PracticeUpdate Conference Series - SSIEM 2018

Dr. Burlina concluded that simultaneous determination of multiple enzyme activities by tandemmass spectrometry, adding specific biochemical markers as confirmatory tests, significantly reduces the need for unnecessary follow-up of newborns with pseudodeficiency enzyme activities or carrier status. The NeoLSDMS/MS assay system for dried blood spot screening proved effective in identifying neonates at risk of lysosomal storage diseases in this study. Establishing cut-off values before starting a screening program is essential to avoid a high number of false positives, which are a source of needless anxiety and unnecessary medical interventions. Long-term follow-up of affected infants may provide important information about the natural history of the disease and their specific mutations, and should allow for optimized treatment outcomes. It has been demonstrated recently that the analytical range of mass spectrometry methods for screening is wider than that of fluorometric methods. Mass spectrometry provides a more accurate value of enzymatic activity, especially for very low values. This feature allows for better differentiation between patients with pathogenic mutations, pseudodeficiency alleles, and/or benign variants at the time of screening. This superior differentiation may, in turn, reduce the number of false positives. “The number of positive patients with the four lysosomal diseases screened was higher than we thought before starting the project,” Dr. Burlina told Elsevier’s PracticeUpdate.

“For Pompe disease and mucopolysaccharidosis I,” he said, “the possibility of diagnosing patients in their first week of life allowed us to start treatment (enzyme replacement therapy for the infant with Pompe disease and enzyme replacement therapy + bone marrow transplantation for the infant with muco- polysaccharidosis I). This early treatment changed the outcome of the diseases.” Dr. Burlina said that the multiplexed NeoLSD assay system for Pompe, Fabry, Gaucher, and mucopolysaccharidosis I has been integrated into the routine workflow of his newborn screening laboratory and has performed well for dried blood spot screening. He added, “We plan to continue our project and evaluation, and to add other diseases, in particular, mucopolysaccharidoses II and VI.”

www.practiceupdate.com/c/73404 " For Pompe disease and mucopolysaccharidosis I, the

possibility of diagnosing patients in their first week of life allowed us to start treatment. This early treatment changed the outcome of the diseases. "

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SSIEM 2018 • PRACTICEUPDATE CONFERENCE SERIES