Multi-ancestry omic Mendelian randomization revealing putative drug targets of COVID-19 severity

Recent omic studies prioritised several drug targets associated with coronavirus disease 2019 (COVID-19) severity. However, little evidence was provided to systematically estimate the effect of drug targets on COVID-19 severity in multiple ancestries. In this study, we applied Mendelian randomization (MR) and colocalization approaches to understand the putative causal effects of 16,059 transcripts and 1,608 proteins on COVID-19 severity in European and effects of 610 proteins on COVID-19 severity in African ancestry. We further integrated genetics, clinical and literature evidence to prioritised additional drug targets. Additional sensitivity analyses including multi-trait colocalization and phenome-wide MR were conducted to test for MR assumptions. MR and colocalization prioritized four protein targets, FCRL3, ICAM5, ENTPD5 and OAS1 that showed effect on COVID-19 severity only in European ancestry and one protein target, SERPINA1, only showed effect in African ancestry (odds ratio [OR] in Africans=0.369, 95%CI=0.203 to 0.668, P=9.96×10−4; OR in Europeans=1.021, P=0.745). One protein, ICAM1, showed suggestive effect on COVID-19 severity in both ancestries (OR in Europeans=1.152, 95%CI=1.063 to 1.249, P=5.94×10−4; OR in Africans=1.481, 95%CI=1.008 to 2.176; P=0.045). The phenome-wide MR of the prioritised targets on 622 complex traits identified 726 potential causal effects on other diseases, providing information on potential beneficial and adverse effects. Our study prioritised six proteins as potential drug targets for COVID-19 severity. Several of them were targets of existing drug under trials of COVID-19 or related to the immune system. Most of these targets showed different effects in European and African ancestries, which highlights the value of multi-ancestry MR in informing the generalizability of COVID-19 drug targets across ancestries. This study provides a first step towards clinical investigation on COVID-19 and other types of coronaviruses. Evidence before this study We searched key terms in PUBMED published before Feb 1st 2022, with the terms: (“COVID-19, “coronavirus”) AND (“omics” or “protein” or “transcript”) AND (“Genome-wide association study” or “Mendelian randomization”). We found multiple studies identified targeted genes or proteins associated with COVID-19. However, there is little human genetics evidence support the ancestry-consistent or ancestry-specific genes/proteins associated with COVID-19. Added value of this study To our knowledge, this is the first comprehensive genetic study that identified protein targets that showed effect on COVID-19 severity in European and African ancestries. Our study identified one protein, SERPINA1, that showed effects on COVID-19 in African ancestry (OR=0.369, P=9.96×10−4), but not in European ancestry (OR=1.021, P=0.745). In addition, our study identified four additional protein targets, FCRL3, ICAM5, ENTPD5 and OAS1, that showed effect on COVID-19 severity in Europeans. One protein ICAM1 showed suggestive effect in both ancestries. Some of these proteins are related to the immune system and/or are targets of existing drug under trials of COVID-19. Implications of all available evidence Our study prioritised six drug targets for COVID-19 severity, five of them showed different effects in European and African ancestries. This suggested that drug targets may have different responses on COVID-19 severity in different ancestries. Our study also highlights the value of intercellular adhesion molecule (ICAM) family in relation with COVID-19 severity in both ancestries. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement JZ is funded by a Vice Chancellor Fellowship from the University of Bristol. This research was also funded by the UK Medical Research Council Integrative Epidemiology Unit (MC UU 00011/1, MC UU 00011/4). This study was funded/supported by the NIHR Biomedical Research Centre at University Hospitals Bristol NHS Foundation Trust and the University of Bristol (TRG). The views expressed in this publication are those of the author(s) and not necessarily those of the NHS, the National Institute for Health Research or the Department of Health and Social Care. YMZ is supported by National Natural Science Foundation of China (81800636). HZ is supported by the University of Michigan Health System Peking University Health Science Center Joint Institute for Translational and Clinical Research (BMU2017JI007). ### Author Declarations I confirm all relevant ethical guidelines have been followed, and any necessary IRB and/or ethics committee approvals have been obtained. Yes The details of the IRB/oversight body that provided approval or exemption for the research described are given below: The project only use publicly available data, therefore no approval needed I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the research group so cannot be used to identify individuals. Yes I understand that all clinical trials and any other prospective interventional studies must be registered with an ICMJE-approved registry, such as ClinicalTrials.gov. I confirm that any such study reported in the manuscript has been registered and the trial registration ID is provided (note: if posting a prospective study registered retrospectively, please provide a statement in the trial ID field explaining why the study was not registered in advance). Yes I have followed all appropriate research reporting guidelines and uploaded the relevant EQUATOR Network research reporting checklist(s) and other pertinent material as supplementary files, if applicable. Yes The data needed for the analysis were available via MR-Base platform. The results is available via the EpiGraphDB platform