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OBJECTIVES: Critically ill patients eliminate levetiracetam (LEV) more rapidly than healthy controls, yet low doses are commonly used for seizure prophylaxis in the ICU setting. We compared the rates of achievement of target serum levels and new onset seizure (clinical and/or electrographic) among patients who received low (500 mg bid) versus high (750-1,000 mg bid) dose LEV. DESIGN: Prospective, observational study. SETTING: Tertiary care, academic center. PATIENTS: We included patients who received prophylactic LEV following traumatic brain injury, intracerebral hemorrhage, spontaneous subarachnoid hemorrhage, or supratentorial neurosurgery between 2019 and 2021. Patients with a history of seizure, antiseizure medication use, or renal failure requiring dialysis were excluded. INTERVENTIONS: None. MEASUREMENTS: LEV levels were obtained at steady state. The impact of low-dose versus high-dose LEV on the primary outcome of target LEV levels (12-46 µg/mL), and the secondary outcome of clinical and/or electrographic seizure, were assessed using multivariable logistic regression analyses adjusting for age, LEV loading dose, BMI, primary diagnosis and creatinine clearance (CrCl). MAIN RESULTS: Of the 205 subjects included in analyses, n = 106 (52%) received LEV 500 mg bid (median 13 mg/kg/d), and n = 99 (48%) received LEV 750-1,000 mg bid (median 25 mg/kg/d). Overall, 111 of 205 patients (54%) achieved target levels: 48 (45%) from the low-dose group versus 63 (64%) from the high-dose group (odds ratio [OR] 2.1; 95% CI, 1.1-3.7; p = 0.009). In multivariable analyses, high-dose LEV predicted target levels (adjusted OR [aOR] 2.23; 95% CI, 1.16-4.27; p = 0.016), and was associated with lower seizure odds (aOR 0.32; 95% CI, 0.13-0.82; p = 0.018) after adjusting for age, loading dose, BMI, diagnosis, and CrCl. CONCLUSIONS: Underdosing of LEV was common, with only 54% of patients achieving target serum levels. Higher doses (750-1,000 mg bid) were more than twice as likely to lead to optimal drug levels and reduced the odds of seizure by 68% compared with low-dose regimens (500 mg bid).
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Anticonvulsivantes , Piracetam , Humanos , Levetiracetam/uso terapéutico , Anticonvulsivantes/uso terapéutico , Piracetam/uso terapéutico , Estudios Prospectivos , Enfermedad Crítica/terapia , Diálisis Renal , Convulsiones/prevención & controlRESUMEN
BACKGROUND: The complexity, high prevalence, and substantial personal and socioeconomic burden collectively render atopic dermatitis (AD) a major public health concern. Using crowdsourced Internet data has the potential to provide unique insights into this concern, as demonstrated by several previous studies. However, a comprehensive comparison across European countries remains lacking. OBJECTIVES: The study aimed to investigate AD-related web searches across Europe to assess spatiotemporal variations and associations between disease-related and external factors. METHODS: AD-related web search data were extracted for 21 European countries between February 2019 and January 2023. Descriptive analysis and autocorrelation functions were performed to examine spatiotemporal patterns. Correlations (r) were used to evaluate the associations between web searches and disease-related, socioeconomic and meteorological data. RESULTS: Over 241 million AD-related web searches were identified, with search volume varying substantially among European countries (p < 0.001) and correlating with AD prevalence and disease burden (both r = 0.51, p = 0.019). Search volume increased between 2019 and 2023 in all countries and seasonally peaked in January and March. Negative correlations with median population age (r = -0.46, p = 0.039), number of general practitioners (r = -0.29, p = 0.226) and specialists (r = -0.27, p = 0.270) were observed. Moderate to strong correlations were found between search volume and cold, humid and windy weather with fewer sunshine hours, while higher online interest typically occurred 1-3 months after such weather conditions. CONCLUSION: The study highlights the great potential of online crowdsourced data analysis, for example, to investigate the impact of climate change or to identify unmet needs at a population level. Furthermore, the growing online interest in AD and the corresponding seasonal peaks emphasize the necessity of adapting treatment plans, intensifying public health campaigns, and disseminating reliable online information by governments and healthcare providers, especially during these periods.
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Dermatitis Atópica , Internet , Dermatitis Atópica/epidemiología , Humanos , Europa (Continente)/epidemiología , Prevalencia , Costo de Enfermedad , Estaciones del Año , Colaboración de las MasasRESUMEN
BACKGROUND: Elevated plasma Lp(a) (lipoprotein(a)) levels are associated with increased risk for atherosclerotic cardiovascular disease and aortic valve stenosis. However, the cell biology of Lp(a) biosynthesis remains poorly understood, with the locations of the noncovalent and covalent steps of Lp(a) assembly unclear and the nature of the apoB-containing particle destined for Lp(a) unknown. We, therefore, asked if apo(a) and apoB interact noncovalently within hepatocytes and if this impacts Lp(a) biosynthesis. METHODS: Using human hepatocellular carcinoma cells expressing 17K (17 kringle) apo(a), or a 17KΔLBS7,8 variant with a reduced ability to bind noncovalently to apoB, we performed coimmunoprecipitation, coimmunofluorescence, and proximity ligation assays to document intracellular apo(a):apoB interactions. We used a pulse-chase metabolic labeling approach to measure apo(a) and apoB secretion rates. RESULTS: Noncovalent complexes containing apo(a)/apoB are present in lysates from cells expressing 17K but not 17KΔLBS7,8, whereas covalent apo(a)/apoB complexes are absent from lysates. 17K and apoB colocalized intracellularly, overlapping with staining for markers of endoplasmic reticulum trans-Golgi, and early endosomes, and less so with lysosomes. The 17KΔLBS7,8 had lower colocalization with apoB. Proximity ligation assays directly documented intracellular 17K/apoB interactions, which were dramatically reduced for 17KΔLBS7,8. Treatment of cells with PCSK9 (proprotein convertase subtilisin/kexin type 9) enhanced, and lomitapide reduced, apo(a) secretion in a manner dependent on the noncovalent interaction between apo(a) and apoB. Apo(a) secretion was also reduced by siRNA-mediated knockdown of APOB. CONCLUSIONS: Our findings explain the coupling of apo(a) and Lp(a)-apoB production observed in human metabolic studies using stable isotopes as well as the ability of agents that inhibit apoB biosynthesis to lower Lp(a) levels.
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Apolipoproteína B-100/metabolismo , Apolipoproteínas A/metabolismo , Hepatocitos/metabolismo , Lipoproteína(a)/metabolismo , Apolipoproteína B-100/química , Apolipoproteínas A/química , Apolipoproteínas A/genética , Sitios de Unión/genética , Células Hep G2 , Humanos , Kringles/genética , Lipoproteína(a)/química , Lisina/química , Redes y Vías Metabólicas , Complejos Multiproteicos/química , Complejos Multiproteicos/genética , Complejos Multiproteicos/metabolismo , Unión Proteica , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismoRESUMEN
Neutrophilic dermatosis of the dorsal hands (NDDH) is an uncommon localized variant of Sweet syndrome first described in 1995. It is characterized by tender erythematous plaques, pustules, and bullae on the dorsa of the hands. A total of 123 cases of NDDH are included in this review. The mean patient age was 62.1 years, and there was a slight female preponderance. Overall, 78.0% of cases had bilateral involvement, and other sites were affected in almost a third of cases. Underlying disease was found in â¼40% of patients, with the most common associations being hematologic disorders (gammopathies, myelodysplasias, or malignancies), recent infection, solid organ tumors, and inflammatory bowel disease. Systemic or topical corticosteroids or both were employed in the treatment of 88.1% of cases, while dapsone, colchicine, and tetracyclines were the most common steroid-sparing agents used. Improvement was often rapid and complete resolution the norm. Although uncommon, NDDH is frequently misdiagnosed, and thus, its exact prevalence is probably underestimated. Misdiagnosis might have significant implications, including treatment delays or incorrect management. Moreover, recognition of NDDH is important, since a correct diagnosis should trigger a search for underlying diseases and proper treatment with corticosteroids, steroid-sparing agents, or both, which is almost invariably curative.
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Dermatitis , Dermatosis de la Mano , Síndrome de Sweet , Humanos , Femenino , Persona de Mediana Edad , Dermatosis de la Mano/diagnóstico , Dermatosis de la Mano/tratamiento farmacológico , Dermatosis de la Mano/complicaciones , Glucocorticoides , Síndrome de Sweet/diagnóstico , Síndrome de Sweet/tratamiento farmacológico , Síndrome de Sweet/complicaciones , Antibacterianos , Dermatitis/complicaciones , VesículaRESUMEN
BACKGROUND: Health-related quality of life (HRQoL) assessment in patients with acne is recommended by several national guidelines. There are several acne-specific HRQoL instruments. OBJECTIVES: Participants of the European Academy of Dermatology and Venereology (EADV) Task Forces (TFs) on QoL and Patient Oriented Outcomes (PO) and Acne, Rosacea, and Hidradenitis Suppurativa (ARHS) agreed to scrutinize aspects of existing acne-specific HRQoL instruments for their relevance in international study. METHODS: Consensus agreement on items related to QoL was reached after an independent assessment by seven experts from the EADV TFs on QoL and PO, and a list of 97 items was prepared and proposed to a group of acne patients. In order to have data from patients to check if any important topics were overseen, another group of acne patients from participating countries was asked to list how acne influenced different aspects of their lives. RESULTS: Based on results obtained from 601 acne patients from nine countries, most of the items and topics showed low relevance for acne patients especially during the previous month or shorter time periods. Based on percentage of relevance and factor analysis, short (6 items) and long (45 items) lists of the most relevant topics were formed. CONCLUSION: Most of the items and topics from the initial list showed low relevance for acne patients. None of the identified acne-specific HRQoL instruments contain all the items that were deemed most relevant to acne patients. For this reason, participating members of the EADV TFs on QoL and PO, and ARHs are in the process of developing a new acne-specific HRQoL instrument.
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Acné Vulgar , Hidradenitis Supurativa , Rosácea , Humanos , Calidad de Vida , Comités Consultivos , Encuestas y CuestionariosRESUMEN
Rivaroxaban is a direct factor Xa inhibitor, recently implemented as a favorable alternative to warfarin in anticoagulation therapy. Rivaroxaban effectively reduces thrombin generation, which plays a major role in the activation of thrombin activatable fibrinolysis inhibitor (TAFI) to TAFIa. Based on the antifibrinolytic role of TAFIa, we hypothesized that rivaroxaban would consequently induce more rapid clot lysis. In vitro clot lysis assays were used to explore this hypothesis and additionally determine the effects of varying TAFI levels and a stabilizing Thr325Ile polymorphism (rs1926447) in the TAFI protein on the effects of rivaroxaban. Rivaroxaban was shown to decrease thrombin generation, resulting in less TAFI activation, thus enhancing lysis. These effects were also shown to be less substantial in the presence of greater TAFI levels or the more stable Ile325 enzyme. These findings suggest a role for TAFI levels and the Thr325Ile polymorphism in the pharmacodynamics and pharmacogenomics of rivaroxaban.
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Carboxipeptidasa B2 , Humanos , Carboxipeptidasa B2/genética , Carboxipeptidasa B2/farmacología , Rivaroxabán/farmacología , Fibrinólisis , Trombina/metabolismo , MutaciónRESUMEN
PURPOSE OF REVIEW: This review summarizes our current understanding of the processes of apolipoprotein(a) secretion, assembly of the Lp(a) particle and removal of Lp(a) from the circulation. We also identify existing knowledge gaps that need to be addressed in future studies. RECENT FINDINGS: The Lp(a) particle is assembled in two steps: a noncovalent, lysine-dependent interaction of apo(a) with apoB-100 inside hepatocytes, followed by extracellular covalent association between these two molecules to form circulating apo(a).The production rate of Lp(a) is primarily responsible for the observed inverse correlation between apo(a) isoform size and Lp(a) levels, with a contribution of catabolism restricted to larger Lp(a) isoforms.Factors that affect apoB-100 secretion from hepatocytes also affect apo(a) secretion.The identification of key hepatic receptors involved in Lp(a) clearance in vivo remains unclear, with a role for the LDL receptor seemingly restricted to conditions wherein LDL concentrations are low, Lp(a) is highly elevated and LDL receptor number is maximally upregulated. SUMMARY: The key role for production rate of Lp(a) [including secretion and assembly of the Lp(a) particle] rather than its catabolic rate suggests that the most fruitful therapies for Lp(a) reduction should focus on approaches that inhibit production of the particle rather than its removal from circulation.
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Apolipoproteínas A , Lipoproteína(a) , Apolipoproteína B-100 , Apolipoproteínas A/metabolismo , Apoproteína(a) , Humanos , Lipoproteína(a)/metabolismo , Receptores de LDLRESUMEN
Elevated plasma lipoprotein(a) (Lp(a)) is an independent, causal risk factor for atherosclerotic cardiovascular disease and calcific aortic valve stenosis. Lp(a) is formed in or on hepatocytes from successive noncovalent and covalent interactions between apo(a) and apoB, although the subcellular location of these interactions and the nature of the apoB-containing particle involved remain unclear. Sortilin, encoded by the SORT1 gene, modulates apoB secretion and LDL clearance. We used a HepG2 cell model to study the secretion kinetics of apo(a) and apoB. Overexpression of sortilin increased apo(a) secretion, while siRNA-mediated knockdown of sortilin expression correspondingly decreased apo(a) secretion. Sortilin binds LDL but not apo(a) or Lp(a), indicating that its effect on apo(a) secretion is likely indirect. Indeed, the effect was dependent on the ability of apo(a) to interact noncovalently with apoB. Overexpression of sortilin enhanced internalization of Lp(a), but not apo(a), by HepG2 cells, although neither sortilin knockdown in these cells or Sort1 deficiency in mice impacted Lp(a) uptake. We found several missense mutations in SORT1 in patients with extremely high Lp(a) levels; sortilin containing some of these mutations was more effective at promoting apo(a) secretion than WT sortilin, though no differences were found with respect to Lp(a) internalization. Our observations suggest that sortilin could play a role in determining plasma Lp(a) levels and corroborate in vivo human kinetic studies which imply that secretion of apo(a) and apoB are coupled, likely within the hepatocyte.
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Proteínas Adaptadoras del Transporte Vesicular , Apolipoproteínas B , Hiperlipidemias , Lipoproteína(a) , Proteínas Adaptadoras del Transporte Vesicular/metabolismo , Animales , Apolipoproteínas A/metabolismo , Apolipoproteínas B/metabolismo , Apoproteína(a) , Células Hep G2 , Humanos , Cinética , Lipoproteína(a)/metabolismo , RatonesRESUMEN
BACKGROUND: Use of lipoprotein(a) concentrations for identification of individuals at high risk of cardiovascular diseases is hampered by the size polymorphism of apolipoprotein(a), which strongly impacts immunochemical methods, resulting in discordant values. The availability of a reference method with accurate values expressed in SI units is essential for implementing a strategy for assay standardization. METHOD: A targeted LC-MS/MS method for the quantification of apolipoprotein(a) was developed based on selected proteotypic peptides quantified by isotope dilution. To achieve accurate measurements, a reference material constituted of a human recombinant apolipoprotein(a) was used for calibration. Its concentration was assigned using an amino acid analysis reference method directly traceable to SI units through an unbroken traceability chain. Digestion time-course, repeatability, intermediate precision, parallelism, and comparability to the designated gold standard method for lipoprotein(a) quantification, a monoclonal antibody-based ELISA, were assessed. RESULTS: A digestion protocol providing comparable kinetics of digestion was established, robust quantification peptides were selected, and their stability was ascertained. Method intermediate imprecision was below 10% and linearity was validated in the 20-400 nmol/L range. Parallelism of responses and equivalency between the recombinant and endogenous apo(a) were established. Deming regression analysis comparing the results obtained by the LC-MS/MS method and those obtained by the gold standard ELISA yielded y = 0.98*ELISA +3.18 (n = 64). CONCLUSIONS: Our method for the absolute quantification of lipoprotein(a) in plasma has the required attributes to be proposed as a candidate reference method with the potential to be used for the standardization of lipoprotein(a) assays.
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Cromatografía Liquida/métodos , Lipoproteína(a)/sangre , Espectrometría de Masas en Tándem/métodos , Calibración , Cromatografía Liquida/normas , Humanos , Lipoproteína(a)/normas , Estándares de Referencia , Reproducibilidad de los Resultados , Espectrometría de Masas en Tándem/normasRESUMEN
Lipoprotein (a) [Lp(a)] is a risk factor for CVD and a target of therapy, but Lp(a) measurements are not globally standardized. Commercially available assays generally use polyclonal antibodies that detect multiple sites within the kringle (K)IV2 repeat region of Lp(a) and may lead to inaccurate assessments of plasma levels. With increasing awareness of Lp(a) as a cardiovascular risk factor and the active clinical development of new potential therapeutic approaches, the broad availability of reagents capable of providing isoform independence of Lp(a) measurements is paramount. To address this issue, we generated a murine monoclonal antibody that binds to only one site on apo(a). A BALB/C mouse was immunized with a truncated version of apo(a) that contained eight total KIV repeats, including only one copy of KIV2 We generated hybridomas, screened them, and successfully produced a KIV2-independent monoclonal antibody, named LPA-KIV9. Using a variety of truncated apo(a) constructs to map its binding site, we found that LPA-KIV9 binds to KIV9 without binding to plasminogen. Fine peptide mapping revealed that LPA-KIV9 bound to the sequence 4076LETPTVV4082 on KIV9 In conclusion, the generation of monoclonal antibody LPA-KIV9 may be a useful reagent in basic research studies and in the clinical application of Lp(a) measurements.
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Anticuerpos Monoclonales/inmunología , Apoproteína(a)/inmunología , Animales , Sitios de Unión , Inmunización , Ratones , Ratones Endogámicos BALB CRESUMEN
BACKGROUND: Lipoprotein(a) [Lp(a)] levels predict the risk of myocardial infarction (MI) in populations of European ancestry; however, few data are available for other ethnic groups. Furthermore, differences in isoform size distribution and the associated Lp(a) concentrations have not fully been characterized between ethnic groups. METHODS: We studied 6086 cases of first MI and 6857 controls from the INTERHEART study that were stratified by ethnicity and adjusted for age and sex. A total of 775 Africans, 4443 Chinese, 1352 Arabs, 1856 Europeans, 1469 Latin Americans, 1829 South Asians, and 1221 Southeast Asians were included in the study. Lp(a) concentration was measured in each participant using an assay that was insensitive to isoform size, with isoform size being assessed by Western blot in a subset of 4219 participants. RESULTS: Variations in Lp(a) concentrations and isoform size distributions were observed between populations, with Africans having the highest Lp(a) concentration (median=27.2 mg/dL) and smallest isoform size (median=24 kringle IV repeats). Chinese samples had the lowest concentration (median=7.8 mg/dL) and largest isoform sizes (median=28). Overall, high Lp(a) concentrations (>50 mg/dL) were associated with an increased risk of MI (odds ratio, 1.48; 95% CI, 1.32-1.67; P<0.001). The association was independent of established MI risk factors, including diabetes mellitus, smoking, high blood pressure, and apolipoprotein B and A ratio. An inverse association was observed between isoform size and Lp(a) concentration, which was consistent across ethnic groups. Larger isoforms tended to be associated with a lower risk of MI, but this relationship was not present after adjustment for concentration. Consistent with variations in Lp(a) concentration across populations, the population-attributable risk of high Lp(a) for MI varied from 0% in Africans to 9.5% in South Asians. CONCLUSIONS: Lp(a) concentration and isoform size varied markedly between ethnic groups. Higher Lp(a) concentrations were associated with an increased risk of MI and carried an especially high population burden in South Asians and Latin Americans. Isoform size was inversely associated with Lp(a) concentration, but did not significantly contribute to risk.
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Lipoproteína(a)/sangre , Infarto del Miocardio/diagnóstico , Adulto , Anciano , Apolipoproteínas A/análisis , Apolipoproteínas B/análisis , Presión Sanguínea , Estudios de Casos y Controles , Complicaciones de la Diabetes/diagnóstico , Etnicidad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Infarto del Miocardio/epidemiología , Infarto del Miocardio/etnología , Oportunidad Relativa , Isoformas de Proteínas/sangre , Factores de Riesgo , FumarRESUMEN
OBJECTIVE: There is evidence for central nervous system complications of coronavirus disease 2019 (COVID-19) infection, including encephalopathy. Encephalopathy caused by or arising from seizures, especially nonconvulsive seizures (NCS), often requires electroencephalography (EEG) monitoring for diagnosis. The prevalence of seizures and other EEG abnormalities among COVID-19-infected patients is unknown. METHODS: Medical records and EEG studies of patients hospitalized with confirmed COVID-19 infections over a 2-month period at a single US academic health system (four hospitals) were reviewed to describe the distribution of EEG findings including epileptiform abnormalities (seizures, periodic discharges, or nonperiodic epileptiform discharges). Factors including demographics, remote and acute brain injury, prior history of epilepsy, preceding seizures, critical illness severity scores, and interleukin 6 (IL-6) levels were compared to EEG findings to identify predictors of epileptiform EEG abnormalities. RESULTS: Of 111 patients monitored, most were male (71%), middle-aged or older (median age 64 years), admitted to an intensive care unit (ICU; 77%), and comatose (70%). Excluding 11 patients monitored after cardiac arrest, the most frequent EEG finding was moderate generalized slowing (57%), but epileptiform findings were observed in 30% and seizures in 7% (4% with NCS). Three patients with EEG seizures did not have epilepsy or evidence of acute or remote brain injury, although all had clinical seizures prior to EEG. Only having epilepsy (odds ratio [OR] 5.4, 95% confidence interval [CI] 1.4-21) or seizure(s) prior to EEG (OR 4.8, 95% CI 1.7-13) was independently associated with epileptiform EEG findings. SIGNIFICANCE: Our study supports growing evidence that COVID-19 can affect the central nervous system, although seizures are unlikely a common cause of encephalopathy. Seizures and epileptiform activity on EEG occurred infrequently, and having a history of epilepsy or seizure(s) prior to EEG testing was predictive of epileptiform findings. This has important implications for triaging EEG testing in this population.
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Encefalopatías/fisiopatología , Encefalopatías/virología , COVID-19/complicaciones , Anciano , COVID-19/fisiopatología , Electroencefalografía , Humanos , Masculino , Persona de Mediana Edad , Monitorización Neurofisiológica , New York , SARS-CoV-2RESUMEN
PURPOSE OF REVIEW: Evidence continues to mount for elevated lipoprotein(a) [Lp(a)] as a prevalent, independent, and causal risk factor for atherosclerotic cardiovascular disease. However, the effects of existing lipid-lowering therapies on Lp(a) are comparatively modest and are not specific to Lp(a). Consequently, evidence that Lp(a)-lowering confers a cardiovascular benefit is lacking. Large-scale cardiovascular outcome trials (CVOTs) of inhibitory mAbs targeting proprotein convertase subtilisin/kexin type 9 inhibitors (PCSK9i) may address this issue. RECENT FINDINGS: Although the ability of PCSK9i to lower Lp(a) by 15-30% is now clear, the mechanisms involved continue to be debated, with in-vitro and in-vivo studies showing effects on Lp(a) clearance (through the LDL receptor or other receptors) and Lp(a)/apolipoprotein(a) biosynthesis in hepatocytes. The FOURIER CVOT showed that patients with higher baseline levels of Lp(a) derived greater benefit from evolocumab and those with the lowest combined achieved Lp(a) and LDL-cholesterol (LDL-C) had the lowest event rate. Meta-analysis of ten phase 3 trials of alirocumab came to qualitatively similar conclusions concerning achieved Lp(a) levels, although an effect independent of LDL-C lowering could not be demonstrated. SUMMARY: Although it is not possible to conclude that PCSK9i specifically lower Lp(a)-attributable risk, patients with elevated Lp(a) could derive incremental benefit from PCSK9i therapy.
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Anticuerpos Monoclonales/uso terapéutico , Aterosclerosis , Lipoproteína(a)/sangre , Inhibidores de PCSK9 , Inhibidores de Serina Proteinasa/uso terapéutico , Aterosclerosis/sangre , Aterosclerosis/tratamiento farmacológico , Humanos , Proproteína Convertasa 9/metabolismoRESUMEN
It is postulated that lipoprotein (a) [Lp(a)] inhibits fibrinolysis, but this hypothesis has not been tested in humans due to the lack of specific Lp(a) lowering agents. Patients with elevated Lp(a) were randomized to antisense oligonucleotide [IONIS-APO(a)Rx] directed to apo(a) (n = 7) or placebo (n = 10). Ex vivo plasma lysis times and antigen concentrations of plasminogen, factor XI, plasminogen activator inhibitor 1, thrombin activatable fibrinolysis inhibitor, and fibrinogen at baseline, day 85/92/99 (peak drug effect), and day 190 (3 months off drug) were measured. The mean ± SD baseline Lp(a) levels were 477.3 ± 55.9 nmol/l in IONIS-APO(a)Rx and 362.1 ± 89.9 nmol/l in placebo. The mean± SD percentage change in Lp(a) for IONIS-APO(a)Rx was -69.3 ± 12.2% versus -5.4 ± 6.9% placebo (P < 0.0010) at day 85/92/99 and -15.6 ± 8.9% versus 3.2 ± 12.2% (P = 0.003) at day 190. Clot lysis times and coagulation/fibrinolysis-related biomarkers showed no significant differences between IONIS-APO(a)Rx and placebo at all time points. Clot lysis times were not affected by exogenously added Lp(a) at concentrations up to 200 nmol/l to plasma with very low (12.5 nmol/l) Lp(a) levels, whereas recombinant apo(a) had a potent antifibrinolytic effect. In conclusion, potent reductions of Lp(a) in patients with highly elevated Lp(a) levels do not affect ex vivo measures of fibrinolysis; the relevance of any putative antifibrinolytic effects of Lp(a) in vivo needs further study.
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Lipoproteína(a)/sangre , Oligonucleótidos Antisentido/genética , Adolescente , Adulto , Anciano , Femenino , Fibrinólisis/genética , Humanos , Lipoproteína(a)/genética , Masculino , Persona de Mediana Edad , Adulto JovenRESUMEN
PURPOSE OF REVIEW: Evidence continues to mount for an important role for elevated plasma concentrations of lipoprotein(a) [Lp(a)] in mediating risk of atherothrombotic and calcific aortic valve diseases. However, there continues to be great uncertainty regarding some basic aspects of Lp(a) biology including its biosynthesis and catabolism, its mechanisms of action in health and disease, and the significance of its isoform size heterogeneity. Moreover, the precise utility of Lp(a) in the clinic remains undefined. RECENT FINDINGS: The contribution of elevated Lp(a) to cardiovascular risk continues to be more precisely defined by larger studies. In particular, the emerging role of Lp(a) as a potent risk factor for calcific aortic valve disease has received much scrutiny. Mechanistic studies have identified commonalities underlying the impact of Lp(a) on atherosclerosis and aortic valve disease, most notably related to Lp(a)-associated oxidized phospholipids. The mechanisms governing Lp(a) concentrations remain a source of considerable dispute. SUMMARY: This article highlights some key remaining challenges in understanding Lp(a) actions and clinical significance. Most important in this regard is demonstration of a beneficial effect of lowering Lp(a), a development that is on the horizon as effective Lp(a)-lowering therapies are being tested in the clinic.
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Estenosis de la Válvula Aórtica/metabolismo , Válvula Aórtica/patología , Aterosclerosis/metabolismo , Calcinosis/metabolismo , Lipoproteína(a)/metabolismo , Trombosis/metabolismo , Animales , Válvula Aórtica/metabolismo , Estenosis de la Válvula Aórtica/patología , Aterosclerosis/patología , Calcinosis/patología , Humanos , Factores de Riesgo , Trombosis/patologíaRESUMEN
Elevated plasma concentrations of lipoprotein(a) (Lp(a)) are a causal risk factor for coronary heart disease (CHD) and calcific aortic valve stenosis (CAVS). Genetic, epidemiological and in vitro data provide strong evidence for a pathogenic role for Lp(a) in the progression of atherothrombotic disease. Despite these advancements and a race to develop new Lp(a) lowering therapies, there are still many unanswered and emerging questions about the metabolism and pathophysiology of Lp(a). New studies have drawn attention to Lp(a) as a contributor to novel pathogenic processes, yet the mechanisms underlying the contribution of Lp(a) to CVD remain enigmatic. New therapeutics show promise in lowering plasma Lp(a) levels, although the complete mechanisms of Lp(a) lowering are not fully understood. Specific agents targeted to apolipoprotein(a) (apo(a)), namely antisense oligonucleotide therapy, demonstrate potential to decrease Lp(a) to levels below the 30-50 mg/dL (75-150 nmol/L) CVD risk threshold. This therapeutic approach should aid in assessing the benefit of lowering Lp(a) in a clinical setting.