Improvement of immune dysregulation and health-related quality of life in individuals with long COVID at 24-months following SARS-CoV-2 infection (preprint)

This study investigated the humoral and cellular immune responses in individuals with long COVID (LC) compared to age and gender matched recovered COVID-19 controls (MC) over 24-months. LC participants showed elevated spike and nucleocapsid IgG levels, higher neutralizing capacity, and increased spike- and nucleocapsid-specific CD4+ T cells, PD-1, and TIM-3 expression on CD4+ and CD8+ T cells at 3- and 8-months, but these differences did not persist at 24-months. Some LC participants had detectable IFN-{beta} and IFN-{gamma} that was attributed to reinfection and antigen re-exposure. Single-cell RNA sequencing at 24-month timepoint revealed similar immune cell proportions and reconstitution of naive T and B cell subsets in LC. No significant differences in exhaustion scores or antigen-specific T cell clones were observed. These findings suggest resolution of immune activation in LC and return to comparable immune responses between LC and MC over time. Improvement in self-reported health-related quality of life at 24-months was also evident in the majority of LC (62%). PTX3, CRP levels and platelet count were associated with improvements in health-related quality of life.

Post-acute COVID-19 cognitive impairment and decline uniquely associate with kynurenine pathway activation: a longitudinal observational study (preprint)

Cognitive impairment and function post-acute mild to moderate COVID-19 are poorly understood. We report findings of 128 prospectively studied SARS-CoV-2 positive patients. Cognition and olfaction were assessed at 2-, 4- and 12-months post-diagnosis. Lung function, physical and mental health were assessed at 2-month post diagnosis. Blood cytokines, neuro-biomarkers, and kynurenine pathway (KP) metabolites were measured at 2-, 4-, 8- and 12-months. Mild to moderate cognitive impairment (demographically corrected) was present in 16%, 23%, and 26%, at 2-, 4- and 12-months post diagnosis, respectively. Overall cognitive performance mildly, but significantly (p

Limited recovery from post-acute sequelae of SARS-CoV-2 (PASC) at eight months of a prospective cohort (preprint)

There is increasing recognition of the prolonged illness following acute coronavirus disease 2019 (COVID-1). In a longitudinal cohort of 99 patients, 32% reported persistent symptoms and 19% had Long COVID (Defined as fatigue or dyspnoea or chest tightness) at median 240 days after initial infection. There was no significant improvement in symptoms or measures of health-related quality of life between 4 and 8-month assessments. In multivariable analysis, female gender (OR 3.2, 95%CI 1.3-7.8, p=0.01) and acute COVID-19 hospitalisation (OR 3.8, 95% 1.1-13.6, p=0.04) were independently associated with Long COVID at 8-months. Only 80% patients reported full recovery at 8 months. Further research is required to understand the immunologic correlates of abnormal recovery and the long-term significance.