Magnetic Lateral Flow Immunoassay for Small Extracellular Vesicles Quantification: Application to Colorectal Cancer Biomarker Detection.

Colorectal cancer (CRC) is the third leading cause of cancer death and the fourth most common cancer in the world. Colonoscopy is the most sensitive test used for detection of CRC; however, their procedure is invasive and expensive for population mass screening. Currently, the fecal occult blood test has been widely used as a screening tool for CRC but displays low specificity. The lack of rapid and simple methods for mass screening makes the early diagnosis and therapy monitoring difficult. Extracellular vesicles (EVs) have emerged as a novel source of biomarkers due to their contents in proteins and miRNAs. Their detection would not require invasive techniques and could be considered as a liquid biopsy. Specifically, it has been demonstrated that the amount of CD147 expressed in circulating EVs is significant higher for CRC cell lines than for normal colon fibroblast cell lines. Moreover, CD147-containing EVs have been used as a biomarker to monitor response to therapy in patients with CRC. Therefore, this antigen could be used as a non-invasive biomarker for the detection and monitoring of CRC in combination with a Point-of-Care platform as, for example, Lateral Flow Immunoassays (LFIAs). Here, we propose the development of a quantitative lateral flow immunoassay test based on the use of magnetic nanoparticles as labels coupled to inductive sensor for the non-invasive detection of CRC by CD147-positive EVs. The results obtained for quantification of CD147 antigen embedded in EVs isolated from plasma sample have demonstrated that this device could be used as a Point-of-Care tool for CRC screening or therapy monitoring thanks to its rapid response and easy operation.

Primary antimicrobial resistance rates and prevalence of Helicobacter pylori infection in the north of Spain. A 13-year retrospective study.

OBJECTIVE: Helicobacter pylori resistance to antimicrobial agents is on the rise and it is thus imperative to be aware of local resistance rates. The main objective of the present study was to describe the evolution of primary antimicrobial resistance in H. pylori, analysing its antibiotic susceptibility over a 13-year period in a region of northern Spain, as well as host-related factors. PATIENTS AND METHODS: Between 2004 and 2016 a total of 3426 patients who met the H. pylori eradication criteria underwent gastroscopy. The gastric biopsies were processed and those testing positive for H. pylori were identified and tested for clarithromycin, metronidazole and levofloxacin susceptibility using E-test. RESULTS: H. pylori was isolated in 1604 (47%) patients, ranging from 63% (133/212) in 2004 to 39% (137/347) in 2016. Primary resistances to clarithromycin, metronidazole and levofloxacin were on average 19% (278/1116), 40% (572/865) and 17% (137/669), respectively. Clarithromycin resistance was 24% (167/686) in females and 15% (11/753) in males (p=0.0002); metronidazole resistance was 29% (72/246) in patients over 70 years compared to 42% (499/1190) in younger patients (p=0.0396); levofloxacin resistance increased with age, being 13% (57/439) in patients ≤55 years, 19% (46/236) for those between 56 and 70, and 26% (34/130) in patients >70 years (p=0.0087). DISCUSSION: A decline in the prevalence of H. pylori infection was observed over the years, along with relatively high rates of primary resistance to clarithromycin, metronidazole and levofloxacin. Variations in resistance rates were found with sex and age.

Risk factors for tuberculosis in inflammatory bowel disease: anti-tumor necrosis factor and hospitalization.

AIMS: To determine risk factors for active tuberculosis in patients with inflammatory bowel diseases. METHODS: Retrospective, case-control study at 4 referral hospitals in Spain. Cases developed tuberculosis after a diagnosis of inflammatory bowel disease. Controls were inflammatory bowel disease patients who did not develop tuberculosis. For each case, we randomly selected 3 controls matched for sex, age (within 5 years) and time of inflammatory bowel disease diagnosis (within 3 years). Inflammatory bowel disease characteristics, candidate risk factors for tuberculosis and information about the tuberculosis episode were recorded. Multivariate analysis and a Chi-squared automatic interaction detector were used. RESULTS: Thirty-four cases and 102 controls were included. Nine of the 34 cases developed active tuberculosis between 1989 and 1999, and 25 became ill between 2000 and 2012. Multivariate regression showed an association between active tuberculosis and anti-TNF (tumor necrosis factor) therapy in the previous 12 months (OR 7.45; 95% CI, 2.39-23.12; p = .001); hospitalization in the previous 6 months (OR 4.38; 95% CI, 1.18-16.20; p = .027); and albumin levels (OR 0.88; 95% CI, 0.81-0.95; p = .001). The median time between the start of biologic therapy and the onset of active tuberculosis was 13 (interquartile range, 1-58) months. Tuberculosis developed after a year of anti-TNF therapy in 53%, and late reactivation occurred in at least 3 of 8 patients. CONCLUSIONS: The main risks factors for developing tuberculosis were anti-TNF therapy and hospitalization. Over half the cases related to anti-TNF treatment occurred after a year.

Efficacy and safety of subcutaneous immunotherapy with polymerized allergen mixtures in polyallergic patients - ARES observational study.

BACKGROUND: Administration of allergen mixtures of many components comprises the most common approach for American allergists regarding the management of polyallergic patients. European allergists, however, are more reluctant to this type of treatment due to the potential drawbacks of mixing extracts. RESEARCH DESIGN AND METHODS: To assess the efficacy and safety of subcutaneous immunotherapy (SCIT) with polymerized allergen mixtures without dilutional effect in polyallergic patients.This observational, prospective, multicenter study included patients (between 5 and 60 years) with respiratory allergic diseases that had been prescribed with SCIT with mixtures of two pollen or mite extracts. Changes in Symptoms and Medication Score (SMS) and in rhinitis quality of life questionnaire (RQLQ), subjective clinical improvement, treatment satisfaction and tolerability were assessed after the 1-year treatment. RESULTS: A total of 115 patients were included in the assessment. Mean global SMS decreased from 3.5 (SD = 1.1) to 1.6 (SD = 1.2) points, with a mean absolute reduction of 1.6 (SD = 1.3) points in the RQLQ score (p < 0.001, Wilcoxon test). General subjective clinical improvements and a good treatment satisfaction and tolerability were observed. CONCLUSION: SCIT with polymerized allergen mixtures from either pollen or mite extracts proved to be an effective and safe treatment option for polyallergic patients suffering from allergic respiratory diseases.

Nanozyme-Based Lateral Flow Immunoassay (LFIA) for Extracellular Vesicle Detection.

Extracellular vesicles (EVs) are biological nanoparticles of great interest as novel sources of biomarkers and as drug delivery systems for personalized therapies. The research in the field and clinical applications require rapid quantification. In this study, we have developed a novel lateral flow immunoassay (LFIA) system based on Fe3O4 nanozymes for extracellular vesicle (EV) detection. Iron oxide superparamagnetic nanoparticles (Fe3O4 MNPs) have been reported as peroxidase-like mimetic systems and competent colorimetric labels. The peroxidase-like capabilities of MNPs coated with fatty acids of different chain lengths (oleic acid, myristic acid, and lauric acid) were evaluated in solution with H2O2 and 3,3,5,5-tetramethylbenzidine (TMB) as well as on strips by biotin-neutravidin affinity assay. As a result, MNPs coated with oleic acid were applied as colorimetric labels and applied to detect plasma-derived EVs in LFIAs via their nanozyme effects. The visual signals of test lines were significantly enhanced, and the limit of detection (LOD) was reduced from 5.73 × 107 EVs/µL to 2.49 × 107 EVs/µL. Our work demonstrated the potential of these MNPs as reporter labels and as nanozyme probes for the development of a simple tool to detect EVs, which have proven to be useful biomarkers in a wide variety of diseases.