Newborn Screening for Severe T and B Cell Lymphopenia Using TREC/KREC Detection: A Large-Scale Pilot Study of 202,908 Newborns.

Newborn screening (NBS) for severe inborn errors of immunity (IEI), affecting T lymphocytes, and implementing measurements of T cell receptor excision circles (TREC) has been shown to be effective in early diagnosis and improved prognosis of patients with these genetic disorders. Few studies conducted on smaller groups of newborns report results of NBS that also include measurement of kappa-deleting recombination excision circles (KREC) for IEI affecting B lymphocytes. A pilot NBS study utilizing TREC/KREC detection was conducted on 202,908 infants born in 8 regions of Russia over a 14-month period. One hundred thirty-four newborns (0.66‰) were NBS positive after the first test and subsequent retest, 41% of whom were born preterm. After lymphocyte subsets were assessed via flow cytometry, samples of 18 infants (0.09‰) were sent for whole exome sequencing. Confirmed genetic defects were consistent with autosomal recessive agammaglobulinemia in 1/18, severe combined immunodeficiency - in 7/18, 22q11.2DS syndrome - in 4/18, combined immunodeficiency - in 1/18 and trisomy 21 syndrome - in 1/18. Two patients in whom no genetic defect was found met criteria of (severe) combined immunodeficiency with syndromic features. Three patients appeared to have transient lymphopenia. Our findings demonstrate the value of implementing combined TREC/KREC NBS screening and inform the development of policies and guidelines for its integration into routine newborn screening programs.

TREC mediated oncogenesis in human immature T lymphoid malignancies preferentially involves ZFP36L2.

The reintegration of excised signal joints resulting from human V(D)J recombination was described as a potent source of genomic instability in human lymphoid cancers. However, such molecular events have not been recurrently reported in clinical patient lymphoma/leukemia samples. Using a specifically designed NGS-capture pipeline, we here demonstrated the reintegration of T-cell receptor excision circles (TRECs) in 20/1533 (1.3%) patients with T-cell acute lymphoblastic leukemia (T-ALL) and T-cell lymphoblastic lymphoma (T-LBL). Remarkably, the reintegration of TREC recurrently targeted the tumor suppressor gene, ZFP36L2, in 17/20 samples. Thus, our data identified a new and hardly detectable mechanism of gene deregulation in lymphoid cancers providing new insights in human oncogenesis.

Prospective Newborn Screening for SCID in Germany: A First Analysis by the Pediatric Immunology Working Group (API).

BACKGR OUND: T-cell receptor excision circle (TREC)-based newborn screening (NBS) for severe combined immunodeficiencies (SCID) was introduced in Germany in August 2019. METHODS: Children with abnormal TREC-NBS were referred to a newly established network of Combined Immunodeficiency (CID) Clinics and Centers. The Working Group for Pediatric Immunology (API) and German Society for Newborn Screening (DGNS) performed 6-monthly surveys to assess the TREC-NBS process after 2.5 years. RESULTS: Among 1.9 million screened newborns, 88 patients with congenital T-cell lymphocytopenia were identified (25 SCID, 17 leaky SCID/Omenn syndrome (OS)/idiopathic T-cell lymphocytopenia, and 46 syndromic disorders). A genetic diagnosis was established in 88%. Twenty-six patients underwent hematopoietic stem cell transplantation (HSCT), 23/26 within 4 months of life. Of these, 25/26 (96%) were alive at last follow-up. Two patients presented with in utero onset OS and died after birth. Five patients with syndromic disorders underwent thymus transplantation. Eight syndromic patients deceased, all from non-immunological complications. TREC-NBS missed one patient, who later presented clinically, and one tracking failure occurred after an inconclusive screening result. CONCLUSION: The German TREC-NBS represents the largest European SCID screening at this point. The incidence of SCID/leaky SCID/OS in Germany is approximately 1:54,000, very similar to previous observations from North American and European regions and countries where TREC-NBS was implemented. The newly founded API-CID network facilitates tracking and treatment of identified patients. Short-term HSCT outcome was excellent, but NBS and transplant registries will remain essential to evaluate the long-term outcome and to compare results across the rising numbers of TREC-NBS programs across Europe.

Effective matching of patients to clinical trials using entity extraction and neural re-ranking.

INTRODUCTION: Clinical trials (CTs) often fail due to inadequate patient recruitment. Finding eligible patients involves comparing the patient's information with the CT eligibility criteria. Automated patient matching offers the promise of improving the process, yet the main difficulties of CT retrieval lie in the semantic complexity of matching unstructured patient descriptions with semi-structured, multi-field CT documents and in capturing the meaning of negation coming from the eligibility criteria. OBJECTIVES: This paper tackles the challenges of CT retrieval by presenting an approach that addresses the patient-to-trials paradigm. Our approach involves two key components in a pipeline-based model: (i) a data enrichment technique for enhancing both queries and documents during the first retrieval stage, and (ii) a novel re-ranking schema that uses a Transformer network in a setup adapted to this task by leveraging the structure of the CT documents. METHODS: We use named entity recognition and negation detection in both patient description and the eligibility section of CTs. We further classify patient descriptions and CT eligibility criteria into current, past, and family medical conditions. This extracted information is used to boost the importance of disease and drug mentions in both query and index for lexical retrieval. Furthermore, we propose a two-step training schema for the Transformer network used to re-rank the results from the lexical retrieval. The first step focuses on matching patient information with the descriptive sections of trials, while the second step aims to determine eligibility by matching patient information with the criteria section. RESULTS: Our findings indicate that the inclusion criteria section of the CT has a great influence on the relevance score in lexical models, and that the enrichment techniques for queries and documents improve the retrieval of relevant trials. The re-ranking strategy, based on our training schema, consistently enhances CT retrieval and shows improved performance by 15% in terms of precision at retrieving eligible trials. CONCLUSION: The results of our experiments suggest the benefit of making use of extracted entities. Moreover, our proposed re-ranking schema shows promising effectiveness compared to larger neural models, even with limited training data. These findings offer valuable insights for improving methods for retrieval of clinical documents.

[Newborn screening for severe combined immunodeficiencies (SCID) in Germany]. / Neugeborenenscreening auf schwere kombinierte Immundefekte (SCID) in Deutschland.

Patients with a severe combined immunodeficiency (SCID) harbor genetic mutations disrupting T cell immunity and hence suffer severe, life-threatening infections or manifestations of immune dysregulation within the first months of their life. The only cure is to correct their immune system, usually by means of hematopoietic stem cell transplantation (HSCT). Pilot studies and national programs in the United States and in European countries have shown that patients can be identified at an early asymptomatic stage through newborn screening. This allows treatment before the occurrence of severe complications, which improves the outcome of curative strategies like HSCT.After assessment by the Federal Joint Committee (G-BA), the SCID screening was implemented into newborn screening in Germany in 2019. The first results of the screening (dry blood spot cards from around 2 million newborns between August 2019 and February 2022) were recently published. As expected, in addition to classic SCID diseases (incidence 1:54,000), infants with syndromic disorders and T cell lymphopenia were also identified. All patients with classic SCID were scheduled for curative treatment. Of the 25 patients with classic SCID, 21 were already transplanted at the time of data analysis. Only one of 21 transplanted patients died due to pre-existing infections. A comparison of the recent screening data with historical data suggests that SCID newborn screening has been successfully implemented in Germany. Patients with SCID are routinely identified very early and scheduled for curative therapy.

The importance of defining the age-specific TREC/KREC levels for detection of various inborn errors of immunity in pediatric and adult patients.

This study aimed to establish physiological TREC/KREC values in a healthy population of different ages to create cut-offs and analyze pediatric patients with various inborn errors of immunity. Dry blood spots and DNA samples purified from whole blood were used for TREC/KREC quantification using real-time PCR. Observed difference (p < 0.001) between methods revealed the isolation method as a factor we need to consider when determinating cut-offs. Data of 713 healthy individuals showed a negative correlation (p < 0.001) between age and TREC/KREC levels with gender difference observed only for KREC in a group of 51-60 years old (p < 0.001). The 5th percentile cut-off values were set for age groups, which allowed us to identify 25% of patients with immunodeficiencies in case of non-zero, borderline values of TREC/KREC. Screening of infants with congenital heart disease identified 11% of patients with lowered TREC/KREC and shows potential for newborn screening of specific groups of patients.

Natural history of infants with non-SCID T cell lymphopenia identified on newborn screen.

Newborn screening (NBS) for severe combined immunodeficiency (SCID) can identify infants with non-SCID T cell lymphopenia (TCL). The purpose of this study was to characterize the natural history and genetic findings of infants with non-SCID TCL identified on NBS. We analyzed data from 80 infants with non-SCID TCL in the mid-Atlantic region between 2012 and 2019. 66 patients underwent genetic testing and 41 (51%) had identified genetic variant(s). The most common genetic variants were thymic defects (33%), defects with unknown mechanisms (12%) and bone marrow production defects (5%). The genetic cohort had significantly lower median initial CD3+, CD4+, CD8+ and CD4/CD45RA+ T cell counts compared to the non-genetic cohort. Thirty-six (45%) had either viral, bacterial, or fungal infection; only one patient had an opportunistic infection (vaccine strain VZV infection). Twenty-six (31%) of patients had resolution of TCL during the study period.

Long-Term Follow-Up of Newborns with 22q11 Deletion Syndrome and Low TRECs.

BACKGROUND: Population-based neonatal screening using T-cell receptor excision circles (TRECs) identifies infants with profound T lymphopenia, as seen in cases of severe combined immunodeficiency, and in a subgroup of infants with 22q11 deletion syndrome (22q11DS). PURPOSE: To investigate the long-term prognostic value of low levels of TRECs in newborns with 22q11DS. METHODS: Subjects with 22q11DS and low TRECs at birth (22q11Low, N=10), matched subjects with 22q11DS and normal TRECs (22q11Normal, N=10), and matched healthy controls (HC, N=10) were identified. At follow-up (median age 16 years), clinical and immunological characterizations, covering lymphocyte subsets, immunoglobulins, TRECs, T-cell receptor repertoires, and relative telomere length (RTL) measurements were performed. RESULTS: At follow-up, the 22q11Low group had lower numbers of naïve T-helper cells, naïve T-regulatory cells, naïve cytotoxic T cells, and persistently lower TRECs compared to healthy controls. Receptor repertoires showed skewed V-gene usage for naïve T-helper cells, whereas for naïve cytotoxic T cells, shorter RTL and a trend towards higher clonality were found. Multivariate discriminant analysis revealed a clear distinction between the three groups and a skewing towards Th17 differentiation of T-helper cells, particularly in the 22q11Low individuals. Perturbations of B-cell subsets were found in both the 22q11Low and 22q11Normal group compared to the HC group, with larger proportions of naïve B cells and lower levels of memory B cells, including switched memory B cells. CONCLUSIONS: This long-term follow-up study shows that 22q11Low individuals have persistent immunologic aberrations and increased risk for immune dysregulation, indicating the necessity of lifelong monitoring. CLINICAL IMPLICATIONS: This study elucidates the natural history of childhood immune function in newborns with 22q11DS and low TRECs, which may facilitate the development of programs for long-term monitoring and therapeutic choices.

Rapid tranquillisation in a psychiatric emergency hospital in Lebanon: TREC-Lebanon - a pragmatic randomised controlled trial of intramuscular haloperidol and promethazine v. intramuscular haloperidol, promethazine and chlorpromazine.

BACKGROUND: Agitated patients constitute 10% of all emergency psychiatric treatment. Management guidelines, the preferred treatment of clinicians differ in opinion and practice. In Lebanon, the use of the triple therapy haloperidol plus promethazine plus chlorpromazine (HPC) is frequently used but no studies involving this combination exists. METHOD: A pragmatic randomised open trial (September 2018-July 2019) in the Lebanese Psychiatric Hospital of the Cross in Beirut Lebanon involving 100 people requiring urgent intramuscular sedation due to aggressive behaviour were given intramuscular chlorpromazine 100 mg plus haloperidol 5 mg plus promethazine 25 mg (HPC) or intramuscular haloperidol 5 mg plus promethazine 25 mg. RESULTS: Primary outcome data were available for 94 (94%) people. People allocated to the haloperidol plus promethazine (HP) group showed no clear difference at 20 min compared with patients allocated to the HPC group [relative risk (RR) 0.84, 95% confidence interval (CI) 0.47-1.50]. CONCLUSIONS: Neither intervention consistently impacted the outcome of 'calm', or 'asleep' and had no discernible effect on the use of restraints, use of additional drugs or recurrence. If clinicians are faced with uncertainty on which of the two intervention combinations to use, the simpler HP is much more widely tested and the addition of chlorpromazine adds no clear benefit with a risk of additional adverse effects.

A Remote Monitoring System to Optimize the Home Management of Oral Anticancer Therapies (ONCO-TreC): Prospective Training-Validation Trial.

BACKGROUND: A platform designed to support the home management of oral anticancer treatments and provide a secure web-based patient-health care professional communication modality, ONCO-TreC, was tested in 3 cancer centers in Italy. OBJECTIVE: The overall aims of the trial are to customize the platform; assess the system's ability to facilitate the shared management of oral anticancer therapies by patients and health professionals; and evaluate system usability and acceptability by patients, caregivers, and health care professionals. METHODS: Patients aged ≥18 years who were candidates for oral anticancer treatment as monotherapy with an Eastern Cooperative Oncology Group performance status score of 0 to 1 and a sufficient level of familiarity with mobile devices were eligible. ONCO-TreC consisted of a mobile app for patients and a web-based dashboard for health care professionals. Adherence to treatment (pill count) and toxicities reported by patients through the app were compared with those reported by physicians in medical records. Usability and acceptability were evaluated using questionnaires. RESULTS: A total of 40 patients were enrolled, 38 (95%) of whom were evaluable for adherence to treatment. The ability of the system to measure adherence to treatment was high, with a concordance of 97.3% (95% CI 86.1%-99.9%) between the investigator and system pill count. Only 60% (3/5) of grade 3, 54% (13/24) of grade 2, and 19% (7/36) of grade 1 adverse events reported by physicians in the case report forms were also reported in the app directly by patients. In total, 94% (33/35) of patients had ≥1 app launch each week, and the median number of daily accesses per patient was 2. Approximately 71% (27/38) and 68% (26/38) of patients used the app for messages and vital sign entering, respectively, at least once during the study period. CONCLUSIONS: ONCO-TreC is an important tool for measuring and monitoring adherence to oral anticancer drugs. System usability and acceptability were very high, whereas its reliability in registering toxicity could be improved. TRIAL REGISTRATION: ClinicalTrials.gov NCT02921724; https://www.clinicaltrials.gov/ct2/show/NCT02921724.

SCID newborn screening: What we've learned.

Newborn screening for severe combined immunodeficiency, the most profound form of primary immune system defects, has long been recognized as a measure that would decrease morbidity and improve outcomes by helping patients avoid devastating infections and receive prompt immune-restoring therapy. The T-cell receptor excision circle test, developed in 2005, proved to be successful in pilot studies starting in the period 2008 to 2010, and by 2019 all states in the United States had adopted versions of it in their public health programs. Introduction of newborn screening for severe combined immunodeficiency, the first immune disorder accepted for population-based screening, has drastically changed the presentation of this disorder while providing important lessons for public health programs, immunologists, and transplanters.

Pneumonia and Related Conditions in Critically Ill Patients-Insights from Basic and Experimental Studies.

Pneumonia is an acute infectious disease with high morbidity and mortality rates. Pneumonia's development, severity and outcome depend on age, comorbidities and the host immune response. In this study, we combined theoretical and experimental investigations to characterize pneumonia and its comorbidities as well as to assess the host immune response measured by TREC/KREC levels in patients with pneumonia. The theoretical study was carried out using the Columbia Open Health Data (COHD) resource, which provides access to clinical concept prevalence and co-occurrence from electronic health records. The experimental study included TREC/KREC assays in young adults (18-40 years) with community-acquired (CAP) (n = 164) or nosocomial (NP) (n = 99) pneumonia and healthy controls (n = 170). Co-occurring rates between pneumonia, sepsis, acute respiratory distress syndrome (ARDS) and some other related conditions common in intensive care units were the top among 4170, 3382 and 963 comorbidities in pneumonia, sepsis and ARDS, respectively. CAP patients had higher TREC levels, while NP patients had lower TREC/KREC levels compared to controls. Low TREC and KREC levels were predictive for the development of NP, ARDS, sepsis and lethal outcome (AUCTREC in the range 0.71-0.82, AUCKREC in the range 0.67-0.74). TREC/KREC analysis can be considered as a potential prognostic test in patients with pneumonia.

Implementation of TREC/KREC detection protocol for newborn SCID screening in Bulgaria: a pilot study.

Neonatal screening for inborn errors of immunity (IEI), based on quantification of T-cell-receptor- excision circles (TRECs) and kappa-deleting recombination-excision circles (KRECs) from dried blood spots (DBS), allows early diagnosis and improved outcomes for the affected children. Determination of TREC/KREC levels from prospectively collected newborns' Guthrie cards and from DBS samples of patients with confirmed IEI was done using a commercial kit. Retrospective assessment of flow cytometry evaluation of TREC/KREC correspondence with lymphocyte subpopulations and evaluation of the correlations between TREC and KREC with immune cells, based on the data from patients with suspected or confirmed immune disorders, were conducted. 2,228 Guthrie cards were tested, 1276 for TREC only and 952 for both TREC and KREC. Eight newborns (0.36%) were TREC positive and 10 (1.05%) had KREC below the cut-off. The re-testing rate was 1.88%. Retrospective analysis demonstrated that the TREC/KREC assay identifies 100% of severe combined immune deficiencies (SCID) cases when DBS were collected at birth. Correlation analysis showed moderate significant correlations between TREC and the absolute numbers of CD4 cells (r = 0.634, p < 0.01) and total T cells (r = 0.536, p < 0.01). The ability of KREC levels to predict abnormal absolute (AUC of 0.772) and relative (AUC 0.731) levels of B cells was demonstrated.

Abnormal SCID Newborn Screening and Spontaneous Recovery Associated with a Novel Haploinsufficiency IKZF1 Mutation.

PURPOSE: IKAROS, encoded by IKZF1, is a member of the IKAROS family of zinc-finger transcription factors playing critical roles in lymphocyte development, differentiation, and tumor suppression. Several studies demonstrated that IKZF1 mutations affecting DNA binding or homo-/hetero-dimerization are mostly associated with common variable immunodeficiency, combined immunodeficiency, or hematologic manifestations. Herein we report a likely de novo, nonsense IKZF1 mutation (p.C182*) in a baby with low T cell receptor excision circles (TREC) identified by newborn screening testing for severe combined immunodeficiency. The patient also presented a profound B cell deficiency at birth. METHODS: Genetic, functional, immunologic, and clinical outcome data associated with this patient and her mutation were evaluated. RESULTS: Mutant p.C182* was detected in the cytoplasm of the patient's primary cells, in contrast to wild type (WT) IKAROS protein, only detected in the nucleus. Functional in vitro assessments revealed that p.C182* was less stable than WT IKAROS protein and failed to bind to its target DNA binding sequence and dimerize with WT IKAROS protein, resulting in impaired pericentromeric targeting and transcriptional repression by means of haploinsufficiency. During follow-up, while a spontaneous recovery of TREC and T cells was observed, B cells improved but not to sustained normal ranges. CONCLUSIONS: Patients with IKAROS-associated diseases can present with SCID-like TREC values through newborn screening testing. IKZF1 mutations should be added to the low TREC differential, although spontaneous recovery has to be considered.

Protective reactive thymus hyperplasia in COVID-19 acute respiratory distress syndrome.

BACKGROUND: Patients with COVID-19 (COVID) may develop acute respiratory distress syndrome with or without sepsis, coagulopathy and visceral damage. While chest CT scans are routinely performed in the initial assessment of patients with severe pulmonary forms, thymus involvement and reactivation have not been investigated so far. METHODS: In this observational study, we systematically scored the enlargement of the thymus and the lung involvement, using CT scans, in all adult patients admitted to the ICU for COVID or any other cause (control group) at one centre between March and April 2020. Initial biological investigations included nasal detection of SARS-CoV-2 ribonucleic acid by polymerase chain reaction (PCR). In a subgroup of 24 patients with different degrees of pulmonary involvement and thymus hypertrophy, plasma cytokine concentrations were measured and the export of mature T cells from the thymus was estimated simultaneously by PCR quantification of T cell receptor excision circles (TRECs). RESULTS: Eighty-seven patients were studied: 50 COVID patients and 37 controls. Non-atrophic or enlarged thymus was more commonly observed in COVID patients than in controls (66% vs. 24%, p < 0.0001). Thymus enlargement in COVID patients was associated with more extensive lung injury score on CT scans (4 [3-5] vs. 2 [1.5-4], p = 0.01), but a lower mortality rate (8.6% vs. 41.2%, p < 0.001). Other factors associated with mortality were age, lymphopaenia, high CRP and co-morbidities. COVID patients had higher concentrations of IL-7 (6.00 [3.72-9.25] vs. 2.17 [1.76-4.4] pg/mL; p = 0.04) and higher thymic production of new lymphocytes (sj/ßTREC ratio = 2.88 [1.98-4.51] vs. 0.23 [0.15-0.60]; p = 0.004). Thymic production was also correlated with the CT scan thymic score (r = 0.38, p = 0.03) and inversely correlated with the number of lymphocytes (r = 0.56, p = 0.007). CONCLUSION: In COVID patients, thymus enlargement was frequent and associated with increased T lymphocyte production, which appears to be a beneficial adaptation to virus-induced lymphopaenia. The lack of thymic activity/reactivation in older SARS-CoV-2 infected patients could contribute to a worse prognosis.

Searching for scientific evidence in a pandemic: An overview of TREC-COVID.

We present an overview of the TREC-COVID Challenge, an information retrieval (IR) shared task to evaluate search on scientific literature related to COVID-19. The goals of TREC-COVID include the construction of a pandemic search test collection and the evaluation of IR methods for COVID-19. The challenge was conducted over five rounds from April to July 2020, with participation from 92 unique teams and 556 individual submissions. A total of 50 topics (sets of related queries) were used in the evaluation, starting at 30 topics for Round 1 and adding 5 new topics per round to target emerging topics at that state of the still-emerging pandemic. This paper provides a comprehensive overview of the structure and results of TREC-COVID. Specifically, the paper provides details on the background, task structure, topic structure, corpus, participation, pooling, assessment, judgments, results, top-performing systems, lessons learned, and benchmark datasets.

A comparative analysis of system features used in the TREC-COVID information retrieval challenge.

The COVID-19 pandemic has resulted in a rapidly growing quantity of scientific publications from journal articles, preprints, and other sources. The TREC-COVID Challenge was created to evaluate information retrieval (IR) methods and systems for this quickly expanding corpus. Using the COVID-19 Open Research Dataset (CORD-19), several dozen research teams participated in over 5 rounds of the TREC-COVID Challenge. While previous work has compared IR techniques used on other test collections, there are no studies that have analyzed the methods used by participants in the TREC-COVID Challenge. We manually reviewed team run reports from Rounds 2 and 5, extracted features from the documented methodologies, and used a univariate and multivariate regression-based analysis to identify features associated with higher retrieval performance. We observed that fine-tuning datasets with relevance judgments, MS-MARCO, and CORD-19 document vectors was associated with improved performance in Round 2 but not in Round 5. Though the relatively decreased heterogeneity of runs in Round 5 may explain the lack of significance in that round, fine-tuning has been found to improve search performance in previous challenge evaluations by improving a system's ability to map relevant queries and phrases to documents. Furthermore, term expansion was associated with improvement in system performance, and the use of the narrative field in the TREC-COVID topics was associated with decreased system performance in both rounds. These findings emphasize the need for clear queries in search. While our study has some limitations in its generalizability and scope of techniques analyzed, we identified some IR techniques that may be useful in building search systems for COVID-19 using the TREC-COVID test collections.

Abnormal Newborn Screening Follow-up for Severe Combined Immunodeficiency in an Amish Cohort with Cartilage-Hair Hypoplasia.

Cartilage-hair hypoplasia (CHH) is an autosomal recessive, short limb skeletal dysplasia with a variable immunologic phenotype. The spectrum of immune function ranges from clinically normal to severe combined immunodeficiency (SCID). Multiple studies have shown that abnormal immune parameters may not predict severe outcomes. Newborn screening (NBS) using T cell receptor excision circle (TREC) assay can now effectively identify infants with severe T cell deficiency who are at risk for SCID. NBS has allowed for cost-effective identification of patients with SCID and improved outcomes with hematopoietic stem cell transplant (HSCT). Ohio reports two abnormal TREC results: decreased and absent TREC. This study evaluated the laboratory and clinical differences in eight Amish patients with CHH with an abnormal TREC result on the NBS. There were four patients with absent TREC and four patients with decreased TREC. The absent TREC patients had lower CD3, CD4, naïve CD4, CD8 cells, and phytohemagglutinin (PHA)-induced lymphocyte proliferation. Three patients with absent TREC were diagnosed with SCID and two underwent successful HSCT. Patients with absent TREC experienced more CHH-related morbidity including anemia requiring transfusion, Hirschsprung's disease, and failure to thrive. No patients with decreased TREC required HSCT. Our study indicates that CHH patients with absent TREC tend to have more severe immunological and clinical phenotype than patients with decreased TREC. Confirmation of these trends in a larger group would guide providers and parents in a timely referral for HSCT, or cost-effective surveillance monitoring of children with a life-threatening illness.

Localizing Binding Sites on Bioconjugated Hydrogen-Bonded Organic Semiconductors at the Nanoscale.

Hydrogen-bonded organic semiconductors are extraordinarily stable organic solids forming stable, large crystallites with the ability to preserve favorable electrical properties upon bioconjugation. Lately, tremendous efforts have been made to use these bioconjugated semiconductors as platforms for stable multifunctional bioelectronics devices, yet the detailed characterization of bio-active binding sites (orientation, density, etc.) at the nanoscale has not been achieved yet. The presented work investigates the bioconjugation of epindolidione and quinacridone, two representative semiconductors, with respect to their exposed amine-functionalities. Relying on the biotin-avidin lock-and-key system and applying the atomic force microscopy (AFM) derivative topography and recognition (TREC) imaging, we used activated biotin to flag crystal-faces with exposed amine functional groups. Contrary to previous studies, biotin bonds were found to be stable towards removal by autolysis. The resolution strength and clear recognition capability makes TREC-AFM a valuable tool in the investigation of bio-conjugated, hydrogen-bonded semiconductors.

Clinical and economic aspects of newborn screening for severe combined immunodeficiency: DEPISTREC study results.

PURPOSE: Severe combined immunodeficiency (SCID) refers to a group of genetic disorders characterized by greatly compromised cellular and humoral immunity. Children with SCID are asymptomatic at birth, but they die from infections within the first months of life if not treated. Quantification of T-cell receptor excision circles is an extremely sensitive screening method for detecting newborns who may have SCID.The goal of the DEPISTREC study was to evaluate the feasibility of nationwide newborn screening for severe T-cell lymphopenia in France as well as its economic and clinical utility. METHODS: The test universally used for neonatal screening for SCID was the quantification of TRECs on Guthrie cards. We compared a group of 190,517 babies from 48 maternities across the country who underwent newborn SCID screening with a control group of 1.4 million babies out of whom 28 were diagnosed with SCID without such screening during the course of the study. RESULTS: Within the screening group, 62 babies were found to be lymphopenic, including three with SCID. The cost of screening ranged from 4.7€ to €8.15 per newborn. The average 18-month cost was €257,574 vs €204,697 in the control group. CONCLUSIONS: In this large-scale study, we demonstrate that routine SCID screening is feasible and effective. This screening offers the additional benefit of aiding in the diagnosis of non-SCID lymphopenia. Economic evaluation allowed us to calculate the cost per test. Newborn screening may also prevent death by SCID before any curative treatment can be administered. The difference in cost between screened and control children could not be ascertained because of the very low numbers and death of one of the children tested.