Lysosphingolipid Quantitation in Plasma and Dried-Blood Spots Using Targeted High-Resolution Mass Spectrometry.

Background: Sphingolipidoses are rare inherited metabolic diseases belonging to lysosomal diseases. Early and accurate diagnosis is crucial for effective management and treatment. In this study, we aimed to develop a robust method to accelerate the diagnosis of these sphingolipidoses using dried blood spots and plasma.

Method: We employed high-resolution mass spectrometry coupled with liquid chromatography (LC-HRMS) to analyze 6 lysosphingolipids (GlcSph/Psychosine, LysoGb3, LysoSM, LysoSM509, LysoGM1, and LysoGM2) on dried blood spots and plasma samples. The method was used to measure the lysosphingolipid levels in a group of 30 control subjects and 204 samples from patients with sphingolipidoses (61 dB and 143 plasma) including Fabry, Gaucher, GM2 Gangliodosis, Niemann-Pick type A/B, and Niemann-Pick type C.

Results: The developed multiplex LC-HRMS method demonstrated linearity, precision, and quantification performances particularly for GlcSph/Psychosine and LysoGb3 on samples including controls and patients with sphingolipidoses. LysoSM showed recovery variability, wherease LysoGM1 and LysoGM2 showed higher matrix effect.

Conclusion: Our study presents a high-resolution mass spectrometry method along with the established cutoff values, providing a valuable tool for targeted screening, accurate diagnosis, and monitoring sphingolipidoses. Furthermore, DBS showed reliable results that lay the path to a broader adoption for screening these diseases.