Role and Clinical Application of Metagenomic Next-Generation Sequencing in Immunocompromised Patients With Acute Respiratory Failure During Veno-Venous Extracorporeal Membrane Oxygenation.

Objectives: There are few studies of metagenomic next-generation sequencing (mNGS) in immunocompromised patients assisted by veno-venous extracorporeal membrane oxygenation (vv-ECMO). The present study is aimed to investigate the pathogen-detected effect and clinical therapy value of mNGS technologies in immunocompromised patients assisted by vv-ECMO. Methods: Our study retrospectively enrolled 46 immunocompromised patients supported by vv-ECMO from Jan 2017 to June 2021 at the First Affiliated Hospital of Zhengzhou University, respectively. Patients were divided into the deterioration group (Group D) (n = 31) and improvement group (Group I) (n = 15) according to their outcomes. Baseline characteristics and etiological data of patients during hospitalization of 2 groups were compared. The pathogens detected by mNGS and antibiotic regimens guided by mNGS in immunocompromised patients assisted by vv-ECMO were analyzed. Results: Compared with Group I, the deterioration patients showed a higher percentage of chronic obstructive pulmonary disease (COPD) (32.3% vs. 6.7%, p < 0.01) and were significantly older (47.77 ± 16.72 years vs. 32 ± 15.05 years, p < 0.01). Within 48 h of being ECMO assisted, the consistency of the samples detected by traditional culture and mNGS at the same time was good (traditional culture vs. mNGS detection, the positive rate of bronchoalveolar lavage fluid (BALF) culture: 26.1% vs. 30.4%; the positive rate of blood sample culture: 12.2% vs. 12.2%, p > 0.05). However, mNGS detected far more pathogen species and strains than conventional culture (30 strains vs. 78 strains, p < 0.01); the most popular pathogen was Klebsiella pneumoniae. Parts of patients had their antibiotic treatment adjustments, and the improvement patients showed less usage of broad-spectrum antibiotics. Conclusions: mNGS may play a relatively important role in detecting mixed pathogens and personalized antibiotic treatment in immunocompromised patients assisted by vv-ECMO.

Heparin-free after 3000 IU heparin loaded in veno-venous ECMO supported acute respiratory failure patients with hemorrhage risk: a novel anti-coagulation strategy.

BACKGROUND: The anti-coagulation protocol of patients with hemorrhage risk primary disease who need extracorporeal membrane oxygenation (ECMO) supported is controversial. This study evaluated the feasibility of a new anti-coagulation strategy, that is heparin-free after 3000 IU heparin loaded in veno-venous ECMO (VV ECMO) supported acute respiratory failure patients with hemorrhage risk. METHODS: A retrospective study was performed in a series of hemorrhage risk patients supported with VV ECMO at the First Affiliated Hospital of Zhengzhou University, between June 2012 to Sept 2020. A total of 70 patients received a low heparin bolus of 3000 units for cannulation but without subsequent, ongoing heparin administration. Patients were divided into survival (n = 25) and non-survival group (n = 45). Data of coagulation, hemolysis and membrane lung function were calculated and analyzed. The complications of patients were recorded. Finally, the binary Logistic regression was conducted. RESULTS: The longest heparin-free time was 216 h, and the mean heparin-free time was 102 h. Compared with survivors, the non-survivors were showed higher baseline SOFA score and lower platelet counts in 0.5 h, 24 h, 48 h and 96 h after ECMO applied. However, there was no significant differences between survivors and non-survivors in ACT, APTT, INR, D-dimer, fibrinogen, LDH, blood flow rate, Δp and Ppost-MLO2 (all p < 0.05) of all different time point. Moreover, only the baseline SOFA score was significantly associated with mortality (p < 0.001, OR(95%CI): 2.754 (1.486-5.103)) while the baseline levels of ACT, APTT, INR, platelet, D-dimer, fibrinogen and LDH have no association with mortality. The percentage of thrombosis complications was 54.3% (38/70) including 3 oxygenator changed but there was no significant difference of complications in survival and non-survival groups (p > 0.05). CONCLUSIONS: The anticoagulation protocol that no heparin after a 3000 units heparin bolus in VV ECMO supported acute respiratory failure patients with hemorrhage risk is feasible.

Follow-up study of the pulmonary function and related physiological characteristics of COVID-19 survivors three months after recovery.

BACKGROUND: The long-term pulmonary function and related physiological characteristics of COVID-19 survivors have not been studied in depth, thus many aspects are not understood. METHODS: COVID-19 survivors were recruited for high resolution computed tomography (HRCT) of the thorax, lung function and serum levels of SARS-CoV-2 IgG antibody tests 3 months after discharge. The relationship between the clinical characteristics and the pulmonary function or CT scores were investigated. FINDINGS: Fifty-five recovered patients participated in this study. SARS-CoV-2 infection related symptoms were detected in 35 of them and different degrees of radiological abnormalities were detected in 39 patients. Urea nitrogen concentration at admission was associated with the presence of CT abnormalities (P = 0.046, OR 7.149, 95% CI 1.038 to 49.216). Lung function abnormalities were detected in 14 patients and the measurement of D-dimer levels at admission may be useful for prediction of impaired diffusion defect (P = 0.031, OR 1.066, 95% CI 1.006 to 1.129). Of all the subjects, 47 of 55 patients tested positive for SARS-CoV-2 IgG in serum, among which the generation of Immunoglobulin G (IgG) antibody in female patients was stronger than male patients in infection rehabilitation phase. INTERPRETATION: Radiological and physiological abnormalities were still found in a considerable proportion of COVID-19 survivors without critical cases 3 months after discharge. Higher level of D-dimer on admission could effectively predict impaired DLCO after 3 months discharge. It is necessary to follow up the COVID-19 patients to appropriately manage any persistent or emerging long-term sequelae. FUNDING: Key Scientific Research Projects of Henan Higher Education Institutions.

Serum miR-21 level: a potential diagnostic and prognostic biomarker for non-small cell lung cancer.

Because lung cancer is the most common cause of cancer death among both men and women, focused efforts are necessary to identify and develop biomarkers that aid in the detection and treatment of this serious disease. Recent research has been aimed at understanding the roles of microRNAs (miRNAs) in tumorigenesis and their utility as cancer biomarkers. Here, miR-21 was investigated as a potential serum biomarker for non-small cell lung cancer (NSCLC). The relative expression level of miR-21 was detected by real-time PCR in the sera of 80 NSCLC patients; sera were also collected from 60 healthy people as a control. The most suitable cut-off value and the prognostic value of serum miR-21 levels were analyzed using a receiver-operating curve. The relative serum miR-21 level in NSCLC patients was significantly higher than that in healthy people (P<0.05). For relative miR-21 expression, the area under the ROC curve was 0.812 (95% CI: 0.736-0.888) with a sensitivity of 73.8% and a specificity of 71.7%, based on a cut-off value of 1.22. NSCLC patients were divided into two groups based on miR-21 expression; those with higher relative expression (≥1.22) had significantly lower survival time than those in the lower expression group (P<0.05). Further, serum miR-21 level and survival time were negatively correlated in NSCLC patients (P<0.05). Thus, miR-21 may be useful as a diagnostic and prognostic indicator of NSCLC.

A toll-like receptor 4 (TLR4) variant is associated with asthma severity.

Asthma is a complex airways disease resulting from the input of both biological and environmental factors. Previous studies of single-nucleotide polymorphisms in toll-like receptor 4 (TLR4), which produces a protein involved in regulating T cell populations, have presented conflicting results regarding its role in asthma severity. In the current study, individuals with asthma were genotyped for variants of TLR4, and the genotypes were compared with asthma severity and T cell subpopulations. TLR4 rs11536879 (A>G) and rs1927907 (G>A) genotypes were determined in 350 asthma patients using TaqMan. Asthma severity was graded by clinical symptoms, and blood markers and lung function measures were also collected. T cell subpopulations were identified from peripheral blood by flow cytometry. No significant correlations were observed between genotypes at TLR4 rs11536879 or rs1927907 and eosinophil counts, total serum IgE, serum hypersensitive C-reactive protein, forced expiratory volume in 1 second (FEV1%), or FEV1/forced vital capacity (FVC) in asthma patients (P > 0.05). However, the GG genotype of rs1927907 was correlated with higher asthma severity (P < 0.05). No associations were detected between genotypes at rs11536879 or rs1927907 and CD4(+)CD25(high) regulatory T cell counts in peripheral blood from asthmatic patients (P > 0.05), but the rs1927907 genotype was associated with TLR4 expression on the surface of CD4(+)CD25(high) regulatory T cells (P < 0.05). Therefore, the TLR4 variant rs1927907 appears to be related to asthma severity and TLR4 expression on the surface of CD4(+)CD25(high) regulatory T cells, suggesting the potential influence of TLR4 on T cell population balances.

Effects of imidapril treatment on aquaporin-2 expression in the kidneys and excretion in the urine of hypertensive rats.

Renal aquaporin-2 (AQP2) is critical for maintaining water balance and is associated with hypertension. Anti-hypertensive drugs, including imidapril, improve kidney function; however, it remains unclear whether these effects are mediated through the regulation of AQP2. In this study, the effects of imidapril on AQP2 expression in the kidneys and excretion in urine were assessed in hypertensive rats. Hypertension was induced in 24 rats, which were randomized into a control group, treated with water only, and an imidapril treatment group (n=12 per group). Blood and urine samples were collected from all rats to determine blood pressure (BP), serum Na+, urine volume and urine osmolality after 8 weeks of treatment. Molecular and immunological techniques were used to measure the expression of AQP2 in the kidneys. Urine AQP2 concentration was detected by indirect enzyme-linked immunosorbent assay (ELISA). The concentration of plasma arginine vasopressin (AVP), a regulator of AQP2 was detected by radioimmunoassay (RIA). Hypertensive rats treated with imidapril exhibited reduced BP and 24-h urine osmolality, with a concomitant increase in 24-h urine volume, compared with control hypertensive rats (P<0.05). Additionally, the expression of Aqp2 mRNA, detected by RT-PCR, and AQP2 protein, detected by immunohistochemistry and western blotting, in renal tissue significantly decreased (P<0.05). Finally, urine AQP2 concentration increased while plasma AVP concentration decreased following imidapril treatment (P<0.05). These findings indicate that imidapril reduces the expression level of AQP2 in renal tissue and accelerates its excretion.

Mitochondrial tRNAMet mutation is associated with clinical and biochemical characteristics in primary hypertension.

Mitochondrial DNA mutations have been increasingly associated with various diseases. An association between the mitochondrial tRNA gene mutation, tRNAMet, and primary hypertension has been suggested. In the present study, the association between the tRNAMet mutation and the development of primary hypertension was investigated by assessing clinical and biological indicators in 800 patients with primary hypertension. General [gender, age, age of onset, body mass index (BMI) and family history] and clinical data (routine blood counts, blood biochemistry profiles and color Doppler echocardiography) were obtained. Venous blood samples were drawn from all the subjects for the separation of white blood cells (WBCs) and DNA extraction. Mitochondrial tRNAMet was amplified using PCR, purified and sequenced; samples identified to have a mutation were sequenced in triplicate for validation. Comparisons were made between 7 hypertensive patients with mutations (0.875%) and 10 age-, gender- and medication­matched hypertensive patients without mutations (controls). A maternal history of hypertension was present in 57.1% of patients with tRNAMet mutations and only 20.0% of patients without mutations. Notably, tRNAMet mutations were associated with a significantly earlier age of hypertension onset, decreased red blood cell (RBC) counts and hemoglobin (Hb) levels and increased total cholesterol (TC), triacylglycerol (TG), high­density lipoprotein cholesterol (HDL-C) and glucose levels (all P<0.05). Heart structure and function differences were also assessed between the two groups. In conclusion, mitochondrial tRNAMet mutations may induce changes in tRNA structure and function, which contributes to the pathogenesis of primary hypertension by disturbing blood lipid metabolism, the steady state of blood cells and cardiac structure and function.

Correlation of von Willebrand factor gene polymorphism and coronary heart disease.

To characterize von Willebrand factor (vWF) gene polymorphisms at site A1381T and the correlation of plasma vWF levels with coronary heart disease, the vWF genotypes at site A1381T were analyzed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) in patients diagnosed with coronary heart disease and normal controls (n=110 per group), and plasma vWF levels were measured by enzyme­linked immunosorbent assay. The results showed that the plasma vWF levels were higher in the experimental group than in the control group and had no association with gender (t=11.69, p<0.05). In the experimental group, the plasma vWF levels were higher in the patients with the AG genotype than in those with the GG genotype (p<0.05). In the control group, the plasma vWF levels of the subjects with blood type O were significantly lower than those of the individuals with other blood types (p<0.05). In the experimental group, all blood types had significantly higher plasma vWF levels than the control group and the difference was significant among different blood types (p<0.05). In summary, vWF gene polymorphisms at site A1381T were not associated with coronary heart disease, but plasma vWF levels were influenced by vWF gene polymorphisms at site A1381T, blood type and coronary heart disease.

Association study of dimethylarginine dimethylaminohydrolase 2 gene polymorphisms and coronary heart disease.

While a number of genetic and environmental risk factors for coronary heart disease (CHD) have been identified, the list of potential risk factors remains long. One candidate is dimethylarginine dimethylaminohydrolase (DDAH2), which is known to be polymorphic in humans. The gene product indirectly increases the endogenous production of nitric oxide, an anti-atherogenic molecule. Therefore, alterations in DDAH2 activity may indirectly result in an increased risk of CHD. We studied allele and genotype distributions for two polymorphic loci of DDAH2, rs805305 and rs2272592, in 180 patients with CHD and 180 healthy controls. Disease history and other clinical data were recorded. Polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) was used to determine the genotype at rs805305, and ligase detection reaction (LDR) was used to determine the genotype at rs2272592. Systolic blood pressure and blood triglyceride and glucose levels were higher, and history of hypertension, diabetes, smoking and alcohol use was more common in the patients with CHD (P<0.05). However, the genotype and allele frequencies at the two polymorphic loci of DDAH2 were not statistically different between the two groups. Therefore, no association was observed between the DDAH2 polymorphisms at rs805305 and rs2272592 and CHD.