ABSTRACT
Reprogramming human somatic cells into a pluripotent state, achieved through the activation of well-defined transcriptional factors known as OSKM factors, offers significant potential for regenerative medicine. While OSKM factors are a robust reprogramming method, efficiency remains a challenge, with only a fraction of cells undergoing successful reprogramming. To address this, we explored genes related to genomic integrity and cellular survival, focusing on iPSCs (A53T-PD1) that displayed enhanced colony stability. Our investigation had revealed three candidate genes CCN3, POSTN, and PTHLH that exhibited differential expression levels and potential roles in iPSC stability. Subsequent analyses identified various protein interactions for these candidate genes. POSTN, significantly upregulated in A53T-PD1 iPSC line, showed interactions with extracellular matrix components and potential involvement in Wnt signaling. CCN3, also highly upregulated, demonstrated interactions with TP53, CDKN1A, and factors related to apoptosis and proliferation. PTHLH, while upregulated, exhibited interactions with CDK2 and genes involved in cell cycle regulation. RT-qPCR validation confirmed elevated CCN3 and PTHLH expression in A53T-PD1 iPSCs, aligning with RNA-seq findings. These genes' roles in preserving pluripotency and cellular stability require further exploration. In conclusion, we identified CCN3, POSTN, and PTHLH as potential contributors to genomic integrity and pluripotency maintenance in iPSCs. Their roles in DNA repair, apoptosis evasion, and signaling pathways could offer valuable insights for enhancing reprogramming efficiency and sustaining pluripotency. Further investigations are essential to unravel the mechanisms underlying their actions.
ABSTRACT
Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by three core impairments: impaired communication, impaired reciprocal social interaction, and restricted, repetitive, and stereotypical behavior patterns. Spectrum refers to the heterogeneity of presentation, severity of symptoms, and medical comorbidities associated with ASD. Among the most common underlying medical conditions are attention-deficit/hyperactivity disorder (ADHD), anxiety, depression, epilepsy, digestive disorders, metabolic disorders, and immune disorders. At present, in the absence of an objective and accurate diagnosis of ASD, such as a blood test, pharmacological management remains a challenge. There are no approved medications to treat the core symptoms of the disorder and behavioral interventions are typically used as first line treatment. Additionally, psychotropic drugs with different mechanisms of action have been approved to reduce associated symptoms and comorbidities, including aripiprazole, risperidone, and haloperidol for irritability and aggression, methylphenidate, atomoxetine, clonidine, and guanfacine for ADHD, and melatonin for sleep disturbances. The purpose of this review is to emphasize that it is imperative to develop objective, personalized diagnostic kits in order to tailor and individualize treatment strategies, as well as to describe the current pharmacological management options available in clinical practice and new prospects that may be helpful in managing ASD's core symptoms.
Subject(s)
Attention Deficit Disorder with Hyperactivity , Autism Spectrum Disorder , Autistic Disorder , Methylphenidate , Child , Humans , Autism Spectrum Disorder/drug therapy , Autistic Disorder/drug therapy , Psychotropic Drugs/therapeutic use , Psychotropic Drugs/pharmacology , Attention Deficit Disorder with Hyperactivity/drug therapy , Methylphenidate/therapeutic useABSTRACT
Thyroid hormone (T3) plays a vital role in brain development and its dysregulation can impact behavior, nervous system function, and cognitive development. Large case-cohort studies have associated abnormal maternal T3 during early pregnancy to epilepsy, autism, and attention deficit hyperactivity disorder (ADHD) in children. Recent experimental findings have also shown T3's influence on the fate of neural precursor cells and raise the question of its convergence with embryonic neural progenitors. Our objective was to investigate how T3 treatment affects neuronal development and functionality at the cellular level. In vitro experiments using neural precursor cells (NPCs) measured cell growth and numbers after exposure to varying T3 concentrations. Time points included week 0 (W0) representing NPCs treated with 100 nM T3 for 5 days, and differentiated cortical neurons assessed at weeks 3 (W3), 6 (W6), and 8 (W8). Techniques such as single-cell calcium imaging and whole-cell patch clamp were utilized to evaluate neuronal activity and function. IHC staining detected mature neuron markers, and RNA sequencing enabled molecular profiling. W6 and W8 neurons exhibited higher action potential frequencies, with W6 showing increased peak amplitudes and shortened inter-spike intervals by 50%, indicating enhanced activity. Transcriptomic analysis revealed that W6 T3-treated neurons formed a distinct cluster, suggesting accelerated maturation. Comparison with the whole transcriptome further unveiled a correlation between W6 neurons treated with T3 and neuronal regulatory elements associated with autism and ADHD. These findings provide insights into T3's impact on neuronal development and potential mechanisms of T3 dysregulation and neurodevelopmental disorders.
ABSTRACT
Somatic cells are reprogrammed with reprogramming factors to generate induced pluripotent stem cells (iPSCs), offering a promising future for disease modeling and treatment by overcoming the limitations of embryonic stem cells. However, this process remains inefficient since only a small percentage of transfected cells can undergo full reprogramming. Introducing miRNAs, such as miR-294 and miR302/3667, with reprogramming factors, has shown to increase iPSC colony formation. Previously, we identified five transcription factors, GBX2, NANOGP8, SP8, PEG3, and ZIC1, which may boost iPSC generation. In this study, we performed quantitative miRNAome and small RNA-seq sequencing and applied our previously identified transcriptome to identify the potential miRNA-mRNA regulomics and regulatory network of other ncRNAs. From each fibroblast (N = 4), three iPSC clones were examined (N = 12). iPSCs and original fibroblasts expressed miRNA clusters differently and miRNA clusters were compared to mRNA hits. Moreover, miRNA, piRNA, and snoRNAs expression profiles in iPSCs and original fibroblasts were assessed to identify the potential role of ncRNAs in enhancing iPSC generation, pluripotency, and differentiation. Decreased levels of let-7a-5p showed an increase of SP8 as described previously. Remarkably, the targets of identifier miRNAs were grouped into pluripotency canonical pathways, on stemness, cellular development, growth and proliferation, cellular assembly, and organization of iPSCs.
Subject(s)
Induced Pluripotent Stem Cells , MicroRNAs , Induced Pluripotent Stem Cells/metabolism , Cellular Reprogramming/genetics , RNA, Messenger/metabolism , MicroRNAs/genetics , MicroRNAs/metabolism , RNA, Untranslated/genetics , RNA, Untranslated/metabolismABSTRACT
Autism spectrum disorder (ASD) is a brain condition characterized by diverse signs and symptoms that appear in early childhood. ASD is also associated with communication deficits and repetitive behavior in affected individuals. Various ASD detection methods have been developed, including neuroimaging modalities and psychological tests. Among these methods, magnetic resonance imaging (MRI) imaging modalities are of paramount importance to physicians. Clinicians rely on MRI modalities to diagnose ASD accurately. The MRI modalities are non-invasive methods that include functional (fMRI) and structural (sMRI) neuroimaging methods. However, diagnosing ASD with fMRI and sMRI for specialists is often laborious and time-consuming; therefore, several computer-aided design systems (CADS) based on artificial intelligence (AI) have been developed to assist specialist physicians. Conventional machine learning (ML) and deep learning (DL) are the most popular schemes of AI used for diagnosing ASD. This study aims to review the automated detection of ASD using AI. We review several CADS that have been developed using ML techniques for the automated diagnosis of ASD using MRI modalities. There has been very limited work on the use of DL techniques to develop automated diagnostic models for ASD. A summary of the studies developed using DL is provided in the Supplementary Appendix. Then, the challenges encountered during the automated diagnosis of ASD using MRI and AI techniques are described in detail. Additionally, a graphical comparison of studies using ML and DL to diagnose ASD automatically is discussed. We suggest future approaches to detecting ASDs using AI techniques and MRI neuroimaging.
ABSTRACT
Extracellular vesicles (EVs) are membrane vesicles released from cells to the extracellular space, involved in cell-to-cell communication by the horizontal transfer of biomolecules such as proteins and RNA. Because EVs can cross the blood-brain barrier (BBB), circulating through the bloodstream and reflecting the cell of origin in terms of disease prognosis and severity, the contents of plasma EVs provide non-invasive biomarkers for neurological disorders. However, neuronal EV markers in blood plasma remain unclear. EVs are very heterogeneous in size and contents, thus bulk analyses of heterogeneous plasma EVs using Western blot and ELISA have limited utility. In this study, using flow cytometry to analyze individual neuronal EVs, we show that our plasma EVs isolated by size exclusion chromatography are mainly CD63-positive exosomes of endosomal origin. As a neuronal EV marker, neural cell adhesion molecule (NCAM) is highly enriched in EVs released from induced pluripotent stem cells (iPSCs)-derived cortical neurons and brain organoids. We identified the subpopulations of plasma EVs that contain NCAM using flow cytometry-based individual EV analysis. Our results suggest that plasma NCAM-positive neuronal EVs can be used to discover biomarkers for neurological disorders.
ABSTRACT
Coronavirus 2019 (COVID-19) is an infectious respiratory disease caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that mainly affects the lungs. COVID-19 symptoms include the presence of fevers, dry coughs, fatigue, sore throat, headaches, diarrhea, and a loss of taste or smell. However, it is understood that SARS-CoV-2 is neurotoxic and neuro-invasive and could enter the central nervous system (CNS) via the hematogenous route or via the peripheral nerve route and causes encephalitis, encephalopathy, and acute disseminated encephalomyelitis (ADEM) in COVID-19 patients. This review discusses the possibility of SARS-CoV-2-mediated Multiple Sclerosis (MS) development in the future, comparable to the surge in Parkinson's disease cases following the Spanish Flu in 1918. Moreover, the SARS-CoV-2 infection is associated with a cytokine storm. This review highlights the impact of these modulated cytokines on glial cell interactions within the CNS and their role in potentially prompting MS development as a secondary disease by SARS-CoV-2. SARS-CoV-2 is neurotropic and could interfere with various functions of neurons leading to MS development. The influence of neuroinflammation, microglia phagocytotic capabilities, as well as hypoxia-mediated mitochondrial dysfunction and neurodegeneration, are mechanisms that may ultimately trigger MS development.
Subject(s)
COVID-19/complications , COVID-19/pathology , Central Nervous System/pathology , Multiple Sclerosis/pathology , Neurodegenerative Diseases/virology , Central Nervous System/virology , Cytokine Release Syndrome/pathology , Cytokines/blood , Cytokines/metabolism , History, 20th Century , Humans , Influenza Pandemic, 1918-1919/statistics & numerical data , Multiple Sclerosis/virology , Neurodegenerative Diseases/pathology , SARS-CoV-2/immunology , Post-Acute COVID-19 SyndromeABSTRACT
Stress granules (SGs) are assemblies of selective messenger RNAs (mRNAs), translation factors, and RNA-binding proteins in small untranslated messenger ribonucleoprotein (mRNP) complexes in the cytoplasm. Evidence indicates that different types of cells have shown different mechanisms to respond to stress and the formation of SGs. In the present work, we investigated how human-induced pluripotent stem cells (hiPSCs/IMR90-1) overcome hyperosmotic stress compared to a cell line that does not harbor pluripotent characteristics (SH-SY5Y cell line). Gradient concentrations of NaCl showed a different pattern of SG formation between hiPSCs/IMR90-1 and the nonpluripotent cell line SH-SY5Y. Other pluripotent stem cell lines (hiPSCs/CRTD5 and hESCs/H9 (human embryonic stem cell line)) as well as nonpluripotent cell lines (BHK-21 and MCF-7) were used to confirm this phenomenon. Moreover, the formation of hyperosmotic SGs in hiPSCs/IMR90-1 was independent of eIF2α phosphorylation and was associated with low apoptosis levels. In addition, a comprehensive proteomics analysis was performed to identify proteins involved in regulating this specific pattern of hyperosmotic SG formation in hiPSCs/IMR90-1. We found possible implications of microtubule organization on the response to hyperosmotic stress in hiPSCs/IMR90-1. We have also unveiled a reduced expression of tubulin that may protect cells against hyperosmolarity stress while inhibiting SG formation without affecting stem cell self-renewal and pluripotency. Our observations may provide a possible cellular mechanism to better understand SG dynamics in pluripotent stem cells.
ABSTRACT
Autism spectrum disorder (ASD) is a childhood-onset neurodevelopmental disorder characterized by social interaction, behavior, and communication challenges. Here, we generated an induced pluripotent stem cell (iPSC) line, QBRIi013-A using a non-integrating Sendai virus from a 6-year-old female diagnosed with ASD and intellectual disability. The QBRIi013-A cell line was fully characterized and exhibited a pluripotency capacity and trilineage differentiation potential. Furthermore, it showed normal karyotype and genetic identity to the patient's PBMCs. Consequently, this iPSC line provides a valuable cell model in understanding the molecular mechanism underlying the complexities of ASD pathogenesis.
Subject(s)
Autism Spectrum Disorder , Induced Pluripotent Stem Cells , Intellectual Disability , Cell Line , Child , Female , Humans , Intellectual Disability/genetics , Sendai virusABSTRACT
Autism spectrum disorder (ASD) is a multifaced neurodevelopmental disorder that becomes apparent during early childhood development. The complexity of ASD makes clinically diagnosing the condition difficult. Consequently, by identifying the biomarkers associated with ASD severity and combining them with clinical diagnosis, one may better factionalize within the spectrum and devise more targeted therapeutic strategies. Currently, there are no reliable biomarkers that can be used for precise ASD diagnosis. Consequently, our pilot experimental cohort was subdivided into three groups: healthy controls, individuals those that express severe symptoms of ASD, and individuals that exhibit mild symptoms of ASD. Using next-generation sequencing, we were able to identify several circulating non-coding RNAs (cir-ncRNAs) in plasma. To the best of our knowledge, this study is the first to show that miRNAs, piRNAs, snoRNAs, Y-RNAs, tRNAs, and lncRNAs are stably expressed in plasma. Our data identify cir-ncRNAs that are specific to ASD. Furthermore, several of the identified cir-ncRNAs were explicitly associated with either the severe or mild groups. Hence, our findings suggest that cir-ncRNAs have the potential to be utilized as objective diagnostic biomarkers and clinical targets.
Subject(s)
Autism Spectrum Disorder/blood , Cell-Free Nucleic Acids/blood , RNA, Long Noncoding/blood , RNA, Small Untranslated/blood , Adolescent , Autism Spectrum Disorder/diagnosis , Biomarkers/blood , Child , Child, Preschool , Female , Humans , MaleABSTRACT
Although many factors have been identified and used to enhance the iPSC reprogramming process, its efficiency remains quite low. In addition, reprogramming efficacy has been evidenced to be affected by disease mutations that are present in patient samples. In this study, using RNA-seq platform we have identified and validated the differential gene expression of five transcription factors (TFs) (GBX2, NANOGP8, SP8, PEG3, and ZIC1) that were associated with a remarkable increase in the number of iPSC colonies generated from a patient with Parkinson's disease. We have applied different bioinformatics tools (Gene ontology, protein-protein interaction, and signaling pathways analyses) to investigate the possible roles of these TFs in pluripotency and developmental process. Interestingly, GBX2, NANOGP8, SP8, PEG3, and ZIC1 were found to play a role in maintaining pluripotency, regulating self-renewal stages, and interacting with other factors that are involved in pluripotency regulation including OCT4, SOX2, NANOG, and KLF4. Therefore, the TFs identified in this study could be used as additional transcription factors that enhance reprogramming efficiency to boost iPSC generation technology.
Subject(s)
Induced Pluripotent Stem Cells/cytology , Transcription Factors/metabolism , Cell Differentiation , Cell Proliferation , Cells, Cultured , Cellular Reprogramming , Humans , Induced Pluripotent Stem Cells/metabolism , Kruppel-Like Factor 4 , Parkinson Disease/metabolism , Parkinson Disease/pathologyABSTRACT
Autism spectrum disorder (ASD) refers to a heterogeneous group of complex neurodevelopmental disorders characterized by social skill and communication deficits, along with stereotyped repetitive behavior. miRNAs, small non-coding RNAs that have been recognized as critical regulators of gene expression, play a key role in the neurodevelopmental transcriptional networks of the human brain. Previous investigations have proven that circulating miRNAs open up new possibilities for the emerging roles of diagnostic and prognostic biomarkers in human disorders and diseases. Biomarker development has been progressively becoming more recognized as a cornerstone in medical diagnosis, paving the way to drug discoveries and limiting the progression of various diseases. Due to the complexity of ASD, considerable endeavors have either unsuccessfully identified biomarkers for the disorder or have not yet been established. Cell-free circulating miRNAs in biofluids are extraordinarily stable and considered to represent the next-generation of clinical, non-invasive, biomarkers for many pathologies including neurological and neurodevelopmental disorders. Here, we conducted a review of all peer-reviewed articles addressing the circulating profiles of miRNAs, mostly performed in serum and saliva samples in individuals with ASD.
ABSTRACT
Introduction: Factor XI (FXI) deficiency is a mild bleeding disorder, common among Ashkenazis, that may be underestimated in Caucasians. Management of FXI deficiency in women is a challenge, due to its unpredictable bleeding tendency and the little evidence available on this issue. Objective: To describe gynaecological/obstetrical bleeding complications and to analyze the effectiveness and safety of the antihaemorrhagic treatment among women with FXI deficiency. Material and methods: A retrospective, observational study of 214 Caucasian subjects with FXI deficiency collected during 20 years (1994-2014) without clinical selection. Results: We identified 95 women with FXI deficiency. Any haemorrhagic event was communicated by 26/95 (27.4%), being abnormal uterine bleeding the most frequently found (12/95, 12.6%). Nine postpartum haemorrhages were recorded from 136 deliveries (6.6%) in 57 women. Four postsurgical bleeding complications were registered among 25 gynaecological surgeries (16%) in 20 women. Abnormal uterine bleeding, postpartum and postsurgical haemorrhages were related to both a positive bleeding history and FXI:C values ≤43.5%. Prophylaxis with fresh frozen plasma, used in 12/25 (48%) gynaecological surgeries, did not prevent from postoperative bleeding in three cases, but two developed severe adverse reactions. Conclusion: Women with FXI deficiency, especially those with a positive history of bleeding or FXI:C ≤43.5%, are at risk of developing gynaecological/obstetrical haemorrhages, most of them mild/moderate. Systematic prophylaxis has questionable effectiveness, but might cause severe side effects
Introducción: La deficiencia del factor XI (FXI) es un trastorno hemorrágico leve, común entre los asquenazíes, que puede subestimarse en los caucásicos. El manejo de la deficiencia de FXI en las mujeres es un desafío, debido a la dificultad para predecir la tendencia hemorrágica y la poca evidencia disponible sobre este tema. Objetivo: Describir las complicaciones hemorrágicas ginecológicas/obstétricas y analizar la efectividad y la seguridad del tratamiento antihemorrágico en mujeres con deficiencia de FXI. Material y métodos: Estudio observacional retrospectivo de 214 sujetos caucásicos con deficiencia de FXI recogidos durante 20 años (1994-2014) sin selección clínica. Resultados: Se identificaron 95 mujeres con deficiencia de FXI. Cualquier evento hemorrágico fue comunicado por 26/95 (27.4%), siendo la hemorragia uterina anormal el más frecuente (12/95, 12.6%). Se registraron nueve hemorragias posparto de 136 partos (6,6%) en 57 mujeres. Se registraron cuatro complicaciones hemorrágicas posquirúrgicas en 25 cirugías ginecológicas (16%) en 20 mujeres. La hemorragia uterina anormal y las hemorragias postparto y posquirúrgicas se relacionaron con una historia positiva para hemorragia y valores de FXI:C ≤ 43.5%. La profilaxis con plasma fresco congelado, utilizado en 12/25 (48%) cirugías ginecológicas, no evitó la hemorragia postoperatoria en tres casos, pero dos desarrollaron reacciones adversas graves. Conclusión: Las mujeres con deficiencia de FXI, especialmente aquellas con una historia positiva para hemorragia o FXI:C ≤ 43.5%, están en riesgo de desarrollar hemorragias ginecológicas/obstétricas, la mayoría de ellas leves/moderadas. La profilaxis sistemática tiene una efectividad cuestionable, pero puede causar efectos secundarios graves
Subject(s)
Humans , Female , Pregnancy , Adolescent , Young Adult , Adult , Hemorrhage/complications , Factor XI Deficiency/therapy , Treatment Outcome , Cohort Studies , Factor XI Deficiency/etiology , Uterine Hemorrhage/complications , Uterine Hemorrhage/therapy , Risk FactorsSubject(s)
Factor XI Deficiency/genetics , Factor XI/genetics , Founder Effect , DNA Mutational Analysis , Europe , Humans , MutationABSTRACT
INTRODUCTION: Factor XI (FXI) deficiency is a mild bleeding disorder, common among Ashkenazis, that may be underestimated in Caucasians. Management of FXI deficiency in women is a challenge, due to its unpredictable bleeding tendency and the little evidence available on this issue. OBJECTIVE: To describe gynaecological/obstetrical bleeding complications and to analyze the effectiveness and safety of the antihaemorrhagic treatment among women with FXI deficiency. MATERIAL AND METHODS: A retrospective, observational study of 214 Caucasian subjects with FXI deficiency collected during 20 years (1994-2014) without clinical selection. RESULTS: We identified 95 women with FXI deficiency. Any haemorrhagic event was communicated by 26/95 (27.4%), being abnormal uterine bleeding the most frequently found (12/95, 12.6%). Nine postpartum haemorrhages were recorded from 136 deliveries (6.6%) in 57 women. Four postsurgical bleeding complications were registered among 25 gynaecological surgeries (16%) in 20 women. Abnormal uterine bleeding, postpartum and postsurgical haemorrhages were related to both a positive bleeding history and FXI:C values ≤43.5%. Prophylaxis with fresh frozen plasma, used in 12/25 (48%) gynaecological surgeries, did not prevent from postoperative bleeding in three cases, but two developed severe adverse reactions. CONCLUSION: Women with FXI deficiency, especially those with a positive history of bleeding or FXI:C ≤43.5%, are at risk of developing gynaecological/obstetrical haemorrhages, most of them mild/moderate. Systematic prophylaxis has questionable effectiveness, but might cause severe side effects.
Subject(s)
Factor XI Deficiency/complications , Factor XI Deficiency/ethnology , Metrorrhagia/etiology , Postoperative Hemorrhage/etiology , Postpartum Hemorrhage/etiology , White People , Adolescent , Adult , Aged , Aged, 80 and over , Factor XI Deficiency/drug therapy , Female , Hemostatics/therapeutic use , Humans , Metrorrhagia/diagnosis , Metrorrhagia/epidemiology , Metrorrhagia/prevention & control , Middle Aged , Postoperative Hemorrhage/diagnosis , Postoperative Hemorrhage/epidemiology , Postoperative Hemorrhage/prevention & control , Postpartum Hemorrhage/diagnosis , Postpartum Hemorrhage/epidemiology , Postpartum Hemorrhage/prevention & control , Retrospective Studies , Risk Factors , Spain/epidemiology , Young AdultABSTRACT
Tissue factor, coagulation factor XII, platelets, and neutrophils are implicated as important players in the pathophysiology of (experimental) venous thrombosis (VT). Their role became evident in mouse models in which surgical handlings were required to provoke VT. Combined inhibition of the natural anticoagulants antithrombin (Serpinc1) and protein C (Proc) using small interfering RNA without additional triggers also results in a venous thrombotic phenotype in mice, most notably with vessel occlusion in large veins of the head. VT is fatal but is fully rescued by thrombin inhibition. In the present study, we used this VT mouse model to investigate the involvement of tissue factor, coagulation factor XII, platelets, and neutrophils. Antibody-mediated inhibition of tissue factor reduced the clinical features of VT, the coagulopathy in the head, and fibrin deposition in the liver. In contrast, genetic deficiency in, and small interfering RNA-mediated depletion of, coagulation factor XII did not alter VT onset, severity, or thrombus morphology. Antibody-mediated depletion of platelets fully abrogated coagulopathy in the head and liver fibrin deposition. Although neutrophils were abundant in thrombotic lesions, depletion of circulating Ly6G-positive neutrophils did not affect onset, severity, thrombus morphology, or liver fibrin deposition. In conclusion, VT after inhibition of antithrombin and protein C is dependent on the presence of tissue factor and platelets but not on coagulation factor XII and circulating neutrophils. This study shows that distinct procoagulant pathways operate in mouse VT, dependent on the triggering stimulus.
Subject(s)
Blood Platelets/metabolism , Factor XII/metabolism , Neutrophils/metabolism , Thromboplastin/metabolism , Venous Thrombosis/blood , Animals , Antithrombin III/antagonists & inhibitors , Disease Models, Animal , Female , Mice , Mice, Inbred C57BL , Protein C/antagonists & inhibitorsABSTRACT
INTRODUCTION: Congenital FXI deficiency, a coagulopathy associated with low bleeding risk but thrombotic protection, is usually diagnosed by prolonged APTT and confirmed by coagulation assays. Recent evidences suggest that FXI deficiency might be underestimated. Sensitive and reliable methods to detect FXI deficiency are required. AIM: To examine the sensitivity of two methods and two contact activators on FXI deficiency screening. METHODS: 140 cases with FXI deficiency, 9 severe and 131 moderate, caused by 11different mutations were recruited. APTT and FXI:C were assessed in ACL-TOP 500coagulometer with silica-based (SynthASil) and ellagic acid-based (SynthAFax) reagents. F12 rs1801020 SNP was genotyped with Taqman probes. RESULTS: Severe FXI deficiency significantly prolonged APTT with both reagents. However, a high proportion of moderate deficiencies would not be detected using APTT, with false negatives of 22% for SynthASil and 12% for SynthAFax. False negatives results mainly corresponded to cases with qualitative deficiency (CRM+: p.Pro538Leu), which also had higher FXI coagulant activity. Using SynthASil, the common F12 rs1801020 variant, associated to low FXII levels, significantly prolonged APTT in moderate FXI deficiency subjects. FXI:C values were significantly higher with SynthAFax than with SynthASil (47.7±12.7 vs. 40.4±14.9), so SynthAFax rendered higher rate of false negatives than SynthASil (7% vs.2%). CONCLUSIONS: Moderate FXI deficiency, particularly CRM+, might be underestimated using current diagnostic methods. The activator, FXI and FXII levels may contribute to a higher rate of false negatives using APTT. Our results suggests that the best screening method for FXI deficiency is FXI:C using silica.