A Multicentre Pilot Study of a Two-Tier Newborn Sickle Cell Disease Screening Procedure with a First Tier Based on a Fully Automated MALDI-TOF MS Platform.

The reference methods used for sickle cell disease (SCD) screening usually include two analytical steps: a first tier for differentiating haemoglobin S (HbS) heterozygotes, HbS homozygotes and ß-thalassemia from other samples, and a confirmatory second tier. Here, we evaluated a first-tier approach based on a fully automated matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS) platform with automated sample processing, a laboratory information management system and NeoSickle® software for automatic data interpretation. A total of 6701 samples (with high proportions of phenotypes homozygous (FS) or heterozygous (FAS) for the inherited genes for sickle haemoglobin and samples from premature newborns) were screened. The NeoSickle® software correctly classified 98.8% of the samples. This specific blood sample collection was enriched in qualified difficult samples (premature newborns, FAS samples, late and very late samples, etc.). In this study, the sensitivity of FS sample detection was found to be 100% on the Lille MS facility and 99% on the Dijon MS facility, and the specificity of FS sample detection was found to be 100% on both MS facilities. The MALDI-MS platform appears to be a robust solution for first-tier use to detect the HbS variant: it is reproducible and sensitive, it has the power to analyze 600-1000 samples per day and it can reduce the unit cost of testing thanks to maximal automation, minimal intervention by the medical team and good overall practicability. The MALDI-MS approach meets today's criteria for the large-scale, cost-effective screening of newborns, children and adults.

The Reliable, Automatic Classification of Neonates in First-Tier MALDI-MS Screening for Sickle Cell Disease.

Previous research has shown that a MALDI-MS technique can be used to screen for sickle cell disease (SCD), and that a system combining automated sample preparation, MALDI-MS analysis and classification software is a relevant approach for first-line, high-throughput SCD screening. In order to achieve a high-throughput "plug and play" approach while detecting "non-standard" profiles that might prompt the misclassification of a sample, we have incorporated various sets of alerts into the decision support software. These included "biological alert" indicators of a newborn's clinical status (e. g., detecting samples with no or low HbA), and "technical alerts" indicators for the most common non-standard profiles, i.e., those which might otherwise lead to sample misclassification. We evaluated these alerts by applying them to two datasets (produced by different laboratories). Despite the random generation of abnormal spectra by one-off technical faults or due to the nature and quality of the samples, the use of alerts fully secured the process of automatic sample classification. Firstly, cases of ß-thalassemia were detected. Secondly, after a visual check on the tagged profiles and reanalysis of the corresponding biological samples, all the samples were correctly reclassified without prompting further alerts. All of the samples for which the results were not tagged were well classified (i.e., sensitivity and specificity = 1). The alerts were mainly designed for detecting false-negative classifications; all the FAS samples misclassified by the software as FA (a false negative) were marked with an alert. The implementation of alerts in the NeoScreening® Laboratory Information Management System's decision support software opens up perspectives for the safe, reliable, automated classification of samples, with a visual check solely on abnormal results or samples. It should now be possible to evaluate the combination of the NeoSickle® analytical solution and the NeoScreening® Laboratory Information Management System in a real-life, prospective study of first-line SCD screening.

Newborn screening for sickle cell disease in Europe: recommendations from a Pan-European Consensus Conference.

Sickle Cell Disease (SCD) is an increasing global health problem and presents significant challenges to European health care systems. Newborn screening (NBS) for SCD enables early initiation of preventive measures and has contributed to a reduction in childhood mortality from SCD. Policies and methodologies for NBS vary in different countries, and this might have consequences for the quality of care and clinical outcomes for SCD across Europe. A two-day Pan-European consensus conference was held in Berlin in April 2017 in order to appraise the current status of NBS for SCD and to develop consensus-based statements on indications and methodology for NBS for SCD in Europe. More than 50 SCD experts from 13 European countries participated in the conference. This paper aims to summarise the discussions and present consensus recommendations which can be used to support the development of NBS programmes in European countries where they do not yet exist, and to review existing programmes.

Use of dried blood spots and inductively coupled plasma mass spectrometry for multi-element determination in blood.

The paper describes the development of an inductively coupled plasma mass spectrometry (ICP MS) method for multitrace element determination in dried blood spots (DBSs). The analytical conditions were optimized using Seronorm™ L-3 and L-1 Certified Reference Materials. The best results were obtained by sampling blood drops on a decontaminated PVDF filter membrane. After drying under metal-free conditions, the DBSs underwent acidic digestion and were analyzed with ICP MS. The method was then validated for As, Cd, Cu, Pb, Mo, Se and Zn. Using a matrix-matched calibration curve, the recovery levels ranged from 96% to 117%. The repeatability and reproducibility were generally below 15%. Limits of quantification ranging from 0.5 to 50 µg/L. In order to investigate the analytical procedure under real sampling conditions, the results obtained from DBSs and liquid blood aliquots (less subject to contamination) from two adult subjects were compared.

MALDI-TOF MS profiling as the first-tier screen for sickle cell disease in neonates: matching throughput to objectives.

PURPOSE: Universal newborn screening for sickle cell diseases (SCDs) is not currently performed in many countries concerned by this public health problem. Owing to the technical and financial limitations of standard profiling methods (IEF coupled to subsequent HPLC), ethnically targeted neonatal screening is often preferred. Here, we demonstrate that MALDI-MS-based SCD newborn screening could be considered as a potential method for a strategy to universal screening because of its high throughput, cost-effectiveness, sensitivity and ability to automatically discriminate sickle haemoglobin. EXPERIMENTAL DESIGN: We carried out a retrospective study of dried blood spots from 844 Guthrie cards. Four determinations of 1000 mass spectra were performed from each tested dried blood spot. RESULTS: The MALDI-MS-based screening was highly correlated with the reference method. Only 2.3% of the samples presented a poor spectral quality. CONCLUSIONS AND CLINICAL RELEVANCE: Given that the overall acquisition, data reprocessing and software-assisted classification (ClinProTools™) time for processing four mass determinations (corresponding to one sample) was around 1 min, 1000 samples can be analysed per day. Rather than seeking to detect as many different haemoglobinopathies as possible, it would become possible to use MALDI-TOF-MS to screen (at a constant cost) as many samples as possible for sickle cell disease.

Potential of the Sebia Capillarys neonat fast automated system for neonatal screening of sickle cell disease.

BACKGROUND: Most screening programs for sickle cell disease (SCD) utilize isoelectric focusing (IEF) or high performance liquid chromatography (HPLC) to detect haemoglobin (Hb) variants. The first method is not automated and becomes too tedious when many samples have to be investigated. The aim of this work is to explore the capacity of an automated capillary electrophoresis (CE) system, with full traceability, as a tool for newborn screening of SCD. METHODS: The Capillarys neonat fast automated system has been developed by Sebia for newborn screening. We performed separate studies using different types of samples to evaluate the utility of the Capillarys for (i) separating Hb S and other variants, and (ii) for performing the routine activity of our laboratory for 20 working days. RESULTS: A throughput of 48 samples per hour with a loading capacity of 192 samples was achieved. Migration times of the major Hb variants were distinct. There were few variants showing similar migration times to Hb S and Hb C and thalassaemia could be detected. In addition, late screening, screening of premature or transfused babies and screening performed using poor quality Guthrie's cards did not interfere with reporting of accurate phenotypes. CONCLUSIONS: Sebia Capillarys neonat fast automated system is a reliable tool for haemoglobinopathy neonatal screening.

Combining immunoreactive trypsinogen and pancreatitis-associated protein assays, a method of newborn screening for cystic fibrosis that avoids DNA analysis.

OBJECTIVES: To evaluate the performance of a strategy in which, after immunoreactive trypsinogen (IRT) determination, genetic analysis is replaced by a biological test, the pancreatitis-associated protein (PAP) enzyme-linked immunosorbent assay (ELISA). STUDY DESIGN: The French newborn screening program includes cystic fibrosis (CF) screening by the IRT/CFTR mutation strategy. PAP was assayed on screening cards, in parallel with IRT, in all newborns from 5 French regions (n = 204,749). Analysis of PAP values in CF and non-CF newborns with elevated IRT allowed direct comparison between the current strategy and the proposed IRT/PAP strategy. RESULTS: A protocol in which newborns with IRT >50 ng/mL and PAP >1.8 ng/mL and those with IRT >100 ng/mL and PAP >1.0 ng/mL are directly recalled for sweat testing would have the same performance as the IRT/CFTR mutation strategy. CONCLUSIONS: The IRT/PAP strategy is an alternative for CF newborn screening, which avoids the drawbacks of genetic analysis and is cheaper and easier to implement than the current IRT/CFTR mutation strategy.

Tumor necrosis factor alpha increases the expression of glycosyltransferases and sulfotransferases responsible for the biosynthesis of sialylated and/or sulfated Lewis x epitopes in the human bronchial mucosa.

There is increasing evidence that inflammation may affect glycosylation and sulfation of various glycoproteins. The present study reports the effect of tumor necrosis factor alpha (TNF-alpha), a proinflammatory cytokine, on the glycosyl- and sulfotransferases of the human bronchial mucosa responsible for the biosynthesis of Lewis x epitope and of its sialylated and/or sulfated derivatives, which are expressed in human bronchial mucins. Fragments of macroscopically normal human bronchial mucosa were exposed to TNF-alpha at a concentration of 20 ng/ml. TNF-alpha was shown to increase alpha1,3-fucosyltransferase activity as well as expression of the two alpha1,3-fucosyltransferase genes expressed in the human airway, FUT3 and FUT4. It had no influence on alpha1,2-fucosyltransferase activity or FUT2 expression. It also increased alpha2,3-sialyltransferase activity and the expression of ST3Gal-III and, more importantly, ST3Gal-IV and both N-acetylglucosamine 6-O-sulfotransferase and galactose 3-O-sulfotransferase. These results are consistent with the observation of oversialylation and increased expression sialyl-Lewis x epitopes on human airway mucins secreted by patients with severe lung infection such as those with cystic fibrosis, whose airways are colonized by Pseudomonas aeruginosa. However, other cytokines may also be involved in this process.