Long-Term Health Outcomes in SARS Survivors: A Clinical Observational Study
A detailed study published in ‘eClinicalMedicine’ analyzed the long-term health outcomes of 14 health workers who survived SARS coronavirus infection between April and June 2003. The study aimed to understand the long-term sequelae 18 years post-infection and involved comprehensive assessments, including physical examinations, laboratory tests, pulmonary function tests, arterial blood gas analysis, chest imaging, and multiomics analyses.
- Persisting Symptoms and Sequelae: The most common symptom among SARS survivors, even 18 years after discharge, was fatigue. The main sequelae included osteoporosis and necrosis of the femoral head. These survivors exhibited significantly lower respiratory and hip function scores compared to controls. While physical and social functioning improved over time, they remained worse than the controls. Emotional and mental health, however, fully recovered.
- Metabolic Alterations: The study identified abnormalities in plasma metabolism, particularly in amino acid and lipid metabolic pathways. SARS survivors showed an increase in ornithine levels, which is linked to osteoporosis and may be a response to fatigue. The decrease in lipid metabolic pathways like glycerophospholipid and sphingolipid metabolism was also observed. These findings suggest that metabolic disorders are possibly related to the physical sequelae observed in these patients.
- Humoral Immune Response: Proteomic analysis indicated that SARS survivors had alterations in their humoral immune defense response, though specific details on these changes were not provided in the summary.
- Cellular Immunity Function: Analysis of peripheral blood mononuclear cells (PBMCs) via single-cell RNA sequencing revealed significant changes in the cellular immunity of SARS survivors. There was a decrease in the proportion of effector memory CD8+ cytotoxic T cells. Additionally, there were changes in the expression levels of various genes, indicating altered survival and generation of these T cells and a possibly enhanced cell-killing ability, despite a decrease in their overall numbers.
In summary, this study provides a comprehensive analysis of the long-term health outcomes in SARS survivors. The findings highlight persistent physical sequelae like fatigue, osteoporosis, and necrosis of the femoral head, as well as significant changes in metabolic and immune functions 18 years post-infection. These insights are crucial for understanding the long-term impacts of severe viral infections and for guiding the management and care of patients recovering from such illnesses.