Urinary homogentisic acid in alkaptonuric and healthy children

Anna V. Oláh, István Ilyés, Attila Szoke, István Csízy, Judit Tóth, J. Varga

Research output: Contribution to journalArticle

9 Citations (Scopus)

Abstract

To detect and follow-up the metabolic status of patients with alkaptonuria (AKU), urinary homogentisic acid (HGA) was measured by gas chromatography. These results were close to values we obtained by colorimetric method (linearity: up to 700 mg/l, detection limit: 1 mg/l, within-run imprecision (CV): 1.2% at 100 mg/l HGA, 4.9% at 10 mg/l, between-run CV:6.8% at 100 mg/l. To determine urinary reference ranges of HGA, 84 healthy children (age: 2 months-18 years) were divided into five age groups. HGA and creatinine were measured in their morning urine. Statistical analysis proved that urinary HGA/creatinine ratio is age-dependent. The ratio is relatively high between 1 and 6 years of age, with large scatter (upper limit of reference ranges given as mean +2 SD: 5.5-7.2 mg/mmol = 0.03-0.04 mmol/mmol creatinine), and it decreases with age. Approximately at the age of 7 years, HGA/creatinine ratio becomes constant, and later it is similar to the adult value (upper limit: 2.8 mg/mmol = 0.017 mmol/mmol creatinine). We monitored a patient during her 1-5th year of life, and her urinary HGA was 80-200 times higher than the upper limit of the age-matched reference ranges. The measurement of HGA supports the decision for starting restricted protein diet and is useful for the evaluation of the effectiveness of therapy.

Original languageEnglish
Pages (from-to)356-359
Number of pages4
JournalClinical Chemistry and Laboratory Medicine
Volume41
Issue number3
DOIs
Publication statusPublished - 2003

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Homogentisic Acid
Creatinine
Reference Values
Alkaptonuria
Protein-Restricted Diet
Nutrition
Gas chromatography
Gas Chromatography
Limit of Detection
Statistical methods
Age Groups
Urine

Keywords

  • Alkaptonuria
  • Homogentisic acid
  • Reference range

ASJC Scopus subject areas

  • Clinical Biochemistry

Cite this

Urinary homogentisic acid in alkaptonuric and healthy children. / Oláh, Anna V.; Ilyés, István; Szoke, Attila; Csízy, István; Tóth, Judit; Varga, J.

In: Clinical Chemistry and Laboratory Medicine, Vol. 41, No. 3, 2003, p. 356-359.

Research output: Contribution to journalArticle

Oláh, Anna V. ; Ilyés, István ; Szoke, Attila ; Csízy, István ; Tóth, Judit ; Varga, J. / Urinary homogentisic acid in alkaptonuric and healthy children. In: Clinical Chemistry and Laboratory Medicine. 2003 ; Vol. 41, No. 3. pp. 356-359.
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