A new study conducted by researchers at the German Sport University Cologne and the University of Wuppertal reveals the long-term hematological effects of COVID-19 on patients, even those with mild cases. The study focuses on the alterations in hematological parameters experienced by patients four months after mild infections.
One of the key findings of the study is the interaction between COVID-19 and red blood cells (RBCs). It has been discovered that the virus can infect erythroid precursors and progenitors, leading to morphological abnormalities of RBCs. The acute phase of the disease is associated with various hematological alterations, including reduced RBC count, hemoglobin concentration, and hematocrit. Patients also show changes in RBC volume and hemoglobin levels, as well as increased red blood cell distribution width. These changes affect the function of RBCs, leading to cold extremities and weak peripheral pulses, indicating microcirculatory dysfunction.
Further investigations have revealed impaired rheological characteristics of RBCs in COVID-19 patients, including decreased deformability, increased blood viscosity, and enhanced aggregation. These changes can be attributed to membrane lipid remodeling and structural protein damage, particularly to the cytoskeleton. Reduced deformability limits the capacity of RBCs to efficiently transport and release oxygen, resulting in tissue hypoxia.
The study also includes patients with milder disease courses and aims to investigate whether hematological and hemorheological changes persist in the long term, even in cases of mild SARS-CoV-2 infections. The findings reveal that hematological parameters related to cell volume and hemoglobin concentration are significantly altered in COVID-19 patients compared to control subjects. RBC deformability and aggregation remain impaired four months after infection, while some parameters, such as RBC deformability and mean cellular volume, show improvement over time.
The study highlights a gender disparity in the impact of COVID-19 on RBC parameters. The differences between healthy control subjects and COVID-19 patients are more pronounced in males than in females. This emphasizes the importance of gender-specific analyses in COVID-19 research.
These findings have implications for the understanding and management of Long-COVID, a condition that affects individuals experiencing prolonged symptoms after COVID-19 infection. The persistent hematological and hemorheological changes observed in this study could affect the efficient transport of oxygen in the body. The study underscores the need for tailored therapies and interventions for Long-COVID patients.
While the study has limitations, including a small number of female participants and the lack of a comparative measurement in the control group, it provides valuable insights into the long-term effects of mild COVID-19 infections on hematological parameters and RBC rheology. Further research is needed to unravel the underlying mechanisms and sex-specific differences in COVID-19, which will contribute to improved patient outcomes and quality of life.