5 Diagnostic test reagents for medical purposes; Diagnostic test reagents for medical use; Diagnostic biomarkers for in vitro testing for medical use; Diagnostic preparations for in vitro testing for medical use; Medical diagnostic test strips for use in the field of sphingolipid and ceramide metabolism; Medical diagnostic test strips for sphingolipid ceramide metabolism; Medical diagnostic reagents and assays for testing of body fluids; Reagents for use in diagnostic tests for medical purposes; Reagents for use in diagnostic tests for medical use