Association between mediterranean diet and metal(loid) exposure in 4-5-year-old children living in Spain.

Even relatively low levels of metals exposure may impact health, particularly among vulnerable populations such as infants and young children. However, little is known about the interplay between simultaneous metal exposures, common in real-life scenarios, and their association with specific dietary patterns. In this study, we have evaluated the association between adherence to Mediterranean diet (MD) and urinary metal concentrations individually and as an exposure mixture in 713 children aged 4-5-years from the INMA cohort study. We used a validated food frequency questionnaire to calculate two MD indexes scores: aMED and rMED. These indexes gather information on various food groups within the MD and score differently. To measure urinary concentrations of cobalt, copper, zinc, molybdenum, selenium, lead, and cadmium as exposure biomarkers, we used inductively coupled plasma mass spectrometry (ICP-MS), coupled with an ion chromatography (IC) equipment for arsenic speciation analysis. We applied linear regression and quantile g-computation, adjusted for confounders, to analyse the association between MD adherence and exposure to the metal mixture. High adherence to MD such as the quintile (Q) 5 MD was associated with higher urinary arsenobetaine (AsB) levels than Q1, with ß values of 0.55 (confidence interval - CI 95% 0.01; 1.09) for aMED and 0.73 (CI 95% 0.13; 1.33) for rMED. Consumption of fish was associated with increased urinary AsB but reduced inorganic arsenic concentrations. In contrast, the aMED vegetables consumption increased urinary inorganic arsenic content. A moderate level of adherence to MD (Q2 and Q3) was associated with lower copper urinary concentrations than Q1, with ß values of -0.42 (CI 95% -0.72; -0.11) for Q2 and -0.33 (CI 95% -0.63; -0.02) for Q3, but only with aMED. Our study, conducted in Spain, revealed that adhering to the MD reduces exposure to certain metals while increasing exposure to others. Specifically, we observed increase in exposure to non-toxic AsB, highlighting the significance of consuming fish/seafood. However, it is crucial to emphasize the necessity for additional efforts in reducing early-life exposure to toxic metals, even when adhering to certain food components of the MD.

Dupilumab to induce tolerance to SLIT-Melocotón®.

Summary: Introduction. Food allergy is an increasing problem for population and treatments inducing tolerance using sublingual immunotherapy is currently under study. Case presentation. Our aim as allergists is to achieve tolerance to sublingual allergen specific immunotherapy with sublingual immunotherapy (SLIT-peach). We present a case report consisting of a 40 year old woman with anaphylactic reactions after eating fruit and other plant-foods due to sensitization to nonspecific lipid transfer proteins (nsLTP). Her diagnose, LTP-syndrome. This protein is the main panallergen in our area and causes crossed reaction to multiple plant foods. The principal allergen in this syndrome is rPru p3, present in peach and most vegetables, fruits, nuts and grains. Serum specific IgE levels were performed using microarrays and positive for seven nsLTPs: rAra h9, rCor a8, nJug r3, rPru p3, rTri a 14, nArt v3 and rPla a3. Immediate reaction to SLIT in the fourth month of maintenance-dose led us to interrupt pru p3 immunotherapy. Immediate reaction to Omalizumab in the fourth dose in Hospital consisting in anaphylaxis prompted us to switch to Dupilumab. After four months with this monoclonal antibody we reintroduced sublingual immunotherapy with pru p3 SLIT-peach® achieving maintenance dose of four drops a day with no clinical reactions. SLIT-peach® in our patient is crucial for her due to her restricted diet, the severity of reactions and lack of quality of life measured by Europevall questionnaire. Conclusions in our case our aim is to achieve SLIT. We report a case of compassionate use with Dupilumab in a patient with multiple food allergy syndrome mediated by nsLTP. There are no cases reported for Dupilumab in this use.

Mean field approach applied to surface deposition on a modified electrode.

In this work we study the deposition phenomena on a modified electrode in the framework of the mean field theory. The electrode surface is modified by irreversible deposition of impurities which can block a fraction of the adsorption sites. Then, an electroactive species is allowed to adsorb on the accessible sites, transferring electric charge and generating a current that can be calculated and measured. Nearest-neighbor lateral interactions are considered both between electroactive particles and between particles and impurities. A modified Bragg-Williams theoretical approach considers both the blocking effects of impurities and the lateral interactions, through different concentrations of impurities and particles. The analysis is based on the study of adsorption isotherms and voltammograms, considering different interaction energies and impurity concentrations. The potentialities and limitations of the analytical approximation are discussed by comparing theoretical predictions with Monte Carlo simulations and experimental measurements in which artificial clay represents the impurity and a [Fe(CN)6]4 redox probe is the species that transfers the charge.

Ultrasonographic and hemodynamic characteristics of patients with symptomatic carotid near-occlusion: results from a multicenter registry study.

PURPOSE: The ultrasonographic and hemodynamic features of patients with carotid near-occlusion (CNO) are still not well known. Our aim was to describe the ultrasonographic and hemodynamic characteristics of a cohort of patients with CNO. METHODS: A prospective, observational, nationwide, and multicenter study was conducted from January/2010 to May/2016. Patients with digital subtraction angiography (DSA)-confirmed CNO were included. We collected information on clinical and demographic characteristics, carotid and transcranial ultrasonography and DSA findings, presence of full-collapse, collateral circulation, and cerebrovascular reactivity (CVR). RESULTS: One hundred thirty-five patients were analyzed. Ultrasonographic and DSA diagnosis of CNO were concordant in only 44%. This disagreement was related to the presence/absence of full-collapse: 45% of patients with CNO with full-collapse were classified as a complete carotid occlusion, and 40% with a CNO without full-collapse were interpreted as severe stenosis (p < 0.001). Mean velocities (mV) and pulsatility indexes (PIs) were significantly lower in the ipsilateral middle cerebral artery compared with the contralateral (43 cm/s vs 58 cm/s, p < 0.001; 0.80 vs 1.00, p < 0.001). Collateral circulation was identified in 92% of patients, with the anterior communicating artery (73%) being the most frequent. CVR was decreased or exhausted in 66% of cases and was more frequent in patients with a poor or absent collateral network compared with patients with ≥ 2 collateral arteries (82% vs 56%, p = 0.051). CONCLUSION: The accuracy of carotid ultrasonography in the diagnosis of CNO seems to be limited, with significant discrepancies with DSA. Decreased ipsilateral mV, PI, and CVR suggest a hemodynamic compromise in patients with CNO.

Discharge properties of morphologically identified vestibular neurons recorded during horizontal eye movements in the goldfish.

Computational capability and connectivity are key elements for understanding how central vestibular neurons contribute to gaze-stabilizing eye movements during self-motion. In the well-characterized and segmentally distributed hindbrain oculomotor network of goldfish, we determined afferent and efferent connections along with discharge patterns of descending octaval nucleus (DO) neurons during different eye motions. Based on activity correlated with horizontal eye and head movements, DO neurons were categorized into two complementary groups that either increased discharge during both contraversive (type II) eye (e) and ipsiversive (type I) head (h) movements (eIIhI) or vice versa (eIhII). Matching time courses of slow-phase eye velocity and corresponding firing rates during prolonged visual and head rotation suggested direct causality in generating extraocular motor commands. The axons of the dominant eIIhI subgroup projected either ipsi- or contralaterally and terminated in the abducens nucleus, Area II, and Area I with additional recurrent collaterals of ipsilaterally projecting neurons within the parent nucleus. Distinct feedforward commissural pathways between bilateral DO neurons likely contribute to the generation of eye velocity signals in eIhII cells. The shared contribution of DO and Area II neurons to eye velocity storage likely represents an ancestral condition in goldfish that is clearly at variance with the task separation between mammalian medial vestibular and prepositus hypoglossi neurons. This difference in signal processing between fish and mammals might correlate with a larger repertoire of visuo-vestibular-driven eye movements in the latter species that potentially required a shift in sensitivity and connectivity within the hindbrain-cerebello-oculomotor network. NEW & NOTEWORTHY We describe the structure and function of neurons within the goldfish descending octaval nucleus. Our findings indicate that eye and head velocity signals are processed by vestibular and Area II velocity storage integrator circuitries whereas the velocity-to-position Area I neural integrator generates eye position solely. This ancestral condition differs from that of mammals, in which vestibular neurons generally lack eye position signals that are processed and stored within the nucleus prepositus hypoglossi.

The neurologist's approach to cerebral infarct and transient ischaemic attack in patients receiving anticoagulant treatment for non-valvular atrial fibrillation: ANITA-FA study.

BACKGROUND AND PURPOSE: The aim of this study was to describe the clinical and epidemiological characteristics of acute ischaemic stroke (AIS) in patients with atrial fibrillation (AF) previously treated with oral anticoagulants (OACs) according to the type of OAC prescribed. Also, to analyze the outcomes of the patients and the therapeutic approach adopted by the neurologist in the acute phase and for secondary prevention. METHODS: We performed a multicenter, observational study based on prospective registries. We included patients with AF treated with OACs admitted for AIS over a 1-year period. Detailed clinical data and functional outcome at 3 months (modified Rankin Scale score) were collected. Patients were divided into two groups according to their pre-AIS anticoagulant therapy: vitamin K antagonists (AIS-VKA) and direct-acting OACs (AIS-DOAC). RESULTS: We recruited 1240 patients (80.4% AIS-VKA and 19.6% AIS-DOAC). In the AIS-DOAC group, transient ischaemic attack was more frequent (18.1% vs. 10.8%; P = 0.001), symptomatic hemorrhagic transformation was less frequent (1.6% vs. 4.6%; P = 0.035) and hospital stay was shorter (median 6 vs. 7 days; P = 0.03). Intravenous thrombolysis was more commonly used in AIS-VKA (9.2% vs. 1.6%; P < 0.001). There were no differences between the groups with respect to mechanical thrombectomy, mortality and modified Rankin Scale score at 3 months. At 3 months, 54% of patients required a DOAC as antithrombotic treatment for secondary prevention. CONCLUSIONS: Patients with AF treated with DOACs who experienced AIS more frequently had transient symptoms (transient ischaemic attack), less symptomatic hemorrhagic transformation and a shorter mean stay than those treated with VKAs. Most patients who had been previously anticoagulated with AIS received long-term treatment with DOACs.

The risk of recurrent stroke at 24 months in patients with symptomatic carotid near-occlusion: results from CAOS, a multicentre registry study.

BACKGROUND AND PURPOSE: The risk of recurrent stroke amongst patients with symptomatic carotid near-occlusion (SCNO) has not been clearly established, and its management remains controversial. The aim was to define the 24-month risk of recurrent stroke and to analyse the effect of the different treatment modalities (medical treatment and revascularization) in a population of patients with SCNO. METHODS: A multicentre, nationwide, prospective study from January 2010 to May 2016 was performed. Patients with angiography-confirmed SCNO were included. The primary end-point was ipsilateral ischaemic stroke including periprocedural events within 24 months following the presenting event. Revascularization results and periprocedural complications, ipsilateral transient ischaemic attack, disabling or fatal stroke, and mortality were also noted. RESULTS: The study population comprised 141 patients from 17 Spanish centres. Seventy patients (49.6%) were treated by revascularization (carotid stenting in 47, endarterectomy in 23). Complete revascularization was achieved in 58 patients (83%). Periprocedural stroke or death occurred in 5.7%. The 24-month cumulative incidence of the primary end-point was 11.1% (95% confidence interval 5.8-16.4; n = 15), 12% in the medical treatment group and 10.2% in the revascularization group, log-rank P = 0.817. The cumulative rates of ipsilateral ischaemic stroke or transient ischaemic attack, disabling or fatal stroke, and mortality, were 17%, 4.5% and 7.5%, respectively. CONCLUSIONS: The rate of ipsilateral ischaemic stroke in patients with SCNO seems to be lower than the known rate associated with severe carotid stenosis without near-occlusion. The potential benefit of revascularization in the prevention of stroke in patients with SCNO may be influenced by the effectiveness and safety of the procedure.

European Space Agency experiments on thermodiffusion of fluid mixtures in space.

This paper describes the European Space Agency (ESA) experiments devoted to study thermodiffusion of fluid mixtures in microgravity environment, where sedimentation and convection do not affect the mass flow induced by the Soret effect. First, the experiments performed on binary mixtures in the IVIDIL and GRADFLEX experiments are described. Then, further experiments on ternary mixtures and complex fluids performed in DCMIX and planned to be performed in the context of the NEUF-DIX project are presented. Finally, multi-component mixtures studied in the SCCO project are detailed.

Effects of isoquinoline alkaloids from Macleaya cordata on physiological, immunological and inflammatory parameters in healthy beagles: Alkaloids in dog nutrition.

The aim of the study was to investigate nutritional, physiological and immunological effects of a plant-derived blend of isoquinoline alkaloids (Sangrovit® Extra) in healthy dogs. Two groups of healthy, adult beagles (N = 10) were tested in a cross-over experiment, lasting two consecutive three-week periods. The experimental group received 1.2 g additive/kg feed, according to the recommendation of 10-20 mg/kg live weight per day. The control group received the same feed without additive. Complete blood count, immunological parameters and amino acid concentrations in serum were assessed. Faeces were analysed for short-chain fatty acids, lactate and ammonium; moreover, their quantity and consistency were determined. Neither feed intake, total apparent nutrient digestibility (crude protein and fat, organic matter, sodium, potassium) were affected by intake of the product. Lymphocyte and monocyte counts were slightly increased in both groups. Elevation was not treatment dependant. IgA, IgG, haptoglobin in serum and flow cytometric phenotyping of peripheral lymphocytes were not affected by alkaloids supplementation. Numerically greater methionine concentrations in blood serum occurred in the experimental group (p = 0.182). Quantity and consistency of faeces and ammonium concentration in faeces were not affected by the additive. Faecal concentrations of short-chain organic acids differed between groups (acetic acid, % of total SCFA: control group 52.3 ± 5.2 vs. experimental group 57.1 ± 4.5, p = 0.042), lactate concentrations (d-, l- and total) did not. Due to the shift of SCFA proportions in faeces, an effect of isoquinoline alkaloids (IQs) on the metabolic activity of intestinal microbiota is probable. In conclusion, the addition of IQs in the given dose was well tolerated and did not have adverse effects in healthy dogs.

Chitosan-triclosan particles modulate inflammatory signaling in gingival fibroblasts.

BACKGROUND AND OBJECTIVES: An important goal of periodontal therapy is the modulation of the inflammatory response. To this end, several pharmacological agents have been evaluated. Triclosan corresponds to an antibacterial and anti-inflammatory agent currently used in periodontal therapy. Chitosan is a natural polymer that may act as a drug delivery agent and exerts antibacterial and anti-inflammatory activities. Therefore, an association between both molecules might be useful to prevent inflammation and tissue destruction in periodontal tissues. MATERIAL AND METHODS: In the present study, we have generated chitosan-triclosan particles and evaluated their morphology, charge, biocompatibility and gene expression analysis in human gingival fibroblasts. RESULTS: The chitosan-triclosan particles size and Z potential were 129 ± 47 nm and 51 ± 17 mV respectively. Human gingival fibroblast viability was not affected by chitosan-triclosan. A total of 1533 genes were upregulated by interleukin (IL)-1ß. On the other hand, 943 were downregulated in fibroblasts stimulated with IL-1ß plus chitosan-triclosan particles. Fifty-one genes were identified as molecular targets upregulated by IL-1 ß and downregulated by the chitosan-triclosan particles. The gene ontology analysis revealed that these genes were enriched in categories related to biological processes, molecular function and cellular components. Furthermore, using real-time reverse transcription-polymerase chain reaction beta-actin, fibronectin, interleukin-6 and IL-1b genes were confirmed as targets upregulated by IL-1ß and downregulated by chitosan-triclosan particles. CONCLUSION: Our results show that chitosan-triclosan particles are able to modulate the inflammatory response in gingival fibroblasts. This effect might be useful in the prevention and/or treatment of inflammation in periodontal diseases.

Relaxation times measurement in single and multiply excited xenon clusters.

Direct measurement of the rates of nonradiative relaxation processes in electronically excited xenon clusters was carried out. The clusters were created in a pulsed supersonic beam and two-photon excited by femtosecond laser pulses with a wavelength of 263 nm. The measurements were performed using the pump-probe method and electron spectroscopy. It is shown that relaxation of light clusters XeN (N < 15) predominantly occurs by desorption of excited xenon atoms with a characteristic time constant of 3 ps. Heavier electronically excited clusters (N > 10) vibrationally relax to the lowest electronically excited state at a rate of about 0.075 eV/ps. Multiply excited clusters are deactivated via energy exchange between excited centers with the ionization of one of them. The production of electrons in this process occurs with a delay of ∼4 ps from the pump pulse, and the process is completed in 10 ps.

The Direct Referral to Endovascular Center criteria: a proposal for pre-hospital evaluation of acute stroke in the Madrid Stroke Network.

BACKGROUND AND PURPOSE: For patients with acute ischaemic stroke due to large-vessel occlusion, it has recently been shown that mechanical thrombectomy (MT) with stent retrievers is better than medical treatment alone. However, few hospitals can provide MT 24 h/day 365 days/year, and it remains unclear whether selected patients with acute stroke should be directly transferred to the nearest MT-providing hospital to prevent treatment delays. Clinical scales such as Rapid Arterial Occlusion Evaluation (RACE) have been developed to predict large-vessel occlusion at a pre-hospital level, but their predictive value for MT is low. We propose new criteria to identify patients eligible for MT, with higher accuracy. METHODS: The Direct Referral to Endovascular Center criteria were defined based on a retrospective cohort of 317 patients admitted to a stroke center. The association of age, sex, RACE scale score and blood pressure with the likelihood of receiving MT were analyzed. Cut-off points with the highest association were thereafter evaluated in a prospective cohort of 153 patients from nine stroke units comprising the Madrid Stroke Network. RESULTS: Patients with a RACE scale score ≥ 5, systolic blood pressure <190 mmHg and age <81 years showed a significantly higher probability of undergoing MT (odds ratio, 33.38; 95% confidence interval, 12-92.9). This outcome was confirmed in the prospective cohort, with 68% sensitivity, 84% specificity, 42% positive and 94% negative predictive values for MT, ruling out 83% of hemorrhagic strokes. CONCLUSIONS: The Direct Referral to Endovascular Center criteria could be useful for identifying patients suitable for MT.

A collaborative system for endovascular treatment of acute ischaemic stroke: the Madrid Stroke Network experience.

BACKGROUND AND PURPOSE: The complexity and expense of endovascular treatment (EVT) for acute ischaemic stroke (AIS) can present difficulties in bringing this approach closer to the patients. A collaborative node was implemented involving three stroke centres (SCs) within the Madrid Stroke Network to provide round-the-clock access to EVT for AIS. METHODS: A weekly schedule was established to ensure that at least one SC was 'on-call' to provide EVT for all those with moderate to severe AIS due to large vessel occlusion, >4.5 h from symptom onset, or within this time-window but with contraindication to, or failure of, systemic thrombolysis. The time-window for treatment was 8 h for anterior circulation stroke and <24 h in posterior stroke. Outcomes measured were re-canalization rates, modified Rankin Scale (mRS) score at 3 months, mortality and symptomatic intra-cranial haemorrhage (SICH). RESULTS: Over a 2-year period (2012-2013), 303 candidate patients with AIS were considered for EVT as per protocol, and 196 (65%) received treatment. Reasons for non-treatment were significant improvement (14%), spontaneous re-canalization (26%), clinical worsening (9%) or radiological criteria of established infarction (31%). Re-canalization rate amongst treated patients was 80%. Median delay from symptom onset to re-canalization was 323 min (p25; p75 percentiles 255; 430). Mortality was 11%; independence (mRS 0-2) was 58%; SICH was 3%. CONCLUSIONS: Implementation of a collaborative network to provide EVT for AIS is feasible and effective. Results are good in terms of re-canalization rates and clinical outcomes.

Quasi-chemical approximation for polyatomic mixtures.

The statistical thermodynamics of binary mixtures of polyatomic species was developed based on a generalization in the spirit of the lattice-gas model and the quasi-chemical approximation (QCA). The new theoretical framework is obtained by combining: (i) the exact analytical expression for the partition function of non-interacting mixtures of linear k-mers and l-mers (species occupying k sites and l sites, respectively) adsorbed in one dimension, and its extension to higher dimensions; and (ii) a generalization of the classical QCA for multicomponent adsorbates and multisite-occupancy adsorption. This process is analyzed using the partial adsorption isotherms corresponding to both species of the mixture. Comparisons with analytical data from Bragg-Williams approximation (BWA) and Monte Carlo simulations are performed in order to test the validity of the theoretical model. Even though a good fitting is obtained from BWA, it is found that QCA provides a more accurate description of the phenomenon of adsorption of interacting polyatomic mixtures.

Endovascular treatment of cerebral venous sinus thrombosis (CVST): Is a complete recanalization required for a good clinical outcome?

The usual therapy in cerebral venous sinus thrombosis (CVST) is based on anticoagulant treatment with adjusted-dose unfractionated heparin. When medical treatment fails, endovascular techniques, such as mechanical thrombectomy, are available. We report a case of a 21-year-old woman with a diagnosis of left CVST, treated by a neurointerventional approach with mechanical thrombectomy using the Penumbra(®) System. Despite the fact that only incomplete recanalization was achieved, a gradual resolution of the thrombus and a progressive clinical improvement occurred.

Factors associated with in-hospital delays in treating acute stroke with intravenous thrombolysis in a tertiary centre. / Identificación de los factores que influyen en el retraso intrahospitalario del inicio de trombólisis intravenosa en el ictus agudo en un hospital terciario.

OBJECTIVE: This study aims to determine which factors are associated with delays in door-to needle (DTN) time in our hospital. This will help us design future strategies to shorten time to treatment with intravenous thrombolysis (IVT). METHODS: Retrospective analysis of a prospective cohort of patients with ischaemic stroke treated with IVT in our hospital between 2009 and 2012. We analysed the relationship between DTN time and the following variables: age, sex, personal medical history, onset-to-door time, pre-hospital stroke code activation, blood pressure and blood glucose level, National Institutes of Health Stroke Scale (NIHSS), computed tomography angiography (CTA) and/or doppler/duplex ultrasound (DUS) performed before IVT, time to hospital arrival, and day of the week and year of stroke. RESULTS: Our hospital treated 239 patients. Median time to treatment in minutes (IQR): onset-to-door, 84 (60-120); door-to-CT, 17 (13-24.75); CT-to needle, 34 (26-47); door-to-needle, 52 (43-70); onset-to-needle, 145 (120-180). Door-to-needle time was significantly shorter when code stroke was activated, at 51 vs. 72min (P=0.008), and longer when CTA was performed, at 59 vs. 48.5min (P=0.004); it was also longer with an onset-to-door time<90min, at 58 vs. 48min (P=0.003). The multivariate linear regression analysis detected 2 factors affecting DTN: code stroke activation (26.3% reduction; P<0.001) and onset-to-door time (every 30min of onset-to-door delay corresponded to a 4.7min increase in DTN time [P=0.02]). On the other hand, CTA resulted in a 13.4% increase in DTN (P=0.03). No other factors had a significant influence on door-to-needle time. CONCLUSIONS: This study enabled us to identify CTA and the «3-hour effect¼ as the 2 factors that delay IVT in our hospital. In contrast, activating code stroke clearly reduces DTN. This information will be useful in our future attempts to reduce door-to-needle times.

Delivery of glutamine synthetase gene by baculovirus vectors: a proof of concept for the treatment of acute hyperammonemia.

Hyperammonemia, a condition present in patients with urea cycle disorders (UCDs) or liver diseases, can cause neuropsychiatric complications, which in the worst cases result in brain damage, coma or death. Diverse treatments exist for the treatment of hyperammonemia, but they have limited efficacy, adverse effects and elevated cost. Gene therapy is a promising alternative that is explored here. A baculovirus, termed Bac-GS, containing the glutamine synthetase (GS) gene was constructed for the in vitro and in vivo treatment of hyperammonemia. Transduction of MA104 epithelial or L6 myoblast/myotubes cells with Bac-GS resulted in a high expression of the GS gene, an increase in GS concentration, and a reduction of almost half of exogenously added ammonia. When Bac-GS was tested in an acute hyperammonemia rat model by intramuscularly injecting the rear legs, the concentration of ammonia in blood decreased 351 µM, in comparison with controls. A high GS concentration was detected in gastrocnemius muscles from the rats transduced with Bac-GS. These results show that gene delivery for overexpressing GS in muscle tissue is a promising alternative for the treatment of hyperammonemia in patients with acute or chronic liver diseases and hepatic encephalopathy or UCD.

Predictors of treatment dropout in self-guided web-based interventions for depression: an 'individual patient data' meta-analysis.

BACKGROUND: It is well known that web-based interventions can be effective treatments for depression. However, dropout rates in web-based interventions are typically high, especially in self-guided web-based interventions. Rigorous empirical evidence regarding factors influencing dropout in self-guided web-based interventions is lacking due to small study sample sizes. In this paper we examined predictors of dropout in an individual patient data meta-analysis to gain a better understanding of who may benefit from these interventions. METHOD: A comprehensive literature search for all randomized controlled trials (RCTs) of psychotherapy for adults with depression from 2006 to January 2013 was conducted. Next, we approached authors to collect the primary data of the selected studies. Predictors of dropout, such as socio-demographic, clinical, and intervention characteristics were examined. RESULTS: Data from 2705 participants across ten RCTs of self-guided web-based interventions for depression were analysed. The multivariate analysis indicated that male gender [relative risk (RR) 1.08], lower educational level (primary education, RR 1.26) and co-morbid anxiety symptoms (RR 1.18) significantly increased the risk of dropping out, while for every additional 4 years of age, the risk of dropping out significantly decreased (RR 0.94). CONCLUSIONS: Dropout can be predicted by several variables and is not randomly distributed. This knowledge may inform tailoring of online self-help interventions to prevent dropout in identified groups at risk.