Homocysteine and serum-lipid levels in pulmonary embolism

Lipid profile and mortality in patients with pulmonary thromboembolism; a systematic review and meta-analysis

INTRODUCTION

Acute pulmonary thromboembolism (PTE) is a life-threatening disease. Considering the availability and accessibility of assessing the serum lipids, this study aims to define the predictive value of lipid profile, as well as the history of lipid disorders, for the mortality of PTE patients.

CONTENT

Clinical studies, in which the relation of lipid profile, including triglyceride (TG), low-density lipoprotein (LDL), high-density lipoprotein (HDL), and total cholesterol, as well as history of imbalance of lipids, with mortality of PTE patients was reported, were included. Non-English articles, reviews, letters, editorials, and non-English papers were excluded. A systematic search was conducted in PubMed, Embase, Scopus, and Web of Science databases. The risk of bias was assessed using the Joanna Briggs Institute (JBI) Critical Appraisal tools and CMA 4 was utilized for the quantitative synthesis. Out of 3,724 records, six studies were included in this systematic review. Lipid profile is suggested as a prognostic marker for survival in patients with PTE so higher initial serum HDL, LDL, and total cholesterol levels were associated with lower mortality rates in PTE patients. In addition, dyslipidemia was found to be associated with mortality of PTE patients. Based on the quantitative synthesis, there was a greater serum level of HDL in the survival group (standardized mean difference: -0.98; 95 % CI: -1.22 to -0.75; p-value<0.01).

SUMMARY AND OUTLOOK

Mortality is lower in PTE patients with greater serum lipid levels; therefore, the early prognosis of PTE may be ascertained by measuring serum lipids within the first 24 h of admission.

Serum metabolic signatures for acute pulmonary embolism identified by untargeted metabolomics

Background and aims

The important metabolic features of acute pulmonary embolism (APE) risk stratification and their underlying biological basis remain elusive. Our study aims to develop early diagnostic models and classification models by analyzing the plasma metabolic profile of patients with APE.

Materials and methods

Serum samples were collected from 68 subjects, including 19 patients with confirmed APE, 35 patients with confirmed NSTEMI, and 14 healthy individuals. A comprehensive metabolic assessment was performed using ultra-performance liquid chromatography-mass spectrometry based on an untargeted metabolomics approach. In addition, an integrated machine learning strategy based on LASSO and logistic regression was used for feature selection and model building.

Results

The metabolic profiles of patients with acute pulmonary embolism and NSTEMI is significantly altered relative to that of healthy individuals. KEGG pathway enrichment analysis revealed differential metabolites between acute pulmonary embolism and healthy individuals mainly involving glycerophosphate shuttle, riboflavin metabolism, and glycerolipid metabolism. A panel of biomarkers was defined to distinguish acute pulmonary embolism, NSTEMI, and healthy individuals with an area under the receiver operating characteristic curve exceeding 0.9 and higher than that of D-dimers.

Conclusion

This study contributes to a better understanding of the pathogenesis of APE and facilitates the discovery of new therapeutic targets. The metabolite panel can be used as a potential non-invasive diagnostic and risk stratification tool for APE.

Autopsy findings in an atypical case of occult massive fatal pulmonary embolism in a backdrop of hyperhomocysteinemia

A 43-year-old apparently healthy male presented with fever and presyncope. He was suspected to have massive pulmonary thromboembolism based on the clinico-biochemical profile. Despite aggressive thrombolytic therapy, he succumbed to his illness within 12 h of admission. Postmortem examination showed massive pulmonary thromboembolism and hyperhomocysteinemia with low high-density lipoproteins (HDL) cholesterol with antemortem blood sample. Herein, we report autopsy findings in a rare case of a young male with occult massive pulmonary thromboembolism without deep vein thrombosis, who had an atypical clinical presentation and was found to have underlying hyperhomocysteinemia and decreased HDLc. An acute, massive PE can present a diagnostic challenge due to the rate and severity of decompensation seen in afflicted patients. A high index of suspicion is required for early detection of pulmonary embolism in a young patient with atypical presentation and without obvious risk factors.

Homocysteine injures vascular endothelial cells by inhibiting mitochondrial activity

The aim of the present study was to investigate the role of homocysteine (Hcy) in the pathogenesis of pulmonary embolism (PE) and the associated molecular mechanisms in human umbilical vein endothelial cells (HUVECs). Hcy contents were detected with high-performance liquid chromatography. Apoptosis was detected by flow cytometry using Annexin-V staining. Cytochrome c oxidase (COX) activity was assessed with an enzyme activity assay, and the expression levels of COX 17 were determined by western blot analysis. Intracellular reactive oxygen species levels were measured using a microplate reader with a fluorescence probe. The results demonstrated that, compared with the control group, the serum Hcy levels were significantly elevated in the PE group, suggesting that Hcy may be an indicator for PE. Following treatment with Hcy, the apoptosis rate was markedly elevated in HUVECs. Moreover, Hcy decreased COX activity and downregulated the expression of COX 17 in HUVECs. Furthermore, Hcy increased the ROS levels in these endothelial cells. However, all the above-mentioned physiopathological changes induced by Hcy in HUVECs could be restored by folic acid. In conclusion, the results of the present study demonstrated that Hcy inhibited COX activity, downregulated COX 17 expression, increased intracellular ROS levels and enhanced apoptosis in endothelial cells.