Direct evidence of lipid transport by the Drs2-Cdc50 flippase upon truncation of its terminal regions.

P4-ATPases in complex with Cdc50 subunits are lipid flippases that couple ATP hydrolysis with lipid transport to the cytoplasmic leaflet of membranes to create lipid asymmetry. Such vectorial transport has been shown to contribute to vesicle formation in the late secretory pathway. Some flippases are regulated by autoinhibitory regions that can be destabilized by protein kinase-mediated phosphorylation and possibly by binding of cytosolic proteins. In addition, the binding of lipids to flippases may also induce conformational changes required for the activity of these transporters. Here, we address the role of phosphatidylinositol-4-phosphate (PI4P) and the terminal autoinhibitory tails on the lipid flipping activity of the yeast lipid flippase Drs2-Cdc50. By functionally reconstituting the full-length and truncated forms of Drs2 in a 1:1 complex with the Cdc50 subunit, we provide compelling evidence that lipid flippase activity is exclusively detected for the truncated Drs2 variant and is dependent on the presence of the phosphoinositide PI4P. These findings highlight the critical role of phosphoinositides as lipid co-factors in the regulation of lipid transport by the Drs2-Cdc50 flippase.

Chilling Requirements of Apricot (Prunus armeniaca L.) Cultivars Using Male Meiosis as a Dormancy Biomarker.

Apricot has undergone an important cultivar renewal during the last years in response to productive and commercial changes in the crop. The impact of the sharka disease (plum pox virus) prompted the release of cultivars resistant/tolerant to this virus, leading to a major cultivar renewal worldwide. This has caused high variability in chilling requirements on new releases that remain unknown in many cases. In many apricot-growing areas, the lack of winter chilling is becoming a limiting factor in recent years. To deal with this situation, growers must choose cultivars well adapted to their areas. However, the information available on the agroclimatic requirements of the cultivars is very limited. To fill this gap, in this work, we have characterized the chilling requirements of 13 new apricot cultivars from Europe (France, Greece and Spain) and North America (USA) in two experimental collections in Aragón (Spain). We established the chilling period using male meiosis as a biomarker for endodormancy release over two years. Chilling requirements ranged from 51.9 Chill Portions (CP) to 70.9 CP. Knowing the chilling requirements of cultivars will help growers to select suitable cultivars adapted to the chill availability of their region.

Visualizing NBD-lipid Uptake in Mammalian Cells by Confocal Microscopy.

Eukaryotic cells use a series of membrane transporters to control the movement of lipids across their plasma membrane. Several tools and techniques have been developed to analyze the activity of these transporters in the plasma membrane of mammalian cells. Among them, assays based on fluorescence microscopy in combination with fluorescent lipid probes are particularly suitable, allowing visualization of lipid internalization in living cells. Here, we provide a step-by-step protocol for mammalian cell culture, lipid probe preparation, cell labeling, and confocal imaging to monitor lipid internalization by lipid flippases at the plasma membrane based on lipid probes carrying a fluorophore at a short-chain fatty acid. The protocol allows studying a wide range of mammalian cell lines, to test the impact of gene knockouts on lipid internalization at the plasma membrane and changes in lipid uptake during cell differentiation. Key features Visualization and quantification of lipid internalization by lipid flippases at the plasma membrane based on confocal microscopy. Assay is performed on living adherent mammalian cells in culture. The protocol can be easily modified to a wide variety of mammalian cell lines.

Reconstitution of ATP-dependent lipid transporters: gaining insight into molecular characteristics, regulation, and mechanisms.

Lipid transporters play a crucial role in supporting essential cellular processes such as organelle assembly, vesicular trafficking, and lipid homeostasis by driving lipid transport across membranes. Cryo-electron microscopy has recently resolved the structures of several ATP-dependent lipid transporters, but functional characterization remains a major challenge. Although studies of detergent-purified proteins have advanced our understanding of these transporters, in vitro evidence for lipid transport is still limited to a few ATP-dependent lipid transporters. Reconstitution into model membranes, such as liposomes, is a suitable approach to study lipid transporters in vitro and to investigate their key molecular features. In this review, we discuss the current approaches for reconstituting ATP-driven lipid transporters into large liposomes and common techniques used to study lipid transport in proteoliposomes. We also highlight the existing knowledge on the regulatory mechanisms that modulate the activity of lipid transporters, and finally, we address the limitations of the current approaches and future perspectives in this field.

Pharmacogenetic Sex-Specific Effects of Methotrexate Response in Patients with Rheumatoid Arthritis.

Methotrexate (MTX) is a commonly used drug for the treatment of rheumatoid arthritis (RA), but its effectiveness can vary greatly among patients. Pharmacogenetics, the study of how genetic variations can affect drug response, has the potential to improve the personalized treatment of RA by identifying genetic markers that can predict a patient's response to MTX. However, the field of MTX pharmacogenetics is still in its early stages and there is a lack of consistency among studies. This study aimed to identify genetic markers associated with MTX efficacy and toxicity in a large sample of RA patients, and to investigate the role of clinical covariates and sex-specific effects. Our results have identified an association of ITPA rs1127354 and ABCB1 rs1045642 with response to MTX, polymorphisms of FPGS rs1544105, GGH rs1800909, and MTHFR genes with disease remission, GGH rs1800909 and MTHFR rs1801131 polymorphisms with all adverse events, and ADA rs244076 and MTHFR rs1801131 and rs1801133, However, clinical covariates were more important factors to consider when building predictive models. These findings highlight the potential of pharmacogenetics to improve personalized treatment of RA, but also emphasize the need for further research to fully understand the complex mechanisms involved.

Bacterial Nanocellulose from Komagataeibacter Medellinensis in Fique Juice for Activated Carbons Production and Its Application for Supercapacitor Electrodes.

This paper presents the results obtained from the chemical activation of bacterial nanocellulose (BCN) using fique juice as a culture medium. BNC activation (BNCA) was carried out with H3PO4 and KOH at activation temperatures between 500 °C to 800 °C. The materials obtained were characterized morphologically, physicochemically, superficially, and electrochemically, using scanning electron microscopy, X-ray photoelectron spectroscopy (XPS), the physisorption of gases N2 and CO2 at 77 K and 273 K, respectively, cyclic voltammetry, chronopotentiometry, and electrochemical impedance spectroscopy (EIS). The samples activated with H3PO4 presented specific surface areas (SBET) around 780 m2 g-1, while those activated with KOH values presented specific surface areas between 680 and 893 m2 g-1. The XPS analysis showed that the PXPS percentage on the surface after H3PO4 activation was 11 wt%. The energy storage capacitance values ranged between 97.5 F g-1 and 220 F g-1 by EIS in 1 M H2SO4. The samples with the best electrochemical performance were activated with KOH at 700 °C and 800 °C, mainly due to the high SBET available and the accessibility of the microporosity. The capacitance of BNCAs was mainly improved by electrostatic effects due to the SBET rather than that of pseudocapacitive ones due to the presence of phosphorus heteroatoms.

Quercetin and Its Fermented Extract as a Potential Inhibitor of Bisphenol A-Exposed HT-29 Colon Cancer Cells' Viability.

Bisphenol A (BPA) promotes colon cancer by altering the physiological functions of hormones. Quercetin (Q) can regulate signaling pathways through hormone receptors, inhibiting cancer cells. The antiproliferative effects of Q and its fermented extract (FEQ, obtained by Q gastrointestinal digestion and in vitro colonic fermentation) were analyzed in HT-29 cells exposed to BPA. Polyphenols were quantified in FEQ by HPLC and their antioxidant capacity by DPPH and ORAC. Q and 3,4-dihydroxyphenylacetic acid (DOPAC) were quantified in FEQ. Q and FEQ exhibited antioxidant capacity. Cell viability with Q+BPA and FEQ+BPA was 60% and 50%, respectively; less than 20% of dead cells were associated with the necrosis process (LDH). Treatments with Q and Q+BPA induced cell cycle arrest in the G0/G1 phase, and FEQ and FEQ+BPA in the S phase. Compared with other treatments, Q positively modulated ESR2 and GPR30 genes. Using a gene microarray of the p53 pathway, Q, Q+BPA, FEQ and FEQ+BPA positively modulated genes involved in apoptosis and cell cycle arrest; bisphenol inhibited the expression of pro-apoptotic and cell cycle repressor genes. In silico analyses demonstrated the binding affinity of Q > BPA > DOPAC molecules for ERα and ERß. Further studies are needed to understand the role of disruptors in colon cancer.

Fermentation Extract of Naringenin Increases the Expression of Estrogenic Receptor ß and Modulates Genes Related to the p53 Signalling Pathway, miR-200c and miR-141 in Human Colon Cancer Cells Exposed to BPA.

The estrogenic receptor beta (ERß) protects against carcinogenesis by stimulating apoptosis. Bisphenol A (BPA) is related to promoting cancer, and naringenin has chemoprotective activities both can bind to ERß. Naringenin in the colon is metabolized by the microbiota. Cancer involves genetic and epigenetic mechanisms, including miRNAs. The objective of the present study was to evaluate the co-exposure effect of colonic in vitro fermented extract of naringenin (FEN) and BPA, to elucidate molecular effects in HT-29 colon cancer cell line. For this, we quantified genes related to the p53 signaling pathway as well as ERß, miR-200c, and miR-141. As an important result, naringenin (IC50 250 µM) and FEN (IC50 37%) promoted intrinsic pathways of apoptosis through phosphatase and tensin homolog (PTEN) (+2.70, +1.72-fold, respectively) and CASP9 (+3.99, +2.03-fold, respectively) expression. BPA decreased the expression of PTEN (-3.46-fold) gene regulated by miR-200. We suggest that once co-exposed, cells undergo a greater stress forcing them to mediate other extrinsic apoptosis mechanisms associated with death domain FASL. In turn, these findings are related to the increase of ERß (5.3-fold with naringenin and 13.67-fold with FEN) gene expression, important in the inhibition of carcinogenic development.

Self-Incompatibility in Apricot: Identifying Pollination Requirements to Optimize Fruit Production.

In recent years, an important renewal of apricot cultivars is taking place worldwide, with the introduction of many new releases. Self-incompatible genotypes tolerant to the sharka disease caused by the plum pox virus (PPV), which can severely reduce fruit production and quality, are being used as parents in most breeding programs. As a result, the self-incompatibility trait present in most of those accessions can be transmitted to the offspring, leading to the release of new self-incompatible cultivars. This situation can considerably affect apricot management, since pollination requirements were traditionally not considered in this crop and information is lacking for many cultivars. Thus, the objective of this work was to determine the pollination requirements of a group of new apricot cultivars by molecular identification of the S-alleles through PCR amplification of RNase and SFB regions with different primer combinations. The S-genotype of 66 apricot cultivars is reported, 41 for the first time. Forty-nine cultivars were considered self-compatible and 12 self-incompatible, which were allocated in their corresponding incompatibility groups. Additionally, the available information was reviewed and added to the new results obtained, resulting in a compilation of the pollination requirements of 235 apricot cultivars. This information will allow an efficient selection of parents in apricot breeding programs, the proper design of new orchards, and the identification and solution of production problems associated with a lack of fruit set in established orchards. The diversity at the S-locus observed in the cultivars developed in breeding programs indicates a possible genetic bottleneck due to the use of a reduced number of parents.

Impact of the COVID-19 lockdown on liver transplant recipients. A single center observational study

Background: the impact of the COVID-19 outbreak and lockdown on liver transplant (LT) patients remains unknown. The aim of this cross-sectional study was to assess the consequences of the COVID-19 pandemic on the physical and mental health of LT patients during the lockdown period.Methods: a web-based questionnaire was emailed to 238 LT patients undergoing regular follow-up at our unit between August and October 2020. This pseudonymized survey explored demographic and lifestyle variables (i.e., eating and physical habits), disruptions in routine medical care, different dimensions of mental health, COVID-19-related mood and coping (worries/anxiety, depression, insomnia, fear of COVID, resilience, etc.) and health perception using different validated instruments.Results: altogether, 48.7 % (116 of 238) LT recipients accepted to participate in the study, 104 of whom gave their consent to publish the data. The median age was 63 years. Up to 39.4 % presented worrying scores indicating moderate/severe generalized anxiety disorder (GAD), whereas 25.5 % exhibited moderate/severe insomnia and only 10.5 % moderate/severe depression. Forty patients (38.5 %) gained weight, 24 % experienced a worsening in their eating habits and 63.4 % referred to practicing less or much less exercise during the lockdown. Only 25 % perceived a worsening in the control of their chronic comorbidities. Missed medical appointments (0.9 %) or poor adherence to therapy (1.9 %) were exceptional.Conclusions: COVID-19 lockdown has negatively impacted the mental and physical health of LT patients. Long-term consequences remain unclear. (AU)

Male Meiosis as a Biomarker for Endo- to Ecodormancy Transition in Apricot.

Dormancy is an adaptive strategy in plants to survive under unfavorable climatic conditions during winter. In temperate regions, most fruit trees need exposure to a certain period of low temperatures to overcome endodormancy. After endodormancy release, exposure to warm temperatures is needed to flower (ecodormancy). Chilling and heat requirements are genetically determined and, therefore, are specific for each species and cultivar. The lack of sufficient winter chilling can cause failures in flowering and fruiting, thereby compromising yield. Thus, the knowledge of the chilling and heat requirements is essential to optimize cultivar selection for different edaphoclimatic conditions. However, the lack of phenological or biological markers linked to the dormant and forcing periods makes it difficult to establish the end of endodormancy. This has led to indirect estimates that are usually not valid in different agroclimatic conditions. The increasing number of milder winters caused by climatic change and the continuous release of new cultivars emphasize the necessity of a proper biological marker linked to the endo- to ecodormancy transition for an accurate estimation of the agroclimatic requirements (AR) of each cultivar. In this work, male meiosis is evaluated as a biomarker to determine endodormancy release and to estimate both chilling and heat requirements in apricot. For this purpose, pollen development was characterized histochemically in 20 cultivars over 8 years, and the developmental stages were related to dormancy. Results were compared to three approaches that indirectly estimate the breaking of dormancy: an experimental methodology by evaluating bud growth in shoots collected periodically throughout the winter months and transferred to forcing chambers over 3 years, and two statistical approaches that relate seasonal temperatures and blooming dates in a series of 11-20 years by correlation and partial least square regression. The results disclose that male meiosis is a possible biomarker to determine the end of endodormancy and estimate AR in apricot.

Autoinhibition and regulation by phosphoinositides of ATP8B1, a human lipid flippase associated with intrahepatic cholestatic disorders.

P4-ATPases flip lipids from the exoplasmic to the cytosolic leaflet, thus maintaining lipid asymmetry in eukaryotic cell membranes. Mutations in several human P4-ATPase genes are associated with severe diseases, for example in ATP8B1 causing progressive familial intrahepatic cholestasis, a rare inherited disorder progressing toward liver failure. ATP8B1 forms a binary complex with CDC50A and displays a broad specificity to glycerophospholipids, but regulatory mechanisms are unknown. Here, we report functional studies and the cryo-EM structure of the human lipid flippase ATP8B1-CDC50A at 3.1 Å resolution. We find that ATP8B1 is autoinhibited by its N- and C-terminal tails, which form extensive interactions with the catalytic sites and flexible domain interfaces. Consistently, ATP hydrolysis is unleashed by truncation of the C-terminus, but also requires phosphoinositides, most markedly phosphatidylinositol-3,4,5-phosphate (PI(3,4,5)P3), and removal of both N- and C-termini results in full activation. Restored inhibition of ATP8B1 truncation constructs with a synthetic peptide mimicking the C-terminal segment further suggests molecular communication between N- and C-termini in the autoinhibition and demonstrates that the regulatory mechanism can be interfered with by exogenous compounds. A recurring (G/A)(Y/F)AFS motif of the C-terminal segment suggests that this mechanism is employed widely across P4-ATPase lipid flippases in plasma membrane and endomembranes.

NBD-lipid Uptake Assay for Mammalian Cell Lines.

All eukaryotic cells are equipped with transmembrane lipid transporters, which are key players in membrane lipid asymmetry, vesicular trafficking, and membrane fusion. The link between mutations in these transporters and disease in humans highlights their essential role in cell homeostasis. Yet, many key features of their activities, their substrate specificity, and their regulation remain to be elucidated. Here, we describe an optimized quantitative flow cytometry-based lipid uptake assay utilizing nitrobenzoxadiazolyl (NBD) fluorescent lipids to study lipid internalization in mammalian cell lines, which allows characterizing lipid transporter activities at the plasma membrane. This approach allows for a rapid analysis of large cell populations, thereby greatly reducing sampling variability. The protocol can be applied to study a wide range of mammalian cell lines, to test the impact of gene knockouts on lipid internalization at the plasma membrane, and to uncover the dynamics of lipid transport at the plasma membrane. Graphic abstract: Internalization of NBD-labeled lipids from the plasma membrane of CHO-K1 cells.

Impact of the COVID-19 lockdown on liver transplant recipients. A single center observational study.

BACKGROUND: the impact of the COVID-19 outbreak and lockdown on liver transplant (LT) patients remains unknown. The aim of this cross-sectional study was to assess the consequences of the COVID-19 pandemic on the physical and mental health of LT patients during the lockdown period. METHODS: a web-based questionnaire was emailed to 238 LT patients undergoing regular follow-up at our unit between August and October 2020. This pseudonymized survey explored demographic and lifestyle variables (i.e., eating and physical habits), disruptions in routine medical care, different dimensions of mental health, COVID-19-related mood and coping (worries/anxiety, depression, insomnia, fear of COVID, resilience, etc.) and health perception using different validated instruments. RESULTS: altogether, 48.7 % (116 of 238) LT recipients accepted to participate in the study, 104 of whom gave their consent to publish the data. The median age was 63 years. Up to 39.4 % presented worrying scores indicating moderate/severe generalized anxiety disorder (GAD), whereas 25.5 % exhibited moderate/severe insomnia and only 10.5 % moderate/severe depression. Forty patients (38.5 %) gained weight, 24 % experienced a worsening in their eating habits and 63.4 % referred to practicing less or much less exercise during the lockdown. Only 25 % perceived a worsening in the control of their chronic comorbidities. Missed medical appointments (0.9 %) or poor adherence to therapy (1.9 %) were exceptional. CONCLUSIONS: COVID-19 lockdown has negatively impacted the mental and physical health of LT patients. Long-term consequences remain unclear.

Male meiosis in sweet cherry is constrained by the chilling and forcing phases of dormancy.

Male meiosis in temperate fruit trees occurs in the anthers once a year, synchronized with the seasons. The alternation of dormant and growth cycles determines the optimum moment for the male gametophyte formation, a process sensitive to both cold and warm temperatures. This ensures pollen viability and subsequent reproduction success that guarantee fruit production. In this work, we explore how male meiosis is framed by seasonality in sweet cherry. For this purpose, the dormant phases, male meiosis and blooming dates were established in four cultivars with different flowering dates and chilling requirements over 7 years. The chilling and heat requirements for each cultivar were empirically estimated, and chilling and heat temperatures were quantified according to the Dynamic and Growing Degree Hours (GDH) models, respectively. Endodormancy was overcome approximately a fortnight earlier during the colder winters than during the milder winters. Against our initial hypothesis, these differences were not clearly reflected in the time of male meiosis. The period between chilling fulfillment and meiosis lasted several weeks, during which a high amount of GDH accumulated. Results showed that male meiosis is conditioned by endodormancy but especially by warm temperatures, during the forcing period. This differs from what has been described in other related species and creates a framework for further studies to understand the strategies of synchronizing dormancy with seasons.

Determination of Self- and Inter-(in)compatibility Relationships in Apricot Combining Hand-Pollination, Microscopy and Genetic Analyses.

Self-incompatibility in Rosaceae is determined by a Gametophytic Self-Incompatibility System (GSI) that is mainly controlled by the multiallelic locus S. In apricot, the determination of self- and inter-(in)compatibility relationships is increasingly important, since the release of an important number of new cultivars has resulted in the increase of cultivars with unknown pollination requirements. Here, we describe a methodology that combines the determination of self-(in)compatibility by hand-pollinations and microscopy with the identification of the S-genotype by PCR analysis. For self-(in)compatibility determination, flowers at balloon stage from each cultivar were collected in the field, hand-pollinated in the laboratory, fixed, and stained with aniline blue for the observation of pollen tube behavior under the fluorescence microscopy. For the establishment of incompatibility relationships between cultivars, DNA from each cultivar was extracted from young leaves and S-alleles were identified by PCR. This approach allows establishing incompatibility groups and elucidate incompatibility relationships between cultivars, which provides a valuable information to choose suitable pollinizers in the design of new orchards and to select appropriate parents in breeding programs.

Agrobacterium tumefaciens Small Lipoprotein Atu8019 Is Involved in Selective Outer Membrane Vesicle (OMV) Docking to Bacterial Cells.

Outer membrane vesicles (OMVs), released from Gram-negative bacteria, have been attributed to intra- and interspecies communication and pathogenicity in diverse bacteria. OMVs carry various components including genetic material, toxins, signaling molecules, or proteins. Although the molecular mechanism(s) of cargo delivery is not fully understood, recent studies showed that transfer of the OMV content to surrounding cells is mediated by selective interactions. Here, we show that the phytopathogen Agrobacterium tumefaciens, the causative agent of crown gall disease, releases OMVs, which attach to the cell surface of various Gram-negative bacteria. The OMVs contain the conserved small lipoprotein Atu8019. An atu8019-deletion mutant produced wildtype-like amounts of OMVs with a subtle but reproducible reduction in cell-attachment. Otherwise, loss of atu8019 did not alter growth, susceptibility against cations or antibiotics, attachment to plant cells, virulence, motility, or biofilm formation. In contrast, overproduction of Atu8019 in A. tumefaciens triggered cell aggregation and biofilm formation. Localization studies revealed that Atu8019 is surface exposed in Agrobacterium cells and in OMVs supporting a role in cell adhesion. Purified Atu8019 protein reconstituted into liposomes interacted with model membranes and with the surface of several Gram-negative bacteria. Collectively, our data suggest that the small lipoprotein Atu8019 is involved in OMV docking to specific bacteria.

Higher prevalence of psoriatic arthritis in the adult population in Spain? A population-based cross-sectional study.

OBJECTIVE: The prevalence of psoriatic arthritis (PsA) is very heterogeneous. There are no data on its frequency in the general population in Spain. The aim of EPISER2016 study was to estimate the prevalence of PsA in people aged ≥20 years in Spain. METHODS: Cross-sectional multicenter population-based study. Subjects from all the autonomous communities in Spain were randomly selected using multistage stratified cluster sampling. Participants in each of the municipalities randomly selected for the study were administered a telephone-based questionnaire to screen for the study diseases. If the participant reported being previously diagnosed, rheumatologists from the participant's reference hospital confirmed the diagnosis based on a review of the clinical history. Subjects not previously diagnosed but whose screening result was positive based on symptoms received a second telephone call from the investigating rheumatologist in order to evaluate the suspicion. If the suspicion remained, an appointment was made at the reference hospital to complete the diagnostic confirmation process according to CASPAR criteria. To calculate the prevalence and its 95% confidence interval (CI), the sample design was taken into account and weighing was calculated considering age, sex and geographic origin. RESULTS: The sample comprised 4916 subjects. The prevalence of PsA was 0.58% (95%CI: 0.38-0.87). All but 1 of the 27 cases (96.30%) had been diagnosed prior to EPISER2016. CONCLUSION: The prevalence of PsA in Spain was among the highest reported to date, only below that reported in Norway (0.67%) and slightly higher than that reported in Italy (0.42%).

Prevalencia de enfermedades reumáticas en población adulta en España (estudio EPISER 2016). Objetivos y metodología / Prevalence of rheumatic diseases in adult population in Spain (EPISER 2016 study): Aims and methodology

Objetivos: Describir la metodología del estudio de prevalencia de las enfermedades reumáticas en la población adulta en España, EPISER 2016, así como sus fortalezas y limitaciones. El objetivo del proyecto es estimar la prevalencia de artritis reumatoide (AR), artropatía psoriásica (APs), espondilitis anquilosante (EA), lupus eritematoso sistémico (LES), síndrome de Sjögren (SS), artrosis (de rodilla, cadera, manos, columna cervical y lumbar), fibromialgia, gota y fractura osteoporótica clínica. Material y método: Estudio transversal multicéntrico de base poblacional en el que participan 45 municipios de las 17 comunidades autónomas. La población de referencia está compuesta por adultos de 20 o más años residentes en España. La recogida de información se llevará a cabo mediante encuesta telefónica empleando el sistema Computer Assisted Telephone Interview (CATI). Las sospechas diagnósticas y los diagnósticos autorreferidos serán estudiadas por reumatólogos del hospital de referencia de los municipios seleccionados. Análisis estadístico: se calcularán las prevalencias de enfermedades reumáticas mediante estimadores y sus IC del 95%. Se calcularán factores de ponderación en función de la probabilidad de selección en cada una de las etapas del muestreo. Se tendrá en cuenta la distribución de la población en España según datos del Instituto Nacional de Estadística. Conclusiones: Los cambios sociodemográficos y en hábitos de vida durante los últimos 16 años justifican la realización de EPISER 2016. El estudio ofrecerá datos actualizados de prevalencia en AR, EA, APs, LES, SS, artrosis, fibromialgia, gota y fractura osteoporótica clínica. Los resultados permitirán comparar los datos con estudios de otros países y con el EPISER 2000

Aims: To describe the methodology of the EPISER 2016 (study of the prevalence of rheumatic diseases in adult population in Spain), as well its strengths and limitations. The aim of this study is to estimate the prevalence of rheumatoid arthritis (RA), psoriatic arthritis (PsA), ankylosing spondylitis (AS), systemic lupus erythematosus (SLE), Sjögren's syndrome (SS), osteoarthritis (knee, hip, hands, and cervical and lumbar spine), fibromyalgia, gout and clinical osteoporotic fracture. Material and method: Population-based, multicenter, cross-sectional study, with the participation of 45 municipalities in the 17 Spanish autonomous communities. The reference population will consist of adults aged 20 years and over residing in Spain. A computer-assisted telephone interview (CATI) system will be used for data collection. Diagnostic suspicions and diagnoses received by the participants will be studied by rheumatologists in the referral hospitals in the selected municipalities. Statistical analysis: the prevalence of the rheumatic diseases will be calculated using estimators and their 95% confidence intervals. Weights will be calculated in each of the sampling stages in accordance with the probability of selection. The distribution of the population in Spain will be obtained from the Spanish Statistics Institute. Conclusions: Sociodemographic and lifestyle changes over the last 16 years justify EPISER 2016. This study will provide current data about the prevalences of RA, AS, PsA, SLE, SS, osteoarthritis, fibromyalgia, gout and clinical osteoporotic fracture. The results will allow comparisons with studies from other countries and EPISER 2000

Prevalence of rheumatic diseases in adult population in Spain (EPISER 2016 study): Aims and methodology. / Prevalencia de enfermedades reumáticas en población adulta en España (estudio EPISER 2016). Objetivos y metodología.

AIMS: To describe the methodology of the EPISER 2016 (study of the prevalence of rheumatic diseases in adult population in Spain), as well its strengths and limitations. The aim of this study is to estimate the prevalence of rheumatoid arthritis (RA), psoriatic arthritis (PsA), ankylosing spondylitis (AS), systemic lupus erythematosus (SLE), Sjögren's syndrome (SS), osteoarthritis (knee, hip, hands, and cervical and lumbar spine), fibromyalgia, gout and clinical osteoporotic fracture. MATERIAL AND METHOD: Population-based, multicenter, cross-sectional study, with the participation of 45 municipalities in the 17 Spanish autonomous communities. The reference population will consist of adults aged 20 years and over residing in Spain. A computer-assisted telephone interview (CATI) system will be used for data collection. Diagnostic suspicions and diagnoses received by the participants will be studied by rheumatologists in the referral hospitals in the selected municipalities. STATISTICAL ANALYSIS: the prevalence of the rheumatic diseases will be calculated using estimators and their 95% confidence intervals. Weights will be calculated in each of the sampling stages in accordance with the probability of selection. The distribution of the population in Spain will be obtained from the Spanish Statistics Institute. CONCLUSIONS: Sociodemographic and lifestyle changes over the last 16 years justify EPISER 2016. This study will provide current data about the prevalences of RA, AS, PsA, SLE, SS, osteoarthritis, fibromyalgia, gout and clinical osteoporotic fracture. The results will allow comparisons with studies from other countries and EPISER 2000.