Genetic Predisposition to Severe COVID-19 Might Increase the Risk of Stroke: A Two-Sample Mendelian Randomization Study

The relationship between COVID-19 and stroke and its risk factors, a Mendelian randomization analysis

BACKGROUND

It remains unclear about the association between stroke and Coronavirus disease 2019 (COVID-19). Therefore, a Mendelian randomization (MR) analysis was conducted to explore the relationship between them.

METHODS

In this study, the most recent large-scale genome-wide association studies (GWASs) were selected from the publicly available COVID-19 GWAS meta-analysis (Round 7) as the exposure. Data from a recent original stroke GWAS were used as the outcome for the experimental group, while the stroke GWAS data from the IEU GWAS database were used as the validation group. In addition, an MR analysis was conducted to explore the causal relationships of susceptibility, hospitalization, and severity of COVID-19 with stroke and its subtypes. In addition, the results of the experimental and validation groups were integrated to perform a meta-analysis.

RESULTS

The MR analysis results corroborated that there was a positively causal relationship between the hospitalization (OR, 1.11; p = 0.015) (ORmeta, 1.11; p < 0.001), and severity (OR, 1.06; p = 0.043) (ORmeta, 1.07; p = 0.002) of COVID-19 and cardioembolic stroke (CES). This result is supported by the validation group and sensitivity analysis.

CONCLUSION

This study demonstrates for the first time that COVID-19 hospitalization and COVID-19 severity are risk factors for CES.

Human genetic associations of the airway microbiome in chronic obstructive pulmonary disease

Little is known about the relationships between human genetics and the airway microbiome. Deeply sequenced airway metagenomics, by simultaneously characterizing the microbiome and host genetics, provide a unique opportunity to assess the microbiome-host genetic associations. Here we performed a co-profiling of microbiome and host genetics with the identification of over 5 million single nucleotide polymorphisms (SNPs) through deep metagenomic sequencing in sputum of 99 chronic obstructive pulmonary disease (COPD) and 36 healthy individuals. Host genetic variation was the most significant factor associated with the microbiome except for geography and disease status, with its top 5 principal components accounting for 12.11% of the microbiome variability. Within COPD individuals, 113 SNPs mapped to candidate genes reported as genetically associated with COPD exhibited associations with 29 microbial species and 48 functional modules (P < 1 × 10-5), where Streptococcus salivarius exhibits the strongest association to SNP rs6917641 in TBC1D32 (P = 9.54 × 10-8). Integration of concurrent host transcriptomic data identified correlations between the expression of host genes and their genetically-linked microbiome features, including NUDT1, MAD1L1 and Veillonella parvula, TTLL9 and Stenotrophomonas maltophilia, and LTA4H and Haemophilus influenzae. Mendelian randomization analyses revealed a potential causal link between PARK7 expression and microbial type III secretion system, and a genetically-mediated association between COPD and increased relative abundance of airway Streptococcus intermedius. These results suggest a previously underappreciated role of host genetics in shaping the airway microbiome and provide fresh hypotheses for genetic-based host-microbiome interactions in COPD.

Genetic liability between COVID-19 and pre-eclampsia/eclampsia: a Mendelian randomization study

OBJECTIVE

The aim of this study was to investigate the possible causal relationship between COVID-19 and the risk of pre-eclampsia/eclampsia using a Mendelian randomized (MR) design.

METHODS

We estimated their genetic correlations and then performed two-sample Mendelian randomization analyses using pooled statistics from the COVID-19 susceptibility/hospitalization genome-wide association study and the pre-eclampsia/eclampsia datasets. The main analyses were performed using the inverse variance weighting method, supplemented by the weighted median method and the MR-Egger method.

RESULTS

We identified a significant and positive genetic correlation between COVID-19 susceptibility and pre-eclampsia/eclampsia [OR = 1.23 (1.01-1.51), p = 0.043]. Meanwhile, hospitalization of COVID-19 was significantly associated with a higher risk of pre-eclampsia/eclampsia [OR = 1.15 (1.02-1.30), p = 0.024]. Consistently, hospitalization of COVID-19 were nominally associated with higher risk of pre-eclampsia [OR = 1.14, (1.01-1.30), p = 0.040]. The results were robust under all sensitivity analyses.

CONCLUSION

These results suggest that COVID-19 may increase the risk of pre-eclampsia/eclampsia. Future development of preventive or therapeutic interventions should emphasize this to mitigate the complications of COVID-19. [Figure: see text].

Investigating the association of breast cancer and stroke: A two-sample Mendelian randomization study

We conducted a two-sample Mendelian randomization (MR) design to evaluate the causal relation between breast cancer and stroke. Genetic variants associated with breast cancer and stroke were both obtained from genome-wide association study summary data. The single nucleotide polymorphisms were selected as instrumental variables. Effect estimates were primarily evaluated using standard inverse variance weighted. Finally, sensitivity analyses were performed for the detection of potential pleiotropy and heterogeneity in the cause-effect evaluation. There was a causal association of ER-positive breast cancer (odds ratio = 0.11, 95% confidence interval: 0.08-0.16, P < .001), and ER-negative breast cancer (odds ratio = 1.04, 95% confidence interval: 1.00-1.07, P = .045) with stroke. MR-egger regression revealed that the cause-effect of ER-positive breast cancer (P < .001) is drove by the directional horizontal pleiotropy, while there was no directional pleiotropy in the cause-effect of ER-negative breast cancer (P = .82). Cochran Q-derived P-value from inverse variance weighted (P = .27) shown that the cause-effect of ER-negative breast cancer on stroke do not need to consider the effect of heterogeneity. In addition, the leave-one-out analysis showed no influential instruments driving the associations, suggesting robust results for all outcomes. The present MR study reveals that ER negative breast cancer increase the risk of stroke.