Efficacy of Phenylalanine- and Tyrosine-Restricted Diet in Alkaptonuria Patients on Nitisinone Treatment: Case Series and Review of Literature.

Teke Kisa P., Eroglu Erkmen S., Bahceci H., Arslan Gulten Z., Aydogan A., Karalar Pekuz Ö. K., ...Daha Fazla

Annals of nutrition & metabolism, cilt.78, sa.1, ss.48-60, 2022 (SCI-Expanded) identifier identifier identifier

  • Yayın Türü: Makale / Tam Makale
  • Cilt numarası: 78 Sayı: 1
  • Basım Tarihi: 2022
  • Doi Numarası: 10.1159/000519813
  • Dergi Adı: Annals of nutrition & metabolism
  • Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Agricultural & Environmental Science Database, BIOSIS, CAB Abstracts, Chemical Abstracts Core, CINAHL, EMBASE, Food Science & Technology Abstracts, MEDLINE, Veterinary Science Database
  • Sayfa Sayıları: ss.48-60
  • Anahtar Kelimeler: Alkaptonuria, Nitisinone, Tyrosine, phenylalanine-restricted diet, Amino acid supplementation, LOW-DOSE NITISINONE, KERATOPATHY
  • Dokuz Eylül Üniversitesi Adresli: Evet

Özet

Introduction: Nitisinone used in alkaptonuria (AKU) can result in keratopathy due to strongly increased tyrosine levels. Methods: This study aimed to investigate nutritional status and changes in plasma tyrosine and phenylalanine and urinary homogentisic acid (u-HGA) levels in 8 adult AKU patients (mean age, 56.3 +/- 4.7 years) who were on tyrosine/phenylalanine-restricted diet together with 2 mg/day nitisinone. Results: The treatment period was 23.4 +/- 6.9 months. Daily dietary protein intake was restricted to 0.8-1.0 g/kg/day. Daily tyrosine intake was restricted to 260-450 mg/day for females and 330-550 mg/day for males. Tyrosine/phenylalanine-free amino acid supplements accounted for an average of 56.1% of daily protein intake. The following assessments were performed: anthropometric and plasma tyrosine level measurements every 2 months; ophthalmological examination every 6 months, and nutritional laboratory analyses and measurements of plasma amino acids and u-HGA once in a year. It was targeted to keep the plasma tyrosine level 700 mu mol/L was detected. The u-HGA level before and after the 1st year of treatment was 1,429.3 +/- 1,073.4 mmol/mol creatinine and 33.6 +/- 9.5 mmol/mol creatinine, respectively. None of the patients developed keratopathy or experienced weight loss and protein or micronutrient deficiency. Conclusion: AKU patients should receive tyrosine/phenylalanine-restricted diet for reducing plasma tyrosine level to the safe range. Tyrosine/phenylalanine-free amino acid supplements can be safely used to enhance dietary compliance. Keratopathy and nutrient deficiency should be frequently monitored.