Inflammatory and vascular biomarkers in post‐COVID‐19 syndrome: A systematic review and meta‐analysis of over 20 biomarkers

Abstract

Severe acute respiratory syndrome coronavirus 2 may inflict a post-viral condition known as post-COVID-19 syndrome (PCS) or long-COVID. Studies measuring levels of inflammatory and vascular biomarkers in blood, serum, or plasma of COVID-19 survivors with PCS versus non-PCS controls have produced mixed findings. Our review sought to meta-analyse those studies. A systematic literature search was performed across five databases until 25 June 2022, with an updated search on 1 November 2022. Data analyses were performed with Review Manager and R Studio statistical software. Twenty-four biomarkers from 23 studies were meta-analysed. Higher levels of C-reactive protein (Standardized mean difference (SMD) = 0.20; 95%

Lactate dehydrogenase contribution to symptom persistence in long COVID: A pooled analysis

“…Sixth, the use of multiple time points run the risk of introducing precision error in our pooled estimates. We identified two systematic reviews that reported on 113 107 and 18, 108 potential biomarkers of long COVID from 28 to 23 included studies with last searches in August and November 2022 respectively 107,108 . Lai et al.…”

“…107 In contrast, Yong et al did a pooled analysis and reported a significantly higher levels of CRP (10 studies), D-dimer (11 studies), LDH (8 studies) and leucocytes (7 studies) in PASC. 108 However, neither of them reported on LDH association with specific PASC domains, most probably due to limited LDH data.…”

Serological markers and long COVID—A rapid systematic review

“…3,4,[10][11][12][13] The aetiology of long COVID remains uncertain, though several underlying pathophysiological mechanisms, such as cellular damage, inflammatory cytokines and a hypercoagulable state, are thought to contribute to long COVID inception and trajectory. 7,[14][15][16][17] Given the complexity of the condition, a diverse range of potential predictors warrant consideration. Older age, female sex, pre-existing conditions (e.g.…”

“…3,4,15,[18][19][20] Additionally, a number of biomarkers have been investigated but currently, there is no consensus as to whether any characterize long COVID. 14,16,17 Investigation of potential serological markers of long COVID, accounting for clinical covariates, may yield pathophysiological insights. To date, several observational studies have compared humoral response between groups with and without persistent symptoms, albeit with highly mixed findings.…”

“…Long COVID can often have debilitating and wide‐ranging impacts, such as diminished quality of life, inability to work or attend school, need for healthcare services, reduced work productivity and reliance on caregiver support 3,4,10–13 . The aetiology of long COVID remains uncertain, though several underlying pathophysiological mechanisms, such as cellular damage, inflammatory cytokines and a hypercoagulable state, are thought to contribute to long COVID inception and trajectory 7,14–17 …”