BACKGROUND: Duchenne Muscular Dystrophy is a severe, incurable disorder caused 
by mutations in the dystrophin gene. The disease is characterized by decreased 
muscle function, impaired muscle regeneration and increased inflammation. In a 
clinical context, muscle deterioration, is evaluated using physical tests and 
analysis of muscle biopsies, which fail to accurately monitor the disease 
progression.
OBJECTIVES: This study aims to confirm and asses the value of blood protein 
biomarkers as disease progression markers using one of the largest longitudinal 
collection of samples.
METHODS: A total of 560 samples, both serum and plasma, collected at three 
clinical sites are analyzed using a suspension bead array platform to assess 118 
proteins targeted by 250 antibodies in microliter amount of samples.
RESULTS: Nine proteins are confirmed as disease progression biomarkers in both 
plasma and serum. Abundance of these biomarkers decreases as the disease 
progresses but follows different trajectories. While carbonic anhydrase 3, 
microtubule associated protein 4 and collagen type I alpha 1 chain decline 
rather constantly over time, myosin light chain 3, electron transfer 
flavoprotein A, troponin T, malate dehydrogenase 2, lactate dehydrogenase B and 
nestin plateaus in early teens. Electron transfer flavoprotein A, correlates 
with the outcome of 6-minutes-walking-test whereas malate dehydrogenase 2 
together with myosin light chain 3, carbonic anhydrase 3 and nestin correlate 
with respiratory capacity.
CONCLUSIONS: Nine biomarkers have been identified that correlate with disease 
milestones, functional tests and respiratory capacity. Together these biomarkers 
recapitulate different stages of the disorder that, if validated can improve 
disease progression monitoring.