First impressions of two new brilliant biomarkers for Pompe disease (LSD) in plasma and urine in comparison to Hex4 and Glc4 in urine

Abstract Pompe disease is a glycogen storage disease type II with acid-α-glucosidase (acid maltase) deficiency. People affected with this disease are unable to degrade glycogen stored in the lysosome and this leading to the accumulation of glycogen in lysosomal storage vacuoles. The incidence is approximately 1 to 40.000 live births. The diagnosis is really a challenge because there is almost no biomarker for determination of the intensity and the future development of symptoms (phenotype). Only Hex4 or more in detail Glc4, a four sugar unit in urine, can give some hints: Sometimes Hex4 or Glc4 are useful markers, sometimes they have very unclear levels. Our search for biomarkers in Pompe disease started about four years ago and different attempts had no outcome. A very intensive check in plasma with HPLC-MS (Orbitrap) and also with HPLC-ELSD (especially fitting for sugars) showed encouraging results. With that knowledge we checked in a preliminary search plasma and urine samples of 19 Pompe patients in comparison to 10 healthy people. The outcome were two brilliant biomarkers fitting for plasma/serum but also for urine. Now these biomarkers will be applied systematically to further samples. A comparison with the until now “best biomarkers for Pompe” (Hex4 and Glc4 in urine) will be presented.