Evaluation of a New Tandem Mass Spectrometry Method for Sickle Cell Disease Newborn Screening.

In France, sickle cell disease newborn screening (SCD NBS) has been targeted to at-risk regions since 1984, but generalization to the whole population will be implemented from November 2024. Although tandem mass spectrometry (MS/MS) is already used for the NBS of several inherited metabolic diseases, its application for SCD NBS has not been widely adopted worldwide. The aim of this study was to evaluate a dedicated MS/MS kit (Targeted MS/MS Hemo, ZenTech, LaCAR Company, Liege, Belgium) for SCD NBS and to compare the results obtained with those from an NBS reference center using matrix-assisted laser desorption/ionization time of flight (MALDI-TOF) and cation-exchange high-performance liquid chromatography (CE-HPLC, Variant NBS, Biorad Laboratories, Inc.

[Uncertainty of measurement and result from a complex calculation: about the risk of fetal Down's syndrome by maternal serum markers].

Screening for fetal Down's syndrome has the peculiarity of combining the biochemical assay of 2 or 3 serum markers with the risk associated with maternal age. If the accuracy of measurement of each parameter is known by the biologist, the uncertainty of the ultimate risk to the patient is not. Indeed, the means of risk calculation involve numerous multi-parameter equations which are not practical for daily use.

Leukocytosis interference in clinical chemistry: Shall we still interpret test results without hematological data?

Background: Extreme leukocytosis is known to induce remarkable variations of some clinical chemistry tests, thus leading to possible clinical misinterpretation. This study aimed to define whether also moderate leukocytosis may influence the stability of glucose and blood gases.

Methods: Blood samples are sent to the local laboratory through a pneumatic tube system.

Pneumatic tube system transport and false hyperkalemia related to leukocytosis: a retrospective analysis.

Unlabelled: Extreme leukocytosis may lead to false hyperkalemia when blood samples are conveyed by pneumatic tube system (PTS). The aim of this study was to define whether even moderate leukocytosis and also non malignancy cells like neutrophils may influence potassium values after PTS transportation.

Materials And Methods: Uncentrifuged blood samples are sent to the local laboratory through PTS.

Benefit of point of care testing in patient with major hyperleukocytosis.

We report a case of a child with major leukocytosis (800 × 10/L) leading to a false increase in plasma potassium and an unexpected spurious decrease in sodium. To suppress interferences due to hyperleukocytosis, our laboratory protocol consists of collecting blood on Clotting Activator/Serum tubes (CAS) and/or carrying samples by human courier. CAS tube analysis showed a decreased level of hyperkalemia and sodium within the reference range (consistent with point of care measurements).