Chronic inflammation, neutrophil activity, and autoreactivity splits long COVID

While immunologic correlates of COVID-19 have been widely reported, their associations with post-acute sequelae of COVID-19 (PASC) remain less clear. Due to the wide array of PASC presentations, understanding if specific disease features associate with discrete immune processes and therapeutic opportunities is important. Here we profile patients in the recovery phase of COVID-19 via proteomics screening and machine learning to find signatures of ongoing antiviral B cell development, immune-mediated fibrosis, and markers of cell death in PASC patients but not in controls with uncomplicated recovery. Plasma and immune cell profiling further allow the stratification of PASC into inflammatory and non-inflammatory types. Inflammatory PASC, identifiable through a refined set of 12 blood markers, displays evidence of ongoing neutrophil activity, B cell memory alterations, and building autoreactivity more than a year post COVID-19. Our work thus helps refine PASC categorization to aid in both therapeutic targeting and epidemiological investigation of PASC.

Mild antecedent COVID-19 associated with symptom-specific post-acute sequelae

BACKGROUND

The impact of COVID-19 severity on development of long-term sequelae remains unclear, and symptom courses are not well defined.

METHODS

This ambidirectional cohort study recruited adults with new or worsening symptoms lasting ≥3 weeks from confirmed SARS-CoV-2 infection between August 2020-December 2021. COVID-19 severity was defined as severe for those requiring hospitalization and mild for those not. Symptoms were collected using standardized questionnaires. Multivariable logistical regression estimated odds ratios (OR) and 95% confidence intervals (CI) for associations between clinical variables and symptoms.

RESULTS

Of 332 participants enrolled, median age was 52 years (IQR 42-62), 233 (70%) were female, and 172 (52%) were African American. Antecedent COVID-19 was mild in 171 (52%) and severe in 161 (48%). In adjusted models relative to severe cases, mild COVID-19 was associated with greater odds of fatigue (OR:1.83, CI:1.01-3.31), subjective cognitive impairment (OR:2.76, CI:1.53-5.00), headaches (OR:2.15, CI:1.05-4.44), and dizziness (OR:2.41, CI:1.18-4.92). Remdesivir treatment was associated with less fatigue (OR:0.47, CI:0.26-0.86) and fewer participants scoring >1.5 SD on PROMIS Cognitive scales (OR:0.43, CI:0.20-0.92). Fatigue and subjective cognitive impairment prevalence was higher 3-6 months after COVID-19 and persisted (fatigue OR:3.29, CI:2.08-5.20; cognitive OR:2.62, CI:1.67-4.11). Headache was highest at 9-12 months (OR:5.80, CI:1.94-17.3).

CONCLUSIONS

Mild antecedent COVID-19 was associated with highly prevalent symptoms, and those treated with remdesivir developed less fatigue and cognitive impairment. Sequelae had a delayed peak, ranging 3-12 months post infection, and many did not improve over time, underscoring the importance of targeted preventative measures.