Direct isolation of small extracellular vesicles from human blood using viscoelastic microfluidics.

Small extracellular vesicles (sEVs; <200 nm) that contain lipids, nucleic acids, and proteins are considered promising biomarkers for a wide variety of diseases. Conventional methods for sEV isolation from blood are incompatible with routine clinical workflows, significantly hampering the utilization of blood-derived sEVs in clinical settings. Here, we present a simple, viscoelastic-based microfluidic platform for label-free isolation of sEVs from human blood. The separation performance of the device is assessed by isolating fluorescent sEVs from whole blood, demonstrating purities and recovery rates of over 97 and 87%, respectively. Significantly, our viscoelastic-based microfluidic method also provides for a remarkable increase in sEV yield compared to gold-standard ultracentrifugation, with proteomic profiles of blood-derived sEVs purified by both methods showing similar protein compositions. To demonstrate the clinical utility of the approach, we isolate sEVs from blood samples of 20 patients with cancer and 20 healthy donors, demonstrating that elevated sEV concentrations can be observed in blood derived from patients with cancer.

exRNA-eCLIP intersection analysis reveals a map of extracellular RNA binding proteins and associated RNAs across major human biofluids and carriers.

Although the role of RNA binding proteins (RBPs) in extracellular RNA (exRNA) biology is well established, their exRNA cargo and distribution across biofluids are largely unknown. To address this gap, we extend the exRNA Atlas resource by mapping exRNAs carried by extracellular RBPs (exRBPs). This map was developed through an integrative analysis of ENCODE enhanced crosslinking and immunoprecipitation (eCLIP) data (150 RBPs) and human exRNA profiles (6,930 samples). Computational analysis and experimental validation identified exRBPs in plasma, serum, saliva, urine, cerebrospinal fluid, and cell-culture-conditioned medium. exRBPs carry exRNA transcripts from small non-coding RNA biotypes, including microRNA (miRNA), piRNA, tRNA, small nuclear RNA (snRNA), small nucleolar RNA (snoRNA), Y RNA, and lncRNA, as well as protein-coding mRNA fragments. Computational deconvolution of exRBP RNA cargo reveals associations of exRBPs with extracellular vesicles, lipoproteins, and ribonucleoproteins across human biofluids. Overall, we mapped the distribution of exRBPs across human biofluids, presenting a resource for the community.

Tissue and Circulating MicroRNA-31, MicroRNA-200b, and MicroRNA-200c Reflects Disease Activity in Crohn's Disease Patients: Results from the BIOMIR Study.

BACKGROUND AND AIMS: MicroRNAs (miR) have altered expression in multiple autoimmune disorders including inflammatory bowel disease. The aim of the study was to assess the tissue and circulating miR-31, miR-200b, and miR-200c expression levels as potential biomarkers for intestinal disease activity in patients with Crohn's disease (CD). METHODS: The study included 45 patients with histopathological confirmed CD and active disease (defined as fecal calprotectin >50 µg/g and Simple Endoscopic Score (SES) of CD >3), and 21 subjects as controls for the validation cohort. Demographic and clinical data, biomarkers (fecal calprotectin), endoscopy data, the expression levels of miR-31, miR-200b, and miR-200c in tissue and serum were assessed (by RT-PCR). Receiver operating characteristic analysis was performed to assess the miR-31, miR-200b, and miR-200c expression levels as potential biomarkers for active CD. RESULTS: Mean fecal calprotectin was 1540±890 µg/g. Mean SES-CD was 8.9±4.2. Tissue and circulating miR- 31 were significantly correlated with fecal calprotectin (r=0.81, r=0.83, p<0.01) and with SES-CD (r=0.82, r=0.79, p<0.01). The expression level of miR-31 was significantly upregulated in CD tissue cases compared to the control tissue samples (6.24±1.57 vs. 3.70±1.44; p <0.01). Similarly, serum miR-31 expression levels in CD patients were significantly upregulated compared to the control serum samples (0.78±0.42 vs. -2.07±1.00; p<0.01). The expression levels of tissue miR-200b and miR-200c were significantly upregulated in CD tissue cases compared to the control tissue samples (-5.25±0.93 vs. -4.69±0.80, p=0.03 for miR-200b, and -0.86±0.96 vs. 0.39±0.66, p<0.01 for miR-200c). Similarly, serum miR-200b and miR-200c expression levels in CD patients were significantly upregulated compared to the control serum samples (p < 0.05). Receiver operating characteristic analysis revealed that the expression levels of the selected miRNAs could help to discriminate active CD patients from healthy controls with very good specificity and sensitivity. CONCLUSIONS: Tissue and circulating miR-31, miR-200b, and miR-200c reflect disease activity in CD patients and can be used as biomarkers for active disease.

The Role of Artificial Intelligence in Monitoring Inflammatory Bowel Disease-The Future Is Now.

Crohn's disease and ulcerative colitis remain debilitating disorders, characterized by progressive bowel damage and possible lethal complications. The growing number of applications for artificial intelligence in gastrointestinal endoscopy has already shown great potential, especially in the field of neoplastic and pre-neoplastic lesion detection and characterization, and is currently under evaluation in the field of inflammatory bowel disease management. The application of artificial intelligence in inflammatory bowel diseases can range from genomic dataset analysis and risk prediction model construction to the disease grading severity and assessment of the response to treatment using machine learning. We aimed to assess the current and future role of artificial intelligence in assessing the key outcomes in inflammatory bowel disease patients: endoscopic activity, mucosal healing, response to treatment, and neoplasia surveillance.

Phase 2 of extracellular RNA communication consortium charts next-generation approaches for extracellular RNA research.

The extracellular RNA communication consortium (ERCC) is an NIH-funded program aiming to promote the development of new technologies, resources, and knowledge about exRNAs and their carriers. After Phase 1 (2013-2018), Phase 2 of the program (ERCC2, 2019-2023) aims to fill critical gaps in knowledge and technology to enable rigorous and reproducible methods for separation and characterization of both bulk populations of exRNA carriers and single EVs. ERCC2 investigators are also developing new bioinformatic pipelines to promote data integration through the exRNA atlas database. ERCC2 has established several Working Groups (Resource Sharing, Reagent Development, Data Analysis and Coordination, Technology Development, nomenclature, and Scientific Outreach) to promote collaboration between ERCC2 members and the broader scientific community. We expect that ERCC2's current and future achievements will significantly improve our understanding of exRNA biology and the development of accurate and efficient exRNA-based diagnostic, prognostic, and theranostic biomarker assays.

Romanian Guidelines for the Diagnosis and Treatment of GERD-induced Respiratory Manifestations.

BACKGROUND AND AIMS: Gastroesophageal reflux disease (GERD) is a common condition present in daily practice with a wide range of clinical phenotypes. In this line, respiratory conditions may be associated with GERD. The Romanian Societies of Gastroenterology and Neurogastroenterology, in association with the Romanian Society of Pneumology, aimed to create a guideline regarding the epidemiology, diagnosis and treatment of respiratory conditions associated with GERD. METHODS: Delphi methodology was used and eleven common working groups of experts were created. The experts reviewed the literature according to GRADE criteria and formulated 34 statements and recommendations. Consensus (>80% agreement) was reached for some of the statements after all participants voted. RESULTS: All the statements and the literature review are presented in the paper, together with their correspondent grade of evidence and the voting results. Based on >80% voting agreement, a number of 22 recommendations were postulated regarding the diagnosis and treatment of GERD-induced respiratory symptoms. The experts considered that GERD may cause bronchial asthma and chronic cough in an important number of patients through micro-aspiration and vagal-mediated tracheobronchial reflex. GERD should be suspected in patients with asthma with suboptimal controlled or after exclusion of other causes, also in nocturnal refractory cough which needs gastroenterological investigations to confirm the diagnosis. Therapeutic test with double dose proton pump inhibitors (PPI) for 3 months is also useful. GERD induced respiratory conditions are difficult to treat; however,proton pump inhibitors and laparoscopic Nissen fundoplication are endorsed for therapy. CONCLUSIONS: This guideline could be useful for the multidisciplinary management of GERD with respiratory symptoms in current practice.

Body Composition as a Modulator of Bone Health Changes in Patients with Inflammatory Bowel Disease.

BACKGROUND: Bone impairment of multifactorial etiology is a common feature in inflammatory bowel disease (IBD). Body composition parameters, which might be selectively modified in these patients, are important determinants of bone strength. Our aim was to investigate the relationship between components of body composition and bone parameters in IBD patients. METHODS: This is a cross-sectional, retrospective study including 80 IBD patients (43 women, 37 men). Lumbar spine (LS), femoral neck (FN) and whole body DXA scans were performed to analyze regional bone mineral density (BMD), as well as body composition, including appendicular skeletal muscle mass index (ASMI), total and visceral fat mass (VAT). Trabecular bone score (TBS) was assessed using iNsight Software. RESULTS: Twenty (25%) IBD patients had inadequate LS-BMD z scores (<=-2DS). Lean mass (LM) was a significant determinant of LS-BMD, after adjusting for age, gender, BMI and fat mass (p < 0.01), while fat mass% remained associated with FN-BMD (p < 0.01). TBS correlated positively with BMI (r = 0.24, p < 0.05), LS-BMD (r = 0.56, p < 0.001), ASMI (r = 0.34, p < 0.001) and negatively with VAT/total fat% (r = -0.27, p < 0.05). Multivariate analysis showed that ASMI, LS-BMD (positively) and VAT/total fat% (negatively) were independently associated with TBS. CONCLUSIONS: In IBD patients, skeletal muscle mass and fat percentage and distribution are important factors associated with bone health.

Longitudinal Human Milk miRNA Composition over the First 3 mo of Lactation in a Cohort of Healthy Mothers Delivering Term Infants.

BACKGROUND: MicroRNAs (miRNAs) are small noncoding RNAs involved in posttranscriptional regulation. miRNAs can be secreted and found in many body fluids, and although they are particularly abundant in breastmilk, their functions remain elusive. Human milk (HM) miRNAs start to raise considerable interest, but a comprehensive understanding of the repertoire and expression profiles along lactation has not been well characterized. OBJECTIVES: This study aimed to characterize the longitudinal profile of HM miRNA between the second week and third month postpartum. METHODS: We used a new sensitive technology to measure HM miRNAs in a cohort of 44 French mothers [mean ± SD age: 31 ± 3.5; BMI (in kg/m2) 21.8 ± 2.3] who delivered at term and provided HM samples at 3 time points (17 ± 3 d, 60 ± 3 d, and 90 ± 3 d) during follow-up visits. RESULTS: We detected 685 miRNAs, of which 35 showed a high and stable expression along the lactation period analyzed. We also described for the first time a set of 11 miRNAs with a dynamic expression profile. To gain insight into the potential functional relevance of this set of miRNAs, we selected miR-3126 and miR-3184 to treat undifferentiated Caco-2 human intestinal cells and then assessed differentially expressed genes and modulation of related biological pathways. CONCLUSIONS: Overall, our study provides new insights into HM miRNA composition and, to our knowledge, the first description of its longitudinal dynamics in mothers who delivered at term. Our in vitro results obtained in undifferentiated Caco-2 human intestinal cells transfected with HM miRNAs also provide further support to the hypothesized mother-to-neonate signaling role of HM miRNAs. This trial was registered at clinicaltrials.gov as NCT01894893.

Characteristics and outcomes of patients with COVID-19 and liver injury: a retrospective analysis and a multicenter experience.

Background and aims. Patients with COVID-19 frequently present abnormal elevated liver function tests of unknown clinical significance. We aimed to investigate the characteristics and factors influencing outcome in patients with confirmed SARS-CoV-2 infection and liver injury on admission.Methods. This is a retrospective observational study of patients hospitalized in two COVID units in Romania. Relevant data on clinical and laboratory parameters and medication administered during the admission were analyzed to identify predictors of a negative outcome. Patients with confirmed COVID-19 and liver function tests (LFTs) above the upper limit of normal were included in the analysis.Results. From 1,207 patients, we identified 134 patients (11%) with abnormal LFTs during hospitalization. The majority of patients had mildly elevated levels and a predominantly cholestatic pattern of liver injury. Patients who received lopinavir/ritonavir were more likely to have increased ALAT levels (p<0.0001). Sixteen patients had pre-existing chronic liver disease, and they were more likely to suffer from severe COVID-19 (p=0.009) and have a negative outcome (p<0.001), but on multivariate analysis, only the severity of COVID-19 was predictive of death (OR 69.9; 95% CI 6.4-761.4).Conclusions. Mild liver injury is relatively common in COVID-19 and possibly influenced by medication. Patients with chronic liver disease are at high risk for negative outcome, but the severity of the infection is the only predictor of death.

Chemically Synthesized, Self-Assembling Small Interfering RNA-Prohead RNA Molecules Trigger Dicer-Independent Gene Silencing.

RNA interference (RNAi) mediated by small interfering RNA (siRNA) duplexes is a powerful therapeutic modality, but the translation of siRNAs from the bench into clinical application has been hampered by inefficient delivery in vivo. An innovative delivery strategy involves fusing siRNAs to a three-way junction (3WJ) motif derived from the phi29 bacteriophage prohead RNA (pRNA). Chimeric siRNA-3WJ molecules are presumed to enter the RNAi pathway through Dicer cleavage. Here, we fused siRNAs to the phi29 3WJ and two phylogenetically related 3WJs. We confirmed that the siRNA-3WJs are substrates for Dicer in vitro. However, our results reveal that siRNA-3WJs transfected into Dicer-deficient cell lines trigger potent gene silencing. Interestingly, siRNA-3WJs transfected into an Argonaute 2-deficient cell line also retain some gene silencing activity. siRNA-3WJs are most efficient when the antisense strand of the siRNA duplex is positioned 5' of the 3WJ (5'-siRNA-3WJ) relative to 3' of the 3WJ (3'-siRNA-3WJ). This work sheds light on the functional properties of siRNA-3WJs and offers a design rule for maximizing their potency in the human RNAi pathway.

COVID-19 Vaccine Does Not Increase the Risk of Disease Flare-Ups among Patients with Autoimmune and Immune-Mediated Diseases.

BACKGROUND: Reports describing post-vaccine autoimmune phenomena, in previously healthy individuals, increased the concerns regarding the risk of disease flare-ups in patients with immune diseases. We aimed to assess the potential risk of disease flare-up, after receiving the COVID-19 (Coronavirus disease 2019) vaccine, during a follow-up period of 6 months. METHODS: We performed a prospective cohort study, enrolling the patients with autoimmune- and immune-mediated diseases who voluntarily completed our questionnaire, both online and during hospital evaluations. Based on their decision to receive the vaccine, the patients were divided into two groups (vaccinated and non-vaccinated). Participants who chose not to receive the vaccine served as a control group in terms of flare-ups. RESULTS: A total of 623 patients, 416 vaccinated and 207 non-vaccinated, were included in the study during hospital evaluations (222/623) and after online (401/623) enrolment. There was no difference concerning the risk of flare-up between vaccinated and non-vaccinated patients (1.16, versus 1.72 flare-ups/100 patients-months, p = 0.245). The flare-ups were associated with having more than one immune disease, and with a previous flare-up during the past year. CONCLUSIONS: We did not find an increased risk of flare-up following COVID-19 vaccination in patients with autoimmune-/immune-mediated diseases, after a median follow-up of 5.9 months. According to our results, there should not be an obvious reason for vaccine hesitancy among this category of patients.

COVID-19 Impact and Vaccination Willingness among Romanian Patients with Autoimmune/Immune-Mediated Diseases.

BACKGROUND: During the COVID-19 pandemic, patients with immune diseases are a vulnerable population. We aimed to evaluate their access to medical care, as well as their awareness and willingness to obtain the vaccine after a year of the SARS-CoV-2 pandemic. METHODS: A cross-sectional, multicenter study was conducted on a questionnaire basis, handled both online as well as in person. RESULTS: 651 patients with autoimmune or immune mediated diseases were enrolled. More than half (339/641 [53%]) reported difficulties in obtaining medical care throughout the pandemic and 135/651 ([21%]) of them were confirmed with COVID-19; 442/651, ([68%]) expressed their willingness to be vaccinated against SARS-CoV-2. The factors associated with an increased probability of vaccination were the male gender (OR = 2.01, CI95% 1.2-3.7, p = 0.001), the patient's opinion that she/he was well informed (OR = 3.2, CI 95% 2.1-6.01, p < 0.001), physician's advice (OR = 2.1, CI 95% 1.3-3.5, p < 0.001), and flu vaccination in the past (OR = 1.5, CI 95% 1.1-2.3, p < 0.001), while those associated with a decreased probability of vaccination were COVID-19 disease in the past medical history (OR = 0.7, CI 95% 0.3-0.95, p = 0.02), and the opinion that patients with autoimmune diseases are at increased risk for adverse reactions (OR = 0.7, CI95% 0.53-0.89, p = 0.001). CONCLUSIONS: Given the fact that considering themselves informed regarding vaccination is the most important factor in order to be immunized against SARS-CoV-2, effective information campaigns would substantially increase willingness.

Assessment of bone quality with trabecular bone score in patients with inflammatory bowel disease.

Inflammatory bowel disease (IBD) patients have a significant risk of developing bone loss. The trabecular bone score (TBS) is a relatively new parameter used to provide information on bone quality. The study cohort included 81 patients with IBD and 81 healthy controls. Blood tests, dual-energy x-ray absorptiometry (DXA), including TBS, were assessed. Harvey-Bradshaw Index (HBI) for Crohn's disease (CD) and the Partial Mayo Score for ulcerative colitis (UC) were used for evaluation of clinical disease activity. Compared with the healthy controls, the IBD patients had lower lumbar spine (LS) bone mineral density (BMD) (1.06 ± 0.18 vs. 1.16 ± 0.15 g/cm2, p < 0.005), hip BMD (0.88 ± 0.13 vs. 0.97 ± 0.13 g/cm2, p < 0.005) and TBS (1.38 ± 0.1 vs. 1.43 ± 0.1, p < 0.005) values. The patients with stricturing CD had lower TBS (1.32 ± 0.13 vs. 1.40 ± 0.9, p = 0.03) and LS BMD (0.92 ± 0.19 vs. 1.07 ± 0.1, p = 0.01) values compared with those with non-stricturing CD. Multivariate regression model analysis identified HBI as independent factor associated with TBS. Our results support that all DXA parameters are lower in patients with IBD than in healthy patients. Moreover, TBS is a valuable tool for assessment of bone impairment in active CD.

Lean mass, magnesium, faecal calprotectin and glucocorticoid exposure as risk factors for low bone mineral density in inflammatory bowel disease patients.

BACKGROUND AND AIM: Low bone mineral density (BMD) is a common complication in patients with inflammatory bowel disease (IBD). However, debates are ongoing with regard to the other involved factors, especially in younger patients. This study aimed to evaluate the parameters that contribute to decreased BMD, focusing on premenopausal women and men aged <50 years. METHODS: This study included 81 patients with IBD and 81 age-, sex- and BMI-matched controls. Blood tests were conducted on IBD patients, and a dual-energy X-ray absorptiometry (DXA) scan was performed on both groups. RESULTS: Low BMD and fragility fracture were found to be more prevalent in IBD patients than in healthy subjects (49.3% vs 23.4%, P = 0.001 and 9.8% vs 1.2%, P = 0.01, respectively). Patients with low BMD were older, with a longer disease duration, higher faecal calprotectin (FC) levels and lower magnesium and lean mass (appreciated as appendicular skeletal muscle index (ASMI)). Multiple regression analysis revealed that ASMI, age and use of glucocorticoids were the independent parameters for decreased BMD. Although 91.3% of the patients had a 25-hydroxy vitamin D level of <30 ng/mL, it was not a statistically significant factor for decreased BMD. CONCLUSION: In our study, the levels of vitamin D did not seem to have an important impact on BMD. Conversely, FC, magnesium and lean mass are important factors, suggesting that good control of disease, adequate magnesium intake and increased lean mass can have a good impact on bone metabolism in patients with IBD.

COVID­19 vaccination and IgG and IgA antibody dynamics in healthcare workers.

Given the current outbreak of coronavirus disease 2019 (COVID­19) and the development and implementation of mass vaccination, data are being obtained by analyzing vaccination campaigns. In the present study, 69 healthcare workers who were exposed to patients with severe acute respiratory syndrome coronavirus­2 were monitored for specific immunoglobulin (Ig)G and IgA levels at different time periods. Prior to vaccination, after the first round of vaccination at 21 days (when the second dose of vaccine was administrated) and 24 days after the second round of vaccination, with an mRNA­based vaccine. The basal IgG and IgA levels in previously infected subjects and non­infected subjects notably differed. Vaccination increased the IgG and IgA levels after the first dose in most subjects from both groups, the levels of which further increased following the second round of vaccination. The associations between IgG and IgA levels following the first and second rounds of vaccination demonstrated that in the entire vaccination group, regardless of prior exposure to the infectious agent, the increment and levels of IgG and IgA were similar. Thus, the levels upon vaccination were statistically similar irrespective of the starting base line prior to vaccination. In the present study, seroconversion was achieved in all subjects following the second round of vaccination, with similar antibodies levels.

High-throughput multiparametric imaging flow cytometry: toward diffraction-limited sub-cellular detection and monitoring of sub-cellular processes.

We present a sheathless, microfluidic imaging flow cytometer that incorporates stroboscopic illumination for blur-free fluorescence detection at ultra-high analytical throughput. The imaging platform is capable of multiparametric fluorescence quantification and sub-cellular localization of these structures down to 500 nm with microscopy image quality. We demonstrate the efficacy of the approach through the analysis and localization of P-bodies and stress granules in yeast and human cells using fluorescence and bright-field detection at analytical throughputs in excess of 60,000 and 400,000 cells/s, respectively. Results highlight the utility of our imaging flow cytometer in directly investigating phase-separated compartments within cellular environments and screening rare events at the sub-cellular level for a range of diagnostic applications.

A plea for a unified approach to sedation in gastrointestinal endoscopy in Romania: results from a prospective multicentric trial.

Background. Adequate sedation is a prerequisite for quality endoscopic examination of the digestive tract. We aimed to evaluate the current practices and safety profile of sedation for gastrointestinal endoscopy in Romania and its impact on the technical success of the procedure and procedure-related adverse events. Methods. We conducted a prospective, multicentric, observational study including all patients undergoing digestive endoscopic procedures under various degrees of sedation. We collected data regarding the endoscopic procedure, type and degree of sedation, drug regimens, personnel in charge of sedation, and relevant patient related information. The main study outcome was the rate of sedation-related adverse events; secondary study outcomes included procedure-related adverse events and the impact of sedation on procedure success. Results. 1,043 consecutive endoscopic procedures from eight Romanian endoscopy units were included in our study. Sedation regimens were highly variable between participating centers, with 566 (54%) of procedures being performed under sedation provided by an anaesthesiologist. Sedation-related adverse events occurred in 40 cases (3.8%), most of them were mild respiratory and cardiovascular events and all reversed spontaneously. On multivariate analysis, male gender, procedure type (endoscopic ultrasound and endoscopic retrograde cholangiopancreatography) and deep sedation were risk factors for complications. The endoscopy unit, ASA status, age and type of sedative did not influence the complication rate. Conclusion. In conclusion, sedation for endoscopic procedures is generally safe, despite a high variability in sedation practices between centers in Romania. Establishing a national guideline on sedation for gastrointestinal endoscopy will ensure consistent and safe practice for these procedures.

Unmet needs in the diagnosis and treatment of Romanian patients with bilio-pancreatic tumors: results of a prospective observational multicentric study.

Background. Biliopancreatic tumors (BPT) are among the most aggressive solid malignancies, and their incidence is rising. Good patient outcome relies heavily on a multidisciplinary approach to therapy, including timely access to endoscopy, surgery and chemo/radiotherapy. We aimed to evaluate current practices as reflected in the management and outcome of patients diagnosed with BPT in the setting of a low-resource medical system in order to identify areas suitable for improvement. Material and methods. We conducted a prospective observational study of patients with pancreatic cancers and extrahepatic cholangiocarcinomas evaluated in 4 referral centers in Romania. We collected data on the pathology of the tumors, staging at diagnosis, ECOG status, surgical interventions, chemo/radiotherapy and endoscopic drainage where applicable. A telephonic follow-up visit at 3 months after the enrollment visit collected additional data regarding evolution, subsequent treatment, performance status and disease-related events and outcomes. Results and conclusions. One hundred seventy-two patients were included in the study during a one-year period at the four participating centers. 72.1% were diagnosed with pancreatic cancer while 27.9% had extrahepatic cholangiocarcinoma. We identified several unmet needs in the current practices of treatment for these malignancies: a lack of pathological confirmation in 25.6% of the cases, a very low percentage of resectable lesions (only 18% of the patients operated with curative intent), and suboptimal choice of drainage in patients who required palliative drainage at their first endoscopic intervention. Significant effort is required to ensure standard-of-care treatment for patient with BPT in low-resource medical systems, including comprehensive auditing and protocol surveillance.

Open Problems in Extracellular RNA Data Analysis: Insights From an ERCC Online Workshop.

We now know RNA can survive the harsh environment of biofluids when encapsulated in vesicles or by associating with lipoproteins or RNA binding proteins. These extracellular RNA (exRNA) play a role in intercellular signaling, serve as biomarkers of disease, and form the basis of new strategies for disease treatment. The Extracellular RNA Communication Consortium (ERCC) hosted a two-day online workshop (April 19-20, 2021) on the unique challenges of exRNA data analysis. The goal was to foster an open dialog about best practices and discuss open problems in the field, focusing initially on small exRNA sequencing data. Video recordings of workshop presentations and discussions are available (https://exRNA.org/exRNAdata2021-videos/). There were three target audiences: experimentalists who generate exRNA sequencing data, computational and data scientists who work with those groups to analyze their data, and experimental and data scientists new to the field. Here we summarize issues explored during the workshop, including progress on an effort to develop an exRNA data analysis challenge to engage the community in solving some of these open problems.