Amino acid profiling of COVID-19 patients blood serum

Main objectives of this study were to analyse metabolomic profile features of patients with COVID-19 using mass spectrometry techniques while taking into account the clinical and laboratory history, and to study the relationship between the severity of COVID-19 symptoms and the concentration of primary metabolites, primarily amino acids. We used frozen blood serum samples of 935 COVID-19 patients from the City Hospital No. 40 biobank collection. Metabolomic profile was studied by HPLS-MS/MS method. R programming language was used for statistical data processing. The difference of metabolic profile of patients with COVID-19 depending on the severity of the disease was revealed based on the performed analysis - for 52 out of 84 detected compounds there were differences with reliability p<0,01. Statistically significant differences in concentration were recorded for organic acids, amino acids and their derivatives. Using samples from the biobank collection, a metabolomic study of the biomaterial of patients hospitalised with the diagnosis of COVID-19 was carried out. According to the results obtained, kynurenine, phenylalanine and acetylcarnitine were associated with the severity of COVID-19 infection. ### Competing Interest Statement The authors have declared no competing interest. ### Funding Statement Supported by Saint Petersburg State University, project ID: 95412780 ### 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 study was approved by the expert ethics board of the St. Petersburg State Health Care Institution "City Hospital No. 40" (protocol No. 171 dated May 18, 2020) I confirm that all necessary patient/participant consent has been obtained and the appropriate institutional forms have been archived, and that any patient/participant/sample identifiers included were not known to anyone (e.g., hospital staff, patients or participants themselves) outside the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, such as any relevant EQUATOR Network research reporting checklist(s) and other pertinent material, if applicable. Yes All data produced in the present study are available upon reasonable request to the authors