointestinal symptoms in patients with cystinosis

BACKGROUND: Cystinosis is a rare autosomal recessive lysosomal storage disease caused by mutations in the CTNS gene, resulting in lysosomal cystine accumulation and multisystem complications, including most notably kidney failure. Gastrointestinal (GI) symptoms are common, varying from feeding difficulties to nausea and bowel problems. These issues increase the risk of malnutrition, a concern that has received limited attention in the literature. METHODS: This mixed-method study assessed the prevalence and impact of GI complaints in 28 cystinosis patients and their caregivers. Quantitave data was collected using the Gastrointestinal Symptoms Questionnaire and the Patient-Generated Subjective Global Assessment (PG-SGA). Seven in-depth interviews were conducted to explore subjective experiences. Additionally, anthropometric measurements were compared to those of healthy individuals and bioelectrical impedance analysis (BIA) was performed in 19 adult patients. RESULTS: GI symptoms were highly prevalent, with all participants reporting at least one symptom in the four weeks preceding assessment. The most commonly reported symptoms included halitosis (68%), bloating (64%), abdominal rumbling (61%), nausea (61%), abdominal pain (54%) and altered stool patterns (54%). Qualitative interviews underscored the profound impact of various GI symptoms on the quality of life. Furthermore, cystinosis patients had significantly lower body mass index (BMI) compared to healthy controls (p < 0.01) and were more frequently underweight (p < 0.01). Overall PG-SGA scores were elevated, with 42.9% needing follow-up and education (score 2-3) and 42.9% needing nutritional intervention (score > 3). BIA revealed reduced muscle mass in 79% of evaluated participants. CONCLUSION: GI symptoms are common and burdensome in cystinosis, significantly impairing quality of life and increasing the risk of malnutrition. Early recognition and targeted intervention, including dietary support, might mitigate the risk of malnutrition and enhance overall quality of life in this patient population. PG-SGA score and BIA measurements assist in recognising the individual need for follow-up and intervention.