Authors: Ponti G, Roli L, Oliva G, Manfredini M, Trenti T, Kaleci S et al.



The Covid-19 pandemic is a global challenge, with rapidly increasing cases from the high infective aetiological agent, the Covid-19 virus. In October 2020, over 48 million confirmed Covid-19 cases and one million deaths were confirmed ( There is an urgent need to identify predictive clinical, epidemiological, genetic and laboratory markers for outcomes, especially regarding microvasculature damage, potentially safely treated with therapeutic interventions. Homocysteine (Hcy) has recently been proposed as a potential predictive biomarker for Covid-19 infection severity.

SARS-CoV-2 transfers methyl group for viral RNA capping from the host cell S-adenosylmethionine (SAM), converted into S-adenosylhomocysteine (SAH). SAH hydrolase (SAHH) removes adenosine from SAH, and produces an intermediate product “homocysteine”, recycled by the remethylation and trans-sulphuration pathway in the human body. In cardiovascular patients, Hcy levels are used as predictive markers of thromboembolic risk, but has not yet been applied to Covid-19 risk stratification. This study aims to evaluate the predictive role of plasma Hcy as a prognostic marker of Covid-19 patients’ outcome. The study was conducted in accordance with the ethical principles of the Declaration of Helsinki and Good Clinical Practices and, in compliance with local regulatory requirements.

A multicenter, retrospective analysis, including patients hospitalized for Covid-19 between April 2020 and September 2020, was performed. Hcy levels were determined using chemiluminescent microparticle immunoassay (Architect Homocysteine assay, Abbott). Venous blood samples were collected upon hospitalization according to standard hospital procedures. Routine laboratory parameters obtained are outlined in Table 1. Patient clinical information and one month survival status after Covid-19 diagnosis were recorded.

Keywords: biomarkers; Covid-19 vulnerability; homocysteine (Hcy); MTHFR677C>T mutations; MTHFR gene; predictor parameters