Phospho-RNA-Seq Highlights Specific Small RNA Profiles in Plasma Extracellular Vesicles.

Small RNAs (sRNAs) are bioactive molecules that can be detected in biofluids, reflecting physiological and pathological states. In plasma, sRNAs are found within extracellular vesicles (EVs) and in extravesicular compartments, offering potential sources of highly sensitive biomarkers. Deep sequencing strategies to profile sRNAs favor the detection of microRNAs (miRNAs), the best-known class of sRNAs. Phospho-RNA-seq, through the enzymatic treatment of sRNAs with T4 polynucleotide kinase (T4-PNK), has been recently developed to increase the detection of thousands of previously inaccessible RNAs. In this study, we investigated the value of phospho-RNA-seq on both the EVs and extravesicular plasma subfractions. Phospho-RNA-seq increased the proportion of sRNAs used for alignment and highlighted the diversity of the sRNA transcriptome. Unsupervised clustering analysis using sRNA counts matrices correctly classified the EVs and extravesicular samples only in the T4-PNK treated samples, indicating that phospho-RNA-seq stresses the features of sRNAs in each plasma subfraction. Furthermore, T4-PNK treatment emphasized specific miRNA variants differing in the 5'-end (5'-isomiRs) and certain types of tRNA fragments in each plasma fraction. Phospho-RNA-seq increased the number of tissue-specific messenger RNA (mRNA) fragments in the EVs compared with the extravesicular fraction, suggesting that phospho-RNA-seq favors the discovery of tissue-specific sRNAs in EVs. Overall, the present data emphasizes the value of phospho-RNA-seq in uncovering RNA-based biomarkers in EVs.

Incidence of congenital and postnatal cytomegalovirus infection during the first year of life in Mexican preterm infants.

Cytomegalovirus infection occurs commonly during infancy. Postnatal infection in term infants is usually asymptomatic; however, infection in preterm infants can be associated with clinical manifestations during the neonatal period. Nevertheless, few studies to assess the frequency of cytomegalovirus infection in preterm infants have been performed outside of high-income countries. We analyzed the incidence of congenital and postnatal cytomegalovirus infection in a cohort of preterm infants. Cytomegalovirus infection was detected during the neonatal period in four of 178 infants; in three of them, the virus was detected during the first 3 weeks of life and, therefore, congenital infection was confirmed (1.7% incidence). Postnatal infection was detected in 44 (36.4%) of 121 infants who were assessed after discharge from the neonatal intensive care unit. Cytomegalovirus infection was significantly associated with the duration of breastfeeding. In addition, we characterized cytomegalovirus strains detected in infants together with sequences available at GenBank, based on sequences of the UL18 gene. Cytomegalovirus UL18-sequences clustered in five distinct clades (A-E), and sequences obtained from infants in our study were distributed in four of the five clades; 44.4% of these sequences were included in clade E. Breastfeeding duration was shorter on average (5.6 months) in infants with sequences in clade E compared to infants with sequences in the other three clades (8.2 months; p = .07). In conclusion, we provide information regarding the high incidence of cytomegalovirus infection in preterm infants. Further studies are warranted to assess if cytomegalovirus strain characteristics are associated with the risk of infection acquisition during infancy.

Utility of circulating serum miRNA profiles to evaluate the potential risk and severity of immune-mediated inflammatory disorders.

Immune-mediated inflammatory disorders (IMID) are a group of diseases that present inflammation as a major pathogenic mechanism. They affect 15% of the population and pose a heavy socio-economic burden. Despite the growing knowledge on the etiopathogenesis of these diseases and the marked improvement in their management, there is a lack of predictive markers of IMID development or severity suitable for early diagnosis and adjustment of treatment intensity. The possibility that certain circulating miRNA profiles could be used as biomarkers of risk of development and/or severity of several autoimmune diseases has fuelled the interest in using them to improve the selection of successful treatments. The multi-pronged approach proposed here sought to reveal circulating miRNAs and miRNA signatures that could act as new predictive biomarkers of IMID development and severity. Our results showed that the circulating levels of miR-19b and miR-26b were significantly decreased (p < 0.001) in IMID patients compared to controls. Furthermore, receiver operating characteristic (ROC) curve analysis showed that these miRNAs were suitable discriminators capable to identify an IMID, with areas under the curve (AUC) of 0.85 and 0.83, respectively. In addition, we established that miR-19a and miR-143 were significantly increased in IMID patients with severe disease (p < 0.05). In summary, our findings identify two different miRNA signatures. One of them is associated with the presence of IMIDs and could lead to the development of tools for their early detection. The second signature is able to discriminate between mild and severe forms of these disorders and could be a putative tool to select patient candidates for a more intense treatment.

Lower frequency of anti-citrullinated protein antibodies among early arthritis patients with high body mass index.

OBJECTIVES: To investigate the role of body mass index (BMI) in the phenotypic and genotypic characteristics of early arthritis patients. METHODS: We analysed the clinical and laboratory parameters from the baseline visit of patients (670 patients [78.51% women]) included in the PEARL study. The WHO definition for low weight, normal weight, overweight and obesity (BMI <18.5, 18.5-25, 25-30 or ≥30 kg/m2, respectively) was applied. Anticitrullinated protein antibodies (ACPA) were studied by ELISA and HLA-DRB1* were genotyped by sequence speci c oligonucleotide probes. The relationship between BMI classification and other variables was analysed using Kruskall-Wallis, Anova and Chi-Square tests. Then multivariate logistic regression was performed to establish the role of BMI in ACPA positivity and ordered logistic regression to establish its relationship with ACPA level. RESULTS: Among the patients studied, 255 (38.06%) were considered overweight and 136 (20.3%) obese. High BMI patients had significantly more pain perception and disability than normal weight patients, whereas no clear differences in disease activity were observed between high BMI and normal weight patients. ACPA positivity was significantly less frequent in overweight and obese patients compared to normal BMI patients. This information was confirmed by adjusting for smoking habit and the presence of shared epitope. CONCLUSIONS: Our data support the theory that high BMI patients suffer more frequently from ACPA-negative RA. Nevertheless, although no disease activity differences were observed, these patients showed higher pain and disability scores since the beginning of disease.

"There is something you must see": breaking down the remission concept in rheumatoid arthritis from a rheumatologist's perspective.

OBJECTIVES: To explore the remission concept in rheumatoid arthritis (RA) and the implications of the existing definitions when applied to clinical practice among rheumatologists with different profiles. METHODS: A qualitative study through focus groups was conducted. Three focus groups were organised from February to March 2016. Each group was composed of rheumatologists with extensive clinical experience with different profiles; experts in basic research (RBR), experts in imaging techniques research (RIR), and experts in clinical research (RCR). The data was collected with audio recording. Verbatim transcriptions of the audio files were made, and a subsequent reflexive thematic analysis assisted by ATLAS.ti (GmbH, Berlin, v. 7) software was performed. RESULTS: From the reflexive thematic analysis, three main themes were generated: (1) remission limitations, (2) instruments or measures to assess remission, and (3) a new definition of remission. Rheumatologists mentioned frequently that the following variables should be considered when developing a new remission definition: inflammatory activity, calprotectin, psychological variables, sex, disease stage, and sociocultural factors. Contrary to what could be expected, all groups acknowledged that their research field could contribute with domains for a gold standard remission instrument, but not in a hierarchical arrangement of importance. The dissonance existing in the entire remission evaluation process was outlined: remission in clinical practice versus remission in clinical trials, remission following the American College of Rheumatology (ACR)/European League Against Rheumatism (EULAR) Boolean versus Musculoskeletal Ultrasound (US) remission, and remission from the rheumatologist's point of view versus the patient's point of view. CONCLUSIONS: Currently, rheumatologists would not accept a domain as more important than others in remission. Our suggestion is, not to generate a universal definition of remission - one that could cover all aspects - but rather to develop definitions of remission for the different settings that could be pondered by the patient's perspective.

Rapid beneficial effect of the IL-6 receptor blockade on insulin resistance and insulin sensitivity in non-diabetic patients with rheumatoid arthritis.

OBJECTIVES: In patients with rheumatoid arthritis (RA), insulin resistance (IR), a component of the metabolic syndrome, is closely linked to the systemic inflammation induced by proinflammatory cytokines such as tumor necrosis factor-α and interleukin (IL)-6. In the present study, we aimed to assess if an intravenous administration of the anti-IL-6 receptor tocilizumab may yield a rapid improvement of IR in RA. METHODS: 50 consecutive non-diabetic patients with RA refractory to methotrexate, undergoing periodic treatment with tocilizumab, were studied. Besides disease activity, serum insulin, insulin/glucose ratio, insulin resistance (HOMA-IR) and insulin sensitivity (QUICKI) indexes were assessed immediately before and 1 hour after the end of an intravenous administration of tocilizumab (given in saline solution over 60 minutes). RESULTS: When comparing baseline data (immediately before) and 1 hour after finishing tocilizumab administration, we observed a dramatic decrease of the serum insulin levels and insulin/glucose ratio. Also, a statistically significant reduction of IR (HOMA-IR: mean± standard deviation immediately before: 2.62±2.03 vs. 1.65±1.15 1 hour after the end of the infusion (p<0.01) and a statistically significant increase of insulin sensitivity (QUICKI immediately before 0.34±0.03 vs. 0.37±0.04 1 hour after the end of tocilizumab infusion (p<0.01) was observed. CONCLUSIONS: The intravenous administration of tocilizumab yields a rapid beneficial effect on IR and insulin sensitivity in non-diabetic RA patients. These findings support the potential beneficial effect of the IL-6 blockade on the mechanisms associated with the development of metabolic syndrome and cardiovascular disease in patients with RA.

Rituximab induces a lasting, non-cumulative remodelling of the B-cell compartment.

OBJECTIVES: Reconstitution of B-cells after their therapeutic depletion with rituximab mimics the ontogeny of the B-cell linage in patients with rheumatoid arthritis. However, little is known about the effects of multiple cycles of treatment on the repletion kinetics and their long-lasting effects on the B-cell compartment. We therefore compared the recovery capacity of the B cell subpopulations between patients who experienced their first cycle of rituximab and those who experienced successive cycles. METHODS: The distribution of the different B-cell subsets was characterised by multiparametric flow cytometry in the peripheral blood of 29 patients in the first rituximab course (naïve cycles) and 40 patients in successive cycles. Samples were obtained at baseline and at 3, 6, and 8 months of each cycle. RESULTS: The baseline percentage of B-cell subsets was similar among successive cycles. Therefore, successive cycles were grouped for comparison with naïve cycles. Patients in naïve cycles had higher percentages at baseline of both total and memory B-cells. However, the recovery of the different B-cell subsets was similar between naïve and successive cycles. In naïve patients the percentage of transitional B-cells significantly correlated with disease activity at baseline. CONCLUSIONS: Rituximab induces a long-term reshape of the B-cell compartment while multiple cycles of rituximab do not induce cumulative effects on B-cell subpopulations. Transitional B-cells seem to be associated with higher disease activity, although further studies are needed to determine if they can be used as a biomarker to predict the need for rituximab retreatment.

Are rheumatologists adhering to the concepts window of opportunity and treat-to-target? Earlier and more intense disease-modifying anti-rheumatic drug treatment over time in patients with early arthritis in the PEARL study.

OBJECTIVES: To analyse changes over time in the treatment with disease modifying anti-rheumatic drugs and biological therapies prescribed to patients from an early arthritis register and whether these changes had an impact on their outcome. METHODS: This was a longitudinal retrospective 2-year study based on data collected in the PEARL study. The population was clustered in three groups depending on year of symptoms onset (2000-2004, 2005-2009, 2010-2014). Intensity of disease-modifying anti-rheumatic drug treatment was calculated and the percentage of patients receiving biological therapy during the first 2-year follow-up was collected. Disease activity and remission at the end of follow-up, as well as radiological progression were the outcomes analysed. Multivariable analyses were fitted to determine which variables including the three period times were associated with the outcomes. RESULTS: A significant increase in treatment intensity was observed in patients with undifferentiated arthritis, getting closer to that prescribed to patients fulfilling the 1987 RA criteria at the last period studied (2010-2014). This finding was associated with a significantly higher percentage of patients in remission and lower progression of the erosion component of the Sharp van der Heijde score. CONCLUSIONS: During the last 15 years, the treatment of patients with early arthritis in our hospital has been progressively increased and it has been associated with significantly better outcomes.

Exploring the remission concept in rheumatoid arthritis with patients and rheumatologists: time for a new approach?

OBJECTIVES: To explore the remission concept in rheumatoid arthritis (RA) and to compare remission definitions and related concepts between rheumatologists and patients with the purpose of identifying similarities and disparities to comprehend the different perspectives of the disease. METHODS: This was a qualitative study of discourse and content analysis through focus groups, conducted from February to March 2016. Four focus groups were set up, each one with different interests: rheumatologists involved in basic research (BR), rheumatologists with high specialisation in imaging techniques (IR), clinical rheumatologists (CR), and patients (PA). RESULTS: There is no consensus in a remission definition in RA; differences exist between-groups, rheumatologists and patients value remission differently, and there are discrepancies within the group of rheumatologists. Rheumatologists highlight quantifiable objective parameters, in contrast, patients did not consider objective measures as the best instruments, and they prefer subjective measures of remission. The data confirmed the existence of two sources of knowledge of the disease, technical (physicians) and experiential (patients). These sources of knowledge should concur in order to establish new remission criteria well-adjusted to reality. CONCLUSIONS: The lack of consensus between key groups implicated in defining remission and remission criteria suggests a new strategy for its operational definition. Our group proposes that subjects with a balance between experiential and technical knowledge, should be the ones in charge of this assignment.

Anti-citrullinated protein antibodies are associated with decreased bone mineral density: baseline data from a register of early arthritis patients.

Since the previous studies showed that anti-citrullinated protein antibodies (ACPA) can induce osteoclasts differentiation and activation, even before arthritis onset, the aim of our study was to determine whether ACPA-positivity is associated with lower bone mineral density (BMD) at baseline visit of a register of early arthritis (EA) patients. The study population comprised 578 patients (80% females) from our EA clinic with a median disease duration, 5.1 months (p25-p75: 6-8); median age, 53.6 years (41.9-66.1), 38% ACPA-positive, and 55% fulfilling 2010 criteria for rheumatoid arthritis. BMD was measured using dual X-ray absorptiometry at lumbar spine, hip, and metacarpophalangeal (MCP) joints of the non-dominant hand to evaluate both systemic and juxta-articular bone mass. ACPA titers were determined through enzyme immunoassay. The effect of ACPA on BMD was analyzed using multivariable analysis based on generalized linear models adjusted for various confounders. ACPA-positive patients showed lower bone mass at lumbar spine and hip, but no differences were observed at MCP joints compared to ACPA-negative patients. However, ACPA-positive patients displayed higher disease activity and disability than ACPA-negative patients. After adjustment for gender, age, body mass index, and other bone-related variables, the presence of ACPA remained significantly associated with lower BMD at the lumbar spine, femoral neck, and hip but not at MCP joints. Disease activity was not associated with baseline bone mass. Our data reinforce the previous preclinical findings suggesting that the systemic bone loss detected at the initial phases of early ACPA-positive arthritis is independent of inflammatory status and, therefore, could be mediated by ACPA.

Effect of timing of casirivimab and imdevimab administration relative to mRNA-1273 COVID-19 vaccination on vaccine-induced SARS-CoV-2 neutralising antibody responses: a prospective, open-label, phase 2, randomised controlled trial.

BACKGROUND: Deeper insight is needed on how monoclonal antibodies (mAbs) affect vaccine-mediated immune responses when targeting the same protein. We describe the first prospective randomised trial designed to understand mAb-mediated alterations in vaccine-induced immune responses to SARS-CoV-2 spike protein epitopes. METHODS: This randomised, open-label, parallel-group study assessed the potential interaction of a mAb combination, casirivimab and imdevimab, with a vaccine, Moderna's mRNA-1273, in healthy SARS-CoV-2 immunologically naive, seronegative adults at six centres in the USA. Participants were randomly assigned (per prespecified randomisation ratios within enrolment waves) according to a computer-generated randomisation scheme, stratified by age (<65 years and ≥65 years), to various intravenous or subcutaneous doses of casirivimab and imdevimab before, after, or at the same time as mRNA-1273 or to mRNA-1273 only. The doses of casirivimab and imdevimab were chosen to mimic various time intervals between receipt of 1200 mg of the mAb and the first dose of a primary series with mRNA-1273. The primary endpoint was vaccine-induced 50% inhibitory dilution neutralising antibody titres to SARS-CoV-2 spike protein, 56 days after the first vaccination. Secondary endpoints included vaccine-induced total antibodies to SARS-CoV-2 antigens and incidence of treatment-emergent adverse events. Exploratory endpoints included blood-derived T-cell and B-cell responses. The per-protocol set was used for the analysis of the primary endpoint and included all randomly assigned participants who received both doses of the vaccine and completed the injection or infusion of casirivimab and imdevimab per protocol, had no evidence of SARS-CoV-2 infection in the past or in the 56 days after the first dose of vaccine, and did not receive any intervention outside of the study that could alter the immune response. Safety was assessed in the safety analysis set, which included all randomly assigned participants who had received one or more doses of mRNA-1273 or any study drug, and analysed based on treatment received. The study is registered with ClinicalTrials.gov, NCT04852978, and is complete. FINDINGS: Between April 29, 2021, and Nov 21, 2022, 807 participants were assessed for eligibility and 295 were randomly assigned. 293 participants were included in the safety analysis set and 260 were included in the per-protocol set. All vaccinated participants developed neutralising antibodies to SARS-CoV-2, with median titres above the published protective threshold (100 IU/mL) against the SARS-CoV-2 D614G variant (considered a reference strain at the time the initial COVID-19 vaccines were developed). Titres were decreased up to 4-fold (median titres 280-450 IU/mL for casirivimab and imdevimab vs 1160 IU/mL for vaccine only on day 56) when casirivimab and imdevimab was given 85 days or less before vaccination (150-1200 mg intravenously) or co-administered subcutaneously (600 mg or 1200 mg) with vaccination. Minimal reduction in neutralisation titres was observed in the 48 mg and 12 mg intravenous groups, corresponding to receipt of casirivimab and imdevimab 113 days and 169 days, respectively, before vaccination, and when administering the vaccine 6 days before the mAb. Across all groups, mAbs had a minimal effect on vaccine-induced total antibodies and T-cell responses to the spike protein. Casirivimab and imdevimab plus mRNA-1273 was generally well tolerated; a slight increase in treatment-emergent adverse events was observed in the casirivimab and imdevimab plus vaccine groups versus the vaccine-only group. INTERPRETATION: Casirivimab and imdevimab administration before or at the time of COVID-19 vaccination reduced the elicitation of SARS-CoV-2 neutralising antibodies, but minimal effect was observed when vaccination occurred before mAb administration. Although the clinical significance of this decrease in neutralisation is unclear, this evidence suggests that further investigation of potential interactions could be warranted before concurrent clinical use of mAbs and vaccines targeting the same viral proteins as their main modes of action for the prevention or treatment of infectious diseases. FUNDING: Regeneron Pharmaceuticals and F Hoffmann-La Roche.

Clinical features and 123I-FP-CIT SPECT imaging in vascular parkinsonism and Parkinson's disease.

OBJECTIVES: To analyse the differences in the clinical features and characteristics of (123)I-labelled 2ß-carbomethoxy-3ß-(4-iodophenyl)-N-(3-fluoropropyl) nortropane ((123)I-FP-CIT) single photon emission CT (SPECT) imaging among patients with vascular parkinsonism (VP) and Parkinson's disease (PD). METHODS: We performed a case-control study to compare clinical features and qualitative and semi-quantitative analyses of (123)I-FP-CIT SPECT images between 106 patients with VP and 280 patients with PD. A case series study was used to search for clinical features related to SPECT or neuroimaging findings among patients with VP. RESULTS: Patients with VP had a higher age at symptom onset and lower disease duration than patients with PD. The most frequent symptom at onset was gait disorder in VP and tremor in PD. Gait disorder, postural instability and falls were more frequent in VP. Rest and mixed tremor were more prevalent in PD. Of the patients who received levodopa treatment in the VP group, only about half had a good response. Qualitatively (123)I-FP-CIT SPECT images were normal in 32.5% of patients with VP and abnormal in all patients with PD. The use of different visual score patterns showed higher ability to differentiate VP from PD. Semi-quantitative analysis showed significantly higher uptake in the striatum, caudate and putamen in VP. The asymmetry index was higher in patients with PD. Among patients with VP, falls were the only clinical feature that demonstrated a correlation with the SPECT visual pattern. CONCLUSION: Our data contribute to the confirmation that VP and PD are two different clinical entities. Neurological signs, response to treatment and qualitative and semi-quantitative (123)I-FP-CIT SPECT analyses may help to make the diagnosis.

Lupus anticoagulant hypoprothrombinemia syndrome: A case report.

Lupus anticoagulant hypoprothrombinemia syndrome (LAHPS) is a rare entity associated with an increased risk of hemorrhage. Corticosteroids have been used in its treatment with favorable results. We present the case of a 54-year-old female patient with a personal history of Lupus diagnosed with LAHPS following an episode of cerebellar hemorrhage.

Tyr³²³-dependent p38 activation is associated with rheumatoid arthritis and correlates with disease activity.

OBJECTIVE: The p38 MAPK is important in the pathogenic immune response in rheumatoid arthritis (RA). The p38 molecule can be activated through phosphorylation on Thr¹8°-Tyr¹8² by upstream MAPK kinases and via an alternative pathway through phosphorylation on Tyr³²³. We undertook this study to quantify the phosphorylation of Tyr³²³ p38 and of Thr¹8°-Tyr¹8² p38 on T cells from healthy controls and patients with RA or ankylosing spondylitis (AS) to identify variables associated with p38 phosphorylation and disease activity. METHODS: We measured p38 phosphorylation on Tyr³²³ and Thr¹8°-Tyr¹8² by flow cytometry and Western blotting on T cells from 30 control subjects, 33 AS patients, 30 patients with RA in remission, and 79 patients with active RA. We collected the clinical characteristics and analyzed correlations between clinical variables, the Disease Activity Score in 28 joints (DAS28), and p38 phosphorylation levels. Multivariate regression analysis was performed to identify variables associated with p38 phosphorylation on Tyr³²³ and Thr¹8°-Tyr¹8². RESULTS: Phosphorylation of p38 on Tyr³²³ was higher in T cells from patients with active RA (P = 0.008 versus healthy controls) than in patients with RA in remission or in patients with AS. Tyr³²³ p38 phosphorylation was associated with disease activity determined by the DAS28 (P = 0.017). Enhanced p38 phosphorylation was linked to Lck-mediated activation of the Tyr³²³-dependent pathway in the absence of upstream MAPKK activation. CONCLUSION: Our results indicate that phosphorylation status on Tyr³²³ p38 correlates with RA disease activity and suggest that the Tyr³²³-dependent pathway is an attractive target for down-regulation of p38 activity in RA patients.

Survival study and factors associated with mortality in Chilean patients on peritoneal dialysis infected with SARS-CoV-2.

The Covid-19 pandemic has been responsible for millions of deaths worldwide. Patients with comorbidities- such as those on peritoneal dialysis (PD)- present higher morbidity and mortality than the general population. We prospectively evaluated all Chilean patients on PD (48 centres) and followed those who had Covid-19 from the beginning of the Covid-19 pandemic in Chile (March 2020) to January 2021 (start of vaccination campaign). We described demographic history, comorbidities, factors related to infection, need for hospitalisation and death due to Covid-19. During the study period, 106 adults on PD were infected by SARS-CoV-2, with a mean age of 53.1 (±16.3) and of which 53.9% were female. From that group, 54.8% required hospitalisation and 24.5% (n = 26) died due to Covid-19. Most of the patients (63.4%) were infected at home and 22.8% during hospitalisation for other reasons. There was a significant association for Covid-19 mortality with: being ≥60 years old, diabetes, time on PD ≥5 years, need for hospitalisation and hospital-acquired infection. At 90 days of follow-up, all deaths associated to Covid-19 occurred before 40 days. We conclude that patients on PD without Covid-19 vaccination have a high mortality and need for hospitalisation associated to Covid-19. To avoid this negative outcome, it is necessary to intensify strategies to avoid contagion, especially in those ≥60 years old, with diabetes and/or ≥5 years spent on PD.

Respiratory Subsets in Patients with Moderate to Severe Acute Respiratory Distress Syndrome for Early Prediction of Death.

Introduction: In patients with acute respiratory distress syndrome (ARDS), the PaO2/FiO2 ratio at the time of ARDS diagnosis is weakly associated with mortality. We hypothesized that setting a PaO2/FiO2 threshold in 150 mm Hg at 24 h from moderate/severe ARDS diagnosis would improve predictions of death in the intensive care unit (ICU). Methods: We conducted an ancillary study in 1303 patients with moderate to severe ARDS managed with lung-protective ventilation enrolled consecutively in four prospective multicenter cohorts in a network of ICUs. The first three cohorts were pooled (n = 1000) as a testing cohort; the fourth cohort (n = 303) served as a confirmatory cohort. Based on the thresholds for PaO2/FiO2 (150 mm Hg) and positive end-expiratory pressure (PEEP) (10 cm H2O), the patients were classified into four possible subsets at baseline and at 24 h using a standardized PEEP-FiO2 approach: (I) PaO2/FiO2 ≥ 150 at PEEP < 10, (II) PaO2/FiO2 ≥ 150 at PEEP ≥ 10, (III) PaO2/FiO2 < 150 at PEEP < 10, and (IV) PaO2/FiO2 < 150 at PEEP ≥ 10. Primary outcome was death in the ICU. Results: ICU mortalities were similar in the testing and confirmatory cohorts (375/1000, 37.5% vs. 112/303, 37.0%, respectively). At baseline, most patients from the testing cohort (n = 792/1000, 79.2%) had a PaO2/FiO2 < 150, with similar mortality among the four subsets (p = 0.23). When assessed at 24 h, ICU mortality increased with an advance in the subset: 17.9%, 22.8%, 40.0%, and 49.3% (p < 0.0001). The findings were replicated in the confirmatory cohort (p < 0.0001). However, independent of the PEEP levels, patients with PaO2/FiO2 < 150 at 24 h followed a distinct 30-day ICU survival compared with patients with PaO2/FiO2 ≥ 150 (hazard ratio 2.8, 95% CI 2.2−3.5, p < 0.0001). Conclusions: Subsets based on PaO2/FiO2 thresholds of 150 mm Hg assessed after 24 h of moderate/severe ARDS diagnosis are clinically relevant for establishing prognosis, and are helpful for selecting adjunctive therapies for hypoxemia and for enrolling patients into therapeutic trials.

The PANDORA Study: Prevalence and Outcome of Acute Hypoxemic Respiratory Failure in the Pre-COVID-19 Era.

OBJECTIVES: To establish the epidemiological characteristics, ventilator management, and outcomes in patients with acute hypoxemic respiratory failure (AHRF), with or without acute respiratory distress syndrome (ARDS), in the era of lung-protective mechanical ventilation (MV). DESIGN: A 6-month prospective, epidemiological, observational study. SETTING: A network of 22 multidisciplinary ICUs in Spain. PATIENTS: Consecutive mechanically ventilated patients with AHRF (defined as Pao2/Fio2 ≤ 300 mm Hg on positive end-expiratory pressure [PEEP] ≥ 5 cm H2O and Fio2 ≥ 0.3) and followed-up until hospital discharge. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Primary outcomes were prevalence of AHRF and ICU mortality. Secondary outcomes included prevalence of ARDS, ventilatory management, and use of adjunctive therapies. During the study period, 9,803 patients were admitted: 4,456 (45.5%) received MV, 1,271 (13%) met AHRF criteria (1,241 were included into the study: 333 [26.8%] met Berlin ARDS criteria and 908 [73.2%] did not). At baseline, tidal volume was 6.9 ± 1.1 mL/kg predicted body weight, PEEP 8.4 ± 3.1 cm H2O, Fio2 0.63 ± 0.22, and plateau pressure 21.5 ± 5.4 cm H2O. ARDS patients received higher Fio2 and PEEP than non-ARDS (0.75 ± 0.22 vs 0.59 ± 0.20 cm H2O and 10.3 ± 3.4 vs 7.7 ± 2.6 cm H2O, respectively [p < 0.0001]). Adjunctive therapies were rarely used in non-ARDS patients. Patients without ARDS had higher ventilator-free days than ARDS (12.2 ± 11.6 vs 9.3 ± 9.7 d; p < 0.001). All-cause ICU mortality was similar in AHRF with or without ARDS (34.8% [95% CI, 29.7-40.2] vs 35.5% [95% CI, 32.3-38.7]; p = 0.837). CONCLUSIONS: AHRF without ARDS is a very common syndrome in the ICU with a high mortality that requires specific studies into its epidemiology and ventilatory management. We found that the prevalence of ARDS was much lower than reported in recent observational studies.

Increased disease activity in early arthritis patients with anti-carbamylated protein antibodies.

The initial management of rheumatoid arthritis (RA) has a high impact on disease prognosis. Therefore, we need to select the most appropriate treatment as soon as possible. This goal requires biomarkers of disease severity and prognosis. One such biomarker may be the presence of anti-carbamylated protein antibodies (ACarPA) because it is associated with adverse long term outcomes as radiographic damage and mortality. Here, we have assessed the ACarPA as short-term prognostic biomarkers. The study was conducted in 978 prospective early arthritis (EA) patients that were followed for two years. Our results show the association of ACarPA with increased levels of all the disease activity measures in the first visit after arthritis onset. However, the associations were more significant with the high levels in local measures of inflammation and physician assessment than with the increases in systemic inflammation and patient-reported outcomes. More notably, disease activity was persistently increased in the ACarPA positive patients during the two years of follow-up. These differences were significant even after accounting for the presence of other RA autoantibodies. Therefore, the ACarPA could be considered short-term prognostic biomarkers of increased disease activity in the EA patients.

Effects of disease activity on lipoprotein levels in patients with early arthritis: can oxidized LDL cholesterol explain the lipid paradox theory?

BACKGROUND: An increased risk of cardiovascular (CV) complications has been described in patients with rheumatoid arthritis (RA). It is the result of the combined effect of classic CV risk factors and others that are specific to the disease. METHODS: We assessed data from 448 early arthritis (EA) patients: 79% women, age (median [p25-p75]) at onset: 55 [44-67] years and disease duration at study entry 5 [3-8] months; and 72% fulfilled the 1987 RA criteria at 2 years of follow-up. Rheumatoid factor was positive in 54% of patients and anti-citrullinated peptide antibodies in 50%. The follow-up of patients ranged from 2 to 5 years with more than 1400 visits with lipoprotein measurements available (mean 2.5 visits/patient). Demographic- and disease-related variables were systematically recorded. Total cholesterol (TC), high-density lipoprotein (HDL-C), and low-density lipoprotein (LDL-C) levels were obtained from routine laboratory tests. Oxidized-LDL (oxLDL-C) levels were assessed using a commercial ELISA kit. We fitted population-averaged models nested by patient and visit to determine the effect of independent variables on serum levels of TC, its fractions, and oxLDL-C. RESULTS: After adjustment for several confounders, high-disease activity was significantly associated with decreased TC, HDL-C, and LDL-C levels and increased oxLDL-C levels. Standardized coefficients showed that the effect of disease activity was greater on oxLDL-C and HDL-C. Interestingly, we observed that those patients with lower levels of LDL-C showed higher oxLDL-C/LDL-C ratios. CONCLUSIONS: High-disease activity in EA patients results in changes in the HDL-C and oxLDL-C levels, which in turn may contribute to the increased risk of CV disease observed in these patients.

Improved classification of rheumatoid arthritis with a score including anti-acetylated ornithine antibodies.

The presence of rheumatoid factor (RF) or anti-cyclic citrullinated peptide (anti-CCP) autoantibodies contributes to the current rheumatoid arthritis (RA) classification criteria. These criteria involve stratification on antibody levels, which limits reproducibility, and underperform in the RA patients without RF and anti-CCP. Here, we have explored if two anti-acetylated peptide antibodies (AAPA), anti-acetylated lysine (AcLys) and anti-acetylated ornithine (AcOrn), could improve the performance of the current criteria. The analysis was done in 1062 prospectively-followed early arthritis (EA) patients. The anti-AcOrn were more informative than the anti-AcLys, the conventional RA antibodies and the anti-carbamylated protein antibodies. The anti-AcOrn produced a classification that did not require antibody levels and showed improved specificity (77.6% vs. 72.6%, p = 0.003) and accuracy (79.0% vs. 75.8%, p = 0.002) over the current criteria. These improvements were obtained with a scoring system that values concordance between anti-AcOrn, RF and anti-CCP. No significant gain was obtained in sensitivity (80.2% vs. 78.8%, p = 0.25) or in improving the classification of the RA patients lacking RF and anti-CCP, although the anti-AcOrn ranked first among the analysed new antibodies. Therefore, the anti-AcOrn antibodies could contribute to the improvement of RA classification criteria by exploiting antibody concordance.