September 27, 2022

Diagnostic biomarker for bone disorder

A urine chemical performs better as a diagnostic biomarker for the soft bone disease hypophosphatasia than other laboratory measures, Vanderbilt researchers have demonstrated.

Hypophosphatasia (HPP) — a rare genetic disorder that impacts the mineralization of bones and teeth — has a wide spectrum of disease presentation and is challenging to diagnose. 

Kathryn Dahir, MD, and colleagues evaluated urine phosphoethanolamine (PEA) as a marker for HPP diagnosis and treatment monitoring. They collected data from the records of 78 adults who were referred to the Vanderbilt Program for Metabolic Bone Disorders for evaluation for HPP; 59 were diagnosed with HPP and 19 were excluded from HPP diagnosis. 

The researchers compared urine PEA in the two groups to other clinical and laboratory measures consistent with HPP. They report in the journal Bone that urine PEA performed better as a diagnostic biomarker for HPP than other laboratory measures. They also showed that urine PEA has utility for monitoring response to enzyme replacement therapy in patients with HPP. 

The study suggests that using urine PEA results to rule in HPP and track response to therapy would assist clinical decision-making.

Other authors of the study include co-first authors Zahra Shajani-Yi, PhD, and Nadia Ayala-Lopez, PhD, and Margo Black, MSN.