ABSTRACT
A novel rare mutation in the pore region of Nav1.5 channels (p.L889V) has been found in three unrelated Spanish families that produces quite diverse phenotypic manifestations (Brugada syndrome, conduction disease, dilated cardiomyopathy, sinus node dysfunction, etc.) with variable penetrance among families. We clinically characterized the carriers and recorded the Na+ current (INa) generated by p.L889V and native (WT) Nav1.5 channels, alone or in combination, to obtain further insight into the genotypic-phenotypic relationships in patients carrying SCN5A mutations and in the molecular determinants of the Nav1.5 channel function. The variant produced a strong dominant negative effect (DNE) since the peak INa generated by p.L889V channels expressed in Chinese hamster ovary cells, either alone (-69.4 ± 9.0 pA/pF) or in combination with WT (-62.2 ± 14.6 pA/pF), was significantly (n ≥ 17, p < 0.05) reduced compared to that generated by WT channels alone (-199.1 ± 44.1 pA/pF). The mutation shifted the voltage dependence of channel activation and inactivation to depolarized potentials, did not modify the density of the late component of INa, slightly decreased the peak window current, accelerated the recovery from fast and slow inactivation, and slowed the induction kinetics of slow inactivation, decreasing the fraction of channels entering this inactivated state. The membrane expression of p.L889V channels was low, and in silico molecular experiments demonstrated profound alterations in the disposition of the pore region of the mutated channels. Despite the mutation producing a marked DNE and reduction in the INa and being located in a critical domain of the channel, its penetrance and expressivity are quite variable among the carriers. Our results reinforce the argument that the incomplete penetrance and phenotypic variability of SCN5A loss-of-function mutations are the result of a combination of multiple factors, making it difficult to predict their expressivity in the carriers despite the combination of clinical, genetic, and functional studies.
Subject(s)
Cricetulus , NAV1.5 Voltage-Gated Sodium Channel , Pedigree , Penetrance , NAV1.5 Voltage-Gated Sodium Channel/genetics , NAV1.5 Voltage-Gated Sodium Channel/metabolism , Humans , Animals , CHO Cells , Female , Male , Adult , Middle Aged , Spain , Loss of Function Mutation , Phenotype , MutationABSTRACT
OBJECTIVE: Diabetes Self-Management Education and Support (DSMES) is a critical component of diabetes care. This study aims to examine the effect of online-based educational interventions on diabetes management compared to face-to-face interventions. METHODS: A systematic review was conducted by searching three databases for studies in English or Spanish between December 2023 and March 2024. The inclusion criteria were studies that compared face-to-face DSMES with online interventions. RESULTS: The follow-up duration of the trials ranged from 1 to 12 months. Multidisciplinary teams delivered online DSMES through various means, including Short Message Service (SMS), telephone calls, video calls, websites, and applications. Online DSMES was found to be comparable to face-to-face interventions in terms of glycated hemoglobin (HbA1c) levels in people with type 1 diabetes (T1D). In contrast, online interventions that focus on weight management in people with type 2 diabetes (T2D) have shown a significant reduction in HbA1c compared to face-to-face interventions. Online DSMES was found to be superior in terms of quality of life and cost-effectiveness in both T1D and T2D. None of the analyzed studies explored the differences between individual and group methodologies. CONCLUSIONS: The current evidence indicates that online DSMES services provide at least comparable biomedical benefits to face-to-face interventions, suggesting that online interventions could be incorporated into clinical practice as a complement or reinforcement. However, further research is needed to explore the potential benefits and effectiveness of online group sessions in DSMES.
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Antecedentes y objetivo La amiloidosis cardiaca por transtiretina (AC-ATTR) es una enfermedad prevalente con la edad. Se recomienda realizar sistemáticamente un estudio genético incluso en los pacientes más añosos. Nuestro objetivo ha sido realizar un análisis de la prevalencia de amiloidosis por transtiretina hereditaria (ATTRv) en ancianos (≥75años) con AC-ATTR y sus implicaciones. Pacientes y método Estudio observacional retrospectivo de la cohorte de pacientes ancianos con AC-ATTR diagnosticados de acuerdo con el protocolo internacional. Analizamos los resultados de la secuenciación del gen TTR, las características diferenciales y sus implicaciones clínicas. Resultados Entre 2016 y 2022 se diagnosticaron 130 pacientes ancianos (89% cohorte) con AC-ATTR (85% varones). En 8 pacientes de los 123 con estudio genético se identificó una variante patogénica en TTR (6,5%), iniciándose tratamiento específico en 4 sujetos (50%). El estudio familiar identificó otro caso y 6 portadores asintomáticos. No hubo diferencias significativas entre características basales ni en los eventos clínicos. Conclusiones La prevalencia de ATTRv en ancianos con AC-ATTR fue del 6,5%, sin observarse características diferenciales que permitan guiar una indicación selectiva del análisis genético (AU)
Background and objective Cardiac transthyretin amyloidosis (CA-ATTR) is a prevalent disease with age. Genetic study is recommended, even in eldest patients. We aim to analyze the prevalence of hereditary transthyretin amyloidosis (ATTRv) in elderly patients (≥75years) with CA-ATTR and its implications. Patients and methodology Retrospective observational study of the cohort of elderly patients with CA-ATTR diagnosed according to the international recommended protocol. We analyze the results of sequencing TTR gene, the differential characteristics and their clinical implications. Results Between 2016 and 2022, 130 elderly patients (89% cohort) were diagnosed with CA-ATTR (85% male). In 8 of the 123 patients with a genetic study, a pathogenic variant in TTR was identified (6.5%), initiating specific treatment in 4 subjects (50%). The family study identified another case and 6 asymptomatic carriers. There were no significant differences between baseline characteristics or in clinical events. Conclusions The prevalence of ATTRv in elderly patients with CA-ATTR was 6.5% without observing differential characteristics that allow guiding a selective indication of genetic analysis (AU)
Subject(s)
Humans , Male , Female , Aged , Heart Diseases/epidemiology , Heart Diseases/genetics , Amyloidosis/epidemiology , Amyloidosis/genetics , Prealbumin/metabolism , Retrospective Studies , Spain/epidemiology , PrevalenceABSTRACT
BACKGROUND AND OBJECTIVE: Cardiac transthyretin amyloidosis (CA-ATTR) is a prevalent disease with age. Genetic study is recommended, even in eldest patients. We aim to analyze the prevalence of hereditary transthyretin amyloidosis (ATTRv) in elderly patients (≥75years) with CA-ATTR and its implications. PATIENTS AND METHODOLOGY: Retrospective observational study of the cohort of elderly patients with CA-ATTR diagnosed according to the international recommended protocol. We analyze the results of sequencing TTR gene, the differential characteristics and their clinical implications. RESULTS: Between 2016 and 2022, 130 elderly patients (89% cohort) were diagnosed with CA-ATTR (85% male). In 8 of the 123 patients with a genetic study, a pathogenic variant in TTR was identified (6.5%), initiating specific treatment in 4 subjects (50%). The family study identified another case and 6 asymptomatic carriers. There were no significant differences between baseline characteristics or in clinical events. CONCLUSIONS: The prevalence of ATTRv in elderly patients with CA-ATTR was 6.5% without observing differential characteristics that allow guiding a selective indication of genetic analysis.
ABSTRACT
Precision medicine utilizing the genetic information of genes involved in the metabolism and disposition of drugs can not only improve drug efficacy but also prevent or minimize adverse events. Polypharmacy is common among multimorbid patients and is associated with increased adverse events. One of the main objectives in health care is safe and efficacious drug therapy, which is directly correlated to the individual response to treatment. Precision medicine can increase drug safety in many scenarios, including polypharmacy. In this report, we share our experience utilizing precision medicine over the past ten years. Based on our experience using pharmacogenetic (PGx)-informed prescribing, we implemented a five-step precision medicine protocol (5SPM) that includes the assessment of the biological-clinical characteristics of the patient, current and past prescription history, and the patient's PGx test results. To illustrate our approach, we present cases highlighting the clinical relevance of precision medicine with a focus on patients with a complex history and polypharmacy.
ABSTRACT
BACKGROUND: Schizophrenia is a severe mental disorder that often manifests within the first three decades of life. Its prognosis is uncertain and may result in a prolonged treatment that could extend throughout the entire lifespan of the patient. Antipsychotic drugs are characterized by a high interindividual variability when considering therapeutic effect and emergence of adverse effects. Such interindividual variability is thought to be associated primarily with pharmacokinetic matters. OBJECTIVE: The objective of this study was to evaluate the economic impact of the application of the 5-Step Precision Medicine model (5SPM), an approach based on the pharmacogenetic analysis of the primary genes involved in the metabolism of the therapy for each patient, restructuring treatment as necessary. PATIENTS AND METHODS: One hundred eighty-eight psychiatry patients were analysed for single nucleotide polymorphisms on genes CYP1A2, CYP2B6, CYP2C9, CYP2C19, CYP2D6, CYP3A5 and ABCB1. Information on patients' diagnosis, pharmacotherapy, and hospitalizations was collected. RESULTS: We achieved a cost-benefit ratio of 3.31-3.59 with a reduction of direct cost (hospitalizations plus pharmacotherapy) with a reduction of total cost in 67% of the patients who underwent the clinical intervention. CONCLUSION: A rational Precision Medicine-based approach to psychiatric patients could result in a reduction on number of drugs required to control exacerbations, and the underlying pathologies, reducing the risk of adverse effects and improving adherence to treatment, leading to a potential decrease in direct costs. This methodology has been shown to be cost-dominant and, being based on a pharmacogenetic analysis, it has a lifelong nature, as the data obtained can be applied to other medical disciplines.
ABSTRACT
Precision medicine applied to psychiatry provides new insight into the promising field of precision psychiatry. Psychotic disorders are heterogeneous, complex, chronic, and severe mental disorders. Not only does the prognosis and the course of the disease vary among patients suffering from psychotic disorders, but the treatment response varies as well. Although antipsychotic drugs are the cornerstone of the treatment of schizophrenia, many patients only partially respond to these drugs. Furthermore, patients often experience adverse events which can lead to poor treatment adherence. Interindividual variability in drug response could be related to age, gender, ethnicity, lifestyle factors, pharmacological interactions, obesity, and genetics, all of which influence the process of drug metabolism. Commonly prescribed antipsychotics are metabolized by cytochrome P450 (CYP450) enzymes, and CYP450 genes are highly polymorphic. Pharmacogenetic testing is increasingly being used to predict a patient's drug response and could help to find the most appropriate therapy for an individual patient. In this report, we describe a psychotic patient who did not receive adequate clinical follow-up and subsequently presented adverse events, which could be explained by his pharmacogenetic profile and the drug interactions resulting from the polypharmacy prescribed.
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INTRODUCTION AND OBJECTIVES: HCN4 variants have been reported to cause combined sick sinus syndrome (SSS) and left ventricular noncompaction (LVNC) cardiomyopathy. This relationship has been proven in few cases and no previous patients have associated left atrial dilatation (LAD). Our objective was to study a familial disorder characterized by SSS, LAD, and hypertrabeculation/LVNC and to identify the underlying genetic and electrophysiological characteristics. METHODS: A family with SSS and LVNC underwent a clinical, genetic, and electrophysiological assessment. They were studied via electrocardiography, Holter recording, echocardiography, and exercise stress tests; cardiac magnetic resonance imaging was additionally performed in affected individuals. Genetic testing was undertaken with targeted next-generation sequencing, as well as a functional study of the candidate variant in Chinese hamster ovary cells. RESULTS: Twelve members of the family had sinus bradycardia, associated with complete criteria of LVNC in 4 members and hypertrabeculation in 6 others, as well as LAD in 9 members. A HCN4 c.1123C>T;(p.R375C) variant was present in heterozygosis in all affected patients and absent in unaffected individuals. Electrophysiological analyses showed that the amplitude and densities of the HCN4 currents (IHCN4) generated by mutant p.R375C HCN4 channels were significantly lower than those generated by wild-type channels. CONCLUSIONS: The combined phenotype of SSS, LAD, and LVNC is associated with the heritable HCN4 c.1123C>T;(p.R375C) variant. HCN4 variants should be included in the genetic diagnosis of LVNC cardiomyopathy and of patients with familial forms of SSS, as well as of individuals with sinus bradycardia and LAD.
Subject(s)
Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels , Sick Sinus Syndrome , Animals , Bradycardia/diagnosis , Bradycardia/genetics , CHO Cells , Cricetinae , Cricetulus , Dilatation , Humans , Hyperpolarization-Activated Cyclic Nucleotide-Gated Channels/genetics , Muscle Proteins/genetics , Phenotype , Potassium Channels/genetics , Sick Sinus Syndrome/diagnosis , Sick Sinus Syndrome/geneticsABSTRACT
El principal objetivo de la farmacogenómica (PGx) es definir un tratamiento farmacológico individualizado basado en el perfil genético de cada paciente, convirtiendo el paradigma clásico de tratamiento clínico centrado en la enfermedad en un nuevo enfoque, la medicina personalizada. Los polimorfismos genéticos pueden modificar la expresión y la función de las enzimas y las proteínas involucradas en la farmacocinética y la farmacodinámica de los fármacos. Así, la presencia de variantes alélicas permite predecir la respuesta farmacológica para garantizar la eficacia y la seguridad del tratamiento. Para la aplicación clínica de la PGx mediante la identificación de dichas variantes existen actualmente 2 planteamientos diferentes: el análisis de genes candidatos y los estudios de asociación genómica. La implementación clínica de la PGx mejora la eficacia, la seguridad y la relación costo-efectividad de los tratamientos; sin embargo, se ha ralentizado debido a una serie de barreras que se revisarán en este trabajo, así como sus posibles soluciones
The main objective of pharmacogenomics (PGx) is defining an individualized pharmacological treatment based on the genetic profile of each patient. Thus, the classical paradigm of clinical treatment focused on the disease is becoming a new approach, Personalized Medicine. The expression and function of enzymes and proteins involved in the drug pharmacokinetics and pharmacodynamics can be modified by genetic polymorphisms. Thereby, the presence of allelic variants allows predicting the pharmacological response guaranteeing the treatment efficacy and safety. Nowadays, two different approaches have been described for the clinical application of PGx by these variants identification: candidate gene analysis and genome wide association studies. Despite improving the effectiveness, safety and cost-effectiveness of treatments, the PGx clinical implementation has slowed down due to a series of barriers that will be reviewed in this work, as well as their possible solutions
Subject(s)
Humans , Pharmacogenetics/trends , Precision Medicine/trends , Polymorphism, Genetic/genetics , Patient-Specific Modeling/trends , Treatment Outcome , Genetic Profile , Interdisciplinary Communication , Cytochrome P-450 Enzyme System/pharmacokinetics , Cytochrome P-450 CYP2E1/pharmacokinetics , ATP-Binding Cassette Transporters/physiologyABSTRACT
There are many factors involved in the effectiveness and efficiency of psychiatric drug treatment. One of them is psychotropic drug metabolism, which takes place mostly in the liver through the P450 enzyme system. However, there are genotypic variants of this system's enzymes that can directly affect both the efficacy and the onset of side effects of a given therapeutic regimen. These genotypic changes could partly explain the lack of efficacy of treatment in certain patients. We report the case of a patient diagnosed with bipolar type I disorder that presented multiple and frequent manic episodes in which the efficacy and tolerability of several pharmacological regimens with mood stabilizers and antipsychotics was scarce. The choice of medical treatment should be based on its efficacy and side effect profile. This decision can be made more accurately using the information provided by pharmacogenetic analysis. This case illustrates the importance of pharmacogenetic studies in clinical practice. The results of pharmacogenetic analysis helped to decide on a better treatment plan to achieve clinical improvement and reduce drug-induced adverse effects.
ABSTRACT
BACKGROUND: Sensorineural hearing loss (SNHL) is the most common sensory impairment. Comprehensive next-generation sequencing (NGS) has become the standard for the etiological diagnosis of early-onset SNHL. However, accurate selection of target genomic regions (gene panel/exome/genome), analytical performance and variant interpretation remain relevant difficulties for its clinical implementation. METHODS: We developed a novel NGS panel with 199 genes associated with non-syndromic and/or syndromic SNHL. We evaluated the analytical sensitivity and specificity of the panel on 1624 known single nucleotide variants (SNVs) and indels on a mixture of genomic DNA from 10 previously characterized lymphoblastoid cell lines, and analyzed 50 Spanish patients with presumed hereditary SNHL not caused by GJB2/GJB6, OTOF nor MT-RNR1 mutations. RESULTS: The analytical sensitivity of the test to detect SNVs and indels on the DNA mixture from the cell lines was > 99.5%, with a specificity > 99.9%. The diagnostic yield on the SNHL patients was 42% (21/50): 47.6% (10/21) with autosomal recessive inheritance pattern (BSND, CDH23, MYO15A, STRC [n = 2], USH2A [n = 3], RDX, SLC26A4); 38.1% (8/21) autosomal dominant (ACTG1 [n = 3; 2 de novo], CHD7, GATA3 [de novo], MITF, P2RX2, SOX10), and 14.3% (3/21) X-linked (COL4A5 [de novo], POU3F4, PRPS1). 46.9% of causative variants (15/32) were not in the databases. 28.6% of genetically diagnosed cases (6/21) had previously undetected syndromes (Barakat, Usher type 2A [n = 3] and Waardenburg [n = 2]). 19% of genetic diagnoses (4/21) were attributable to large deletions/duplications (STRC deletion [n = 2]; partial CDH23 duplication; RDX exon 2 deletion). CONCLUSIONS: In the era of precision medicine, obtaining an etiologic diagnosis of SNHL is imperative. Here, we contribute to show that, with the right methodology, NGS can be transferred to the clinical practice, boosting the yield of SNHL genetic diagnosis to 50-60% (including GJB2/GJB6 alterations), improving diagnostic/prognostic accuracy, refining genetic and reproductive counseling and revealing clinically relevant undiagnosed syndromes.
Subject(s)
Genomics , Hearing Loss/diagnosis , Hearing Loss/genetics , Adolescent , Adult , Child , Child, Preschool , Female , High-Throughput Nucleotide Sequencing , Humans , INDEL Mutation , Infant , Infant, Newborn , Male , Middle Aged , Phenotype , Spain , Young AdultABSTRACT
Heterogeneity defines both the natural history of asthma as well as patient's response to treatment. Pharmacogenomics contribute to understand the genetic basis of drug response and thus to define new therapeutic targets or molecular biomarkers to evaluate treatment effectiveness. This review is initially focused on different genes so far involved in the pharmacological response to asthma treatment. Specific considerations regarding allergic asthma, the pharmacogenetics aspects of polypharmacy and the application of pharmacogenomics in new drugs in asthma will also be addressed. Finally, future perspectives related to epigenetic regulatory elements and the potential impact of systems biology in pharmacogenetics of asthma will be considered.
Subject(s)
Asthma/drug therapy , Asthma/genetics , Asthma/metabolism , Biomarkers/metabolism , Humans , Pharmacogenetics/methodsSubject(s)
Antidepressive Agents/therapeutic use , Bipolar Disorder/drug therapy , Bipolar Disorder/genetics , Cytochrome P-450 CYP2D6/genetics , Pharmacogenetics/methods , Polymorphism, Genetic/genetics , Antidepressive Agents/adverse effects , Antidepressive Agents/metabolism , Bipolar Disorder/metabolism , Cytochrome P-450 CYP2D6/metabolism , Humans , Pharmacogenetics/trends , Treatment OutcomeABSTRACT
The application of new high-throughput technologies to the study of asthma and other complex diseases is providing a huge amount of genetic information. Particularly, next-generation sequencing generates thousands of variants that have not been previously related to the studied diseases. These new genetic variants require validation both at methodological and clinical level. In this sense, for methodological validation the capillary electrophoresis (CE) sequencing based on Sanger technique continues to be the reference technique. The aim of this chapter is to provide a systematic approach of the in silico procedures to the confirmation of the new genetic variants and to their assessment for the pathogenic condition determination.
Subject(s)
Asthma/genetics , Computational Biology/methods , Genetic Variation , Computer Simulation , Electrophoresis, Capillary , Genetic Predisposition to Disease , High-Throughput Nucleotide Sequencing , Humans , Sequence Analysis, DNAABSTRACT
One of the main concerns in psychiatric care is safety related to drug management. Pharmacogenetics provides an important tool to assess causes that may have contributed the adverse events during psychiatric therapy. This study illustrates the potential of pharmacogenetics to identify those patients for which pharmacogenetic-guided therapy could be appropriate. It aimed to investigate CYP2D6 genotype in our psychiatric population to assess the value of introducing pharmacogenetics as a primary improvement for predicting side effects.A broad series of 224 psychiatric patients comprising psychotic disorders, depressive disturbances, bipolar disorders, and anxiety disorders was included. The patients were genotyped with the AmpliChip CYP450 Test to analyzing 33 allelic variants of the CYP2D6 gene.All bipolar patients with poor metabolizer status showed maniac switching when CYP2D6 substrates such as selective serotonin reuptake inhibitors were prescribed. No specific patterns were identified for adverse events for other disorders.We propose to utilize pharmacogenetic testing as an intervention to aid in the identification of patients who are at risk of developing affective switching in bipolar disorder treated with selective serotonin reuptake inhibitors, CYP2D6 substrates, and inhibitors.
Subject(s)
Antidepressive Agents, Second-Generation/adverse effects , Bipolar Disorder/drug therapy , Cytochrome P-450 CYP2D6/genetics , Genotype , Selective Serotonin Reuptake Inhibitors/adverse effects , Antidepressive Agents, Second-Generation/therapeutic use , Bipolar Disorder/enzymology , Bipolar Disorder/genetics , Cytochrome P-450 CYP2D6/metabolism , Genetic Markers , Humans , Patient Safety , Quality Improvement , Selective Serotonin Reuptake Inhibitors/therapeutic use , Treatment OutcomeABSTRACT
AIM: Antiretroviral treatment implies a high cost to the healthcare system. The aim of this study was to evaluate the clinical and economic impact of efavirenz (EFV) dose adjustment by monitoring plasma concentrations and pharmacogenetic analysis of the 516G>T CYP2B6 polymorphism. MATERIALS & METHODS: One hundred and ninety HIV patients treated with EFV were studied. Plasma EFV concentrations were measured by HPLC with ultraviolet detection, and pharmacogenetic analysis was performed by Real Time (RT)-PCR. RESULTS: One hundred and ninety patients initially treated with a standard dose of EFV (600 mg/day) were studied. In 31 (16.3%) patients, EFV dose was reduced. A total of 87.1% of patients were heterozygous/homozygous carriers (GT/TT). CD4(+) count increased while the minimum steady-state plasma concentration and adverse effects decreased significantly after dose adjustment. Considering only the dose reduction, the adjustments accounted for a saving of 43,539 /year. CONCLUSION: The individualization of EFV dosage guided by genotyping 516G>T CYP2B6 and therapeutic drug monitoring could increase the efficiency of EFV use in antiretroviral treatment.
Subject(s)
Benzoxazines/administration & dosage , Cytochrome P-450 CYP2B6/genetics , HIV Infections/genetics , Adult , Alkynes , Anti-HIV Agents/administration & dosage , Anti-HIV Agents/pharmacokinetics , Benzoxazines/pharmacokinetics , Cost-Benefit Analysis , Cyclopropanes , Drug Monitoring , Female , Genotype , HIV/drug effects , HIV Infections/drug therapy , HIV Infections/pathology , Humans , Male , Middle Aged , PharmacogeneticsABSTRACT
BACKGROUND: CYP2D6, a major drug-metabolizing enzyme, is encoded by a highly polymorphic and complex gene locus. We have identified a patient who failed to produce a CYP2D6 genotype with the AmpliChip P450 Test (AmpliChip), whereas his CYP2C19 genotype was readily determined. The aim of this investigation was to fully characterize the patient's CYP2D6 gene locus to resolve the AmpliChip no-call. METHODS: The case, a brother, and son were genotyped with the AmpliChip and subsequently characterized using long-range (XL)-PCR coupled with TaqMan assay technology. Copy number variation was assessed by XL-PCR and quantitative PCR. Selected XL-PCR products were sequenced. RESULTS: The AmpliChip also produced a no-call for the son; the brother produced a result. The two alleles of the case were subsequently found to carry additional gene units that likely caused the AmpliChip no-calls. One was characterized as a CYP2D6*68+*4 tandem (CYP2D6*68 is a hybrid gene composed of 2D6 and 2D7), the other as a rare CYP2D6*13+*2 tandem (CYP2D6*13 is a 2D7/2D6 hybrid formerly known as CYP2D6*77). A novel CYP2D6*2 subvariant was identified in the son; the brother also carried the CYP2D6*68+*4 tandem. CONCLUSIONS: The implementation of pharmacogenetics-guided drug therapy relies on accurate clinical-grade genotype analysis. Although the AmpliChip is deemed to be a reliable platform, numerous more recently discovered allelic variants and gene arrangements are not detected or trigger no-calls. Although such cases may be rare, the clinical/genetic testing community must be aware of the challenges of CYP2D6 testing on the AmpliChip platform and implications regarding accuracy of test results.
Subject(s)
Cytochrome P-450 CYP2D6/genetics , DNA Mutational Analysis/methods , Genotype , Aged , Alleles , Computer Simulation , DNA Copy Number Variations/genetics , False Negative Reactions , Genetic Loci/genetics , Humans , MaleABSTRACT
OBJECTIVES: Multiplexing technologies based on the use of microspheres as the solid phase have opened new possibilities for the analysis of autoantibodies. As an alternative to the traditional immunoassays, it is possible to use these methods in combination with flow cytometry for simultaneous measurement of anti-thyroid peroxidase (anti-TPO) and anti-thyroglobulin (anti-Tg) antibodies. DESIGN AND METHODS: We studied 127 serum samples sent to our laboratory for the quantitation of anti-TPO and anti-Tg antibodies. Clinical information was available for all of the patients studied. The samples were analyzed simultaneously for both antibodies by flow cytometry (FIDIS, BMD, France), and individually for each of the antibodies by an automated enzyme immunoassay (UniCap, Pharmacia Diagnostics, Germany). RESULTS: A significant association between the results was observed. The kappa agreement indices between the methods were 0.859 and 0.832 for anti-TPO and anti-Tg, respectively. Discrepant results between the two techniques were observed with no common cause. Anti-TPO and anti-Tg antibodies exhibited a non-Gaussian distribution. The areas under the ROC curves were similar for both methods used; for anti-TPO, 0.884 (Pharmacia) and 0.853 (BMD), and for anti-Tg, 0.833 (Pharmacia) and 0.837 (BMD). CONCLUSION: Cytometry multiplex technology offers a true alternative to conventional immunoassays in the analysis of anti-TPO and anti-Tg antibodies.
Subject(s)
Autoantibodies/analysis , Autoimmune Diseases/diagnosis , Flow Cytometry/methods , Iodide Peroxidase/immunology , Thyroglobulin/immunology , Thyroid Diseases/diagnosis , Adult , Female , Fluoroimmunoassay/methods , Humans , Immunoenzyme Techniques/methods , Male , Microspheres , Middle Aged , Reproducibility of ResultsABSTRACT
BACKGROUND: The measurement of antinuclear antibodies (ANA) is used in the autoimmune laboratory for the screening of connective tissue diseases (CTD). ANA measurements are mainly performed by indirect immunofluorescence (IIF) on HEp-2 cells or by enzyme immunoassay (EIA). The objective of this study was to clinically evaluate an automated EIA for extractable nuclear antigens (ENA) which lacks anti-dsDNA for the screening of CTD. METHODS: The study involved a total of 170 serum samples, 54 from patients with CTD, 26 from patients with other autoimmune diseases, and 90 from patients with non-autoimmune diseases. For all sera, ANA detection was performed by IIF and by EliA Symphony (Pharmacia Diagnostics, Freiburg, Germany), an ENA screening which detects the following autoantibodies: SSA/Ro, SSB/La, U1RNP (70 kDa, A, C), Scl-70, JO-1, centromere B and Sm. Also, anti-dsDNA (EliA dsDNA, Pharmacia Diagnostics, Freiburg, Germany) was measured on all samples. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), efficiency, positive likelihood ratio (PLR), and negative likelihood ratio (NLR) were calculated. RESULTS: Diagnostic efficiency was similar for IIF (82.6%) and EliA Symphony (82.3%), as well as PLR (6.5 for IIF, and 7.3 for Eli Symphony), and NLR (0.35 for IIF, and 0.41 for EliA Symphony). The combined measurement of EliA Symphony and dsDNA increased sensitivity but not PLR. Area under receiver operator characteristic (ROC) curve was similar for IIF (0.847) and EliA Symphony (0.823). CONCLUSIONS: The results of the study demonstrate that EliA Symphony solely or combined with anti-dsDNA detection has an efficiency similar to HEp-2 cells IIF with a cut-off of 1:160 for the diagnosis of CTD.