Why fatigue from long COVID goes beyond simply feeling tired Fatigue Coronavirus Disease COVID LongCOVID medrxivpreprint ErasmusMC
Study: Severe fatigue as symptom of long COVID is characterized by increased expression of inflammatory genes in monocytes, increased serum pro-inflammatory cytokines, and increased CD8+ T-lymphocytes: A putative dysregulation of the immune-brain axis, the coagulation process, and auto-inflammation to explain the diversity of long COVID symptoms. Image Credit: eamesBot / Shutterstock
Research has identified a connection between CFS-related fatigue and an increase in cytotoxic T-lymphocytes and cytokines. Recent studies have also found an increase in T- and B-lymphocytes and inflammatory cytokines in patients convalescing from COVID-19. However, a comprehensive clinical and immunologic profiling of long COVID patients associating immunological abnormalities with the clinical manifestations of long COVID is lacking.
The researchers tested the expression of genes involved in inflammation in the circulating monocytes using reverse transcribed complementary deoxyribonucleic acid , which was then subjected to quantitative polymerase chain reaction . Long COVID patients without severe fatigue displayed improvement in fitness in the follow-up period but experienced a significant reduction in CD45RO- naïve CD4+ T-lymphocyte percentage, known as naive CD4+ lymphocytopenia. They also had reduced CD4+ T regulatory lymphocytes.