[Tetra-saccharide glucose as a diagnostic biomarker for Pompe disease: a study with 35 patients]

Abstract

Background and objectives: Pompe disease is a disorder originating from an acid alpha-glycosidase (AAG) enzyme deficiency. This disease produces an accumulation of lysosomal glycogen in different tissues, whereby the skeletal and heart muscles are especially involved. The established diagnosis is achieved through the identification of the AAG deficiency. There are also other secondary diagnostic biomarkers, such as tetra-saccharide glucose (Glc4), which shows high levels in the urine of these patients. In this study it is highlighted the usefulness of Glc4 as a diagnostic biomarker for Pompe disease in its different forms of presentation, using a high-performance liquid chromatography with ultraviolet detection (HPLC/UV) adapted to the study.

Patients and methods: A total of 75 individuals have been analyzed: 40 healthy controls and 35 patients diagnosed with Pompe disease. Twenty-four hour samples of urine were collected from all of the patients and their Glc4 levels were determined by means of HPLC/UV.

Results: The evaluation of the urinary Glc4 shows a high discrimination ability between healthy/sick individuals. In addition, the results obtained have allowed to establish the most appropriate level of decision or cut-off point for the identification of sick people.

Conclusions: Glc4 urinary levels are found to be high in patients suffering from Pompe disease and even though increased levels are also found in other conditions, the existence of a AAG deficiency together with a compatible clinical symptoms, prove very helpful for a correct diagnosis of this serious disease.

Keywords: Biomarcador diagnóstico; Curva característica operativa del receptor; Diagnostic biomarker; Enfermedad de Pompe; Glucosa tetrasacárido; Pompe disease; Receiver operating characteristic curve; Tetra-saccharide glucose.